Coats-like Exudative Vitreoretinopathy in Retinitis Pigmentosa – Ocular Manifestations and Treatment Outcomes

Abstract Objective To provide a comprehensive review of the ocular manifestations, outcomes, and genetic findings in patients with Coats-like retinitis pigmentosa (RP). Design M ulti-center, retrospective, non-consecutive case series. Subjects Patients with a diagnosis of RP presenting with Coats-like exudative vitreoretinopathy between January 1, 2008 and October 1, 2019. Methods Evaluation of ocular findings at RP diagnosis and at time of presentation of Coats-like exudative vitreoretinopathy, pedigree analysis, genetic testing, retinal imaging, and anatomic outcomes after treatment. Main Outcome Measures Visual acuity, ophthalmoscopy, optical coherence tomography, fluorescein angiography, and identification of genetic mutations. Results 9 patients diagnosed with RP and presenting with Coats-like exudative vitreoretinopathy were included. Median age at time of RP diagnosis was 8 years (range, 1 - 22 years), and median age at presentation of Coats-like exudative vitreoretinopathy was 18 years (range 1 - 41 years). 7 patients were female, and 2 were male. The genetic cause of disease was identified in 6 patients. 3 patients presented with Coats-like fundus findings at the time of RP diagnosis. Exudative retinal detachment (ERD) localized to the infratemporal periphery was present in all cases, with bilateral disease observed in 7 patients. In all treated patients, focal laser photocoagulation (LP) was used to treat leaking telangiectasias and to limit further ERD expansion. Cystoid macular edema refractory to carbonic anhydrase inhibitor therapy, and ultimately amenable to treatment with intravitreal anti-vascular endothelial growth factor injection was observed in 4 patients. Conclusion Coats-like vitreoretinopathy is present in up to 5% of all RP patients. The term “Coats-like RP” is colloquially used to describe this disease state which can present at the time of RP diagnosis, or more commonly develops late during the clinical course of patients with longstanding RP. Coats-like RP is distinct from Coats disease in that exudative pathology occurs exclusively in the setting of a coexisting RP diagnosis, is restricted to the infratemporal retina, can affect both eyes, and does not demonstrate a male sex bias. Given the risk of added vision loss posed by exudative vitreoretinopathy in patients with RP, a heightened awareness of this condition is critical in facilitating timely intervention.