A 9-year-old healthy boy was seen for long-standing poor vision in his left eye. The right eye was healthy. His visual acuity was 20/400 OS with a normal anterior segment. Ophthalmoscopic examination results revealed a combined hamartoma of the retina and retinal pigment epithelium.
Combined hamartoma of the retina and retinal pigment epithelium is a rare, benign, congenital, and hamartomatous malformation that was first described by Gass.1 These lesions are typically unilateral; bilateral presentation is more frequently associated with phakomatoses, such as neurofibromatosis, for which the patient had negative genetic testing results.2,3 Combined hamartomas can have a variable appearance and location but are typically gray-blue with thickened preretinal tissue that can contract and displace surrounding retina and blood vessels (Figure).4 Which specific retinal layers are involved can differ between patients; a recent classification scheme has been proposed to better describe these tumors.5 Combined hamartomas of the retina and retinal pigment epithelium can cause substantial vision loss, and surgery may be required if retinal detachment occurs.6