Impact of Navigation-Assisted Transsphenoidal Surgery on Residual Tumor Volume and Retinal Nerve Fiber Layer Thickness in Pituitary Adenoma

Impact of Navigation-Assisted Transsphenoidal Surgery on Residual Tumor Volume and Retinal Nerve Fiber Layer Thickness in Pituitary Adenoma | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Impact of Navigation-Assisted Transsphenoidal Surgery on Residual Tumor Volume and Retinal Nerve Fiber Layer Thickness in Pituitary Adenoma Okan Salih, Ayhan Kanat, Bulent Ozdemir, Serdar Durmaz, Cihangir Erturk, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8800806/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Aim: Predicting visual outcomes following transsphenoidal surgery for pituitary adenoma remains challenging. Intraoperative neuronavigation is occasionally used during pituitary surgery; however, its effect on visual outcomes is not fully understood. This study aimed to investigate the impact of navigation-assisted transsphenoidal surgery on postoperative residual tumor volume and retinal nerve fiber layer (RNFL) changes. Methods: A retrospective analysis was performed on 27 consecutive patients who underwent microscopic transsphenoidal surgery for pituitary adenoma. Patients were divided into two groups: Group 1 (non-navigation-assisted) and Group 2 (navigation-assisted). Postoperative residual tumor volume and RNFL thickness changes were compared between groups. Results: Group 1 consisted of 17 patients (63%) with a mean preoperative tumor volume of 4.84 ± 1.24 cm³, while Group 2 included 10 patients (37%) with a mean preoperative volume of 8.91 ± 1.18 cm³. The postoperative residual volume was significantly higher in Group 1 (3.06 ± 0.78 cm³) compared with Group 2 (1.12 ± 0.26 cm³; p = 0.031). Although RNFL thinning was observed postoperatively in both groups, navigation-assisted surgery did not result in statistically significant differences in RNFL thickness. Conclusion: Navigation-assisted transsphenoidal surgery enables significantly greater tumor volume reduction without substantially altering postoperative RNFL thickness. These findings suggest that neuronavigation improves surgical precision and extent of resection while maintaining visual structural integrity. navigation-assisted transsphenoidal surgery residual tumor volume retinal nerve fiber layer pituitary adenoma Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Pituitary adenomas (PAs) are among common intracranial tumors, with an estimated prevalence of approximately 20% in the general population[ 1 ]. Because of the important nearby neurovascular pathways, the lesions' varying sizes and extensions, and possible hormonal imbalances, pituitary adenoma surgery is a complicated treatment[ 2 ]. In addition to achieving tumor removal, surgical management aims to preserve critical neurovascular structures to prevent complications that may compromise quality of life. Neurosurgical procedures are inherently complex and susceptible to a “domino effect,” whereby minor technical inaccuracies can result in significant downstream complications. The evolution of diagnostic neuroradiology, beginning with the development of X-ray technology, has profoundly influenced modern neurosurgery[ 3 ]. Advanced imaging modalities and neuronavigation systems now allow more accurate identification of tumor boundaries, facilitating wider yet safer resections. Image-guided surgery enhances three-dimensional anatomical understanding of lesions and adjacent structures, thereby reducing unintended intraoperative events. Despite technological advances, limited data exist regarding the effectiveness of navigation in pituitary adenoma surgery, particularly with respect to tumor resection extent and visual outcomes. Transsphenoidal surgery, first introduced in 1907, remains the preferred approach for sellar tumors due to its safety and efficacy profile. Nevertheless, pituitary adenomas continue to pose surgical challenges because of their proximity to the optic apparatus, cavernous sinus, and major vascular structures [ 4 ]. Pituitary can cause endocrine abnormalities[ 5 ], headaches, visual impairment, and cognitive impairment. Of these, visual impairment is the most prevalent symptom, reported by 32–70% of patients[ 6 ]. Visual impairment in pituitary adenoma is commonly caused by optic chiasmal compression, leading to retrograde degeneration of the retinal nerve fiber layer (RNFL). Optical coherence tomography (OCT) provides a non-invasive and quantitative method for assessing RNFL thickness and has emerged as a valuable prognostic tool for visual recovery. However, the relationship between surgical technique, tumor resection extent, and RNFL changes remains incompletely understood. The introduction of navigation technologies has improved surgical stability in the field of neurosurgery[ 7 ]. This study evaluates postoperative residual tumor volume and RNFL changes in patients undergoing microscopic transsphenoidal surgery with or without neuronavigation, aiming to clarify the potential benefits and limitations of navigation-assisted techniques. Materials and Methods Study Design and Patient Selection Following approval from the appropriate ethics committee and in accordance with institutional guidelines, a retrospective analysis was conducted on patients who underwent microscopic transsphenoidal surgery for pituitary adenoma between 2020 and 2024. Written informed consent had been obtained from all patients at the time of treatment. As this study was a retrospective chart review, a clinical trial registration number was not applicable. Medical records, radiological imaging, and ophthalmological data were reviewed. Patients were excluded if they did not complete postoperative follow-up or lacked postoperative magnetic resonance imaging (MRI). Patients with primary suprasellar lesions such as craniopharyngiomas were also excluded. Exclusion Criteria Patients were excluded if they had: pre-existing anterior or posterior segment pathology, retinal disease, glaucoma, strabismus, corneal disease, previous ocular surgery or trauma, age-related macular degeneration, or significant myopia; systemic diseases affecting the retina or optic nerve, including diabetes mellitus; postoperative complications requiring additional surgery (e.g., intracranial hemorrhage or early tumor recurrence); incomplete follow-up or missing postoperative MRI examinations. Group Allocation Patients were divided into two groups according to the surgical technique used: Group 1 (Standard Group, SG) : Transsphenoidal surgery without neuronavigation Group 2 (Navigation Group, NG) : Transsphenoidal surgery with intraoperative neuronavigation assistance All patients underwent preoperative and postoperative MRI for evaluation of tumor resection extent. Ophthalmological Examination All patients underwent a comprehensive preoperative ophthalmological examination performed by the same ophthalmologist (H.F.), including best-corrected visual acuity assessment using the Snellen chart (20 feet), slit-lamp biomicroscopy, intraocular pressure measurement, pupil examination, fundus examination, standard automated perimetry (SAP), and optical coherence tomography (OCT). Peripapillary retinal nerve fiber layer (RNFL) thickness measurements were obtained using spectral-domain OCT (NIDEK RS-3000 Advance, Japan) without pupil dilation, following the protocol described by Findik et al. [ 8 ]. Postoperative ophthalmological evaluations were performed approximately three months after surgery when available. Preoperative Imaging and Navigation Planning Preoperative assessment included endocrine evaluation and contrast-enhanced MRI, which served as the gold standard for sellar tumor assessment. In navigation-assisted cases, contrast-enhanced MRI datasets were imported into the neuronavigation system. Image fusion and manual delineation of the lesion were performed after accurate image registration. Patient Positioning and Surgical Technique All procedures were performed under general anesthesia using a unilateral endonasal transsphenoidal microscopic approach. Patients were positioned supine with the head in a neutral position and the trunk elevated approximately 30°. In navigation-assisted procedures, a reference array was secured to a rigid head clamp, and neuronavigation registration was completed before bone removal. Following sphenoidotomy and sellar floor opening, navigation accuracy was verified. Tumor resection was performed using standard microsurgical instruments, including curettes, suction devices, and ultrasonic aspirators. The neuronavigation system was used intraoperatively to identify tumor boundaries, adjacent neurovascular structures, and residual tumor tissue prior to reconstruction. Tumor Volume Measurement Preoperative and postoperative pituitary adenoma volumes were calculated using contrast-enhanced T1-weighted MRI sequences acquired on a 3.0-T MRI system (GE Discovery MR750, GE Healthcare, USA). Tumor segmentation was performed using Three-Dimensional Slicer software. Manual delineation of tumor boundaries was conducted using the “Segment Editor” tool. Tumor volume was calculated based on three-dimensional segmentation. Data Collection and Follow-Up Clinical data, radiological findings, endocrinological evaluations, surgical outcomes, complications, and ophthalmological results were collected retrospectively. Visual acuity, visual field testing, and RNFL measurements were assessed preoperatively and approximately three months postoperatively when available. Patients were monitored postoperatively for electrolyte imbalance, diabetes insipidus, and cerebrospinal fluid leakage. Statistical Analysis Post-hoc power analysis was performed using G*Power version 3.1.9.7, indicating a minimum required sample size of 16 patients (α = 0.05, power = 90%, effect