Refractory coats' disease of adult onset

We present the case of an 18-year-old Caucasian male with a unilateral macular star and retinal vascular anomalies compatible with adult onset Coats' disease.

Diagnosis was based on fundoscopic, fluorescein angiography and optical coherence tomography findings.

The patient presented to our emergency department with complaints of low vision in his left eye (LE) detected 10 days before. The best-corrected visual acuity in the LE was 20/50. Fundoscopy of the LE evidenced a complete macular star. Optical coherence tomography showed increased retinal thickness, infiltration of the retinal wall, and detachment of the neuroepithelium. Angiography revealed no appreciable diffusion in the macula. Above the superior temporal (ST) arcade, anomalies in the retinal vasculature were found, with interruption of the peripheral vessels and vessels which were 'sausage'-like. After 1 month, the LE vision evolved to hand movements. Laser photocoagulation was performed in the ST quadrant. Intravitreal injection of bevacizumab 1.25 mg/0.05 ml and photodynamic therapy were performed without any significant changes, progression of ST serous detachment of the neuroepithelium, and finally progression to macular fibrosis.

Coats' disease is usually diagnosed in childhood, but rare cases may occur in adults. Those cases usually have a more indolent course which was not observed in our patient. When there is macular involvement, prognosis is more guarded, despite treatment.