Alpha-Adrenergic Antagonists and Iris Dynamics: Challenges and Solutions in Cataract Surgery

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Numerous studies have demonstrated the association between α1-ARAs like Tamsulosin and increased surgical risks for patients undergoing cataract surgery. This study aims to identify and study the effects of α1-ARAs on iris parameters and the subsequent operative challenges encountered during cataract surgery. Methods: A cross-sectional, prospective study involving 30 patients on α1-ARAs planned for cataract surgery and equal number of age and sex matched controls were subjected to evaluation of changes on iris parameters and subsequent challenges in cataract surgery. Results: The study group had statistically significant lesser pupil diameter. Iris thickness at sphincter muscle region (SMR) was similar between groups (P = 0.53). Significantly lower values of iris thickness at dilator muscle region (DMR) found in treated subjects (P = <0.001). There was statistically significant difference between DMR/SMR ratio of two groups (P<0.001). Multiple regression analysis revealed longer duration of α1-ARAs treatment correlated with reduced DMR/SMR ratio (P = 0.001; r = 0.47). Conclusion: α1-ARAs have implications for pupil size regulation and surgical procedures involving the eye. Tamsulosin is more potent than alfuzosin in inducing IFIS. Systemic α1-ARAs lower values of DMR thickness, DMR/SMR ratio and reduces pupillary diameter. Therefore, ophthalmologists, primary care physicians, urologists, and patients should be aware of the potential difficulties that these drugs pose for cataract surgery. Alpha Adrenergic antagonists Tamsulosin Pupillary diameter Intraoperative floppy iris syndrome (IFIS) Figures Figure 1 Figure 2 INTRODUCTION Alpha-1 adrenergic receptor antagonists (α1-ARAs) or Alpha-1 blockers consist of drugs that block the effect of catecholamines on alpha-1 adrenergic receptors in smooth muscle tissues. They are commonly used in the management of benign prostatic hyperplasia (BPH), hypertension and post-traumatic stress disorder [ 1 ]. BPH involves the use of tamsulosin which is a selective α 1A -ARA that helps in alleviating urinary symptoms. However, their pharmacological action extends to ocular tissues, more precisely, the smooth muscle of iris dilator muscle, leading to side effects that are particularly significant during cataract surgery making it more challenging with increased risk of complications [ 2 ]. The mechanism by which α1-ARAs induce these changes involves the inhibition of alpha-1 receptors in the iris dilator muscle, resulting in reduced muscle tone and, consequently, smaller pupil diameters with decreased iris rigidity. The implications of these effects in ophthalmology are relevant with the increasing prevalence of primary users of these medications among the aging population who are undergoing cataract surgery. One of the most characteristic ocular side effects associated with α1-ARAs is intraoperative floppy iris syndrome (IFIS), first described by Chang and Campbell in 2005 [ 3 ]. It is characterized by a triad of symptoms: fluttering and bellowing of iris stroma, propensity for the pupil to constrict during surgery, and tendency for the iris to prolapse toward the incisions. This syndrome complicates phacoemulsification by making it more challenging for the surgeon to operate, thus increasing the risk of intraoperative and postoperative complications. Schreiner et al. (2009) documented that patients on tamsulosin present with significantly smaller preoperative pupil sizes, necessitating additional surgical interventions [ 4 ]. Blouin et al. (2007) noted that while alfuzosin and other α1-ARAs are less frequently associated with IFIS than tamsulosin, they still pose a considerable risk for intraoperative complications [ 5 ]. Numerous other studies have demonstrated the association between selective α1-ARAs drugs like Tamsulosin and increased surgical risks for patients undergoing cataract surgery [ 3 ] [ 6 ]. Understanding the impact of α1-ARAs on iris parameters is crucial for planning and executing cataract surgery. Awareness and appropriate management strategies can mitigate risks and improve surgical outcomes. In this study we aim to identify and study the effects of α1-ARAs on iris parameters and the subsequent operative challenges encountered during cataract surgery as a result of morphological changes induced in the iris by these agents. By providing a comprehensive analysis of these effects and discussing effective management strategies, this research seeks to enhance the surgical approach and outcomes for patients on these drugs. Aim and objectives Study the effects of α1-ARAs on iris parameters and subsequent challenges in cataract surgery. MATERIALS AND METHODS Study design This prospective review was conducted for 60 patients, taken from general ophthalmology outpatients department, who were planned cataract surgery. This evaluation was conducted after dividing the study participants into two groups. The first / study group included thirty patients on α1-ARAs and thirty similar age-sex matched controls were inducted in the second / control group. Inclusion criteria were : Diagnosis of cataract requiring surgical intervention. Use of α1-ARAs (e.g., tamsulosin, alfuzosin) for at least three months prior to surgery. Availability of complete medical records and follow-up data. Exclusion criteria included : Previous intraocular surgery. Co-existing ocular pathologies (e.g., glaucoma, uveitis). Use of other medications affecting pupil size (e.g., anticholinergics). Strategies to remove confounding : All cases performed by same surgeon (right handed). All surgeries carried out using topical anaesthesia. 