Observation of ultrastructural changes in cultured retinal pigment epithelium following exposure to blue light

Abstract

The RPE cells can be damaged directly by blue light after excluding the possible influence of phagosomes. This primary culture of RPE can also serve as an in vitro model for the study of light damage to the RPE.

Blue light-induced apoptosis in cultured retinal pigment epithelium cells of the rat

“…Treatment of the animals was consistent with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. RPE cells were isolated as described previously [21,22]. Briefly, enucleated eyeballs were incubated at 37°C in 20% O 2 and 5% CO 2 consecutively in 0.1% crude bacterial collagenase (Sigma, St. Louis, Mo., USA; Type I) and 0.2% dispase (Godo Shusei, Tokyo, Japan), followed by incubation in 0.05% trypsin-0.02% EDTA (Gibco, Grand Island, N.Y., USA) for another 30 min.…”

“…Previously, we demonstrated damage of cultured RPE cells after exposure to 1 mW/cm 2 of blue light limited to the mitochondria, which became swollen with disrupted membranes [22]. After exposure to blue light for 12-36 h at 2.0 mW/cm 2 , those structures, arranged in membranous loops called whorls of membrane, were visible in cytoplasm in the RPE [21,22]. RPE cells exposed to blue light for 36 h at 4.0 mW/cm 2 showed lysis of nucleus and cytoplasm, which was compatible with necrosis [21,22] .…”

“…After exposure to blue light for 12-36 h at 2.0 mW/cm 2 , those structures, arranged in membranous loops called whorls of membrane, were visible in cytoplasm in the RPE [21,22]. RPE cells exposed to blue light for 36 h at 4.0 mW/cm 2 showed lysis of nucleus and cytoplasm, which was compatible with necrosis [21,22] . However, we could not confirm that RPE cells were induced to programmed cell death by blue light in any condition.…”

Retinal light toxicity

“…These two classes of retinal damage have been shown in both rodent and primate models. 46,85,87,88,[90][91][92][93] Ophthalmoscopic evidence of underlying photochemical retinal toxicity may not always be present on examination. More severe photochemical retinal toxicity will manifest within the first few days of exposure as outer retinal whitening.…”

Local Fundus Response to Blue (LED and Laser) and Infrared (LED and Laser) Sources

“…Photoreceptor changes followed. However, the presence of the retina is not necessary for the PE cellular changes (Pang et al, 1988) which may occur in culture. Pigment redistribution is a general response in the early pathology of the PE cells (Morris and Henkind, 1979).…”