[The dye laser: experimental and clinical results in subretinal macular neovascularization]

The tunable dye laser provides now a large assortment of monochromatic wavelengths that allow selective targeting on individual tissues in the retina, according to in vitro studies showing extinction coefficient of ocular pigments (xanthophyllic pigment, rhodopsin, melanin, lipofuschin, hemoglobin) for different laser wavelengths. Confluent heavy and juxtafoveolar laser burns in eyes of cynomolgus monkeys showed, after 38 days, similar lesions in all the wavelength studied (green, red, yellow, orange) at the level of the choriocapillaris, Bruch's membrane, pigment epithelium and photoreceptor's layers. However, the inner retina layers were discretely more damaged with yellow and orange than with green and red. In clinical approach, the effects of these different wavelength haven been compared in human eyes presenting with subfoveol new vessels and disciform age-related macular degeneration. After healing, the scar was similar biomicroscopically, and on fluorescein angiography with all wavelengths studied (green, red, yellow, orange). In conclusion, dye laser seems to be efficient and easily tunable for photocoagulation in macular area.