2.8 mm main entry port and 15-degree side port was used in all cases. Data collection Anterior segment was examined by means of slit lamp. Detailed mydriatic fundus examination was done by 90D slit lamp bio-microscopy, direct and indirect ophthalmoscopy. Data collected included demographic information (age, sex), duration and type of alpha-adrenergic antagonist use, preoperative pupil diameter and iris characteristics, intraoperative complications (e.g., IFIS, iris prolapse, zonular dehiscence), surgical duration, postoperative outcomes (e.g., BCVA, intraocular pressure, complications). Using anterior segment optical coherence tomography (AS-OCT), dilator muscle region (DMR) iris thickness measured at half distance between the scleral spur & the pupillary margin and sphincter muscle region (SMR) iris thickness measured 0.75 mm from the pupillary margin. The ratio between the DMR/SMR to compensate for possible intersubject variability and pupillary diameter were also studied. Statistical analysis The recorded data was analysed using commercial software (SPSS Version 24.0; SPSS, Inc., Chicago, IL, USA). Descriptive statistics to summarize clinical characteristics and patient demographics. The t -test was used to compare the pupillary diameter and DMR/SMR ratio in patients on α1-ARAs and control group. The pupillary diameter and DMR/SMR ratio width was correlated with the duration of treatment with α1-ARAs. A p -value of < 0.05 were considered statistically significant. Ethical issues This study adheres strictly to the tenets of the Declaration of Helsinki. All aspects of this study were vetted by the institutional ethical committee. All patients signed an informed consent. Title of the committee- Institutional Ethics Committee Affiliation- Command Hospital (Central Command), Lucknow − 226002 (UP) Country- India Approval number- IEC Registration No: EC/NEW/INST/2021/2471 RESULTS The mean age of the study group was 70.9 ± 7.5 years (n = 30). The mean age of control group was 67.1 ± 8.1 years (n = 30). There was no statistically significant difference between the two groups (P = 0. 061). Sex, eye color and laterality were not significant. Drugs usage: In the study group, out of 30 participants, 27 patients were on Tamsulosin, two patients were on Alphazosin and one patient was on combination therapy with both Tamsulosin and Alphazosin. Photopic pupillary diameter was reduced in the study group 2.08 ± 0.8 mm when compared to the controls wherein it was 2.5 ± 0.6 mm. (p = 0.0001) (Figure 1). Table 1. Comparison of demographic and morphological data between both groups Parameter Study group, n = 30 (Range) Control Group. n = 30 (Range) P-value Age 70.9 ± 7.5 67.1 ± 8.1 0.061 Photopic pupillary diameter (mm) 2.08 ± 0.8 (1.28-3.2) 2.52 ± 0.6 (1.7-3.9) 0.0001 Iris thickness measurements DMR (μm) 354.6 ± 83.7 (176.7 – 522) 446.9 ± 92.6 (291.3 – 611) <0.001 SMR (μm) 473.2 ± 76.5 (359.3 681.3) 460.5 ± 99.5 (328.3 – 745) 0.530 DMR/SMR ratio 0.75 ± 0.2 (0.36 – 1.07) 0.98 ± 0.1 (0.79 – 1.23) <0.001 SMR: Sphincter Muscle Region; DMR: Dilator Muscle Region Events during cataract surgery: Out of 30 participants in study group, 28 patients were taken up for cataract surgery. Intraoperatively, 22 patients (78.57%) had IFIS, two patients (7.14%) developed posterior capsular rent (PCR) and four patients (14.28%) had iris chaffing. In the control group, all 30 patients underwent cataract surgery with no intraoperative IFIS, PCR or iris chaffing. DISCUSSION α1-ARAs are frequently used in treatment of Hypertension and symptomatic Benign prostatic hypertrophy (BPH) [ 7 ]. Of the three subtypes of alpha-1 receptors (a, b, and d), the alpha-1a receptor dominates in the iris dilator muscle as well as in the smooth muscles of the prostate tissue. Also, the beta Tamsulosin is subtype specific and has affinity 20 times for the alpha-1a receptor [ 8 ]. The pupillary dilatation is severely impeded by the use of α1-ARAs, however, the frequency and severity of pathological alterations in the iris morphology is most marked with use of Tamsulosin (α 1A -ARA) [ 9 ] [ 10 ] [ 11 ]. Our observations regarding the reduction in pupil diameter and iris rigidity among patients receiving α1-ARAs are consistent with existing literature. There is scientific evidence establishing the association between the use of α1-ARAs in Intraoperative floppy iris syndrome (IFIS) [ 12 ], a term, coined by Chang and Campbell in 2005 [ 1 ]. These are the possible alterations resulting in the clinical entity of IFIS. This consists of fluttering and bellowing of iris stroma, propensity for the pupil to constrict during surgery, and tendency for the iris to prolapse toward the incisions. Few studies have mentioned that IFIS has been noted even in patients who had stopped tamsulosin 2 years before cataract surgery [ 13 ] [ 14 ]. However, minimum duration of intake of tamsulosin leading to IFIS has never been suggested or remarked upon by any of the studies. In our study the results show marked changes in the iris morphology in patients with a past or current history of α1-ARAs usage as compared to age-matched controls. There was statistically significant decrease in the DMR thickness, lower DMR/SMR ratios and smaller pupillary diameters. This is in consonance with the first report by Prata TS et al[ 15 ] which demonstrated structural alteration in the iris dilator muscle region in patients using α1-ARAs. We found no significant difference in the SMR thickness which showed no statistically significant difference between the study patients and control group. Altered iris morphology was present in 68% of treated patients compared to controls. This figure is in sync with the reported prevalence of clinical IFIS in 62.5–93.8% patients on tamsulosin or with history of tamsulosin use [ 16 ] [ 17 ] [ 18 ] [ 19 ]. These alterations in iris can lead to myriad of complications that range from poor visibility of the operative field, iris damage, posterior capsule rupture and posterior dislocation of lens material intraoperatively. The surgical challenges posed by IFIS and other complications related to α1-ARAs necessitate specific management strategies. Strategies such as medication review, preoperative discontinuation of alpha-blockers when feasible and modification of surgical techniques can help optimize outcomes and minimize complications. Preoperative planning is crucial, including a thorough medication review and consideration of discontinuing α1-ARAs prior to surgery when feasible. However, this approach must be balanced against the potential risks of interrupting treatment for the underlying condition. Alternative medications, such as non-selective α-ARA, may also be considered in consultation with the patient’s primary care provider. A study by Chang DF (2008) suggested preoperative administration of alpha-adrenergic agonists may help improve iris tone and mitigate the risk of IFIS during surgery [ 20 ]. Similar study by Bucci Jr FA, et al (2012) found that preoperative use of topical phenylephrine and