size = 0.8). Statistical analyses were conducted using IBM SPSS Statistics version 29.0. Continuous variables were expressed as mean ± standard deviation or median with interquartile range, depending on distribution. Categorical variables were reported as absolute values and percentages. Comparisons between groups were performed using the independent samples t-test or Mann–Whitney U test for continuous variables and chi-square or Fisher’s exact test for categorical variables. A p-value < 0.05 was considered statistically significant. Results A total of 27 patients were included in the analysis. Seventeen patients (63%) underwent transsphenoidal surgery without neuronavigation (Group 1), while ten patients (37%) underwent navigation-assisted surgery (Group 2). The mean preoperative tumor volume was 4.84 ± 1.24 cm³ in Group 1 and 8.91 ± 1.18 cm³ in Group 2. Although tumors were larger in the navigation-assisted group, the difference in preoperative volume between groups was not statistically significant (p > 0.05). Preoperative and postoperative tumor volume data are summarized in Table 1 . Postoperative residual tumor volume was significantly higher in Group 1 (3.06 ± 0.78 cm³) compared with Group 2 (1.12 ± 0.26 cm³), demonstrating a statistically significant benefit of navigation-assisted surgery (p = 0.031). Estimated marginal means further illustrated this difference (Fig. 2 ). Representative MRI images demonstrating preoperative and postoperative tumor volume changes in both groups are shown in Fig. 3 . Graphical illustration demonstrating improved extent of tumor resection achieved with navigation-assisted transsphenoidal surgery was shown in Fig. 4 . The study population consisted of 15 male and 12 female patients. No statistically significant differences were observed between groups with respect to age or sex distribution (Table 2 ). Preoperative and postoperative ophthalmological evaluations were available for 16 of the 27 patients. Overall, statistically significant postoperative thinning of RNFL thickness was observed when comparing preoperative and postoperative measurements across the cohort (Table 3 ). Sectoral analysis revealed greater thinning in the temporal and nasal RNFL quadrants (Table 4 ). However, no statistically significant differences in RNFL changes were detected between the navigation-assisted and non-navigation-assisted groups. The graphical abstract illustrates the comparative design and key findings of the study evaluating navigation-assisted versus conventional microscopic transsphenoidal surgery for pituitary adenoma. The schematic highlights the two surgical approaches and demonstrates that navigation-assisted surgery achieves a greater reduction in postoperative residual tumor volume compared with non-navigation-assisted surgery. In parallel, the visual pathway assessment using optical coherence tomography is depicted, emphasizing that postoperative retinal nerve fiber layer thickness shows no significant differences between the two groups. Overall, the graphical abstract summarizes the central message that intraoperative neuronavigation improves the extent of safe tumor resection without substantially affecting retinal nerve fiber layer structural integrity (Fig. 5 ). The flow diagram presents the patient selection process and study workflow. Patients undergoing microscopic transsphenoidal surgery for pituitary adenoma between 2020 and 2024 were retrospectively screened. Exclusion criteria included incomplete follow-up, absence of postoperative magnetic resonance imaging, non-adenomatous sellar lesions, and pre-existing ocular or systemic conditions affecting the visual pathway. Eligible patients were divided into two groups based on the surgical technique used: transsphenoidal surgery without neuronavigation (Group 1) and navigation-assisted transsphenoidal surgery (Group 2). Preoperative and postoperative tumor volumes were assessed using magnetic resonance imaging, and retinal nerve fiber layer thickness was evaluated using optical coherence tomography. The diagram summarizes the allocation, analysis, and outcome assessment of both groups (Fig. 5 ) Table 1: The preoperative and postoperative volume values for both groups are displayed in tnis table. Group 1: Navigation non-used, Group 2: navigation-assisted Navigation Group1 (Navigation not used) Group 2 (Navigation-asisted) Mean Standard Deviation Median Mean Standard Deviation Median Preoperative volume 4,8458 5,0351 3,8730 8,9139 6,8516 7,9695 Postoperative pvolume 3,0628 4,8181 1,5480 1,1283 1,4728 ,7670 Table 2 Bbetween 2020 and 2024, had all clinical data retrospectively analyzed, including medical records, radiologic evaluations, and RNFL changes. Patients' genders are displayed. in the table Frequency Percent Valid Male 15 53,6 Female 12 42,9 Total 27 96,4 Total 27 100,0 Table 3 Statistical significance of differences preoperative and post operative RNFL findings are seen Test Statistics a Z Asymp. Sig. (2-tailed) postoperative volume – preoperative volume -3,516 b ,000 postoperative right RNFL average – preoperative right RNFL average -3,519 b ,000 postoperative RNFL right superior – preoperative RNFL rigth superior -2,704 b ,007 postoperative RNFL right nasal- preoperative RNFL right nasal -3,438 b ,001 post operatıve RNFL right inferior- preoperative RNFL right inferior -3,529 b ,000 postoperative RNFL right temporal- preoperative RNFL right temporal -3,524 b ,000 postoperative RNFL left average- preoperative RNFL left average -3,520 b ,000 postoperative RNFL left superior – preoperative RNFL left superior -3,276 b ,001 postoperative RNFL left temporal – preoperative RNFL left temporal -3,430 b ,001 postoperative RNFL left inferior – preoperative RNFL left inferior -2,967 b ,003 postoperative RNFL left nasal – ,preoperative RNFL left nasal -3,568 b ,000 postoperative mean deviatıon right– preoperative mean deviation right -1,087 b ,277 postoperative pattern standard devition right-preoperative pattern standard deviation right -,724 c ,469 postoperative mean deviation left- preoperative mean deviation left -1,395 c ,163 postoperative pattern standard deviation left-preoperative pattern standard deviation left -1,592 c ,111 a. Wilcoxon Signed Ranks Test b. Based on positive ranks. c. Based on negative ranks. Table 4: The finding shows that there are thinning of RNLF finding, especially temporal and nasal RNLFs. Group 1 (Navigation-not used) Group 2 (Navigation used Mean Standard Deviation Mean Standard Deviation preoperative RNFL left average 99,56 7,81 94,66 10,61 postoperative RNFL left average- 95,59 7,91 91,50 9,35 preoperative RNFL left superior 127 15 119 11 postoperative RNFL left superior 123 14 117 11 preoperative RNFL left temporal 66 9 61 7 postoperative RNFL left temporal 63 8 58 7 preoperative RNFL left inferior 130 9 124 13 postoperative RNFL left inferior 126 9 122 11 preoperative RNFL left nasal 76 10 74 16 postoperative RNFL left nasal 71 11 70 15 The finding of lefte eye Group 1 (Navigation-not used) Group 2 (Navigation used Mean Standard Deviation Mean Standard Deviation preoperative RNFL right average 92,81 10,79 92,41 10,87 postoperative RNFL right average- 89,78 10,66 89,22 10,66 preoperative RNFL right superior 120 16 122 17 postoperative RNFL right superior 119 15 119 17 preoperative RNFL right temporal 78 9 75 14 postoperative RNFL right temporal 76 8 72 14 preoperative RNFL right inferior 109 14 114 14 postoperative RNFL right inferior 105 15 111 14 preoperative RNFL right nasal 64 12 59 8 postoperative RNFL right nasal 59 13 55 7 No major new neurological deficits or vascular injuries were observed postoperatively. Cerebrospinal fluid leakage occurred in eight patients, transient visual disturbances in two patients, and diabetes insipidus requiring additional management in twelve patients. No postoperative hematomas were detected. Discussion Transsphenoidal surgery remains the primary surgical approach for pituitary adenomas and provides effective decompression of the optic apparatus while minimizing surgical morbidity. Nevertheless, the extent of tumor resection is often constrained by adenoma size, invasiveness, and proximity to critical neurovascular structures. In the present study, navigation-assisted microscopic transsphenoidal surgery was associated with significantly lower postoperative residual tumor volumes compared with the conventional non-navigation-assisted approach, without inducing substantial differences in postoperative retinal nerve fiber layer (RNFL) thickness. Intraoperative neuronavigation has become an important adjunct in modern neurosurgical practice by improving spatial orientation and anatomical accuracy, particularly in complex regions such as the sellar and parasellar compartments. Navigation facilitates real-time identification of tumor margins and surrounding eloquent structures, including the optic chiasm, cavernous sinus, and internal carotid arteries. In this series, navigation-assisted procedures achieved greater tumor volume reduction despite a tendency toward larger preoperative adenoma volumes, suggesting that neuronavigation contributes meaningfully to enhanced surgical precision and extent of resection. The volume is a significant issue in the neurosurgical practice[ 9 ]. Accurate assessment of adenoma volume is increasingly recognized as a key factor in pituitary surgery planning and outcome evaluation. Volumetric analysis provides a more reliable representation of tumor burden than linear measurements alone and allows for objective comparison of surgical efficacy. In this study, three-dimensional MRI-based volumetric measurements demonstrated that navigation-assisted surgery resulted in significantly smaller postoperative residual volumes. These findings are consistent with previous reports indicating that advanced intraoperative