Diode laser-induced mitosis in the rabbit retinal pigment epithelium

BACKGROUND AND OBJECTIVE: The induction of retinal pigment epithelium (RPE) proliferation without damaging the inner layers of the retina might be helpful in patients with RPE atrophic changes and degeneration. This study aimed to induce mitosis in the RPE of the rabbit after subthreshold photocoagulation with the diode laser. RESULTS: Neither morphological alterations nor mitotic activity was found after 5-mJ energies. Retinal layers were not affected and RPE hyperplasia appeared in the treated areas associated with mitotic activity when 10 mJ was used. Mitosis induction and retinal damage appeared with 20, 50, and 100 mJ and were associated with ophthalmoscopic damage. MATERIALS AND METHODS: Twenty-five male Dutch rabbits received retinal photocoagulation usincg an 8 10-nm diode laser with different power settings and exposure times. The eyes were processed for light microscopy, electron transmission microscopy, and immunohistochemistry. CONCLUSIONS: The use of subthreshold 8 10-nm diode laser treatment may induce mitosis in the RPE without causing damage to the neighboring layers.