Abstract
Purpose :
To assess thickness and disorganization of the inner retinal layers measurements on optical coherence tomography (OCT) as predictive indicators of post-operative visual recovery following vitrectomy for visually significant epiretinal membrane (ERM) to aid in pre-operative assessment.
Methods :
A retrospective chart review of 31 eyes in 31 patients at Illinois Retina Associates who underwent pars plana vitrectomy with ERM and internal limiting membrane (ILM) peeling in the year 2015. Inclusion criteria required a pre-op Snellen visual acuity of at least 20/200, minimum follow up of one year, and complete pre-op OCT imaging including a five-line raster. For each patient, change from baseline visual acuity at one year follow up was calculated using LogMAR equivalent and lines of vision. Vertical distance from the ILM to the inner nuclear layer (INL) and from the ILM to the outer plexiform layer (OPL) was measured on the four non-central, non-foveal cross-sections within the five-line raster; the mean of these four values was calculated for each patient. Disorganization of the inner retinal layers (DRIL) was defined as loss of the normal distinction between the inner plexiform layer (IPL) and INL on the foveal cross-section. The results within each group were compared using a two-tailed T test.
Results :
Patients with a mean pre-op ILM to INL thickness of ≥230 μm had a mean 2.5 lines of vision gained (p=0.037) and a mean LogMAR change of -0.25 (p=0.029), as compared to patients with <230 μm who showed a mean 0.23 lines gained and mean LogMAR change of -0.029. Pre-op visual acuity was similar in both groups, as was macular thickness (p=0.24). Correlation between ILM to OPL thickness and vision gain was not significant. DRIL was observed in only 4 eyes (13%); its presence/absence failed to achieve significance both in lines gained (1.2 in eyes without DRIL vs. 2.1 in eyes with DRIL; p=0.54) and LogMAR (-0.1 vs. -0.2; p=0.37).
Conclusions :
Mean pre-op ILM to INL thickness of ≥230 μm on macular OCT correlated with a more favorable post-operative visual result after vitrectomy for symptomatic ERM. Central macular thickness, ILM to OPL thickness, and presence of DRIL did not correlate with visual outcome in our dataset. A larger and higher-powered study would help confirm these findings.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.