ketorolac combination was effective in reducing the severity of IFIS and improving surgical outcomes in patients on tamsulosin [ 21 ]. Intraoperative management techniques are equally important in preventing or addressing the potential complications. The use of mechanical devices such as iris hooks or rings, like the Malyugin ring, can help maintain pupil dilation and stability during surgery. Viscomydriasis, which involves the injection of a cohesive viscoelastic agent, can also aid in maintaining pupil size and preventing iris prolapse. Additionally, modifications in phacoemulsification techniques, such as adjusting fluidics settings and carefully manipulating the iris, can help manage its instability and reduce the risk of complications. While this study provides valuable insights into the effects of α1-ARAs on iris parameters and cataract surgery outcomes, several limitations must be acknowledged. The nature of the study design introduces the potential for selection bias and limits causal inference. Future prospective studies with larger sample sizes are needed to validate our findings and elucidate the underlying mechanisms driving medication-specific differences in IFIS risk. Furthermore, our study did not assess the impact of α1-ARAs on postoperative complications or long-term visual outcomes as it primarily focused on the immediate perioperative period. To evaluate their implications on long-term ocular health and visual function, longitudinal studies with extended follow-up periods are warranted. Additionally, studies evaluating comparative effectiveness of different management strategies for IFIS, including preoperative medication review, intraoperative techniques, and postoperative care protocols, are needed to establish evidence-based guidelines to further optimize surgical outcomes. CONCLUSION In conclusion, appropriate pre-operative assessment which includes history of BPH or HTN treatment especially in elderly patients should be elicited as α1-ARAs have a significant impact on iris behavior, leading to increased challenges in cataract surgery, particularly due to IFIS. Systemic α1-ARAs lower values of DMR thickness, DMR/SMR ratio and reduces pupillary diameter. Severity of pathological alterations in iris morphology is most marked with use of Tamsulosin (α 1A -ARA). Communication among the treating physicians about treatment with α1-ARAs is essential and discontinuation of α1-ARAs prior to cataract surgery may be considered. Declarations Source(s) of support in the form of Grants, Equipment, Drugs: The authors have no relevant financial or non-financial interests to disclose. Acknowledgement(s): Nil Conflict of Interests: The authors declare that there is no conflict of interest. Informed consent was obtained from all individual participants included in the study. Author Contributions’ Statement (CRedIT Statement) : All authors contributed to the study conception and design. Material preparation was done by Dr Jaya Kaushik & Dr Meenu Dangi, data collection was done by Dr Rakesh Kumar Jha & Dr Ankita Singh and analysis was performed by Dr Sumit Goyal. The first draft of the manuscript was written by Dr Rishi Sharma and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. References Nickel JC, Méndez-Probst CE, Whelan TF, Paterson RF, Razvi H. 2010 Update: Guidelines for the Management of Benign Prostatic Hyperplasia. Can Urol Association J. 2013;4:310–16. Chatziralli IP, Sergentanis TN. Risk factors for intraoperative floppy iris syndrome: a meta-analysis. Ophthalmology. 2011;118(4):730–5. Chang DF, Campbell JR. Intraoperative floppy iris syndrome associated with tamsulosin. J Cataract Refract Surg. 2005;31(4):664–73. Schreiner B, Hengerer F, Dick HB. Impact of tamsulosin on pupil diameter and intraoperative complications during cataract surgery. Am J Ophthalmol. 2009;148(4):504–10. Blouin MC, Blouin J, Perreault S, Lapointe A, Dragomir A. Intraoperative floppy-iris syndrome associated with alpha1-adrenoreceptors: comparison of tamsulosin and alfuzosin. J Cataract Refract Surg. 2007;33(7):1227–34. Chang DF, Campbell JR, Colin J, Schweitzer C, Study Surgeon Group. Prospective masked comparison of intraoperative floppy iris syndrome severity with tamsulosin versus alfuzosin. Ophthalmology. 2014;121(4):829–34. Foglar R, Shibata K, Horie K, Hirasawa A, Tsujimoto G. Use of recombinant alpha 1-adrenoceptors to characterize subtype selectivity of drugs for the treatment of prostatic hypertrophy. Eur J Pharmacol. 1995;288(2):201–7. Hieble JP, Bylund DB, Clarke DE, et al. International Union of Pharmacology. X. Recommendation for nomenclature of alpha 1-adrenoceptors: consensus update. Pharmacol Rev. 1995;47(2):267–70. Pärssinen O, Leppänen E, Keski-Rahkonen P, Mauriala T, Dugué B, Lehtonen M. Influence of tamsulosin on the iris and its implications for cataract surgery. Invest Ophthalmol Vis Sci. 2006;47(9):3766–71. Prata TS, Palmiero PM, Angelilli A, et al. Iris morphologic changes related to alpha(1)-adrenergic receptor antagonists implications for intraoperative floppy iris syndrome. Ophthalmology. 2009;116(5):877–81. Leonardi A, Hieble JP, Guarneri L, et al. Pharmacological characterization of the uroselective alpha-1 antagonist Rec 15/2739 (SB 216469): role of the alpha-1L adrenoceptor in tissue selectivity, part I. J Pharmacol Exp Ther. 1997;281(3):1272–83. Sallam A, Gunasekera V, Kashani S, Toma M. Awareness of IFIS among primary care physicians. J Cataract Refract Surg 2008; Aug 34(8): 1230. Chang DF, Campbell JR. Intraoperative floppy iris syndrome associated with tamsulosin. J Cataract Refract Surg. 2005;31(4):664–73. Taguchi K, Saitoh M, Sato S, Asano M, Michel MC. Effects of tamsulosin metabolites at alpha-1 adrenoceptor subtypes. J Pharmacol Exp Ther. 1997;280(1):1–5. Prata TS, Palmiero PM, Angelilli A, et al. Iris morphologic changes related to alpha(1)-adrenergic receptor antagonists implications for intraoperative floppy iris syndrome. Ophthalmology. 2009;116(5):877–81. Srinivasan S, Radomski S, Chung J, Plazker T, Singer S, Slomovic AR. Intraoperative floppy-iris syndrome during cataract surgery in men using alpha-blockers for benign prostatic hypertrophy. J Cataract Refract Surg. 2007;33(10):1826–7. Chang DF, Osher RH, Wang L, Koch DD. Prospective multicenter evaluation of cataract surgery in patients taking tamsulosin (Flomax). Ophthalmology. 