technologies improve the completeness of tumor resection without increasing complication rates. The optic nerve sheath, an indistensible subarachnoidal region, envelops the optic nerve as a component of the central nervous system[ 10 ]. This link allows CSF to move easily between the intracranial and intraorbital subarachnoid spaces, which may be the cause of papill-edema[ 11 ], a typical neuro-opthalmological exam finding of neurosurgical diseases. Visual dysfunction associated with pituitary adenomas is primarily caused by compression of the optic chiasm and optic nerves, leading to retrograde degeneration of retinal ganglion cell axons and subsequent thinning of the RNFL It has been demonstrated that the RNFL's condition is a critical predictor of vision recovery following tumor removal[ 12 ]. Optical coherence tomography (OCT) has emerged as a valuable, non-invasive tool for quantifying RNFL thickness and assessing the structural integrity of the visual pathway[ 8 ], [ 13 ]. In the present study, postoperative RNFL thinning was observed across the cohort, particularly in the temporal and nasal quadrants, which is consistent with the known vulnerability of crossing nasal fibers in chiasmal compression. Importantly, navigation-assisted surgery did not result in statistically significant differences in RNFL changes when compared with conventional transsphenoidal surgery. This observation aligns with previous studies demonstrating that RNFL thickness often continues to decrease after surgical decompression, even in cases where visual function improves[ 14 ]. The absence of RNFL recovery is likely attributable to irreversible axonal loss rather than persistent mechanical compression, suggesting that postoperative visual improvement reflects restoration of conduction in surviving axons rather than regeneration of damaged retinal nerve fibers [ 15 ]. Several mechanisms have been proposed to explain visual impairment in pituitary adenoma, including direct mechanical compression of the optic chiasm, vascular compromise of the chiasmal blood supply, or a combination of both[ 16 ]. Although neuronavigation may enhance the safety and completeness of decompression, direct evaluation of chiasmal microvascular alterations remains challenging. Consequently, while navigation-assisted surgery may reduce the risk of iatrogenic injury and facilitate more effective tumor removal, its influence on postoperative RNFL thickness appears limited.The findings of this study suggest that the principal benefit of neuronavigation in transsphenoidal pituitary surgery lies in improved tumor resection rather than modulation of optic nerve structural recovery. From a clinical standpoint, achieving maximal safe resection is essential for reducing residual disease and recurrence risk while preserving neurological function. The ability of neuronavigation to enhance resection accuracy without increasing visual morbidity supports its role as a valuable adjunct in selected cases, particularly those involving large or anatomically complex pituitary adenomas. Clinical Implications The findings of this study have important implications for the surgical management of pituitary adenomas. Navigation-assisted microscopic transsphenoidal surgery enables a significantly greater extent of tumor resection compared with conventional techniques, even in cases involving larger or anatomically complex adenomas. Improved resection accuracy may reduce postoperative residual tumor burden, which is clinically relevant for lowering the risk of recurrence and the need for adjuvant therapies.The absence of significant differences in postoperative retinal nerve fiber layer (RNFL) thickness between navigation-assisted and non-navigation-assisted procedures suggests that the primary benefit of neuronavigation lies in enhancing surgical precision rather than directly influencing optic nerve structural recovery. This finding supports the safe use of navigation-assisted surgery without increasing the risk of visual pathway injury.From a practical perspective, neuronavigation may be particularly valuable in patients with large tumors, distorted sellar anatomy, or close proximity to critical neurovascular structures, where accurate intraoperative orientation is essential. Incorporating navigation into transsphenoidal pituitary surgery can aid surgeons in achieving maximal safe resection while maintaining visual and neurological integrity, thereby supporting improved long-term clinical outcomes. Limitations This study has several limitations that should be considered when interpreting the findings. First, the retrospective design inherently limits causal inference and is subject to selection bias. In particular, navigation-assisted surgery was more commonly performed in patients with larger pituitary adenomas, which may have influenced the observed differences in postoperative residual tumor volume between the groups. Second, the relatively small sample size restricts the statistical power and generalizability of the results. Although post-hoc power analysis suggested that the sample size was adequate to detect differences in tumor volume reduction, more subtle differences in retinal nerve fiber layer (RNFL) changes may have remained undetected. Studies with limited sample sizes may fail to reveal true population differences, even when they exist[ 17 ]. Third, postoperative ophthalmological evaluations were not available for all patients, which may have affected the assessment of RNFL changes. In addition, RNFL alterations following optic chiasm decompression are known to evolve over months or years, whereas the postoperative follow-up period in this study was limited to approximately three months. Longer follow-up durations may be required to fully characterize the temporal progression of RNFL changes after surgery. Another limitation relates to the interpretation of early postoperative magnetic resonance imaging (MRI). Postoperative edema, hemorrhage, and the presence of surgical packing materials can complicate accurate delineation of residual tumor tissue. Although volumetric measurements were performed using standardized three-dimensional segmentation techniques, these factors may have influenced postoperative volume calculations. Finally, perioperative physiological factors, such as transient diabetes insipidus, electrolyte imbalance, and other postoperative systemic changes, were not evaluated in detail and may have indirectly influenced visual or neurological outcomes. Prospective studies with larger patient cohorts, standardized imaging protocols, longer follow-up periods, and comprehensive functional assessments are required to validate the present findings and further clarify the role of navigation-assisted transsphenoidal surgery in the management of pituitary adenomas. Conclusion This retrospective comparative study demonstrates that navigation-assisted microscopic transsphenoidal surgery for pituitary adenomas achieves significantly greater postoperative tumor volume reduction compared with conventional non-navigation-assisted techniques. The use of intraoperative neuronavigation enhances surgical orientation and precision, enabling more effective tumor resection without increasing surgical morbidity. Although postoperative thinning of the retinal nerve fiber layer was observed, navigation-assisted surgery did not result in significant differences in RNFL changes when compared with standard transsphenoidal surgery. These findings suggest that the primary benefit of neuronavigation lies in improving the extent of safe tumor removal rather than directly influencing optic nerve structural recovery. Overall, navigation-assisted transsphenoidal surgery represents a valuable technological adjunct in the management of pituitary adenomas, particularly in cases involving large or anatomically complex tumors. Its integration into surgical practice may contribute to improved resection outcomes while maintaining visual and neurological safety. Declarations Author Contribution O.S., A.K., B. O., S. D., C.E. wrote the main manuscript text, F.T., O.L. G., H. F., M. K prepared figures 1-5. 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Neuropsychiatr Dis Treat 19:2745–2754 Yolas C, Kanat A, Zeynal M, Hakan Sahin M, Kursat Karadag M, Nuri Keles O et al (2023) From Nose to Lumbar Spinal Cord; Reduced Sperm Numbers occur by Olfactory Bulbectomy-releted Onuf’s Nucleus Degeneration; New Experimental Evidence for Kallmann Syndrome. Neuroendocrinology Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8800806","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":589122499,"identity":"990886fe-714a-450f-a591-4ef97ca6dec9","order_by":0,"name":"Okan Salih","email":"","orcid":"","institution":"Bayburt Government Hospital","correspondingAuthor":false,"prefix":"","firstName":"Okan","middleName":"","lastName":"Salih","suffix":""},{"id":589122500,"identity":"d196563c-c2e1-47f0-9518-821adf80a50d","order_by":1,"name":"Ayhan 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University","correspondingAuthor":false,"prefix":"","firstName":"Muhammet","middleName":"","lastName":"Kaim","suffix":""}],"badges":[],"createdAt":"2026-02-05 21:08:59","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8800806/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8800806/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102597842,"identity":"7f8e56c4-9996-4aa9-8f55-f4fe8f80e51f","added_by":"auto","created_at":"2026-02-13 12:26:40","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":107505,"visible":true,"origin":"","legend":"\u003cp\u003eIntraoperative neuronavigation setup demonstrating the positioning and calibration of the navigation system (Stryker Navigation, Kalamazoo, MI, USA) used during microscopic transsphenoidal pituitary surgery.\u003c/p\u003e","description":"","filename":"Figure1navigation.