Abstract
Purpose :
To investigate the natural progression of epiretinal membranes (ERMs) visualized on swept source OCT (ssOCT) en-face images.
Methods :
This is a retrospective study of 57 eyes from 47 glaucoma and glaucoma-suspect patients (age 67.6±8.0 yrs) with “complex” ERMs seen on ssOCT wide field scans (Topcon, Japan) and at least 2 scans > 6 months apart. Complex ERMs, which were defined as a hyper-reflective layer overlying the internal limiting membrane (ILM) with a gap separating it from retinal nerve fiber layer (RNFL), are seen as dark regions on en-face images obtained by averaging the reflective intensity of a 52 μm-thick slab below the ILM/ERM layer (Figs. 1, 2). [1, 2] Changes in ERMs were assessed by comparing en-face images and confirming with b-scans (Fig. 1). ERMs were classified as “progressing” if there was a increase in ERM area on en-face images or significant morphological changes (e.g., a new macular hole) on b-scans; as “regressing” if there was a decrease in ERM area on en-face images or ERM disappearance on b-scans; and “stable” if otherwise. Foveal thickness (FT) was measured, and Snellen visual acuity (VA) and risk factors for secondary ERMs were obtained by chart review. Chart history and VA was not available for 1 eye (stable), which was excluded from these analyses.
Results :
As seen on en-face images and b-scans, 15 eyes (26.3%; follow-up: 18.3 to 51.0 mos) showed progressing ERMs (e.g., Fig. 1A, B); 7 eyes (12.3%; follow-up: 21.3 to 36.4 mos) showed regressing ERMs (e.g., Fig. 1C, D); and 35 eyes (61.4%; follow-up: 6.0 to 55.2 mos) were stable (e.g. Fig. 2). Mean changes in FT were 50.1±44.9 μm for progressing, 1.6±6.0 μm for regressing, and 0.3±13.7 μm for stable (one way ANOVA p <10-6). Mean changes in VA (converted to logMAR) were 0.04±0.10 (progressing), -0.03±0.11 (regressing), and 0.00±0.12 (stable) logMAR (not significant, one way ANOVA p = 0.35). 17 eyes (6 progressing, 1 regressing, 10 stable) had risk factors for secondary ERM, including uveitis, retinal detachment, and surgery (e.g. cataract surgery, trabeculectomy, vitrectomy).
Conclusions :
The ERMs in the majority (61%) of eyes were stable over 6 to 55 months of follow-up. Changes, which could occur over intervals as short as 6 months, included increasing/decreasing ERM size, changes in ERM/RNFL attachment, and associated retinal defects such as macular holes. 1. Hood et al. IOVS (2016) 2. De Cuir et al. IOVS (2014)
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.