Clinical and Echographic Features of Retinochoroidal and Optic Nerve Colobomas

We reported the clinical and echographic features of colobomas, prevalence of retinal detachment, and associated visual acuity in these patients.

The study is a nonrandomized consecutive case series of 140 colobomatous eyes in 98 patients (age range, 0-83 years). Coloboma depth, width, volume, and relative coloboma excavation (coloboma depth/axial length) were measured using standardized echographic images. The presence of structural and other ocular abnormalities was noted. The clinical and echographic findings present were correlated with visual acuity of the patient. In addition, these features were correlated with the presence or absence of retinal detachment.

Increased relative coloboma excavation was significantly associated with an increased risk of retinal detachment. A relative coloboma excavation (ratio of coloboma depth to axial length) greater than 0.15 was associated with an increased risk of retinal detachment (52%), compared to those with a relative coloboma excavation less than 0.15 (23%, P = 0.014). The presence of any structural abnormality and the presence of a retrobulbar cyst were associated with increased risk of retinal detachment and severe visual impairment (worse than 20/200). Increased coloboma depth, width, volume, and relative coloboma excavation were not associated with increased risk of severe visual impairment.

Clinical and echographic features of colobomas may be used in predicting the risk of retinal detachment. Measuring relative coloboma excavation upon presentation may alter follow-up and assist in the diagnosis of retinal detachment.