title: Spectral sensitivity of the blood-retinal barrier at the pigment epithelium for blue light in the 400-500 nm range.
abstract: To specify the spectral sensitivity of the retinal pigment epithelium (RPE) for blue light damage, pigmented rabbits were exposed to light of 408, 418, 439, 455, 485, and 500 nm (half-peak bandwidth approximately 12 nm). The range of radiant exposure was 15-275 J cm-2 (1.7-19 mW cm-2 for 0.5-5 h). Vitreous fluorophotometry was used to functionally evaluate the blood-retinal barrier at the RPE in vivo, and electron microscopy to visualize RPE ultrastructure in vitro. A significant increase in permeability of the blood-retinal barrier was seen only after exposure to light of 418 nm. Radiant exposure at threshold for permeability increase was 18 J cm-2. Electron microscopy of the RPE demonstrated dispersion and clumping of melanin granules. The results suggest that the RPE is most sensitive to light in the range 412-425 nm, possibly due to damage-mediating chromophores such as cytochrome c oxidase and lipofuscin.
authors.affiliation: Department of Ophthalmology, Leiden University Hospital, The Netherlands.
authors.forename: B J
authors.initials: BJ
authors.lastname: Putting
authors.forename: J A
authors.initials: JA
authors.lastname: van Best
authors.forename: R C
authors.initials: RC
authors.lastname: Zweypfenning
authors.forename: G F
authors.initials: GF
authors.lastname: Vrensen
authors.forename: J A
authors.initials: JA
authors.lastname: Oosterhuis
mesh_terms: D000818:Animals; D001813:Blood-Retinal Barrier / Q000528:radiation effects*; D002463:Cell Membrane Permeability / Q000528:radiation effects; D015590:Fluorophotometry; D005654:Fundus Oculi; D008027:Light / Q000009:adverse effects*; D010857:Pigment Epithelium of Eye / Q000528:radiation effects* / Q000648:ultrastructure; D011817:Rabbits; D011833:Radiation Injuries, Experimental / Q000473:pathology / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D012684:Sensory Thresholds; D014822:Vitreous Body / Q000502:physiology