Coloboma

Coloboma is a congenital developmental deformity of the upper eyelid, which appears as a cleft in the eyelid. The defective eyelid is often unable to function properly, leaving the eye exposed and at risk for inflammation and the development of ulcers unless it is surgically repaired.

This deformity is seen in collies and related breeds (Shetland sheepdog, Australian shepherd) as well as in Labrador retriever and Saint Bernard as part of their ocular maldevelopment syndrome, or in other animals as isolated lesions. as an inherited disorder, it represents part of collie eye anomaly, but also occurs sporadically as non-inherited birth defect. In both cases, the size of the defect varies from dog to dog. The lesion is non-progressive and can be found in one or both eyes. If the defect is large, vision will be compromised.

Types of Coloboma

• Typical coloboma - lies in the fetal fissure - this is a region which extends ventrally from the optic disk to the cornea - would be considered the 6 o'clock area.
• Atypical coloboma - occurs in a region other than the fetal fissure.

Treatment of Coloboma

There is no effective treatment and it is best to avoid breeding affected dogs.

Canine Eye Diseases and Vision Disorders