Low-dose fractionated percutaneous teletherapy in age-related macular degeneration with subfoveolar neovascularization - 3-year results

Aim: The effect of low dose fractionated percutaneous teletherapy to visual acuity and the changes in subfoveolar neovascular membranes in age-related macular degeneration were investigated. Patients and Method: 126 eyes of 118 patients (age 55-89 years; mean 74 ys. ) were treated. Best distal and near visual acuity was assessed prior to (= initial visual acuity [IVA]) and 3, 6, 12, 18, 24, 30 and 36 months after teletherapy. Fluorescein angiography was performed prior to and 6, 12, 24 a nd 36 months after radiation therapy. For analysis patients were divided in to different groups by IVA and membrane size. Maximal duration of observati on was 36 months. Teletherapy was done by a 9-MeV photon Linear accelerator through a lateral port in half-beam technique with a single dose of 2 Gy u p to a total dose of 20 Gy within 12 days. Results: No severe negative side effects have been observed. Eight patients reported of epiphora and four patients complained of transient sicca syndr ome. Visual acuity decreased more than one line in the group IVA 0.05-0.2. The group IVA 0.3-0.5 remained unchanged for 1 year. We found a tendency fo r increased visual acuity in group IVA greater than or equal to 0.6 for 18 months. After that time both groups showed decreased Visual acuity, hut all these patients reported of reduced metamorphopsia and increased color and contrast perception. Conclusions: There is an influence of low dose fractionated percutaneous te letherapy on Visual acuity, subfoveal neovascular membranes and metamorphop sia. IVA and duration of anamnesis play an important role. There seems to b e no persistent effect; possibly increased dosage will bring a benefit.