Pre-operative optical coherence tomography predictors: Do they hold any relevance in the era of inverted internal limiting membrane flap in large macular holes?

Purpose: To study the relevance of preoperative OCT predictors in large macular holes (MH) treated using the inverted ILM peel technique. Methods: Prospective study of 95 patients undergoing vitrectomy for large MH between January 2019 and December 2020 was performed by dividing the patients into groups depending on various quantitative parameters and indices of MH such as base diameter (BD), hole form factor (HFF), macular hole index (MHI), diameter hole index (DHI), and tractional hole index (THI) by using parameters such as minimal hole diameter, hole height, nasal and temporal arm lengths. Depending upon the duration of symptoms, patients were divided into three groups: <3 months, 3–6 months, and >6 months. Anatomical success rate, type of closure, and postoperative vision gain were analyzed in relation to the abovementioned diameters, indices, and duration to see if any significance existed. Results: The mean age of patients included in the study was 60.48 ± 13.88 years, with female preponderance (males: females = 37:58). Change in logMAR was statistically significant individually with all studied parameters (P < 0.0001) without influence of size of hole and other indices. BD and DHI levels showed significant association with type of closure as indicated by P values of 0.017 and 0.048, respectively. Duration of symptoms showed no significance in terms of anatomical and functional success. Conclusion: OCT predictors of MH success seem to have lost relevance with inverted flap surgeries as 100% anatomical success is achieved with this technique, with 95.78% (91/95) achieving type 1 closure with statistically significant equivalent functional gain across the indices with no effect of duration of symptoms.

Refractive prediction by various intraocular lens formulas using optical biometry and effect of ocular parameters on their accuracy

Purpose: To assess the prediction accuracy of intraocular lens (IOL) formulas and study the effect of axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), and lens thickness (LT) on the accuracy of formulas using optic biometry. Methods: This study was performed on 164 eyes of 164 patients who underwent uneventful cataract surgery. Ocular biometry values were measured using Lenstar?900, and intraocular lens (IOL) power was calculated using the SRK/T, SRK II, Hoffer Q, Holladay 2, and Barrett Universal II formulas. We evaluated the extent of bias within each formula for different ocular biometric measurements and explored the relationship between the prediction error and the ocular parameters by using various IOL formulas. Results: The summarization of refractive prediction error and absolute prediction error for each IOL formulation was performed after adjusting the mean refractive error to zero. The deviation in the error values was minimum for SRK/T (0.265) followed by Holladay 2 (0.327) and Barret (0.382). Further, SRK/T had the lowest median (0.15) and mean (0.198) absolute error as compared to other formulations. For the above formulations, 100% of the eyes were in the diopter range of ±1.0. It was observed that the overall distribution of error was closer to zero for SRK/T, followed by Holladay 2 and then Barrett. Conclusion: In summary, we found that accuracy was better in SRK/T formula. We achieved a better understanding of how each variable in the formulas is relatively weighed and the influencing factors in the refraction prediction.