Retinal detachments associated with choroidal colobomas

Abstract

To summarize the characteristics of the retinal detachments (RDs) that are associated with choroidal colobomas that occur in pediatric and adult patients. A choroidal coloboma is a rare disorder that results from an incomplete closure of the embryonic optic fissure, and their size can range from small colobomas with isolated chorioretinal involvement to large colobomas affecting the iris, choroid, retina, and optic nerve. A RD is occasionally associated with choroidal colobomas, and histological studies of the area of the choroidal coloboma show an absence of normal choroidal tissue, retinal pigment epithelium (RPE), and retina. Near the margin of the coloboma, the inner retinal layer has a central continuation of the marginal intercalary membrane (ICM) within the coloboma. The outer layer folds back, becomes disorganized, and fuses with the RPE. The inner retina gradually thins and merges with the marginal ICM with a high incidence of tears of the ICM developing along the edge of the coloboma or toward the center. Because of the high association of the causative retinal breaks being located within the colobomatous area, vitrectomy, endolaser photocoagulation around the margin of coloboma, and long-term tamponade with silicone oil or gas are recommended treatments. In addition, the presence of the macula within the area of the laser photocoagulation should be considered. However, the recurrence rate is high and multiple surgeries are required to reattach the detached retina.

Keywords: Choroidal coloboma; scleral buckling; vitrectomy; vitreoretinal surgery.

Figure 1

Fundus photographs of the left eye of a 26-year-old male with a choroidal coloboma at the initial visit. (a) Ultra-widefield image showing an asymptomatic localized retinal detachment connected to the edge of the choroidal coloboma (arrows). (b) Ultrasoundsonography showing excavated staphyloma (arrows) around the optic disc. (c) Fluorescein angiographic (FA) image at an early phase showing a diffuse hyperfluorescent lesion (arrows) at the edge of the coloboma corresponding to the localized retinal detachment. (d) FA image at a late phase showing a window defect at the hyperfluorescent lesion of the localized retinal detachment. The lesion of the coloboma has turned more hyperfluorescent. (e and f) Widefield optical coherence tomographic image showing a local retinal detachment (arrow) connected from the detachment of marginal intercalary membrane. The vitreous traction (arrowheads) is connected to the central intercalary membrane

Figure 2

Fundus photographs of the same patient visited 1 year after the initial visit due to acute visual disturbance by an extended retinal detachment associated with a choroidal coloboma. (a) Ultra-widefield image showing the retinal detachment connected to the edge of the choroidal coloboma (arrows). (b) Fundus autofluorescent image showing a dark area corresponding to a retinal detachment (arrows). (c) Optical coherence tomographic (OCT) image showing that the retinal detachment is connected to the choroidal coloboma. The inner retina within the coloboma is connected to an intercalary membrane (ICM). (d) Ultrawide-angle image showing a complete retinal reattachment from the edge of the choroidal coloboma by endolaser scars (arrowheads). Laser photocoagulation was also performed around the iatrogenic break (arrow). (e) Fluorescein autofluorescence image showing the absence of the dark area corresponding to the retinal reattachment. Laser scars can be seen at the edge of the coloboma (arrowheads) and the iatrogenic break. (f) OCT image showing that the retinal detachment was disconnected by the laser scars (arrowheads) and persistent fluid beneath the ICM (arrow) at the choroidal coloboma

Figure 3

A 34-year-old woman with a retinal detachment associated with choroidal coloboma with cyanoacrylate retinopexy. (a) Fundus image was taken in 2004 after vitrectomy with cyanoacrylate retinopexy. The cyanoacrylate glue (arrowheads) was applied at the inferior quadrants of choroidal coloboma. (b) Fundus image taken in 2024 after a vitrectomy with cyanoacrylate retinopexy (arrowheads). The cyanoacrylate glue has persisted at the same position for 20 years. (c) Magnified fundus image. Cyanoacrylate glue (arrowheads) was applied to the inferior quadrants of the choroidal coloboma. (d) Ultra-widefield image showing that the retina is reattached after more than 20 years