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8800806/v1/510265808577fb1ba9c01217.jpg"},{"id":102597847,"identity":"37c6f3da-8153-4f1e-a6b0-b6776799d6cc","added_by":"auto","created_at":"2026-02-13 12:26:41","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":59196,"visible":true,"origin":"","legend":"\u003cp\u003eEstimated marginal means of postoperative residual pituitary adenoma volumes in the non-navigation-assisted group (Group 1) and the navigation-assisted group (Group 2), demonstrating significantly lower residual volumes in the navigation group.\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8800806/v1/60905eeaf0ccc1dbc201c8ee.jpg"},{"id":102597763,"identity":"22d52c30-7f89-4244-b69b-9dd831d5fec2","added_by":"auto","created_at":"2026-02-13 12:26:28","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":88864,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative magnetic resonance imaging (MRI) examples of tumor volume changes.\u003cbr\u003e\n(A–C) Preoperative and postoperative contrast-enhanced T1-weighted MRI images of a patient from Group 1 (non-navigation-assisted), showing residual tumor following surgery.\u003cbr\u003e\n(D–F) Corresponding MRI images of a patient from Group 2 (navigation-assisted), demonstrating a smaller postoperative residual tumor volume compared with Group 1.\u003c/p\u003e","description":"","filename":"figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8800806/v1/2e8d3e32c435cfc078f2f986.jpg"},{"id":102598021,"identity":"cb3adaaf-78c4-46fc-93fb-74cf51e64535","added_by":"auto","created_at":"2026-02-13 12:27:03","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":50567,"visible":true,"origin":"","legend":"\u003cp\u003eGraphical illustration demonstrating improved extent of tumor resection achieved with navigation-assisted transsphenoidal surgery.\u003c/p\u003e","description":"","filename":"Figure4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8800806/v1/420e2db081bb1389c2bea413.jpg"},{"id":102597854,"identity":"b497655b-fd38-441a-b74c-a6d5456de04a","added_by":"auto","created_at":"2026-02-13 12:26:44","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":226459,"visible":true,"origin":"","legend":"\u003cp\u003eGraphical abstract summarizing the study design, comparison between navigation-assisted and non-navigation-assisted transsphenoidal surgery, and key findings regarding residual tumor volume and retinal nerve fiber layer (RNFL) changes.\u003c/p\u003e","description":"","filename":"Figure5GraphicalabstractandflowdiagramChatGPTImage5ub2026194227.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8800806/v1/e9a0a12e17e46bd44b44410b.jpeg"},{"id":103680695,"identity":"2e3e62cb-df96-42b0-aecb-3db9501f7f6d","added_by":"auto","created_at":"2026-03-01 08:09:46","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1246487,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8800806/v1/75d44bdd-8aad-469e-8a21-f91dbc5a2cff.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Impact of Navigation-Assisted Transsphenoidal Surgery on Residual Tumor Volume and Retinal Nerve Fiber Layer Thickness in Pituitary Adenoma","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePituitary adenomas (PAs) are among common intracranial tumors, with an estimated prevalence of approximately 20% in the general population[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Because of the important nearby neurovascular pathways, the lesions' varying sizes and extensions, and possible hormonal imbalances, pituitary adenoma surgery is a complicated treatment[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. In addition to achieving tumor removal, surgical management aims to preserve critical neurovascular structures to prevent complications that may compromise quality of life. Neurosurgical procedures are inherently complex and susceptible to a \u0026ldquo;domino effect,\u0026rdquo; whereby minor technical inaccuracies can result in significant downstream complications.\u003c/p\u003e \u003cp\u003eThe evolution of diagnostic neuroradiology, beginning with the development of X-ray technology, has profoundly influenced modern neurosurgery[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Advanced imaging modalities and neuronavigation systems now allow more accurate identification of tumor boundaries, facilitating wider yet safer resections. Image-guided surgery enhances three-dimensional anatomical understanding of lesions and adjacent structures, thereby reducing unintended intraoperative events. Despite technological advances, limited data exist regarding the effectiveness of navigation in pituitary adenoma surgery, particularly with respect to tumor resection extent and visual outcomes. Transsphenoidal surgery, first introduced in 1907, remains the preferred approach for sellar tumors due to its safety and efficacy profile. Nevertheless, pituitary adenomas continue to pose surgical challenges because of their proximity to the optic apparatus, cavernous sinus, and major vascular structures [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Pituitary can cause endocrine abnormalities[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], headaches, visual impairment, and cognitive impairment. Of these, visual impairment is the most prevalent symptom, reported by 32\u0026ndash;70% of patients[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Visual impairment in pituitary adenoma is commonly caused by optic chiasmal compression, leading to retrograde degeneration of the retinal nerve fiber layer (RNFL). Optical coherence tomography (OCT) provides a non-invasive and quantitative method for assessing RNFL thickness and has emerged as a valuable prognostic tool for visual recovery. However, the relationship between surgical technique, tumor resection extent, and RNFL changes remains incompletely understood. The introduction of navigation technologies has improved surgical stability in the field of neurosurgery[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. This study evaluates postoperative residual tumor volume and RNFL changes in patients undergoing microscopic transsphenoidal surgery with or without neuronavigation, aiming to clarify the potential benefits and limitations of navigation-assisted techniques.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Design and Patient Selection\u003c/h2\u003e \u003cp\u003e Following approval from the appropriate ethics committee and in accordance with institutional guidelines, a retrospective analysis was conducted on patients who underwent microscopic transsphenoidal surgery for pituitary adenoma between 2020 and 2024. Written informed consent had been obtained from all patients at the time of treatment. As this study was a retrospective chart review, a clinical trial registration number was not applicable. Medical records, radiological imaging, and ophthalmological data were reviewed. Patients were excluded if they did not complete postoperative follow-up or lacked postoperative magnetic resonance imaging (MRI). Patients with primary suprasellar lesions such as craniopharyngiomas were also excluded.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eExclusion Criteria\u003c/h3\u003e\n\u003cp\u003ePatients were excluded if they had:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003epre-existing anterior or posterior segment pathology, retinal disease, glaucoma, strabismus, corneal disease, previous ocular surgery or trauma, age-related macular degeneration, or significant myopia;\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003esystemic diseases affecting the retina or optic nerve, including diabetes mellitus;\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003epostoperative complications requiring additional surgery (e.g., intracranial hemorrhage or early tumor recurrence);\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eincomplete follow-up or missing postoperative MRI examinations.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e\n\u003ch3\u003eGroup Allocation\u003c/h3\u003e\n\u003cp\u003ePatients were divided into two groups according to the surgical technique used:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eGroup 1 (Standard Group, SG)\u003c/b\u003e: Transsphenoidal surgery without neuronavigation\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eGroup 2 (Navigation Group, NG)\u003c/b\u003e: Transsphenoidal surgery with intraoperative neuronavigation assistance\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eAll patients underwent preoperative and postoperative MRI for evaluation of tumor resection extent.\u003c/p\u003e\n\u003ch3\u003eOphthalmological Examination\u003c/h3\u003e\n\u003cp\u003eAll patients underwent a comprehensive preoperative ophthalmological examination performed by the same ophthalmologist (H.F.), including best-corrected visual acuity assessment using the Snellen chart (20 feet), slit-lamp biomicroscopy, intraocular pressure measurement, pupil examination, fundus examination, standard automated perimetry (SAP), and optical coherence tomography (OCT).\u003c/p\u003e \u003cp\u003ePeripapillary retinal nerve fiber layer (RNFL) thickness measurements were obtained using spectral-domain OCT (NIDEK RS-3000 Advance, Japan) without pupil dilation, following the protocol described by Findik et al. [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Postoperative ophthalmological evaluations were performed approximately three months after surgery when available.\u003c/p\u003e\n\u003ch3\u003ePreoperative Imaging and Navigation Planning\u003c/h3\u003e\n\u003cp\u003ePreoperative assessment included endocrine evaluation and contrast-enhanced MRI, which served as the gold standard for sellar tumor assessment. In navigation-assisted cases, contrast-enhanced MRI datasets were imported into the neuronavigation system. Image fusion and manual delineation of the lesion were performed after accurate image registration.