Outcomes of the Haigis-L formula for calculating intraocular lens power in extreme long axis eyes after myopic laser in situ keratomileusis.

PURPOSE: To evaluate the accuracy of refractive prediction by the Haigis-L formula compared to four other IOL power calculation formulas in eyes with extremely long axial lengths (AL > 29.0 mm) after LASIK. SETTING: Shanghai Eye Disease and Prevention Treatment Center, Shanghai, China. DESIGN: Retrospective case series. METHODS: Twenty-nine eyes from 19 patients were available for analysis. The primary outcome measure was the arithmetic refractive prediction error (RPE), defined as the difference between the actual postoperative refractive error and the intended formula-derived refractive target. The main outcome measure was the median absolute refraction prediction error (MedAE). The accuracy of the Haigis-L was compared with Barrett True K No History, Shammas-PL, SRK/Tcorrected K, and Holladay 2corrected K methods to calculate IOL power. RESULTS: The Haigis-L formula had a significantly larger MedAE than Shammas-PL and SRK/Tcorrected K formulas (P = 0.005 and P = 0.015, respectively), a smaller percentage of eyes within ±1.50 diopter (D) of predicted error in refraction compared with Shammas-PL and SRK/Tcorrected K formulas (P = 0.014 and P = 0.005, respectively). The refractive prediction errors of 6 eyes with corneal keratometry of less than 35 D by Haigis-L all had more than 1.95 D of myopic overestimation, while none of the other four methods resulted in an absolute error over 1.95 D. CONCLUSIONS: The Haigis-L formula was relatively accurate in predicting extreme long axis (>29.0 mm) eyes after myopic LASIK surgery but less accurate for eyes with extremely flat corneas (<35 D). SRK/Tcorrected K and Shammas-PL performed better than the other methods for refractive prediction in this type of eyes. SYNOPSIS: Haigis-L performed worse than SRK/Tcorrected K and Shammas-PL in predicting IOL power in extremely long axis (>29.0 mm) eyes after myopic LASIK, especially with extremely flat corneas (K < 35 D).

Short-Term Changes in Retinal Vasculature and Layer Thickness after Phacoemulsification Surgery.

Purpose: To evaluate the short-term influence of uncomplicated phacoemulsification on fundus structure and vasculature change.Methods: A total of 51 eyes from 51 patients with mild-to-moderate cataracts were included. Retinal vessel density, perfusion density, and layer thickness in both macular and peripapillary areas were scanned by OCT at baseline and at 1 day, 1 week, and 1 month after cataract surgery. Cumulative dissipated energy (CDE), U/S total time (USTT) and total aspiration time (TAT) were recorded as parameters of surgical injury to analyze the surgical influence on fundus change.Results: There was a significant increase up in retinal vasculature parameters in both macular and optic nerve area after the surgery. The retinal layer thickness had pronounced increase from 1 week after the surgery (all p < .05, repeated-measures analysis of variance). Retinal nerve fiber layer (RNFL) thickness and ganglion cell layer (GCL) thickness increased more rapidly than other layers. There was a positive correlation between CDE and vasculature changes from 1 week to 1 month (Vessel density in macular to CDE: standardized ß = 0.448, p = .005; Perfusion density in peripapillary area to CDE: standardized ß = 0.382, p = .015).Conclusions: Retinal vasculature and layer thickness increased in short-term follow-up after cataract surgery. Whether these changes would persist over a longer period needs to be verified.