SubRPE

SubRPE refers to the subretinal pigment epithelium space, the anatomical compartment between the retinal pigment epithelium (RPE) and Bruch's membrane. The RPE rests on a thin basement membrane that abuts Bruch's membrane, and the subRPE space is a potential space that can become occupied by fluid, blood, lipid-rich deposits, or other material in disease.

In clinical practice, subRPE involvement is most often described in the context of diseases affecting the outer retina and choroid, such as age-related macular degeneration (AMD). SubRPE material can accumulate in several forms, including hemorrhage beneath the RPE, sub-RPE drusen-like deposits, or the detachment of the RPE itself from Bruch's membrane (pigment epithelium detachment or PED) with accumulation within the subRPE space. The presence and composition of subRPE contents influence imaging appearance and prognosis.

Imaging of subRPE is primarily performed with optical coherence tomography (OCT), which can reveal elevation of the RPE, hyperreflective or lobulated contents, and the relationship to Bruch's membrane. Other modalities, such as fluorescein or indocyanine green angiography and OCT angiography, may help identify underlying neovascularization or other vascular abnormalities associated with subRPE changes.

SubRPE pathology is often related to underlying conditions that affect the choroid and outer retina. Management and prognosis depend on the specific disease process (for example, subRPE hemorrhage or sub-RPE CNV in AMD) and typically focus on treating the underlying condition to preserve vision.