\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003ePatient Positioning and Surgical Technique\u003c/h2\u003e \u003cp\u003eAll procedures were performed under general anesthesia using a unilateral endonasal transsphenoidal microscopic approach. Patients were positioned supine with the head in a neutral position and the trunk elevated approximately 30\u0026deg;. In navigation-assisted procedures, a reference array was secured to a rigid head clamp, and neuronavigation registration was completed before bone removal.\u003c/p\u003e \u003cp\u003eFollowing sphenoidotomy and sellar floor opening, navigation accuracy was verified. Tumor resection was performed using standard microsurgical instruments, including curettes, suction devices, and ultrasonic aspirators. The neuronavigation system was used intraoperatively to identify tumor boundaries, adjacent neurovascular structures, and residual tumor tissue prior to reconstruction.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eTumor Volume Measurement\u003c/h3\u003e\n\u003cp\u003ePreoperative and postoperative pituitary adenoma volumes were calculated using contrast-enhanced T1-weighted MRI sequences acquired on a 3.0-T MRI system (GE Discovery MR750, GE Healthcare, USA). Tumor segmentation was performed using Three-Dimensional Slicer software. Manual delineation of tumor boundaries was conducted using the \u0026ldquo;Segment Editor\u0026rdquo; tool. Tumor volume was calculated based on three-dimensional segmentation.\u003c/p\u003e\n\u003ch3\u003eData Collection and Follow-Up\u003c/h3\u003e\n\u003cp\u003eClinical data, radiological findings, endocrinological evaluations, surgical outcomes, complications, and ophthalmological results were collected retrospectively. Visual acuity, visual field testing, and RNFL measurements were assessed preoperatively and approximately three months postoperatively when available. Patients were monitored postoperatively for electrolyte imbalance, diabetes insipidus, and cerebrospinal fluid leakage.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003ePost-hoc power analysis was performed using G*Power version 3.1.9.7, indicating a minimum required sample size of 16 patients (α\u0026thinsp;=\u0026thinsp;0.05, power\u0026thinsp;=\u0026thinsp;90%, effect size\u0026thinsp;=\u0026thinsp;0.8). Statistical analyses were conducted using IBM SPSS Statistics version 29.0. Continuous variables were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation or median with interquartile range, depending on distribution. Categorical variables were reported as absolute values and percentages. Comparisons between groups were performed using the independent samples t-test or Mann\u0026ndash;Whitney U test for continuous variables and chi-square or Fisher\u0026rsquo;s exact test for categorical variables. A p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 27 patients were included in the analysis. Seventeen patients (63%) underwent transsphenoidal surgery without neuronavigation (Group 1), while ten patients (37%) underwent navigation-assisted surgery (Group 2). The mean preoperative tumor volume was 4.84\u0026thinsp;\u0026plusmn;\u0026thinsp;1.24 cm\u0026sup3; in Group 1 and 8.91\u0026thinsp;\u0026plusmn;\u0026thinsp;1.18 cm\u0026sup3; in Group 2. Although tumors were larger in the navigation-assisted group, the difference in preoperative volume between groups was not statistically significant (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). Preoperative and postoperative tumor volume data are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Postoperative residual tumor volume was significantly higher in Group 1 (3.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78 cm\u0026sup3;) compared with Group 2 (1.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26 cm\u0026sup3;), demonstrating a statistically significant benefit of navigation-assisted surgery (p\u0026thinsp;=\u0026thinsp;0.031). Estimated marginal means further illustrated this difference (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Representative MRI images demonstrating preoperative and postoperative tumor volume changes in both groups are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Graphical illustration demonstrating improved extent of tumor resection achieved with navigation-assisted transsphenoidal surgery was shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. The study population consisted of 15 male and 12 female patients. No statistically significant differences were observed between groups with respect to age or sex distribution (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Preoperative and postoperative ophthalmological evaluations were available for 16 of the 27 patients. Overall, statistically significant postoperative thinning of RNFL thickness was observed when comparing preoperative and postoperative measurements across the cohort (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Sectoral analysis revealed greater thinning in the temporal and nasal RNFL quadrants (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). However, no statistically significant differences in RNFL changes were detected between the navigation-assisted and non-navigation-assisted groups. The graphical abstract illustrates the comparative design and key findings of the study evaluating navigation-assisted versus conventional microscopic transsphenoidal surgery for pituitary adenoma. The schematic highlights the two surgical approaches and demonstrates that navigation-assisted surgery achieves a greater reduction in postoperative residual tumor volume compared with non-navigation-assisted surgery. In parallel, the visual pathway assessment using optical coherence tomography is depicted, emphasizing that postoperative retinal nerve fiber layer thickness shows no significant differences between the two groups. Overall, the graphical abstract summarizes the central message that intraoperative neuronavigation improves the extent of safe tumor resection without substantially affecting retinal nerve fiber layer structural integrity (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). The flow diagram presents the patient selection process and study workflow. Patients undergoing microscopic transsphenoidal surgery for pituitary adenoma between 2020 and 2024 were retrospectively screened. Exclusion criteria included incomplete follow-up, absence of postoperative magnetic resonance imaging, non-adenomatous sellar lesions, and pre-existing ocular or systemic conditions affecting the visual pathway. Eligible patients were divided into two groups based on the surgical technique used: transsphenoidal surgery without neuronavigation (Group 1) and navigation-assisted transsphenoidal surgery (Group 2). Preoperative and postoperative tumor volumes were assessed using magnetic resonance imaging, and retinal nerve fiber layer thickness was evaluated using optical coherence tomography. The diagram summarizes the allocation, analysis, and outcome assessment of both groups (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e)\u003c/p\u003e\u003cp\u003eTable 1: The preoperative and postoperative volume values for both groups are displayed in tnis table. Group 1: Navigation non-used, Group 2: navigation-assisted\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" valign=\"bottom\" style=\"width: 24px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"6\" valign=\"bottom\" style=\"width: 75px;\"\u003e\n \u003cp\u003eNavigation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\" valign=\"bottom\" style=\"width: 34px;\"\u003e\n \u003cp\u003eGroup1\u003c/p\u003e\n \u003cp\u003e(Navigation not used)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"bottom\" style=\"width: 41px;\"\u003e\n \u003cp\u003eGroup 2\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(Navigation-asisted)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 9px;\"\u003e\n \u003cp\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 12px;\"\u003e\n \u003cp\u003eStandard Deviation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 12px;\"\u003e\n \u003cp\u003eMedian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 12px;\"\u003e\n \u003cp\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 17px;\"\u003e\n \u003cp\u003eStandard Deviation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 12px;\"\u003e\n \u003cp\u003eMedian\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 24px;\"\u003e\n \u003cp\u003ePreoperative volume\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e4,8458\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e5,0351\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3,8730\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e8,9139\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17px;\"\u003e\n \u003cp\u003e6,8516\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e7,9695\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 24px;\"\u003e\n \u003cp\u003ePostoperative pvolume\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e3,0628\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e4,8181\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e1,5480\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e1,1283\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17px;\"\u003e\n \u003cp\u003e1,4728\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e,7670\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBbetween 2020 and 2024, had all clinical data retrospectively analyzed, including medical records, radiologic evaluations, and RNFL changes. Patients' genders are displayed. in the