Stellate Nonhereditary Idiopathic Foveomacular Retinoschisis and Central Anomalous Retinoschisis with mid-PEripheral Traction (CARPET)

Purpose: To report the clinical and multimodal imaging (MMI) findings and long-term follow-up of stellate nonhereditary idiopathic foveomacular retinoschisis (SNIFR) contiguous with midperipheral retinoschisis (MPRS) and to describe a severe SNIFR variant termed CARPET (Central Anomalous Retinoschisis with mid-PEripheral Traction). Design: Retrospective case series. Subjects: Eleven patients (15 eyes) with SNIFR contiguous with MPRS in at least 1 eye at baseline or final follow-up. Methods: Multimodal imaging features, including cross-sectional and en face macular and peripheral spectral-domain OCT and OCT angiography, were reviewed in all cases at baseline and at the final follow-up visit. Main outcome measures: Various courses (including progression, regression, or stability) of MPRS or SNIFR over time were evaluated. Results: Midperipheral retinoschisis exhibited centripetal progression to SNIFR in 5 eyes of 3 patients with follow-up of 67, 60, and 27 months, respectively, with maintenance of excellent visual acuity (range: 20/25-20/20) in 4 of these 5 eyes. In 2 eyes of 2 patients (including 1 eye with initial centripetal progression of MPRS to SNIFR), MPRS contiguous with SNIFR spontaneously resolved with long-term follow-up (77 and 25 months, respectively). Stellate nonhereditary idiopathic foveomacular retinoschisis contiguous with MPRS partially regressed after 48 months in 1 patient, and was stable after 54 months in another. A distinctive midperipheral microvasculopathy, associated with MPRS that was contiguous with SNIFR, was identified in 7 eyes of 4 patients. Finally, 3 eyes of 3 patients exhibited additional unique features, including central neurosensory detachment and outer lamellar macular hole, which were associated with significant midperipheral traction, representing a severe variant subtype of SNIFR that we refer to as CARPET. Two of these 3 eyes progressed with short-term follow-up of 6 and 2 months, respectively, whereas the schisis resolved and vision improved after pars plana vitrectomy in the third case. Conclusions: Midperipheral retinoschisis can progress to SNIFR over multiple years of follow-up. Stellate nonhereditary idiopathic foveomacular retinoschisis with MPRS can also spontaneously resolve or remain stable. Midperipheral retinoschisis can additionally be complicated by a midperipheral inner retinal microvasculopathy. Finally, CARPET may represent a unique and severe variant form of SNIFR driven by midperipheral vitreoretinal traction and associated with significant vision loss. Financial disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.