Scanning laser system for photodynamic therapy of choroidal neovascularization.
OBJECTIVE
In order to improve selectivity of photodynamic therapy (PDT) to choroidal neovascularization (CNV) associated with age-related macular degeneration, a laser scanning technique was applied to perform focal laser irradiation to the retina, and the occlusion effects of a new device to the choriocapillaris were evaluated in primate eyes.


METHODS
The device contains lasers for fundus observation of 785 nm and for PDT of 670 nm, matching the absorption peak of a photosensitizer, ATX-S10(Na). The laser irradiated the shape on the retina specified before treatment and shut off automatically when the predetermined treatment was achieved. The occlusion of the choriocapillaris after PDT was documented by fluorescein and indocyanine green angiography and histology.


RESULTS
The area designated for PDT was easily drawn on the touch-screen monitor, and occlusion of the choriocapillaris was achieved precisely in the area pre-selected for treatment with 5 J/cm(2) or more of radiance following administration of 8 mg/kg ATX-S10(Na).


CONCLUSIONS
This device is useful for irradiating CNV of any shape, sparing the surrounding retina. Since our previous studies suggested that selective occlusion of CNV would decrease not only the functional disturbance caused by PDT, but also the recurrence of CNV, the present device may allow more effective PDT than the slit-lamp system presently used.
Obana
Akira
A
Department of Ophthalmology and Visual Sciences, Osaka City University Graduate School of Medicine, Osaka City, 545-8585 Japan. akira-kun@med.osaka-cu.ac.jp
Gohto
Yuko
Y
D000818:Animals; D002829:Choroid / Q000098:blood supply / Q000601:surgery; D020256:Choroidal Neovascularization / Q000628:therapy*; D004396:Coloring Agents; D004195:Disease Models, Animal; D005451:Fluorescein Angiography; D007208:Indocyanine Green; D017075:Laser Coagulation; D008252:Macaca fascicularis; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011166:Porphyrins / Q000627:therapeutic use*
C117772:ATX S10Na(II); D004396:Coloring Agents; D017319:Photosensitizing Agents; D011166:Porphyrins; D007208:Indocyanine Green