Abstract
Purpose :
To investigate microstructural changes of central retinal layers before, during and after surgery correlated to visual acuity outcome in eyes with epiretinal membrane (ERM) obtaining vitrectomy with membrane peeling and tamponade.
Hypothesis is: Tight adhesion of ERM and internal limiting membrane during membrane peeling and therefore high intraoperative stretching of the retina is correlated with a lower visual acuity outcome.
Methods :
This study analyzed retrospectively data of 50 eyes of 50 patients with initial diagnosis of ERM, who underwent retinal surgery with vitrectomy and membrane peeling.
Videos of intraoperative procedure were recorded in each of the 50 eyes by iOCT (Zeiss, LUMERA Rescan). Central retinal thickness (CRT) in the foveal region before, during and after membrane peeling was measured with ImageJ software (NIH).
Furthermore, preoperative as well as three and six months postoperative obtained BCVA and analysis of SD-OCT (Heidelberg Engineering, Germany) imaging before and three months after surgery were included.
Statistical analysis was performed by using the SPSS software (IBM, Version 25).
Results :
As an approximate value for level of retinal stretching exercised by the surgeon`s instruments during membrane peeling the ratio between foveal thickness in the moment of peeling and foveal thickness right before peeling was calculated. The mean ratio was 1,28 (SD= 0,32) and did not show a significant correlation to visual acuity outcome after surgery (p= 0,5515). Therefore, membrane peeling caused a mean foveal stretching of 28%.
A mean reduction of 5,1% (SD= 0,11) of foveal thickness right after peeling in comparison with foveal thickness right before peeling was detected.
Mean visual acuity was 0,38 (SD= 0,18) in the preoperative and 0,50 (SD= 0,25) in the six months postoperative examination.
CRT was reduced from a mean of 505µm (SD= 158) preoperatively to a mean of 432µm (SD= 87) postoperatively.
Conclusions :
Although this study did not prove the hypothesis of a correlation between retinal over-stretching during membrane peeling and a lower outcome of BCVA in patients with epiretinal membrane surgery, intraoperative OCT is an emerging technology, which allows to visualize intraoperative procedures in segmentation of retinal layers.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.