Recently,<unk>  has been understood to be part of the pachychoroid spectrum. In pachychoroid spectrum disorders, of which CSR represents stage II, the choroid, the highly vascularized layer below the retina, is thickened and congested with increased blood vessel diameter, especially in the deep choroid (the so-called Haller's layer). This results in increased pressure from the deep choroid against the superficial choroid close to the retina, damaging the fine blood vessels (capillaries) needed to supply oxygen and nutrients to the retinal pigment epithelium and retina. Additionally, fluid can leak from these damaged vessels and accumulate under the retina. Different stages of the pachychoroid are defined depending on the amount of cumulative damage. If there are defects in the retinal pigment epithelium without accumulation of fluid below the retina, a pachychoroid pigmentepitheliopathy (PPE) is present. Accumulation of fluid results in<unk>  (CSR). The development of secondary blood vessels, so-called choroidal neovascularization (CNV) leads to pachychoroid neovasculopathy (PNV). If parts of these new vessels bulge outward, so-called aneurysms develop within this CNV, defining pachychoroid aneurysmal type 1 CNV (or, still widely used, polypoidal choroidal vasculopathy (PCV)). Since the individual stages develop one after the other from the respective preliminary stage, pachychoroidal diseases of the macula are divided into 4 stages according to Siedlecki, Schworm and Priglinger: Pachychoroid spectrum disorders of the macula (after Siedlecki et al.) 0 Uncomplicated pachychoroid (UCP) I Pachychoroid pigmentepitheliopathy (PPE) II<unk>  <unk>  III Pachychoroid neovasculopathy (PNV) a) with neurosensory detachment (=subretinal fluid) b) without neurosensory detachment (no subretinal fluid) IV Pachychoroid aneurysmal type 1 choroidal neovascularization (PAT1) (also polypoidal choroidal vasculopathy, PCV)
Central serous chorioretinopathy
Vitreoretinopathy
Ocular ischemic syndrome
Optic neuritis
Ischemic optic neuropathy
Posterior ischemic optic neuropathy
Anterior ischemic optic neuropathy
Toxoplasmic chorioretinitis