Differences in Axial Length and IOLs Power Basing on Alternative A-Scan or Fellow-Eye Biometry in Macular-off Rhegmatogenous Retinal Detachment Eyes

Abstract Background: To observe the potential refractive prediction error basing on alternative A-scan ultrasound and fellow-eye biometry for phacovitrectomy in macula-off rhegmatogenous retinal detachment (RRD) eyes, when the optic biometry IOLMaster fails to obtain data.Methods: Phakic macula-off RRD eyes without axial length (AL) measured using IOLMaster were included. Vitrectomy with silicone oil tamponade but not lens extraction was performed. Preoperative AL was measured using A-scan ultrasound, and postoperative AL, as well as fellow-eye biometry, was obtained using IOLMaster. The IOLs power was calculated according to preoperative A-scan, postoperative IOLMaster and fellow-eye AL.Results: AL measured by alternative A-scan (AL-US) was 25.39±2.14 mm, and AL of fellow-eyes (AL-FE) was 25.85±2.16 mm, and AL in eyes with silicone oil tamponade (AL-SO) was 26.08±2.53 mm. The Bland-Altman agreements among AL-US, AL-FE and AL-SO were well (95.5%, 21/22 of cases were in LoA). The mean IOLs power calculated using AL-US (Power-US) was 16.81±7.19 D, using AL-FE (Power-FE) was 14.74±6.95 D, and using AL-SO (Power-SO) was 13.54±8.32 D. The difference between AL-US and AL-SO was significant (P0.05). The difference between Power-US and Power-SO was significant (P0.05).Conclusion: The alternative A-scan ultrasound leads to a significant difference in AL and prediction error in IOLs power, while fellow-eye biometry provided similar results compared with those of silicone oil-filled eyes after RRD repair.