table\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFrequency\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePercent\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eValid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e53,6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e42,9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e96,4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100,0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eStatistical significance of differences preoperative and post operative RNFL findings are seen\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eTest Statistics\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eZ\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAsymp. Sig. (2-tailed)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative volume \u0026ndash;\u003c/p\u003e \u003cp\u003epreoperative volume\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-3,516\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative right RNFL average \u0026ndash; preoperative right RNFL average\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-3,519\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative RNFL right superior \u0026ndash;\u003c/p\u003e \u003cp\u003epreoperative RNFL rigth superior\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-2,704\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,007\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative RNFL right nasal-\u003c/p\u003e \u003cp\u003epreoperative RNFL right nasal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-3,438\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epost operatıve RNFL right inferior-\u003c/p\u003e \u003cp\u003epreoperative RNFL right inferior\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-3,529\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative RNFL right temporal-\u003c/p\u003e \u003cp\u003epreoperative RNFL right temporal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-3,524\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative RNFL left average-\u003c/p\u003e \u003cp\u003epreoperative RNFL left average\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-3,520\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative RNFL left superior \u0026ndash;\u003c/p\u003e \u003cp\u003epreoperative RNFL left superior\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-3,276\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative RNFL left temporal \u0026ndash;\u003c/p\u003e \u003cp\u003epreoperative RNFL left temporal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-3,430\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative RNFL left inferior \u0026ndash;\u003c/p\u003e \u003cp\u003epreoperative RNFL left inferior\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-2,967\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,003\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative RNFL left nasal \u0026ndash;\u003c/p\u003e \u003cp\u003e,preoperative RNFL left nasal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-3,568\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative mean deviatıon\u003c/p\u003e \u003cp\u003eright\u0026ndash; preoperative mean deviation right\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-1,087\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,277\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative pattern standard devition right-preoperative pattern standard deviation right\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-,724\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,469\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative mean deviation left-\u003c/p\u003e \u003cp\u003epreoperative mean deviation left\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-1,395\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,163\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epostoperative pattern standard deviation left-preoperative pattern standard deviation left\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-1,592\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e,111\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003ea. Wilcoxon Signed Ranks Test\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eb. Based on positive ranks.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003ec. Based on negative ranks.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eTable 4: \u003c/strong\u003eThe finding shows that there are thinning of RNLF finding, especially temporal and nasal RNLFs.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"446\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" valign=\"bottom\" style=\"width: 112px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" valign=\"bottom\" style=\"width: 334px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 167px;\"\u003e\n \u003cp\u003eGroup 1 (Navigation-not used)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 167px;\"\u003e\n \u003cp\u003eGroup 2 (Navigation used\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 69px;\"\u003e\n \u003cp\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 98px;\"\u003e\n \u003cp\u003eStandard Deviation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 69px;\"\u003e\n \u003cp\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 98px;\"\u003e\n \u003cp\u003eStandard Deviation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 112px;\"\u003e\n \u003cp\u003epreoperative \u0026nbsp;RNFL left average\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e99,56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e7,81\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e94,66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e10,61\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 112px;\"\u003e\n \u003cp\u003epostoperative RNFL left average-\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e95,59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e7,91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e91,50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e9,35\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 112px;\"\u003e\n \u003cp\u003epreoperative \u0026nbsp;RNFL left superior\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e127\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e119\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 112px;\"\u003e\n \u003cp\u003epostoperative RNFL left superior\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e123\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e117\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 112px;\"\u003e\n \u003cp\u003epreoperative \u0026nbsp;RNFL left temporal\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 112px;\"\u003e\n \u003cp\u003epostoperative RNFL left temporal\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 112px;\"\u003e\n \u003cp\u003epreoperative \u0026nbsp;RNFL left inferior\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e130\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e124\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 112px;\"\u003e\n \u003cp\u003epostoperative RNFL left inferior\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e126\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e122\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 112px;\"\u003e\n \u003cp\u003epreoperative \u0026nbsp;RNFL left nasal\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 112px;\"\u003e\n \u003cp\u003epostoperative RNFL left nasal\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eThe finding of lefte eye\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"448\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" valign=\"bottom\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" valign=\"bottom\" style=\"width: 334px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 167px;\"\u003e\n \u003cp\u003eGroup 1 (Navigation-not used)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 167px;\"\u003e\n \u003cp\u003eGroup 2 (Navigation used\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 69px;\"\u003e\n \u003cp\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 98px;\"\u003e\n \u003cp\u003eStandard Deviation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 69px;\"\u003e\n \u003cp\u003eMean\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 98px;\"\u003e\n \u003cp\u003eStandard Deviation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epreoperative \u0026nbsp;RNFL right average\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e92,81\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e10,79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e92,41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e10,87\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epostoperative RNFL right average-\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e89,78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e10,66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e89,22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e10,66\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epreoperative \u0026nbsp;RNFL right superior\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e120\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e122\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epostoperative RNFL right superior\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e119\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e119\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epreoperative \u0026nbsp;RNFL right temporal\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epostoperative RNFL right temporal\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epreoperative \u0026nbsp;RNFL right inferior\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e109\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e114\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epostoperative RNFL right inferior\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e105\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e111\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epreoperative \u0026nbsp;RNFL right nasal\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e64\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epostoperative RNFL right nasal\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 98px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\u003c/br\u003e\u003cp\u003eNo major new neurological deficits or vascular injuries were observed postoperatively. Cerebrospinal fluid leakage occurred in eight patients, transient visual disturbances in two patients, and diabetes insipidus requiring additional management in twelve patients. No postoperative hematomas were detected.