Optical Coherence Tomography (OCT) Characteristics of Pseudophakic Cystoid Macular Edema (PCME) and their Correlation with Visual Acuity

Abstract

Purpose : To evaluate the relationship between various OCT characteristics of PCME and the best-corrected visual acuity (BCVA).

Methods : A retrospective chart series of all patients who developed PCME within six months of cataract surgery as documented on the FastMAC 25-slice OCT scan on Spectralis® (Heidelberg Engineering, Heidelberg, GE). Exclusion criteria included prior history of macular edema, uveitis, or retinal surgery. Data recorded were logMAR BCVA at the time of diagnosis and various OCT characteristics within a 1mm² area centered at the fovea including location of cysts, presence of subretinal fluid (SRF), structural integrity of both the external limiting membrane (ELM) and ellipsoid zone (EZ), central foveal thickness (CFT), and central subfield thickness (CST).

Results : 19 eyes of 18 patients were included in this study. Cysts in only outer retinal layers were seen in 26.3% of eyes (mean BCVA 0.42 ± 0.16), 15.8% of eyes had cysts only in inner retinal layers (mean BCVA 0.93 ± 0.29), and 57.9% of eyes had cysts in both inner and outer retinal layers (mean BCVA 0.47 ± 0.28). There was a statistically significant difference in BCVA between eyes with cysts in only outer retinal layers vs. eyes with cysts in only inner retinal layers (p=0.02).

ELM was noted to be intact with no disruptions in 31.6% of eyes (mean BCVA 0.35 ± 0.17) while 68.4% of eyes had at least one disruption (mean BCVA was 0.61 ± 0.31). 26.3% of eyes had a continuous EZ (mean BCVA was 0.30 ± 0.13) while 73.7% of eyes had some disruption (mean BCVA was 0.61 ± 0.30). Only one eye had SRF across all five slices and the BCVA was 1.00. 42.1% of eyes had SRF at the central foveal slice (mean BCVA 0.69 ± 0.23) while 57.9% of eyes had no SRF (mean BCVA 0.41 ± 0.30). 31.6% of eyes had CFT>CST (mean BCVA was 0.73 ± 0.31) while the remaining 68.4% had mean BCVA 0.43 ± 0.26. The difference in BCVA was statistically significant between eyes with continuous and disrupted ELMs (p=0.01) and EZs (p=0.02), presence and absence of SRF (p=0.04), and CFT>CST and CST>CFT (p=0.04).

Conclusions : In eyes with PCME, there may be a correlation between BCVA and various anatomic characteristics observed on OCT. Eyes with inner retinal cysts were seen to have worse vision than those with cysts in outer layers. Two-thirds of PCME eyes had disruption of ELM and EZ and had worse VA than those that had no disruption.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.