Clinical and imaging characteristics of outer retinal folds in eyes with retinitis

Purpose: To describe clinical and imaging characteristics of the outer retinal folds (ORF) in cases of retinitis, retinochoroiditis, and chorioretinitis. Methods: Retrospective review of retinitis cases with presence of ORFs either at presentation or during follow up. Results: ORFs were seen adjacent to retinitis lesions in 16 eyes of 14 cases (retinitis post-febrile illness n = 10, toxoplasma retinochoroiditis n = 2, fungal chorioretinitis n = 2) either at presentation (n = 2) or during follow up (n = 14). Optical coherence tomography (OCT) appearance was outer retinal vertical stout lesions involving ellipsoid, external limiting membrane, and outer nuclear layer. All the cases had a presence of past or concurrent subretinal fluid and/or subretinal hyperreflective material when ORF was seen. ORF resolved with variable outer retinal atrophy over a mean period of 2.86 months. Conclusion: ORF is observed in cases of retinitis with subretinal fluid either at presentation or during resolution. It is not specific to any etiological disease. Differentiation of this sign from vertical outer retinal stripes in viral retinitis on OCT is important to avoid misinterpretation.