This 57yo female presented with an asymptomatic, unilateral choroidal coloboma inferior to the right optic nerve.
Triton swept-source OCT shows a total loss of the RPE and a near-complete absence of the choroid within the coloboma, with marked thinning of the overlying retina. There is also an outpouching of the underlying sclera.
Learning Points:
Choroidal colobomas are most commonly due to failure of the optic vesicle and choroidal fissure to close during fetal development. Lesions like this may also be from other causes, including toxoplasmosis. Choroidal coloboma can present as solitary or multiple lesions. Visual prognosis depends on the location and involvement of the optic nerve and macula.
