PPRCA is a rare disease characterized by perivenous aggregations of pigment clumping associated with zonal areas of retinochoroidal atrophy distributed along the retinal veins. Patients are typically asymptomatic and the disease process is non-progressive or slowly progressive [
1]. The underlying etiology of PPRCA remains controversial and a hereditary nature appeared to be a reasonable assumption since McKay et al. reported a dominantly inherited PPRCA in a family with a heterozygous
CRB1 variant [
3]. Similarly, Obata et al. described PPRCA in two Japanese siblings with variable expressivity [
5]. However, in a recent large-cohort study of 23 patients, Shona et al. found no evidence of a genetic basis because 96% of patients had no familial history of inherited ocular disease [
6]. Interestingly, there a several evidence in the literature reporting PPRCA onset after an episode of intraocular inflammation, including tuberculosis, congenital syphilis, Behçet disease, measles and rubella immunization or vaccination [
6]. To our knowledge, we report the first case of PPRCA associated with VKH disease and positive HLA-DR4. This further raises the possibility of triggering inflammatory events on a background of genetic predisposition.
Multimodal imaging techniques have led to better characterization of PPRCA [
7]. In our case, geographic areas of RPE loss on SD-OCT corresponded to areas of reduced AF and thinning of the outer retinal layers colocalized with the linear increased AF. We also documented cystic macular edema (CME) which has exceptionally been described in PPRCA [
6]. The authors postulated that the underlying pathogenesis may be comparable to retinitis pigmentosa-associated CME, including blood-retinal barrier breakdown, dysfunction of the RPE pumping function, Müller cells failure and vitreous traction [
8]. Intriguingly, SD-OCT scan through the atrophic lesions showed perivenular thickening of the RNFL. This observation has been reported only in one case [
9]. This singular SD-OCT feature is of physiopathological interest; in fact, it was hypothesized that choroidal atrophy resulting in decreased choroidal perfusion and subsequent insufficient metabolic supply for the outer retinal layers preceded the photoreceptors degeneration and then the RPE loss [
10]. Perivascular thickening of the RNFL may support an additional vessel-based etiology for PPRCA rather than a RPE-based mechanism only. It has to be noted that chronic stages of VKH disease may present with several patterns of chorioretinal atrophy, including peripapillary atrophy, multiple nummular atrophic scars, irregular areas of atrophy and sectoral chorioretinal atrophy, which could have masqueraded as PPRCA [
11]. In our case, the localized areas of retinal disturbance with normal chorioretinal paravenous zone in between lesions further suggest PPRCA diagnosis. Conversely, Huang et al. suggested that PPRCA following inflammatory retinal vein vasculopathy, resulting from various causes previously cited, are not real PPRCA and should be termed pseudo PPRCA [
12]. In fact, a previous medical history is rarely found and appears to be a confounding rather than a causative factor [
13].