Choroidal Coloboma Image Report
Title: Choroidal Coloboma Image Report
Author(s): Eileen S. Hwang, MD, PhD; Akbar Shakoor, MD
Image: Figure 1. Montage color fundus photograph of the left eye demonstrating an anomalous optic nerve and a choroidal coloboma
Keywords/Main Subjects: Choroidal Coloboma
Diagnosis: Choroidal Coloboma
Brief Description: The patient is a 65 year old female who presented for an abnormality found on a diabetic screening examination. She reported that she had a history of a congenital abnormality of her left eye and had poor vision in that eye since she was young. On examination, her visual acuity in the left eye with correction was 20/200. She had an iris coloboma from 6:00 to 8:00. Her left optic nerve had an anomalous appearance. She had a large well-demarcated, hypopigmented, excavated area of her retina inferior to the optic disc in the left eye.
Choroidal coloboma is a rare developmental abnormality that is caused by problems with closure of the embryonic fissure. In the area of the coloboma, the choroid and the outer layers of the retina are missing. On the surface of the coloboma, there is a thin intercalary membrane consisting of inner layers of the retina. The intercalary membrane is prone to breaks, and patients with choroidal colobomas may have up to a 40% risk of retinal detachment (Gopal, 1998). Detachments are most likely to occur in the second and third decades of life. In the absence of a retinal break or detachment, a choroidal coloboma can be observed. When intervention is required, diode laser demarcation of the coloboma is preferred over argon laser since diode laser causes less damage to the nerve fiber layer. To tamponade retinal detachments in patients with choroidal colobomas, silicone oil has been used with success (Schubert, 2005).
References: Schubert HD. Structural organization of choroidal colobomas of young and adult patients and mechanism of retinal detachment. Trans Am Ophthalmol Soc. 2005;103:457-72.
Gopal L, Badrinath SS, Sharma T, Parikh SN, Shanmugam MS, Bhende PS, Agrawal R, Deshpande DA. Surgical management of retinal detachments related to coloboma of the choroid. Ophthalmology. 1998 May;105(5):804-9.
Relevant links: Ort, Victoria, and David Howard. Development of the Eye. Retrieved 9 June 2015. http://education.med.nyu.edu/courses/macrostructure/lectures/lec_images/eye.html
Series: Moran Eye Center Image Report
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