---
title: Coloboma
description: "Coloboma is a congenital gap or defect in ocular structures caused by incomplete closure of the embryonic fissure. It can involve the iris, lens, retina, choroid, or optic nerve. ## Presentation Severity depends on which structures are affected. - Iris…"
url: "https://bluefinvision.com/knowledge-base/topics/conditions-diseases/coloboma/"
updated: "2025-12-16"
category: "Conditions & Diseases"
---

# Coloboma

Coloboma is a congenital gap or defect in ocular structures caused by incomplete closure of the embryonic fissure. It can involve the iris, lens, retina, choroid, or optic nerve.

## Presentation

Severity depends on which structures are affected.

- Iris coloboma producing a keyhole-shaped pupil but often good vision
- Retinochoroidal or optic nerve coloboma causing field defects and reduced acuity
- Association with microphthalmia and systemic syndromes in some cases
- Often bilateral, with variable refractive errors

## Management

Treatment is supportive and preventative.

- Glasses, contact lenses, and sometimes cosmetic iris devices
- Amblyopia therapy and low-vision support where needed
- Monitoring for retinal detachment around the coloboma edges
- Genetic and systemic evaluation if syndromic features are present