Session Title: Vitreoretinal Surgery I
Session Date/Time: Thursday 17/09/2015 | 08:30-10:30
Paper Time: 09:42
First Author: : L.Wagenfeld GERMANY
Co Author(s): : S. Dulz C. Skevas B. Stemplewitz S. Linke G. Richard A. Frings
PURPOSE:To investigate if the presence of a macular edema in cases of epiretinal membranes influences IOL power calculation in combined cataract and vitrectomy procedures.
Single center retrospective case series, University Medical Center Hamburg, Department of Ophthalmology
The refractive results of patients who underwent combined phacoemulsification, IOL implantation and vitreoretinal surgery for epiretinal membrane without (group 1) or with (group 2) macular edema were retrospectively reviewed. IOL calculation was performed using an IOL Master (Carl Zeiss Meditec, Jena). The main outcome measure was the IOL power prediction error (PE, observed minus expected refraction). Furthermore the correlation between preoperative macular thickness or absolute change of macular thickness and dioptric shift was investigated.
Forty-seven eyes of 47 consecutive patients were enrolled. Regardless of the IOL formula used, the PE was higher on average in eyes without macular edema vs. PE in eyes with macular edema (e.g. for Haigis formula; group 1: 0.65 ± 0.67 D vs. group 2: 0.58 ± 0.37 D; 58.0% of group 1 and 38% of group 2 within ±0.50 D). A correlation between myopic dioptric shift and preoperative macular thickness as well as change of macular thickness after the operation was observed. This association was more markedly pronounced in group 1.
In our study myopic shift is less pronounced and IOL power calculation is more accurate in cases of epiretinal membranes with macular edema compared to cases with epiretinal membranes without macular edema. A possible explanation could be that in cases of sole traction, outer retinal structures show more alteration and therefore lead to more inaccurate axial length measurement.