TY - JOUR
T1 - Effects of Repeated Photic Exposures on the Monkey Macula
AU - Borges, José
AU - Li, Zong Yi
AU - Tso, Mark O.M.
PY - 1990/5
Y1 - 1990/5
N2 - The posterior pole of the eyes of rhesus monkeys was exposed to the light of an indirect ophthalmoscope. The tissue changes caused by repeated (three to five) photic injuries were compared with those produced by a single photic insult. The ophthalmoscopic and angiographic examinations showed a progressive involvement of the foveal area after multiple exposures to light. Histopathologic study showed that after one exposure the retinal pigment epithelium appeared focally atrophic. Plaques of proliferated retinal pigment epithelium could also be seen, and on the anterior surface of these plaques a layer of relatively cuboidal hypopigmented retinal pigment epithelial cells was present. With multiple exposures, focal areas of total absence of retinal pigment epithelium were seen in these eyes. The eyes that received only one exposure showed partially regenerated photoreceptor outer segments. After repeated photic exposures, the photoreceptor outer segments failed to regenerate even 6 to 8 months after the last exposure. In one eye exposed five times for 60 minutes, areas of total absence of photoreceptor cells could be seen, and the inner nuclear layer was directly apposed to Bruch's membrane. These experimental exposures to the light of an indirect ophthalmoscope were 60 to 120 minutes long and were not comparable to clinical exposures of the ophthalmoscope in patient examination. Our observation highlighted the cumulative effects of repeated light injury to the retinal pigment epithelial and photoreceptor cells and also showed the similarity between this animal model of photic maculopathy and the changes present in the eyes of human patients with atrophic agerelated macular degeneration.
AB - The posterior pole of the eyes of rhesus monkeys was exposed to the light of an indirect ophthalmoscope. The tissue changes caused by repeated (three to five) photic injuries were compared with those produced by a single photic insult. The ophthalmoscopic and angiographic examinations showed a progressive involvement of the foveal area after multiple exposures to light. Histopathologic study showed that after one exposure the retinal pigment epithelium appeared focally atrophic. Plaques of proliferated retinal pigment epithelium could also be seen, and on the anterior surface of these plaques a layer of relatively cuboidal hypopigmented retinal pigment epithelial cells was present. With multiple exposures, focal areas of total absence of retinal pigment epithelium were seen in these eyes. The eyes that received only one exposure showed partially regenerated photoreceptor outer segments. After repeated photic exposures, the photoreceptor outer segments failed to regenerate even 6 to 8 months after the last exposure. In one eye exposed five times for 60 minutes, areas of total absence of photoreceptor cells could be seen, and the inner nuclear layer was directly apposed to Bruch's membrane. These experimental exposures to the light of an indirect ophthalmoscope were 60 to 120 minutes long and were not comparable to clinical exposures of the ophthalmoscope in patient examination. Our observation highlighted the cumulative effects of repeated light injury to the retinal pigment epithelial and photoreceptor cells and also showed the similarity between this animal model of photic maculopathy and the changes present in the eyes of human patients with atrophic agerelated macular degeneration.
UR - http://www.scopus.com/inward/record.url?scp=0025277698&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025277698&partnerID=8YFLogxK
U2 - 10.1001/archopht.1990.01070070113047
DO - 10.1001/archopht.1990.01070070113047
M3 - Article
C2 - 2334332
AN - SCOPUS:0025277698
SN - 0003-9950
VL - 108
SP - 727
EP - 733
JO - Archives of ophthalmology
JF - Archives of ophthalmology
IS - 5
ER -