Online Photo Diagnosis
By Gregory W. DeNaeyer, OD, FAAO
The first photo shows a patient who has an iris coloboma, which presents as a keyhole notch in the inferior quadrant of the iris. An iris coloboma is a congenital defect secondary to failure of the optic fissure to close during embryonic development. Other types of colobomas can include notched defects of the ciliary body, retina, and choroid. Patients who have a coloboma may also have other malformations including a cleft palate/lip.
Unfortunately, an iris coloboma can degrade optics, and it leaves the patient susceptible to photophobia and glare. It can be corrected surgically, as was the case for the patient in Figure 2. An alternative to surgery would be to fit the patient in a prosthetic contact lens. Prosthetic lenses for this condition perform best with a black backing to completely block light verses cosmetic colored contact lenses that are translucent.
Snell, RS. Lemp, MA. Clinical Anatomy of The Eye. Blackwell Scientific Publications, Inc. 1989.