Yellow dye laser thermotherapy of choroidal neovascularisation in age related macular degeneration

Aim-A pilot study of the feasibility of using dye laser thermotherapy (LTT) at a subcoagulation temperature to occlude newly formed vessels in patient s with age related macular degeneration (AMD). Methods-Choroidal neovascularisation (CNV) in 24 eyes with exudative AMD wa s treated with a continuous wave yellow laser at 578 nm. Parameters were an exposure time of 2 or 5 seconds, a spot size of 750 or 1000 mum, and a las er power of 100-200 mW. The clinical end point was a greyish discoloration at the treatment site. The effect of thermotherapy was documented by ophtha lmoscopic and fluorescein angiographic examination. The follow up after LTT was 4-16 months, mean 5 months. Results-LTT resulted in total occlusion of newly formed vessels in 15 eyes (62.5%). Neovascular outgrowth within 6 weeks and recurrences 2-4 months af ter LTT were observed, each in three eyes. In six of the nine eyes with occ lusion of CNV without recurrence the choriocapillaris remained perfused; in two eyes only the large choroidal vessels remained perfused. In six eyes p igmentary changes were the only ophthalmoscopic and fluorescein angiographi c signs of treatment. The effect of LTT is rather unpredictable. Conclusion-CNV in AMD can effectively be treated by yellow dye laser thermo therapy with preservation of choroidal perfusion. The technique requires do simetric adaptation.