Research on accuracy of different IOL power calculation following the combination of phacoemulsification and vitrectomy in eyes with idiopathic macular epiretinal membrane / 中华实验眼科杂志

ABSTRACT

Objective To evaluate the accuracy of intraocular lens (IOL) power calculation using IOL-Master in patients underwent phacoemulsification and vitrectomy for idiopathic macular epiretinal membrane (IMEM) concurrent with age-related cataract (ARC).Methods A prospective study was designed.A total of 32 patients (32 eyes) with ARC (ARC group) and 30 patients (30 eyes) with ARC and IMEM (ARC+IMEM group) were enrolled from March 2013 to July 2015 in the Hangzhou District of Eye Hospital of Wenzhou Medical University.All the surgeries were performed by the same experienced surgeon and the same IOL (Adapt-AO) was implanted.IOL power was calculated by both SRK-T and Haigis formulas.The central macular thickness was measured by OCT preoperatively and postoperatively.The mean postoperative refractive prediction error (ME),mean absolute postoperative prediction error (MAE) and percentage of eyes achieved target refraction within ± 0.25,± 0.50 and ± 1.00 D were compared between the 2 groups.The correlation between the refractive error and macular thickness change was evaluated.Results The ME and MAE calculated by Haigis were (-0.47±0.66)D and (0.63±0.44)D in ARC+IMEM group,and (-0.18±0.74)D and (0.68±0.65)D in ARC group.The ME and MAE calculated by SRK-T were (-0.60 ±0.59) D and (0.73 ±0.41) D in ARC +IMEM group,and (-0.23 ±0.85)D and (0.75 ±0.69)D in ARC group.No significant differences were found between the two groups in each formula (all at P＞0.05).There was no significant difference of MAE distribution between the two groups in Haigis formula.In SRK-T formula,the percentage of MAE≤0.25 D in the ARC+IMEM group was significantly higher than that in the ARC group (x2 =7.114,P=0.007).In the A RC+IMEM group,the change of the macular thickness was (-97.4± 115.3)μm,which was statistically correlated with the ME of H aigis and SRK-T formulas (r=0.369,P =0.045;r =0.421,P =0.021).Conclusions There is a tendency toward myopia shift in patients underwent phacoemulsification and vitrectomy compared with conventional phacoemulsification.The myopia shift shows a significant correlation with macular thickness changes.Haigis formula performs better than SRK-T formula with the condition of un-optimized parameters.