Abstract
Purpose :
To determine the prevalence, characteristics of hyporeflective intraretinal spaces (HIRS) secondary to idiopathic epiretinal membranes (ERMs) using spectral domain optical coherence tomography (SD OCT)
Methods :
Design: Retrospective, observational case series.
Materials : The files of 257 consecutive eyes operated with the diagnosis of ERMs between January 2017 and December 2017 were reviewed . Secondary ERMs (n =101) and other retinal disorders, i.e. diabetic retinopathy, vein occlusion, glaucoma, ( n= 43) were excluded. One hundred and thirty three eyes with idiopathic ERMs were included and divided in two groups: HIRS + group and HIRS - group (eyes without preoperative HIRS).
Main Outcome Measures: The preoperative prevalence of HIRS in patients with idiopathic ERMs. The SD OCT features included central foveal thickness (CFT), the defect of the cone outer segment tips (COST) and ellipsoid lines, the presence of subfoveal deposit.
Results :
The prevalence of HIRS in idiopathic ERMs was of 8.91% (14/157 eyes) . The HIRS appeared as homogeneous clusters of the internal nuclear layer (7 eyes), heterogeneous clusters (5 eyes) and retinal splitting spaces (2 eyes). The comparison of HIRS+ group with HIRS-group showed no significant difference in the proportion of pseudophakic eyes (28.6% vs. 28.3%; p>0.05), in the preoperative CFT (485.00 ± 60.59 µm vs 447.20 ± 76.56 µm, p= 0.04338), in the disruption of the ellipsoid layer (35.7% vs 38.4%, p> 0.05) and the COST line (35.7% vs 59.6%, p> 0.05), in the subfoveal deposits (42.9% versus 41.4%, p > 0.05), and in the preoperative BCVA (0.62 ± 0,31 logMAR vs 0.41 ± 0.19 logMAR, p= 0.62414). The number of eyes with a partial posterior vitreous detachment (PVD) was significantly higher in the HIRS + group (57.2 % versus 9.1% p= 0.0001) ; consequently the presence of complete PVD was higher in the HIRS – Group (83.8 % versus 35.7%, p= 0.0003).No difference about the absence of PVD was found between the both groups ( 7.1%, p> 0.05).
Conclusions :
The prevalence of HIRS in idiopathic ERMs was 8.91% prior to surgery. The HIRS presented a higher rate of partial PVD which suggests their origin may be tractional. The predilection for the internal nuclear layer (INL) and the preserved outer retinal layers may suggest also a role of Muller cells dysfunction in HIRS occurrence.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.