Coats-like exudative vasculopathy in a patient with Bardet-Biedl syndrome.

We report a case of Bardet-Biedl syndrome (BBS) complicated by bilateral Coats-like exudative vasculopathy with exudative retinal detachment and neovascular glaucoma (NVG). A 10-year-old boy noticed decreased visual acuity and was referred to our clinic. He had a history of retinitis pigmentosa, renal dysfunction, obesity, and a delay in mental development at 4 years of age. Genetic testing confirmed BBS with compound heterozygous variants detected in the BBS2 gene. His visual acuity was light perception in both eyes, and the intraocular pressure (IOP) was 14 mmHg in the right eye and 35 mmHg in the left eye. Fundus examination revealed severe exudative changes in both eyes with vitreous hemorrhage in the left eye. In the right eye, fluorescein angiography showed limited retinal vascular circulation and a nonperfused peripheral area in the equatorial region with multiple sites of neovascularization. Panretinal photocoagulation was performed on the right eye, and vitrectomy was performed on the left eye for the NVG. The left eye had proliferative membranes throughout the periphery. Postoperatively, the IOP of the right eye was elevated accompanied by iris rubeosis. Aflibercept was injected Intravitreally and lens-sparing vitrectomy was performed on the right eye with additional endophotocoagulation. One month later, the visual acuity remained at light perception in both eyes. The IOP was well controlled with topical medication at 18 mmHg for the right eye and 20 mmHg for the left eye. The Coats-like exudative lesions associated with eyes with the BBS2 gene variants and retinal vascular occlusion likely led to the NVG.