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eTranssphenoidal surgery remains the primary surgical approach for pituitary adenomas and provides effective decompression of the optic apparatus while minimizing surgical morbidity. Nevertheless, the extent of tumor resection is often constrained by adenoma size, invasiveness, and proximity to critical neurovascular structures. In the present study, navigation-assisted microscopic transsphenoidal surgery was associated with significantly lower postoperative residual tumor volumes compared with the conventional non-navigation-assisted approach, without inducing substantial differences in postoperative retinal nerve fiber layer (RNFL) thickness.\u003c/p\u003e \u003cp\u003eIntraoperative neuronavigation has become an important adjunct in modern neurosurgical practice by improving spatial orientation and anatomical accuracy, particularly in complex regions such as the sellar and parasellar compartments. Navigation facilitates real-time identification of tumor margins and surrounding eloquent structures, including the optic chiasm, cavernous sinus, and internal carotid arteries. In this series, navigation-assisted procedures achieved greater tumor volume reduction despite a tendency toward larger preoperative adenoma volumes, suggesting that neuronavigation contributes meaningfully to enhanced surgical precision and extent of resection.\u003c/p\u003e \u003cp\u003eThe volume is a significant issue in the neurosurgical practice[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Accurate assessment of adenoma volume is increasingly recognized as a key factor in pituitary surgery planning and outcome evaluation. Volumetric analysis provides a more reliable representation of tumor burden than linear measurements alone and allows for objective comparison of surgical efficacy. In this study, three-dimensional MRI-based volumetric measurements demonstrated that navigation-assisted surgery resulted in significantly smaller postoperative residual volumes. These findings are consistent with previous reports indicating that advanced intraoperative technologies improve the completeness of tumor resection without increasing complication rates.\u003c/p\u003e \u003cp\u003eThe optic nerve sheath, an indistensible subarachnoidal region, envelops the optic nerve as a component of the central nervous system[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. This link allows CSF to move easily between the intracranial and intraorbital subarachnoid spaces, which may be the cause of papill-edema[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], a typical neuro-opthalmological exam finding of neurosurgical diseases. Visual dysfunction associated with pituitary adenomas is primarily caused by compression of the optic chiasm and optic nerves, leading to retrograde degeneration of retinal ganglion cell axons and subsequent thinning of the RNFL It has been demonstrated that the RNFL's condition is a critical predictor of vision recovery following tumor removal[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Optical coherence tomography (OCT) has emerged as a valuable, non-invasive tool for quantifying RNFL thickness and assessing the structural integrity of the visual pathway[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In the present study, postoperative RNFL thinning was observed across the cohort, particularly in the temporal and nasal quadrants, which is consistent with the known vulnerability of crossing nasal fibers in chiasmal compression.\u003c/p\u003e \u003cp\u003eImportantly, navigation-assisted surgery did not result in statistically significant differences in RNFL changes when compared with conventional transsphenoidal surgery. This observation aligns with previous studies demonstrating that RNFL thickness often continues to decrease after surgical decompression, even in cases where visual function improves[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The absence of RNFL recovery is likely attributable to irreversible axonal loss rather than persistent mechanical compression, suggesting that postoperative visual improvement reflects restoration of conduction in surviving axons rather than regeneration of damaged retinal nerve fibers [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Several mechanisms have been proposed to explain visual impairment in pituitary adenoma, including direct mechanical compression of the optic chiasm, vascular compromise of the chiasmal blood supply, or a combination of both[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Although neuronavigation may enhance the safety and completeness of decompression, direct evaluation of chiasmal microvascular alterations remains challenging. Consequently, while navigation-assisted surgery may reduce the risk of iatrogenic injury and facilitate more effective tumor removal, its influence on postoperative RNFL thickness appears limited.The findings of this study suggest that the principal benefit of neuronavigation in transsphenoidal pituitary surgery lies in improved tumor resection rather than modulation of optic nerve structural recovery. From a clinical standpoint, achieving maximal safe resection is essential for reducing residual disease and recurrence risk while preserving neurological function. The ability of neuronavigation to enhance resection accuracy without increasing visual morbidity supports its role as a valuable adjunct in selected cases, particularly those involving large or anatomically complex pituitary adenomas.\u003c/p\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eClinical Implications\u003c/h2\u003e \u003cp\u003eThe findings of this study have important implications for the surgical management of pituitary adenomas. Navigation-assisted microscopic transsphenoidal surgery enables a significantly greater extent of tumor resection compared with conventional techniques, even in cases involving larger or anatomically complex adenomas. Improved resection accuracy may reduce postoperative residual tumor burden, which is clinically relevant for lowering the risk of recurrence and the need for adjuvant therapies.The absence of significant differences in postoperative retinal nerve fiber layer (RNFL) thickness between navigation-assisted and non-navigation-assisted procedures suggests that the primary benefit of neuronavigation lies in enhancing surgical precision rather than directly influencing optic nerve structural recovery. This finding supports the safe use of navigation-assisted surgery without increasing the risk of visual pathway injury.From a practical perspective, neuronavigation may be particularly valuable in patients with large tumors, distorted sellar anatomy, or close proximity to critical neurovascular structures, where accurate intraoperative orientation is essential. Incorporating navigation into transsphenoidal pituitary surgery can aid surgeons in achieving maximal safe resection while maintaining visual and neurological integrity, thereby supporting improved long-term clinical outcomes.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eLimitations\u003c/h2\u003e \u003cp\u003eThis study has several limitations that should be considered when interpreting the findings. First, the retrospective design inherently limits causal inference and is subject to selection bias. In particular, navigation-assisted surgery was more commonly performed in patients with larger pituitary adenomas, which may have influenced the observed differences in postoperative residual tumor volume between the groups. Second, the relatively small sample size restricts the statistical power and generalizability of the results. Although post-hoc power analysis suggested that the sample size was adequate to detect differences in tumor volume reduction, more subtle differences in retinal nerve fiber layer (RNFL) changes may have remained undetected. Studies with limited sample sizes may fail to reveal true population differences, even when they exist[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Third, postoperative ophthalmological evaluations were not available for all patients, which may have affected the assessment of RNFL changes. In addition, RNFL alterations following optic chiasm decompression are known to evolve over months or years, whereas the postoperative follow-up period in this study was limited to approximately three months. Longer follow-up durations may be required to fully characterize the temporal progression of RNFL changes after surgery. Another limitation relates to the interpretation of early postoperative magnetic resonance imaging (MRI). Postoperative edema, hemorrhage, and the presence of surgical packing materials can complicate accurate delineation of residual tumor tissue. Although volumetric measurements were performed using standardized three-dimensional segmentation techniques, these factors may have influenced postoperative volume calculations. Finally, perioperative physiological factors, such as transient diabetes insipidus, electrolyte imbalance, and other postoperative systemic changes, were not evaluated in detail and may have indirectly influenced visual or neurological outcomes. Prospective studies with larger patient cohorts, standardized imaging protocols, longer follow-up periods, and comprehensive functional assessments are required to validate the present findings and further clarify the role of navigation-assisted transsphenoidal surgery in the management of pituitary adenomas.