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

Abstract

Purpose: To provide a comprehensive review of the ocular manifestations, outcomes, and genetic findings in patients with Coats-like retinitis pigmentosa (RP).

Design: Multicenter, retrospective, nonconsecutive case series.

Participants: Patients with a diagnosis of RP demonstrating 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 results, OCT results, fluorescein angiography results, and identification of genetic mutations.

Results: Nine patients diagnosed with RP and demonstrating 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). Seven patients were female, and 2 were male. The genetic cause of disease was identified in 6 patients. Three patients demonstrated Coats-like fundus findings at the time of RP diagnosis. Exudative retinal detachment (ERD) localized to the infratemporal periphery was present in all patients, with bilateral disease observed in 7 patients. In all treated patients, focal laser photocoagulation 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.

Conclusions: Coats-like vitreoretinopathy is present in up to 5% of all RP patients. The term Coats-like RP is used colloquially 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 pathologic features occur 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 gender 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.

Figure 1.

Wide-field fundus photographs of the right eye from patient 1 at presentation of Coats-like RP, and after treatment with focal laser photocoagulation. Fundus photograph (A) at presentation demonstrates exudative retinal detachment with overlying telangiectasias and retinal hemorrhages, with marked improvement in size of exudative retinal detachment and regression of vascular tortuosity after laser photocoagulation to the infratemporal periphery (B) at 6 month follow-up.

Figure 2.

Mid-phase and late-phase fluorescein angiography images of the left eye from patient 3 at presentation of Coats-like RP, and after treatment with laser photocoagulation and intravitreal anti-VEGF injection. Fluorescein angiography (A,B) at presentation demonstrates macular leakage and peripheral non-perfusion with hyperfluorescence of telangiectatic vessels. Fluorescein angiography at 6 month follow-up demonstrates improvement in petalloid macular leakage and near complete resolution of peripheral hyperfluorescence.

Figure 3.

Optical coherence tomography of the right eye from patient 3 before and after treatment with intravitreal anti-VEGF injection at six week intervals. Optical coherence tomography demonstrates (A) severe cystoid macular edema at presentation of Coats-like RP, (B) near complete resolution after treatment with intravitreal bevacizumab observed at 6 month follow-up, (C) emergence of tachyphylaxis to bevacizumab and recurrence of worsening cystoid macular edema at 1 year follow-up, and (D) continued improvement at 2 year follow-up after switching to intravitreal aflibercept.