Optical coherence tomographic evaluation of the outer retinal architecture in Oguchi disease.

BACKGROUND: To report the changes in the optical coherence tomography (OCT) images of the outer retinal layers after prolonged dark adaptation in a patient with Oguchi disease. CASE: A 75-year-old woman showed the typical golden-yellow fundus reflex of Oguchi disease, and the coloration returned to normal after prolonged dark adaptation. Fourier domain OCT (FD-OCT) was performed on the patient's left eye before and after prolonged dark adaptation. OBSERVATIONS: Before dark adaptation, the FD-OCT images at the fovea had three identifiable reflection bands, namely, the external limiting membrane (ELM), the border between the photoreceptor inner and outer segments (IS/OS line), and the retinal pigment epithelium (RPE)/Bruch band. The paramacular area had only the ELM and RPE/Bruch bands. After 4 h of dark adaptation, the IS/OS line was also detected in the paramacular area.
CONCLUSIONS: The absence of the IS/OS line in the extramacular regions in the partly dark adapted condition was most likely due to a defect in the rod photoreceptors of this area. The emergence of the IS/OS line after prolonged dark adaptation suggests that microarchitectural changes occur in the photoreceptors and that the changes may be correlated with the improvement of rod function.