2007;114(5):957–64. Takmaz T, Can I. Clinical features, complications, and incidence of intraoperative floppy iris syndrome in patients taking tamsulosin. Eur J Ophthalmol. 2007;17(6):909–13. Panagis L, Basile M, Friedman AH, Danias J. Intraoperative floppy iris syndrome: report of a case and histopathologic analysis. Arch Ophthalmol. 2010;128(11):1437–41. Chang DF, Braga-Mele R. Intraoperative Floppy Iris Syndrome: Pathophysiology, prevention and Treatment. J Cataract Refractive Surg. 2008;34(11):2008–12. Bucci FA Jr, Fluet AT, Yo C. A randomised prospective masked trial of topical phenylephrine and ketorolac in preventing intraoperative floppy-iris syndrome in patients on tamsulosin undergoing cataract surgery. Clin Ophthalmol. 2012;6:1913–6. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 03 Oct, 2024 Read the published version in BMC Ophthalmology → Version 1 posted Editorial decision: Revision requested 12 Jul, 2024 Editor assigned by journal 11 Jul, 2024 Submission checks completed at journal 11 Jul, 2024 First submitted to journal 06 Jul, 2024 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. 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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-4697443","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":325980120,"identity":"54e322be-3ac7-41d9-b933-8fe03ff98525","order_by":0,"name":"Jaya Kaushik","email":"","orcid":"","institution":"Command Hospital (CC), Lucknow","correspondingAuthor":false,"prefix":"","firstName":"Jaya","middleName":"","lastName":"Kaushik","suffix":""},{"id":325980122,"identity":"628e269e-2884-419c-af1a-b42716efde56","order_by":1,"name":"Rishi Sharma","email":"","orcid":"","institution":"Command Hospital (CC), Lucknow","correspondingAuthor":false,"prefix":"","firstName":"Rishi","middleName":"","lastName":"Sharma","suffix":""},{"id":325980123,"identity":"ef66daf6-0835-4e23-9d53-479fe23d2661","order_by":2,"name":"Sumit Goyal","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA4klEQVRIiWNgGAWjYJCCAwwMNvX8zMxAmkFChjgtBxjSEiTb2RJAWniIteZwgsF5HgMQm7AW+RnZiYc/MDDnGRzm+fzqRo0FDwP74aMb8GkxuJG7AegwtmLJw7zbrHOOAR3Gk5Z2A68WCbAWHsY+oBbjHDagFgkeM7xa5GeAtUgwNhzmeWac848ILQwQhxkkTjjMw/w4t40ILQZn3m44cMYgwViymc2MObdPgoeNkF/k23M3f6io+C/Hz3/48eecb3Vy/OyHj+F3GMQuMMkmASYJK0cA5g+kqB4Fo2AUjIKRAwD1TUpvKQd9egAAAABJRU5ErkJggg==","orcid":"","institution":"Military Hospital, Bareilly","correspondingAuthor":true,"prefix":"","firstName":"Sumit","middleName":"","lastName":"Goyal","suffix":""},{"id":325980124,"identity":"1905c642-0bb5-4f7d-a412-afc4fedc7fb6","order_by":3,"name":"Meenu Dangi","email":"","orcid":"","institution":"Command Hospital (CC), Lucknow","correspondingAuthor":false,"prefix":"","firstName":"Meenu","middleName":"","lastName":"Dangi","suffix":""},{"id":325980126,"identity":"bac80b7f-890b-46d5-8d3e-57eb718fd698","order_by":4,"name":"Rakesh Kumar Jha","email":"","orcid":"","institution":"Military Hospital, Wellington","correspondingAuthor":false,"prefix":"","firstName":"Rakesh","middleName":"Kumar","lastName":"Jha","suffix":""},{"id":325980127,"identity":"dba615f7-331c-4ce2-b123-beac34c270b2","order_by":5,"name":"Ankita Singh","email":"","orcid":"","institution":"Military Hospital, Bathinda","correspondingAuthor":false,"prefix":"","firstName":"Ankita","middleName":"","lastName":"Singh","suffix":""}],"badges":[],"createdAt":"2024-07-06 15:32:19","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4697443/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4697443/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12886-024-03705-1","type":"published","date":"2024-10-03T15:57:07+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":62187374,"identity":"cdc24235-33a3-4c1e-b9fe-60d923383ad1","added_by":"auto","created_at":"2024-08-10 12:10:43","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":59103,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of photopic pupillary diameter between the two groups.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4697443/v1/4a29f80bb150ecc4b135d5ed.png"},{"id":62188929,"identity":"43b01d87-f994-4ca1-89ff-3cae0d941deb","added_by":"auto","created_at":"2024-08-10 12:18:43","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":59968,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of DMR, SMR and DMR/SMR ratio between both groups\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4697443/v1/e634506e22909803de77272e.png"},{"id":66096757,"identity":"2f2cf965-a2e0-4468-a3b6-6cbd497f14d0","added_by":"auto","created_at":"2024-10-07 16:09:43","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":459428,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4697443/v1/f65fef0d-a076-4fc1-a3c0-a5647d582f5e.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eAlpha-Adrenergic Antagonists and Iris Dynamics: Challenges and Solutions in Cataract Surgery\u003c/p\u003e","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eAlpha-1 adrenergic receptor antagonists (α1-ARAs) or Alpha-1 blockers consist of drugs that block the effect of catecholamines on alpha-1 adrenergic receptors in smooth muscle tissues. They are commonly used in the management of benign prostatic hyperplasia (BPH), hypertension and post-traumatic stress disorder [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. BPH involves the use of tamsulosin which is a selective α\u003csub\u003e1A\u003c/sub\u003e-ARA that helps in alleviating urinary symptoms.\u003c/p\u003e \u003cp\u003eHowever, their pharmacological action extends to ocular tissues, more precisely, the smooth muscle of iris dilator muscle, leading to side effects that are particularly significant during cataract surgery making it more challenging with increased risk of complications [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. The mechanism by which α1-ARAs induce these changes involves the inhibition of alpha-1 receptors in the iris dilator muscle, resulting in reduced muscle tone and, consequently, smaller pupil diameters with decreased iris rigidity. The implications of these effects in ophthalmology are relevant with the increasing prevalence of primary users of these medications among the aging population who are undergoing cataract surgery.