Exploring Laser Treatment for Macular Degeneration
Researchers here demonstrate that they can use very short bursts of laser light to somewhat reduce levels of extracellular waste deposits known as drusen present in the aged retina. The mechanisms of action remain to be explored in greater depth, however:
Age-related macular degeneration (AMD) is a leading cause of vision loss, characterized by drusen deposits and thickened Bruch's membrane (BM). This study details the capacity of nanosecond laser treatment to reduce drusen and thin BM while maintaining retinal structure. Fifty patients with AMD had a single nanosecond laser treatment session and after 2 years, change in drusen area was compared with an untreated cohort of patients. The retinal effect of the laser was determined in human and mouse eyes using immunohistochemistry and compared with untreated eyes. In a mouse model with thickened BM, the effect of laser treatment was quantified using electron microscopy and quantitative PCR.In patients with AMD, nanosecond laser treatment reduced drusen load at 2 years. Retinal structure was not compromised in human and mouse retina after laser treatment, with only a discrete retinal pigment epithelium (RPE) injury, and limited mononuclear cell response observed. BM was thinned in the mouse model 3 months after treatment, with the expression of matrix metalloproteinase-2 and -3 increased. Nanosecond laser resolved drusen independent of retinal damage and improved BM structure, suggesting this treatment has the potential to reduce AMD progression.