INTACT RETINAL TISSUE AND RETINAL PIGMENT EPITHELIUM IDENTIFIED WITHIN A COLOBOMA BY HIGH-SPEED, ULTRAHIGH-RESOLUTION OPTICAL COHERENCE TOMOGRAPHY

Abstract

Purpose—To report on a posterior segment coloboma manifesting unusual morphology as determined by high-speed, ultrahigh resolution optical coherence tomography imaging (hsUHROCT). Methods—A 47-year-old patient with bilateral colobomas was evaluated via fundus examination and hsUHR-OCT. Results—Imaging with hsUHR-OCT showed intact retinal pigment epithelium (RPE) within the posterior segment coloboma. Most of the retinal layers appeared to continue into the coloboma, although they exhibited slight attenuation. The external limiting membrane (ELM) was clearly visible continuing within the coloboma, suggesting that Muller cells and the inner segments of the photoreceptors were still present in this area. The junction between the inner and outer segments of the photoreceptors ended at the margin of the coloboma, which may be due to either photoreceptor disruption or a change in the orientation of the outer segments. Conclusion—hsUHR-OCT demonstrated the presence of Muller cells and photoreceptor inner segments within a posterior segment coloboma. The retinal pigment epithelium (RPE) was intact within the coloboma, representing an unusual morphology.