Coats Disease With Macular Nodule

Purpose: To describe a case series of Coats disease with macular nodule mimicking retinoblastoma. Methods: Retrospective case series. Results: Of 339 patients with Coats disease, 7 (2%) with macular nodules were included. All had a referral diagnosis of retinoblastoma. All were males (mean age-6 y). The most common presenting complaint was decreased vision (n=4, 57%). Median best corrected visual acuity at presentation was counting fingers close to face, which was maintained at last follow-up (mean, 8 months). The nodule had a mean diameter of 5x4x3 mm, was grayish white, and bilobed (n=3, 43%), or dome shaped (n=4, 57%) with surface pigmentation (n=4, 57%), involving fovea (n=5, 71%), with surrounding exudates and second- or third-order retinal vessels. OCT (n=4) showed a well-defined hyperreflective subretinal nodule with posterior shadowing, cysts, and exudates. USG (n=6) showed an echodense intraocular nodule with moderate internal reflectivity with hyperechoic foci in 2 (33%) cases. FFA showed early- and mid-phase hypo-fluorescence with focal leakage with late-phase hyperfluorescence. Focal green laser photocoagulation of the telangiectatic vessels was performed in 5, one underwent subretinal fluid drainage and scleral buckling, and one was observed. Conclusion: Macular nodule in Coats disease represents a preferential accumulation of lipid in the macula. This rare variant of Coats disease can mimic retinoblastoma process. Be aware of this entity to ensure appropriate diagnosis and treatment.