Purpose: To correlate high-definition optical coherence tomography (HD OCT) and fundus examination findings at different phases of vitelliform macular dystrophy and to determine the anatomic location of vitelliform material.
Design: Prospective, noncomparative, observational case series.
Methods: A complete ophthalmologic examination, including fundus biomicroscopy and HD OCT, was performed in 11 consecutive patients with a diagnosis of vitelliform macular dystrophy.
Results: Using HD OCT, we were able to demonstrate for the first time the presence of previtelliform lesions, characterized by a thicker layer between the retinal pigment epithelium (RPE) and the inner segment and outer segment (IS/OS) interface. At this stage, a normal-appearing RPE and IS/OS interface were found in two of four eyes. In all progressive stages from the vitelliform to the vitelliruptive, the vitelliform material was visualized by HD OCT as an highly reflective lesion located between the hyporeflective outer nuclear layer and the hyperreflective RPE layer, associated or not to an optically empty lesion. At these stages, a disrupted IS/OS interface and an almost normal appearance of all major intraretinal layers was detected. At the vitelliruptive and atrophic stages, on some parts, the HD OCT scan revealed hyperreflective mottling on the RPE layer, probably representing areas of focal RPE hypertrophy. The atrophic stage and the fibrotic stage were characterized by thinning of all the retinal layers and diffuse loss of the IS/OS interface. In our series, mean best-corrected visual acuity impairment showed a statistically significant correlation to the presence of focal disruption or diffuse loss of the IS/OS interface (P = .002), as well as to a more advanced stage of the disease (P = .01). A more advanced stage of the disease showed a strong statistically significant correlation to the presence of diffuse loss of the IS/OS interface (P < .001).
Conclusions: Based on the HD OCT findings, we hypothesize that early changes in vitelliform macular dystrophy involve the layer between the RPE and the IS/OS interface, first with accumulation of material beneath the sensory retina, and then with disruption and attenuation of IS and OS; late changes seem to affect the RPE, which undergoes hypertrophy, disruption, and attenuation.