Long-term effect of prophylactic laser treatment for bilateral soft drusen

Large drusen is a known risk factor for the development of late complications of age-related macular degeneration (AMD) and drusen reduction has been found by our previous study. To prospectively evaluate the efficacy and safety of prophylactic laser treatment in Chinese patients with bilateral soft drusen, we examined the structure and function of the macula 8 years after treatment.

Ten patients with more than 10 soft drusen (> 125 mm) and best corrected visual acuity ≥ 20/25 in each eye participated in the study. One eye, with relatively more drusen, was exposed to an argon laser (514 nm) to achieve a barely visible retinal lesion. The contralateral eye was used as a control. Fluorescein angiography, Amsler tests, Fourier-domain optical coherence tomography and visual evoked potential tests were carried out 8 years later.

No choroidal neovascularization was seen in the laser-treated eyes or control eyes. There were no significant differences in visual acuity or P100 latency and amplitude between the laser treated eyes and contralateral eyes (t = 1.685, 1.184; P > 0.05). The thickness of the retinal pigment epithelium of the treated eyes was less than that of the contralateral eyes (t = -4.540; P < 0.05). The full retinal thickness in treated eyes was slightly, but insignificantly, reduced relative to contralateral eyes (t = -1.746; P > 0.05).

The treatment was associated with a reduction in retinal pigment epithelium thickness elevation compared with the contralateral eyes. Macular function was not impaired.