Spectral sensitivity of the blood-retinal barrier at the pigment epithelium for blue light in the 400-500 nm range.
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.
Putting
B J
BJ
Department of Ophthalmology, Leiden University Hospital, The Netherlands.
van Best
J A
JA
Zweypfenning
R C
RC
Vrensen
G F
GF
Oosterhuis
J A
JA
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