Outer Retinal Erosion and Outer Retinal Pinching at the Origin of Subretinal Fluid in Central Serous Chorioretinopathy.

To characterize early outer retinal changes at the site of origin of subretinal fluid (SRF) in central serous chorioretinopathy (CSCR). To investigate their pathophysiologic and clinical significance. Retrospective, nonconcurrent, multicenter cohort study. A total of 87 eyes of 87 patients with primary or recurrent CSCR (episode duration <4 months) and one or more fluorescein angiographic leaks. In a series of cases of recently active CSCR, we analyzed changes occurring in the retina and subretinal space at the site of fluorescein leaks, taking into account similar finding already reported in the literature. Following the distinction of two basic findings definable as outer retinal erosion (ORE) and outer retinal pinching (ORP), we investigated associated clinical and morphological patterns. Volumetric quantification of SRF and pigment epithelial detachment (PED) was performed using artificial intelligence-enhanced algorithms (Discovery, RetinAI). Three-dimensional configurations of SRF volumes performed using custom scripts (MATLAB, MathWorks) provided complementary visualization of the retinal changes. Sixty patients had available follow-up of median 19 months. In these patients, time-to-event analysis with stratified log-rank test was performed to evaluate the development of foveal atrophy and posterior cystoid retinal degeneration (PCRD). SRF and PED volume. Development of foveal atrophy and PCRD. The cohort was divided according to the presence of ORE (43/87) and ORP (44/87) findings. ORP cases showed more frequent history of steroid use (40.9% vs 18.6%, P = .011), significantly higher SRF volumes (median 1763 vs 720 nL, P = .0005), more frequent PEDs (77.3% vs 46.9%, P = .027), and higher PED volumes (median 14.5 vs 0 nL, P = .0002). PCRD developed exclusively in ORP+ cases (7/28 eyes), with a median time to occurrence of 225 days, with no event in the ORE+ group (0/32 eyes). PCRD had an incidence of 0 versus 15.4 events per 100 person-years in ORE+ and ORP+ groups, and was associated with lower best-corrected visual acuity at the event (median = 0.3 vs 0.1 logMAR). No case developed foveal atrophy during the follow-up. ORE and ORP are two distinct disease pathways in CSCR. ORP cases, characterized by focal retinal pigment epithelium photoreceptor adherence and high-volume SRF, show significant risk of transition toward PCRD and limited visual loss.