Dynamic Anatomic Changes During Epiretinal Membrane Peeling Surgery Measured Using Intraoperative OCT

Abstract

Purpose : To assess the changes in macular thickness measured on intraoperative optical coherence tomography (iOCT) during vitrectomy surgery for peeling idiopathic epiretinal membranes (ERM), and their association with anatomic and visual outcomes.

Methods : Intraoperative OCT (iOCT) images were captured using a commercial iOCT device before and after epiretinal membrane (ERM) peeling. Average retinal thickness was measured from the 1mm- and 3mm-diameter circles centered on the fovea (central macular thickness or CMT, and macular thickness or MT, respectively) using custom semi-automated segmentation software. Clinical factors including logMAR visual acuity (VA) and CMT were collected before, and up to 4 months after surgery.

Results : Seventeen patients (mean age 65.3 ±9 years) with idiopathic ERM and high-quality iOCT images were included. Mean VA prior to surgery was logMAR 0.41 ± 0.12 (Snellen 20/51), with mean CMT of 484.1 ± 83µm, with no association between VA and CMT (p=0.97). Preoperative CMT (484.1 ± 83µm) measured in office correlated with CMT measured on iOCT before membrane peeling (467.87 ± 68µm) (p=0.04). Average intraoperative MT showed a decrease from 429.3 ± 44µm to 414.3 ± 50µm on iOCT after membrane peeling, although this difference was not significant (p=0.11). Interestingly, the change in MT on iOCT after membrane peeling showed a possible association with anatomic change of CMT from before to 1 month (p=0.061) and 4 months (p=0.056) after surgery. These intraoperative changes were not associated with visual gains at months 1 (p=0.279) or 4 (p=0.79).

Conclusions : Intraoperative OCT demonstrates intraoperative retinal thickness reduction after membrane peeling that may predict postoperative anatomic improvement, but not visual changes.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.