Bilateral colobomas with avascular peripheral retina: case report

Abstract

Ocular coloboma is relatively rare condition with an incidence of 2.4–8.0/100,000 live births. It typically arises from a failed closure of the embryonic fissure during the fifth to seventh gestational weeks. Associated ocular abnormalities can occur in up to 15% of cases, including microphthalmia, anophthalmia, anisometropia, retinal detachment (RD), cataract, choroidal neovascularization, and hypoplasia of the optic nerve. We present a unique case of bilateral colobomas of the choroid, iris, and lens associated with bilateral avascular peripheral retina. A full-term, 12-year-old female patient with a history of bilateral colobomas was referred to our practice by her pediatric ophthalmologist, who had been following her for some time, for suspicion of retinal detachment in her left eye. On office presentation, her visual acuities were 20/80 OD and 20/400 OS. Anteriorly, her ocular examination revealed colobomatous irides inferiorly and clear lenses. Posterior examination revealed an inferior coloboma at the disc with attached retina OD (Fig. 1) and a hemorrhagic exudative retinal detachment with possible subretinal hemorrhage OS (Fig. 2), with the question of a choroidal neovascular membrane as the source. A fluorescein angiogram obtained at the time of the examination under anesthesia revealed no such membrane but, interesting, demonstrated avascular peripheral retina bilaterally with late leakage OS (Figs. 3 and 4). Subsequently, laser photocoagulation was applied OD to prevent a similar scenario in this eye. As far as we are aware, this is the first published case of bilateral chorioretinal colobomas seen with an avascular peripheral retina. This case grants new insight at the complex and interwoven nature by which ocular structures develop, hinting at a possible common genetic pathway between retinal vasculogenesis and closure of