\u003c/p\u003e \u003cp\u003eOne of the most characteristic ocular side effects associated with α1-ARAs is intraoperative floppy iris syndrome (IFIS), first described by Chang and Campbell in 2005 [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. It is characterized by a triad of symptoms: fluttering and bellowing of iris stroma, propensity for the pupil to constrict during surgery, and tendency for the iris to prolapse toward the incisions. This syndrome complicates phacoemulsification by making it more challenging for the surgeon to operate, thus increasing the risk of intraoperative and postoperative complications.\u003c/p\u003e \u003cp\u003eSchreiner et al. (2009) documented that patients on tamsulosin present with significantly smaller preoperative pupil sizes, necessitating additional surgical interventions [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Blouin et al. (2007) noted that while alfuzosin and other α1-ARAs are less frequently associated with IFIS than tamsulosin, they still pose a considerable risk for intraoperative complications [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Numerous other studies have demonstrated the association between selective α1-ARAs drugs like Tamsulosin and increased surgical risks for patients undergoing cataract surgery [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eUnderstanding the impact of α1-ARAs on iris parameters is crucial for planning and executing cataract surgery. Awareness and appropriate management strategies can mitigate risks and improve surgical outcomes. In this study we aim to identify and study the effects of α1-ARAs on iris parameters and the subsequent operative challenges encountered during cataract surgery as a result of morphological changes induced in the iris by these agents. By providing a comprehensive analysis of these effects and discussing effective management strategies, this research seeks to enhance the surgical approach and outcomes for patients on these drugs.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eAim and objectives\u003c/strong\u003e \u003cp\u003eStudy the effects of α1-ARAs on iris parameters and subsequent challenges in cataract surgery.\u003c/p\u003e \u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design\u003c/h2\u003e \u003cp\u003e This prospective review was conducted for 60 patients, taken from general ophthalmology outpatients department, who were planned cataract surgery. This evaluation was conducted after dividing the study participants into two groups. The first / study group included thirty patients on α1-ARAs and thirty similar age-sex matched controls were inducted in the second / control group.\u003c/p\u003e \u003cp\u003e \u003cem\u003eInclusion criteria were\u003c/em\u003e:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eDiagnosis of cataract requiring surgical intervention.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eUse of α1-ARAs (e.g., tamsulosin, alfuzosin) for at least three months prior to surgery.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eAvailability of complete medical records and follow-up data.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e \u003cp\u003e \u003cem\u003eExclusion criteria included\u003c/em\u003e:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003ePrevious intraocular surgery.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eCo-existing ocular pathologies (e.g., glaucoma, uveitis).\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eUse of other medications affecting pupil size (e.g., anticholinergics).\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e \u003cp\u003e \u003cem\u003eStrategies to remove confounding\u003c/em\u003e:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eAll cases performed by same surgeon (right handed).\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eAll surgeries carried out using topical anaesthesia.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e2.8 mm main entry port and 15-degree side port was used in all cases.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eData collection\u003c/h2\u003e \u003cp\u003eAnterior segment was examined by means of slit lamp. Detailed mydriatic fundus examination was done by 90D slit lamp bio-microscopy, direct and indirect ophthalmoscopy.\u003c/p\u003e \u003cp\u003eData collected included demographic information (age, sex), duration and type of alpha-adrenergic antagonist use, preoperative pupil diameter and iris characteristics, intraoperative complications (e.g., IFIS, iris prolapse, zonular dehiscence), surgical duration, postoperative outcomes (e.g., BCVA, intraocular pressure, complications).\u003c/p\u003e \u003cp\u003eUsing anterior segment optical coherence tomography (AS-OCT), dilator muscle region (DMR) iris thickness measured at half distance between the scleral spur \u0026amp; the pupillary margin and sphincter muscle region (SMR) iris thickness measured 0.75 mm from the pupillary margin. The ratio between the DMR/SMR to compensate for possible intersubject variability and pupillary diameter were also studied.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eThe recorded data was analysed using commercial software (SPSS Version 24.0; SPSS, Inc., Chicago, IL, USA). Descriptive statistics to summarize clinical characteristics and patient demographics. The \u003cem\u003et\u003c/em\u003e-test was used to compare the pupillary diameter and DMR/SMR ratio in patients on α1-ARAs and control group. The pupillary diameter and DMR/SMR ratio width was correlated with the duration of treatment with α1-ARAs. A \u003cem\u003ep\u003c/em\u003e-value of \u0026lt;\u0026thinsp;0.05 were considered statistically significant.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eEthical issues\u003c/strong\u003e \u003cp\u003e This study adheres strictly to the tenets of the Declaration of Helsinki. All aspects of this study were vetted by the institutional ethical committee. All patients signed an informed consent.\u003c/p\u003e \u003c/p\u003e \u003cp\u003eTitle of the committee- Institutional Ethics Committee\u003c/p\u003e \u003cp\u003eAffiliation- Command Hospital (Central Command), Lucknow \u0026minus;\u0026thinsp;226002 (UP)\u003c/p\u003e \u003cp\u003eCountry- India\u003c/p\u003e \u003cp\u003eApproval number- IEC Registration No: EC/NEW/INST/2021/2471\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cp\u003eThe mean age of the study group was 70.9 \u0026plusmn; 7.5 years (n = 30). The mean age of control group was 67.1 \u0026plusmn; 8.1 years (n = 30). There was no statistically significant difference between the two groups (P = 0. 