Inner, outer, and full-thickness retinal folds after rhegmatogenous retinal detachment repair: A review

Partial-thickness folds of the inner retina and outer retina, as well as full-thickness retinal folds, may occur after the repair of rhegmatogenous retinal detachment. Although these can look similar on clinical examination, imaging with optical coherence tomography facilitates differentiation. With optical coherence tomography analysis, inner retinal folds exhibit corrugations of the inner retina while outer retinal folds display hyperreflective lesions located just above the retinal pigment epithelium that may extend into the outer nuclear layer. In the case of a classic full-thickness retinal fold, all layers of the neurosensory retina may separate together from the retinal pigment epithelium with retinal reduplication and base-to-base photoreceptor orientation. We review the pathogenesis, risk factors, prevention, and management options of retinal folds. As the terminology for retinal folds is diverse, we highlight optical coherence tomography-based descriptions for retinal folds that have been used in the literature. Factors predicting visual recovery, mechanisms of spontaneous fold regression, and the effect of internal limiting membrane peeling on the incidence of folds are potential areas of future study.