Abstract
Purpose :
To describe the microstructural changes in proliferative vitreoretinopathy(PVR) detected on baseline swept-source optical coherence tomography(SS-OCT) in rhegmatogenous retinal detachment(RRD).
Methods :
A prospective cohort of primary RRDs, presenting to St. Michael’s Hospital from January 2020-July 2023, were assessed at presentation for signs of PVR. Posterior pole or ultra-widefield SS-OCT was graded for predominant type of PVR (pre, intra or subretinal), and associated retinal abnormalities were characterized.
Results :
Forty-three patients had signs of PVR on baseline SS-OCT, of which 67%(29/43) were male, mean age of 55.8 years old, and 72%(31/43) were phakic. Mean baseline logMAR vison was 1.2 with a duration of fovea-off of 45.4 days and RRD extent of 7.3 clock hours. Of those, 65.3%(28/43) presented with subretinal PVR and 34.7%(15/43) presented with intra-retinal PVR detected with OCT. Pre-retinal PVR was only observed together with the intra-retinal type. Sub-retinal PVR appears on SS-OCT as a hyperreflective line in contact with the neurosensory retina or as an amorphous band over the RPE. The former may cause folding of the outer retina if photoreceptor segments are still intact or extend over areas of photoreceptor loss if there is retinal thinning and signs of atrophy. Subretinal PVR was significantly associated with shallow regulated RRDs on clinical examination. In contrast, intra-retinal PVR was associated with bullous dysregulated RRDs, and it was only noticed in patients with concurrent outer retinal corrugations. Intra-retinal PVR is observed as a thickening of the inner retina with disorganization of retinal layers, with folding of both the inner and outer retina. Initial signs of intraretinal PVR were noticed in areas of RRD baseline morphologic stage 4, where ORCs were fused together, leading to outer retinal folds. On the contrary, subretinal PVR was associated with RRD morphologic baseline stage 5.
Conclusions :
We present a novel conceptual framework for PVR in RRD based on OCT. The type of PVR observed was associated with baseline RRD clinical status (regulated vs dysregulated), per Muni et al 2022. PVR formation seems to be associated with a proliferative pathway (when intra-retinal) vs an apoptotic/atrophic pathway (when subretinal). Recognizing the spectrum of morphological changes on OCT may assist with early and accurate diagnosis of PVR and allow for improved assessment of the efficacy of novel therapeutic agents.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.