061). Sex, eye color and laterality were not significant.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eDrugs usage:\u003c/em\u003e In the study group, out of 30 participants, 27 patients were on Tamsulosin, two patients were on Alphazosin and one patient was on combination therapy with both Tamsulosin and Alphazosin.\u003c/p\u003e\n\u003cp\u003ePhotopic pupillary diameter was reduced in the study group 2.08 \u0026plusmn; 0.8 mm when compared to the controls wherein it was 2.5 \u0026plusmn; 0.6 mm. (p = 0.0001) (Figure 1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1.\u003c/strong\u003e Comparison of demographic and morphological data between both groups\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"26.677852348993287%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eParameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.859060402684563%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eStudy group, n = 30\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(Range)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.711409395973153%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eControl Group. n = 30\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(Range)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.751677852348994%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eP-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"26.677852348993287%\" valign=\"top\"\u003e\n \u003cp\u003eAge\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.859060402684563%\" valign=\"top\"\u003e\n \u003cp\u003e70.9\u0026nbsp;\u0026plusmn;\u0026nbsp;7.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.711409395973153%\" valign=\"top\"\u003e\n \u003cp\u003e67.1\u0026nbsp;\u0026plusmn;\u0026nbsp;8.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.751677852348994%\" valign=\"top\"\u003e\n \u003cp\u003e0.061\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"26.677852348993287%\" valign=\"top\"\u003e\n \u003cp\u003ePhotopic pupillary diameter (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.859060402684563%\" valign=\"top\"\u003e\n \u003cp\u003e2.08 \u0026plusmn; 0.8\u003c/p\u003e\n \u003cp\u003e(1.28-3.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.711409395973153%\" valign=\"top\"\u003e\n \u003cp\u003e2.52 \u0026plusmn; 0.6\u003c/p\u003e\n \u003cp\u003e(1.7-3.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.751677852348994%\" valign=\"top\"\u003e\n \u003cp\u003e0.0001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eIris thickness measurements\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"26.677852348993287%\" valign=\"top\"\u003e\n \u003cp\u003eDMR (\u0026mu;m)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.859060402684563%\" valign=\"top\"\u003e\n \u003cp\u003e354.6 \u0026plusmn; 83.7\u003c/p\u003e\n \u003cp\u003e(176.7 \u0026ndash; 522)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.711409395973153%\" valign=\"top\"\u003e\n \u003cp\u003e446.9 \u0026plusmn; 92.6\u003c/p\u003e\n \u003cp\u003e(291.3 \u0026ndash; 611)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.751677852348994%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"26.677852348993287%\" valign=\"top\"\u003e\n \u003cp\u003eSMR (\u0026mu;m)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.859060402684563%\" valign=\"top\"\u003e\n \u003cp\u003e473.2 \u0026plusmn; 76.5\u003c/p\u003e\n \u003cp\u003e(359.3 681.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.711409395973153%\" valign=\"top\"\u003e\n \u003cp\u003e460.5 \u0026plusmn; 99.5\u003c/p\u003e\n \u003cp\u003e(328.3 \u0026ndash; 745)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.751677852348994%\" valign=\"top\"\u003e\n \u003cp\u003e0.530\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"26.677852348993287%\" valign=\"top\"\u003e\n \u003cp\u003eDMR/SMR ratio \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"28.859060402684563%\" valign=\"top\"\u003e\n \u003cp\u003e0.75 \u0026plusmn; 0.2\u003cbr\u003e\u0026nbsp;(0.36 \u0026ndash; 1.07)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.711409395973153%\" valign=\"top\"\u003e\n \u003cp\u003e0.98 \u0026plusmn; 0.1\u003c/p\u003e\n \u003cp\u003e(0.79 \u0026ndash; 1.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.751677852348994%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eSMR: Sphincter Muscle Region; DMR: Dilator Muscle Region\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eEvents during cataract surgery:\u003c/em\u003e Out of 30 participants in study group, 28 patients were taken up for cataract surgery. Intraoperatively, 22 patients (78.57%) had IFIS, two patients (7.14%) developed posterior capsular rent (PCR) and four patients (14.28%) had iris chaffing. In the control group, all 30 patients underwent cataract surgery with no intraoperative IFIS, PCR or iris chaffing.\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eα1-ARAs are frequently used in treatment of Hypertension and symptomatic Benign prostatic hypertrophy (BPH) [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Of the three subtypes of alpha-1 receptors (a, b, and d), the alpha-1a receptor dominates in the iris dilator muscle as well as in the smooth muscles of the prostate tissue. Also, the beta Tamsulosin is subtype specific and has affinity 20 times for the alpha-1a receptor [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. The pupillary dilatation is severely impeded by the use of α1-ARAs, however, the frequency and severity of pathological alterations in the iris morphology is most marked with use of Tamsulosin (α\u003csub\u003e1A\u003c/sub\u003e-ARA) [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Our observations regarding the reduction in pupil diameter and iris rigidity among patients receiving α1-ARAs are consistent with existing literature.\u003c/p\u003e \u003cp\u003eThere is scientific evidence establishing the association between the use of α1-ARAs in Intraoperative floppy iris syndrome (IFIS) [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], a term, coined by Chang and Campbell in 2005 [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. These are the possible alterations resulting in the clinical entity of IFIS. This consists of fluttering and bellowing of iris stroma, propensity for the pupil to constrict during surgery, and tendency for the iris to prolapse toward the incisions. Few studies have mentioned that IFIS has been noted even in patients who had stopped tamsulosin 2 years before cataract surgery [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. However, minimum duration of intake of tamsulosin leading to IFIS has never been suggested or remarked upon by any of the studies.