Longitudinal Change in Retinal Layer Thicknesses in Subjects with Proliferative Diabetic Retinopathy Treated with Intravitreal Afliberecept

Abstract

Purpose : To evaluate longitudinal changes in thickness of retinal sublayers in eyes of patients with proliferative diabetic retinopathy (PDR) and no diabetic macular edema treated with intravitreal afliberecept.

Methods : Forty eyes of 40 subjects were enrolled in this IRB-approved prospective, randomized, clinical trial (RECOVERY Trial; NCT: 02863354). All subjects underwent ultra-widefield fluorescein angiography (UWF FA) (Optos 200Tx), and spectral domain optical coherence tomography (OCT) at baseline and month 12. The thickness of multiple macular layers (from the retinal nerve fiber layer through the choroid) were automatically segmented using customized reading center software (3D-OCTOR). All segmentation errors in all B-scans were manually corrected before calculation of thicknesses for the individual layers. All regions of non-perfusion on stereographically projected UWF FA images were manually segmented and quantified using Image J. Measurements were compared between baseline and month 12 using paired t test and a p value of ≤ 0.05 was considered as statistically significant (statistical analysis using SPSS 18.0).

Results : The mean age of study subjects was 48 ± 12 years and 19 were female. Thickness of the nerve fiber layer (NFL), ganglion cell layer (GCL), inner plexiform layer (IPL), outer plexiform layer (OPL), outer nuclear layer (ONL), ellipsoid zone (EZ) and choroid were all significantly decreased at month 12 compared with baseline (p < 0.05; Table 1). There was no significant difference in the thickness of the inner nuclear layer (p = 0.1), however. Despite these changes in macular retinal sublayer thickness, the total retinal non perfusion (RNP) area did not significantly (p = 0.83) differ at month 12 (218 ± 127) compared with baseline (216 ± 160).

Conclusions : The thickness of multiple retinal sublayers appears to decrease over time in eyes receiving intravitreal aflibercept for proliferative diabetic retinopathy. However, there was no significant change in RNP area. The relationship between changes in thickness of the different retinal layers in the macula and RNP area in the periphery, over time, warrants further investigation.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.