Long-term follow-up of a case of Coats disease in a 10-year-old boy with spontaneous peeling of preretinal macular fibrosis: a case report

BACKGROUND: Coats disease is a retinal vascular disorder characterized by aneurysms and telangiectasias. Macular fibrosis is a complication of Coats disease that results in vision loss. Macular fibrosis rarely develops in the natural course and often occurs after treatment with intravitreal bevacizumab, photocoagulation, or cryotherapy. Here, we have described an unusual case of spontaneous peeling of preretinal macular fibrosis in a patient with untreated Coats disease. CASE PRESENTATION: A 10-year-old Japanese boy presented with vision loss in his left eye. The patient’s left visual acuity was 20/28. Fundus examination of his left eye revealed thick preretinal macular fibrosis around the optic disc and macula. In addition, retinal telangiectasis, microaneurysms, hard exudates, and retinal hemorrhages were observed in the left peripheral temporal retina. We diagnosed his condition as Coats disease with preretinal macular fibrosis. Two months later, optical coherence tomography revealed preretinal macular fibrosis detachment at the foveal lesion without any treatment. During follow-up, preretinal macular fibrosis at the macular lesion was completely detached. Further, posterior vitreous detachment was observed and the shape of the macula and the patient’s left visual acuity had improved. CONCLUSIONS: In our case, both formation and spontaneous peeling of preretinal macular fibrosis occurred without any treatment for Coats disease, which is an unusual finding. Vitreous changes might have occurred during the natural clinical course, causing subsequent posterior vitreous detachment and resulting in spontaneous peeling of fibrosis.