Cystoid macular edema in peripheral exudative hemorrhagic chorioretinopathy

Dear Editor, Peripheral exudative hemorrhagic chorioretinopathy (PEHCR) is primarily a peripheral disease of the elderly that presents with peripheral subretinal and/or sub-retinal pigment epithelium (RPE) hemorrhage with subretinal exudates. However, macular changes can be seen in up to 48% of cases.[1,2] These include RPE changes, drusen, choroidal neovascular membrane (CNVM), subretinal fluid or blood extending from the periphery, and rarely, cystoid macular edema (CME).[1-6] We analyzed 72 PEHCR cases that presented to us between January 2007 to December 2022 and noticed that 10 eyes of 9 of these patients presented with or developed CME during the course of the disease, without any vascular network or polypoidal lesion in the macular region or extension of the PEHCR lesion into the macular region. The absence of a neovascular network or polypoidal lesion in the macular region was confirmed using OCT, FFA, and ICGA. All eyes had PEHCR lesions in the temporal mid-periphery and CME [Figs. 1 and 2]. The mean BCVA of the 10 eyes was 0.68 ± 0.60 logMAR (Snellen equivalent 20/100) at presentation. The mean central macular thickness was 461 ± 145.3 µm at presentation. Our cases received an average of 10 ± 6 intravitreal antiVEGF injections per eye for CME and the peripheral lesion. One eye underwent laser treatment to the peripheral lesion after the resolution of CME. The mean final central macular thickness was 331 ± 100.3 µm, and the mean final BCVA was 0.33 ± 0.19 logMAR (Snellen equivalent 20/40). The mean follow-up period was 44.6 ± 23.3 months.Figure 1: Fundus fluorescein angiogram showing petalloid hyperfluorescence in the macular region (a) and blocked fluorescence in the temporal region with mild hyperfluorescence at the inferior edge (c) in a case of PEHCR. Indocyanine green angiogram showing stippled cyanescence in the macular region (b) and mixed cyanescence in the periphery (d). Fundus photo montage showing a peripheral mound in the temporal quadrant with peripheral subretinal hemorrhage and exudation (e) and its resolution 1 year after treatment (f). Optical coherence tomography showing cystoid macular edema before treatment (g) and reduction in CME after treatment with intravitreal antiVEGF (h)Figure 2: Multimodal imaging in a case of PEHCR. (a) Widefield fundus photo (Optos) showing temporal hemorrhagic pigment epithelial detachment (PED) with exudates. (b) Fundus fluorescein angiogram showing blocked fluorescence with surrounding hyperfluorescence in the periphery and hyperfluorescence in the macular region. OCT showing (d) cystoid macular edema and (e) its resolution after antiVEGF therapy. Optos fundus photo (c) showing CRA patches in the periphery and resolution of hemorrhagic PED in the temporal region 4 years after presentationIn this series, the PEHCR lesions were located in the periphery, with no part of the lesion component, such as subretinal hemorrhage, fluid, or exudate, reaching the macula. We did not observe any neovascular network or polypoidal lesions in the macular region, either clinically or on multimodal imaging, including OCT, FFA, and ICGA. We found that all eyes with CME had the PEHCR lesion, or part of it, in the temporal quadrant, involving the mid-periphery. In the cohort of 72 eyes, PEHCR lesions were present in the temporal, mid-peripheral region in 41 eyes, 10 of which developed CME. Eyes with temporal PEHCR lesions only in the far periphery (n = 26) and eyes with lesion not involving the temporal quadrant (n = 5) did not develop CME, and this difference was statistically significant (P = 0.0030447). In a recent study, Vandefonteyne et al.[3] found CME in 13.2% of eyes with PEHCR. Other authors have also reported a few cases of CME concurrent with PEHCR.[1,4-6] The exact mechanism by which CME develops in PEHCR is not fully understood. PEHCR is likely associated with VEGF-driven neovascularization originating from the choriocapillaris or pars plana.[7] PEHCR lesions in the temporal mid-periphery could be associated with the release of VEGF or other cytokines closer to the macula, which may contribute to the occurrence of CME in these eyes, as opposed to those where the lesion was farther from the macula. Intravitreal antiVEGF therapy was associated with a reduction in central macular thickness and improvement in visual acuity in our case series [Fig. 2c and 2d]. Various studies have documented the efficacy of antiVEGF therapy for vitreous hemorrhage or PEHCR lesions involving or threatening the macula.[3,8,9] However, no studies have specifically examined the role of antiVEGF in cases where CME is the primary cause of visual loss in PEHCR. Elderly patients presenting with CME should undergo a thorough peripheral retinal examination to ensure that PEHCR, among other potential causes of CME, is not overlooked. Correct diagnosis and management with antiVEGF injections appear to be associated with favorable outcomes. Financial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.