Subretinal Fluid

Abstract

Synonyms Neurosensory retinal detachment; Serous detachment of the sensory retina; Subretinal exudation Definition Subretinal fluid corresponds to the accumulation of a clear or lipid-rich exudate (serous fluid) in the subretinal space, i.e., between the neurosensory retina (NSR) and the underlying retinal pigment epithelium (RPE), in the absence of retinal breaks, tears, or traction (Kanski et al. 2011). It represents a breakdown of the normal anatomical arrangement of the retina and its supporting tissues, i.e., the RPE, Bruch's membrane, and the choroid. Etiology and Classification Changes in choroidal flow, poor scleral outflow, breakdown of the RPE, and leakage/breakdown of normal or abnormal retinal vessels are the pathophysiological mechanisms that are isolated or in combination associated with subretinal fluid accumulation (Wolfensberger and Tufail 2000). There are some defining features, however, that are common to all cases of subretinal fluid: (1) serous fluid accumulation between the NSR and the RPE in the absence of a rhegmatogenous or tractional component; (2) a characteristic shifting of this fluid with postural changes; (3) a smooth, dome-shaped appearance of the detached retina lacking corrugations or fixed folds; and (4) the presence of associated local (ocular) or systemic conditions (Yanoff and Duker 2014). Identifying a precise etiology can be challenging since the causes of subretinal fluid accumulation are broad and heterogeneous, encompassing several ocular and systemic pathologies. For matters of systematization, an etiologic-based classification is portrayed here: 1.