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis retrospective comparative study demonstrates that navigation-assisted microscopic transsphenoidal surgery for pituitary adenomas achieves significantly greater postoperative tumor volume reduction compared with conventional non-navigation-assisted techniques. The use of intraoperative neuronavigation enhances surgical orientation and precision, enabling more effective tumor resection without increasing surgical morbidity. Although postoperative thinning of the retinal nerve fiber layer was observed, navigation-assisted surgery did not result in significant differences in RNFL changes when compared with standard transsphenoidal surgery. These findings suggest that the primary benefit of neuronavigation lies in improving the extent of safe tumor removal rather than directly influencing optic nerve structural recovery. Overall, navigation-assisted transsphenoidal surgery represents a valuable technological adjunct in the management of pituitary adenomas, particularly in cases involving large or anatomically complex tumors. Its integration into surgical practice may contribute to improved resection outcomes while maintaining visual and neurological safety.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eO.S., A.K., B. O., S. D., C.E. wrote the main manuscript text, F.T., O.L. G., H. F., M. K prepared figures 1-5. All authors reviewed the manuscript\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eNam SM, Hwang JH, Byun YH, Park SS, Kim JH, Kim MS et al (2026) Clinical characteristics and risk factors of delayed ophthalmoplegia following cavernous sinus exploration in endoscopic pituitary adenoma surgery: Delayed transient ophthalmoplegia. Pituitary 29(1):32\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMaroufi SF, Doğruel Y, Pour-Rashidi A, Kohli GS, Parker CT, Uchida T et al (2024) Current status of artificial intelligence technologies in pituitary adenoma surgery: a scoping review. Pituitary\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKanat A, Tsianaka E, Gasenzer ER, Drosos E (2022) Some Interesting Points of Competition of X-Ray using during the Greco-Ottoman War in 1897 and Development of Neurosurgical Radiology: A Reminiscence. Turk Neurosurg 32(5):877\u0026ndash;881\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM\u0026uuml;sl\u0026uuml;man AM, Cansever T, Yilmaz A, Kanat A, Oba E, \u0026Ccedil;avuşoǧlu H et al (2011) Surgical results of large and giant pituitary adenomas with special consideration of ophthalmologic outcomes. World Neurosurg 76:1\u0026ndash;2\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGould J, Singh A, Patel S, Yaffe N, Li G, Blanpain L et al (2025) Surgical management in very elderly patients with pituitary adenoma: a multivariable assessment of the surveillance, epidemiology, and end results database. Pituitary 29(1):18\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXia L, Wenhui J, Xiaowen Y, Wenfang X, Wei Z, Yanjun H et al (2022) Predictive value of macular ganglion cell-inner plexiform layer thickness in visual field defect of pituitary adenoma patients: a case-control study. Pituitary 25(4):667\u0026ndash;672\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee MH, Im YH, Shin JH, Lee TK (2025) The efficacy of minimally invasive intraoperative ultrasound in endoscopic pituitary surgery. Pituitary 29(1):17\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFindik H, Kanat A, Celiker FB, Celiker M, Beyazal M, Ozdemir B et al (2020) What Are We Missing From Asymmetric Relationship Between the Retinal Nerve Fiber Layer Thickness Profiles and Sphenoid Sinus Volume? J Craniofac Surg 31(2):e210\u0026ndash;e214\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYilmaz A, Musluman AM, Kanat A, Cavusoglu H, Terzi Y, Aydin Y (2011) The correlation between hematoma volume and outcome in ruptured posterior fossa arteriovenous malformations indicates the importance of surgical evacuation of hematomas. Turk Neurosurg 21(2):152\u0026ndash;159\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuvercin AR, Besir A, Kanat A, Yazar U, Findik H (2023) Interesting negative correlation between transorbital optic nerve sheath diameter and Evans\u0026rsquo; index values; can it be predictive for failure of endoscopic third ventriculostomy? Int J Neurosci 133(7):812\u0026ndash;818\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFindik H, Kanat A, Aydin MD, Guvercin AR, Ozmen S (2024) New Evidence for Regulatory Role of Trigeminal Ganglion on the Intraocular Pressure Following Subarachnoid Hemorrhage. J Neurol Surg Cent Eur Neurosurg 85(2):137\u0026ndash;141\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQiao N, Ye Z, Shen M, Shou X, Wang Y, Li S et al (2016) Retinal nerve fiber layer changes after transsphenoidal and transcranial pituitary adenoma resection. Pituitary 19(1):75\u0026ndash;81\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGel MS, Kanat A, Seker D, Koc H, Daltaban IS, Findik H et al (2024) Changes in retinal nerve fiber layer thickness may be the cause of post-COVID-19 headaches. Neurol Res. ;1\u0026ndash;10\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoon CH, Hwang SC, Ohn YH, Park TK (2011) The time course of visual field recovery and changes of retinal ganglion cells after optic chiasmal decompression. Invest Ophthalmol Vis Sci 52(11):7966\u0026ndash;7973\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMenon S, Nair S, Kodnani A, Hegde A, Nayak R, Menon G (2023) Retinal nerve fiber layer thickness and its correlation with visual symptoms and radiological features in pituitary macroadenoma. J Neurosci Rural Pract 14(1):41\u0026ndash;47\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen Y, Li X, Song X, Cong L, Zhang Y (2023) Microvascular Changes in Pituitary Adenoma Correlate with Structural Measurements and Visual Field Loss. Neuropsychiatr Dis Treat 19:2745\u0026ndash;2754\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYolas C, Kanat A, Zeynal M, Hakan Sahin M, Kursat Karadag M, Nuri Keles O et al (2023) From Nose to Lumbar Spinal Cord; Reduced Sperm Numbers occur by Olfactory Bulbectomy-releted Onuf\u0026rsquo;s Nucleus Degeneration; New Experimental Evidence for Kallmann Syndrome. Neuroendocrinology\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"navigation-assisted transsphenoidal surgery, residual tumor volume, retinal nerve fiber layer, pituitary adenoma","lastPublishedDoi":"10.21203/rs.3.rs-8800806/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8800806/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eAim:\u003c/h2\u003e \u003cp\u003ePredicting visual outcomes following transsphenoidal surgery for pituitary adenoma remains challenging. Intraoperative neuronavigation is occasionally used during pituitary surgery; however, its effect on visual outcomes is not fully understood. This study aimed to investigate the impact of navigation-assisted transsphenoidal surgery on postoperative residual tumor volume and retinal nerve fiber layer (RNFL) changes.\u003c/p\u003e\u003ch2\u003eMethods:\u003c/h2\u003e \u003cp\u003eA retrospective analysis was performed on 27 consecutive patients who underwent microscopic transsphenoidal surgery for pituitary adenoma. Patients were divided into two groups: Group 1 (non-navigation-assisted) and Group 2 (navigation-assisted). Postoperative residual tumor volume and RNFL thickness changes were compared between groups.\u003c/p\u003e\u003ch2\u003eResults:\u003c/h2\u003e \u003cp\u003eGroup 1 consisted of 17 patients (63%) with a mean preoperative tumor volume of 4.84\u0026thinsp;\u0026plusmn;\u0026thinsp;1.24 cm\u0026sup3;, while Group 2 included 10 patients (37%) with a mean preoperative volume of 8.91\u0026thinsp;\u0026plusmn;\u0026thinsp;1.18 cm\u0026sup3;. The postoperative residual volume was significantly higher in Group 1 (3.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78 cm\u0026sup3;) compared with Group 2 (1.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26 cm\u0026sup3;; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.031). Although RNFL thinning was observed postoperatively in both groups, navigation-assisted surgery did not result in statistically significant differences in RNFL thickness.\u003c/p\u003e\u003ch2\u003eConclusion:\u003c/h2\u003e \u003cp\u003eNavigation-assisted transsphenoidal surgery enables significantly greater tumor volume reduction without substantially altering postoperative RNFL thickness. These findings suggest that neuronavigation improves surgical precision and extent of resection while maintaining visual structural integrity.\u003c/p\u003e","manuscriptTitle":"Impact of Navigation-Assisted Transsphenoidal Surgery on Residual Tumor Volume and Retinal Nerve Fiber Layer Thickness in Pituitary Adenoma","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-13 12:25:23","doi":"10.21203/rs.3.rs-8800806/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"46d91de9-21d8-4d33-a1b7-fa97130c45b5","owner":[],"postedDate":"February 13th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-01T08:09:10+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-13 12:25:23","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8800806","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8800806","identity":"rs-8800806","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}