\u003c/p\u003e \u003cp\u003eIn our study the results show marked changes in the iris morphology in patients with a past or current history of α1-ARAs usage as compared to age-matched controls. There was statistically significant decrease in the DMR thickness, lower DMR/SMR ratios and smaller pupillary diameters. This is in consonance with the first report by Prata TS et al[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] which demonstrated structural alteration in the iris dilator muscle region in patients using α1-ARAs. We found no significant difference in the SMR thickness which showed no statistically significant difference between the study patients and control group. Altered iris morphology was present in 68% of treated patients compared to controls. This figure is in sync with the reported prevalence of clinical IFIS in 62.5–93.8% patients on tamsulosin or with history of tamsulosin use [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e] [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThese alterations in iris can lead to myriad of complications that range from poor visibility of the operative field, iris damage, posterior capsule rupture and posterior dislocation of lens material intraoperatively. The surgical challenges posed by IFIS and other complications related to α1-ARAs necessitate specific management strategies.\u003c/p\u003e \u003cp\u003eStrategies such as medication review, preoperative discontinuation of alpha-blockers when feasible and modification of surgical techniques can help optimize outcomes and minimize complications. Preoperative planning is crucial, including a thorough medication review and consideration of discontinuing α1-ARAs prior to surgery when feasible. However, this approach must be balanced against the potential risks of interrupting treatment for the underlying condition. Alternative medications, such as non-selective α-ARA, may also be considered in consultation with the patient’s primary care provider. A study by Chang DF (2008) suggested preoperative administration of alpha-adrenergic agonists may help improve iris tone and mitigate the risk of IFIS during surgery [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Similar study by Bucci Jr FA, et al (2012) found that preoperative use of topical phenylephrine and ketorolac combination was effective in reducing the severity of IFIS and improving surgical outcomes in patients on tamsulosin [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIntraoperative management techniques are equally important in preventing or addressing the potential complications. The use of mechanical devices such as iris hooks or rings, like the Malyugin ring, can help maintain pupil dilation and stability during surgery. Viscomydriasis, which involves the injection of a cohesive viscoelastic agent, can also aid in maintaining pupil size and preventing iris prolapse. Additionally, modifications in phacoemulsification techniques, such as adjusting fluidics settings and carefully manipulating the iris, can help manage its instability and reduce the risk of complications.\u003c/p\u003e \u003cp\u003eWhile this study provides valuable insights into the effects of α1-ARAs on iris parameters and cataract surgery outcomes, several limitations must be acknowledged. The nature of the study design introduces the potential for selection bias and limits causal inference. Future prospective studies with larger sample sizes are needed to validate our findings and elucidate the underlying mechanisms driving medication-specific differences in IFIS risk. Furthermore, our study did not assess the impact of α1-ARAs on postoperative complications or long-term visual outcomes as it primarily focused on the immediate perioperative period. To evaluate their implications on long-term ocular health and visual function, longitudinal studies with extended follow-up periods are warranted. Additionally, studies evaluating comparative effectiveness of different management strategies for IFIS, including preoperative medication review, intraoperative techniques, and postoperative care protocols, are needed to establish evidence-based guidelines to further optimize surgical outcomes.\u003c/p\u003e \u003cp\u003e\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eIn conclusion, appropriate pre-operative assessment which includes history of BPH or HTN treatment especially in elderly patients should be elicited as α1-ARAs have a significant impact on iris behavior, leading to increased challenges in cataract surgery, particularly due to IFIS. Systemic α1-ARAs lower values of DMR thickness, DMR/SMR ratio and reduces pupillary diameter. Severity of pathological alterations in iris morphology is most marked with use of Tamsulosin (α\u003csub\u003e1A\u003c/sub\u003e-ARA). Communication among the treating physicians about treatment with α1-ARAs is essential and discontinuation of α1-ARAs prior to cataract surgery may be considered.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eSource(s) of support\u003c/strong\u003e in the form of Grants, Equipment, Drugs: The authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement(s):\u0026nbsp;\u003c/strong\u003eNil\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interests:\u0026nbsp;\u003c/strong\u003eThe authors declare that there is no conflict of interest.\u003c/p\u003e\n\u003cp\u003eInformed consent was obtained from all individual participants included in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions’ Statement (CRedIT Statement)\u003c/strong\u003e:\u003c/p\u003e\n\u003cp\u003eAll authors contributed to the study conception and design. Material preparation was done by Dr Jaya Kaushik \u0026amp; Dr Meenu Dangi, data collection was done by Dr Rakesh Kumar Jha \u0026amp;\u0026nbsp;\u003cbr\u003e\u0026nbsp;Dr Ankita Singh and analysis was performed by Dr Sumit Goyal. The first draft of the manuscript was written by Dr Rishi Sharma and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eNickel JC, M\u0026eacute;ndez-Probst CE, Whelan TF, Paterson RF, Razvi H. 2010 Update: Guidelines for the Management of Benign Prostatic Hyperplasia. Can Urol Association J. 2013;4:310\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChatziralli IP, Sergentanis TN. Risk factors for intraoperative floppy iris syndrome: a meta-analysis. Ophthalmology. 