摘要： PURPOSE. We examined if light induces changes in the retinal structure that can be observed using optical coherence tomography (OCT). METHODS. Normal C57BL/6J mice (age 3–6 months) adapted to either room light (15 minutes to ~5 hours, 50–500 lux) or darkness (overnight) were imaged using a Bioptigen UHR-OCT system. Confocal histologic images were obtained from mice killed under light- or dark-adapted conditions. RESULTS. The OCT image of eyes adapted to room light exhibited signi?cant increases (6.1 6 0.8 lm, n ? 13) in total retina thickness compared to the same eyes after overnight dark adaptation. These light-adapted retinal thickness changes occurred mainly in the outer retina, with the development of a hypore?ective band between the RPE and photoreceptor-tip layers. Histologic analysis revealed a light-evoked elongation between the outer limiting membrane and Bruch’s membrane from 45.8 6 1.7 lm in the dark (n ? 5) to 52.1 6 3.7 lm (n ? 5) in the light. Light-adapted retinas showed an increase of actin staining in RPE apical microvilli at the same location as the hypore?ective band observed in OCT images. Elongation of the outer retina could be detected even with brief light exposures, increasing 2.1 6 0.3 lm after 15 minutes (n ? 9), and 4.1 6 1.0 lm after 2 hours (n ? 6). Conversely, dark-adaptation caused outer retinal shortening of 1.4 6 0.4 lm (n ? 7) and 3.0 6 0.5 lm (n ? 8) after 15 minutes and 2 hours, respectively. CONCLUSIONS. Light-adaption induces an increase in the thickness of the outer retina and the appearance of a hypore?ective band in the OCT image. This is consistent with previous reports of light-induced ?uid accumulation in the subretinal space.