2011;118(4):730\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChang DF, Campbell JR. Intraoperative floppy iris syndrome associated with tamsulosin. J Cataract Refract Surg. 2005;31(4):664\u0026ndash;73.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchreiner B, Hengerer F, Dick HB. Impact of tamsulosin on pupil diameter and intraoperative complications during cataract surgery. Am J Ophthalmol. 2009;148(4):504\u0026ndash;10.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBlouin MC, Blouin J, Perreault S, Lapointe A, Dragomir A. Intraoperative floppy-iris syndrome associated with alpha1-adrenoreceptors: comparison of tamsulosin and alfuzosin. J Cataract Refract Surg. 2007;33(7):1227\u0026ndash;34.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChang DF, Campbell JR, Colin J, Schweitzer C, Study Surgeon Group. Prospective masked comparison of intraoperative floppy iris syndrome severity with tamsulosin versus alfuzosin. Ophthalmology. 2014;121(4):829\u0026ndash;34.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFoglar R, Shibata K, Horie K, Hirasawa A, Tsujimoto G. Use of recombinant alpha 1-adrenoceptors to characterize subtype selectivity of drugs for the treatment of prostatic hypertrophy. Eur J Pharmacol. 1995;288(2):201\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHieble JP, Bylund DB, Clarke DE, et al. International Union of Pharmacology. X. Recommendation for nomenclature of alpha 1-adrenoceptors: consensus update. Pharmacol Rev. 1995;47(2):267\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eP\u0026auml;rssinen O, Lepp\u0026auml;nen E, Keski-Rahkonen P, Mauriala T, Dugu\u0026eacute; B, Lehtonen M. Influence of tamsulosin on the iris and its implications for cataract surgery. 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J Cataract Refractive Surg. 2008;34(11):2008\u0026ndash;12.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBucci FA Jr, Fluet AT, Yo C. A randomised prospective masked trial of topical phenylephrine and ketorolac in preventing intraoperative floppy-iris syndrome in patients on tamsulosin undergoing cataract surgery. Clin Ophthalmol. 2012;6:1913\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-ophthalmology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"boph","sideBox":"Learn more about [BMC Ophthalmology](http://bmcophthalmol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/boph","title":"BMC Ophthalmology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Alpha Adrenergic antagonists, Tamsulosin, Pupillary diameter, Intraoperative floppy iris syndrome (IFIS)","lastPublishedDoi":"10.21203/rs.3.rs-4697443/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4697443/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eAlpha-1 adrenergic receptor antagonists (α1-ARAs) are frequently used in treatment of Hypertension and symptomatic benign prostatic hypertrophy (BPH). Numerous studies have demonstrated the association between α1-ARAs like Tamsulosin and increased surgical risks for patients undergoing cataract surgery. This study aims to identify and study the effects of α1-ARAs on iris parameters and the subsequent operative challenges encountered during cataract surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003eA cross-sectional, prospective study involving 30 patients on α1-ARAs planned for cataract surgery and equal number of age and sex matched controls were subjected to evaluation of changes on iris parameters and subsequent challenges in cataract surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eThe study group had statistically significant lesser pupil diameter. Iris thickness at sphincter muscle region (SMR) was similar between groups (P = 0.53). Significantly lower values of iris thickness at dilator muscle region (DMR) found in treated subjects (P = \u0026lt;0.001). There was statistically significant difference between DMR/SMR ratio of two groups (P\u0026lt;0.001). Multiple regression analysis revealed longer duration of α1-ARAs treatment correlated with reduced DMR/SMR ratio (P = 0.001; r = 0.47).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003e\u0026nbsp;α1-ARAs have implications for pupil size regulation and surgical procedures involving the eye. Tamsulosin is more potent than alfuzosin in inducing IFIS. Systemic α1-ARAs lower values of DMR thickness, DMR/SMR ratio and reduces pupillary diameter. Therefore, ophthalmologists, primary care physicians, urologists, and patients should be aware of the potential difficulties that these drugs pose for cataract surgery.\u003c/p\u003e","manuscriptTitle":"Alpha-Adrenergic Antagonists and Iris Dynamics: Challenges and Solutions in Cataract Surgery","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-08-10 12:10:38","doi":"10.21203/rs.3.rs-4697443/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-07-12T06:01:47+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-07-11T12:52:18+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-07-11T12:51:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Ophthalmology","date":"2024-07-06T15:30:52+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-ophthalmology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"boph","sideBox":"Learn more about [BMC Ophthalmology](http://bmcophthalmol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/boph","title":"BMC Ophthalmology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"31f26b5e-8385-444f-96ab-0a645407efda","owner":[],"postedDate":"August 10th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-10-07T16:00:17+00:00","versionOfRecord":{"articleIdentity":"rs-4697443","link":"https://doi.org/10.1186/s12886-024-03705-1","journal":{"identity":"bmc-ophthalmology","isVorOnly":false,"title":"BMC Ophthalmology"},"publishedOn":"2024-10-03 15:57:07","publishedOnDateReadable":"October 3rd, 2024"},"versionCreatedAt":"2024-08-10 12:10:38","video":"","vorDoi":"10.1186/s12886-024-03705-1","vorDoiUrl":"https://doi.org/10.1186/s12886-024-03705-1","workflowStages":[]},"version":"v1","identity":"rs-4697443","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4697443","identity":"rs-4697443","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}