Selective retina therapy (SRT) in patients with geographic atrophy due to age-related macular degeneration
- 229 Downloads
For geographic atrophy (GA) due to age-related macular degeneration (AMD) there is so far no approved treatment option. Usually, increased autofluorescence (AF) levels of different patterns adjacent to the atrophic area indicate lipofuscin-laden retinal pigment epithelium (RPE) cells at a high risk for apoptosis. Herein, SRT was used to selectively treat these cells to stimulate RPE proliferation, in order to reduce or ideally stop further growth of the atrophic area.
Material and methods
Six eyes of six patients with bilateral equally pronounced GA were treated by SRT, while the fellow eye served as control. Irradiation was performed using a prototype SRT laser (Medical Laser Center Lübeck, Nd:YLF laser; 527 nm; 200 ns/1.7 µs pulse duration; 30 repetitive pulses at 100 Hz). Test lesions with increasing energies were applied at the lower vessel arcade to determine the individual angiographic and ophthalmoscopic threshold radiant exposures. Treatment was then performed in the area of increased AF adjacent to the GA using energies between both thresholds. The GA progression rates of treated and fellow eyes were evaluated.
After a 1-year follow-up, a progression of the atrophic area was observed in the treated eyes (0.7–8.0 mm2/yr, mean 3.0 mm2/yr; 46%/yr) whereas the progression rates of the fellow eyes were insignificantly lower (0.46–4.04 mm2/yr, mean 1.9 mm2/yr; 30%/yr; p = 0.134). The progression rate in the treated eyes of two patients increased significantly, while in the other four patients, the progression rates were nearly the same between both eyes. Moreover, one of these two eyes showed an unexpected RPE reaction after treatment, since all laser lesions led to RPE atrophy and thus an accelerated enlargement of the GA occurred.
SRT in the hyperautofluorescent areas of GA was not able to stop or slow down the progression of GA. However, modified treatment strategies might be more promising, e.g. placing the spots outside the hyperautofluorescent areas where RPE apoptosis is postulated. Moreover, SRT studies on GA might be more successfully performed on specific subgroups of GA, based on autofluorescence and other findings.
KeywordsGeographic atrophy AMD RPE Laser photocoagulation SRT Selective retina treatment
The authors would like to thank the Dr. Werner Jackstaedt Foundation in Wuppertal, Germany, for the generous financial support of this ongoing study.
- 14.Roider J, Brinkmann R, Wirbelauer C et al (1999) Retinal sparing by selective retinal pigment epithelial photocoagulation. Arch Opthalmol 117:1028–1034Google Scholar
- 24.Gabel VP, Birngruber R, Hillenkamp F (1978) Visible and near infrared light absorption in pigment epithelium and choroid. In: Shimizu K (ed) International Congress Series No. 450, XXIII Concilium Ophthalmologicum, Kyoto. Excerpta Medica, Princeton, NJ, pp 658–662Google Scholar
- 28.Sunness JS, Margalit E, Srikumaran D, Applegate CA, Tian Y, Perry D, Hawkins BS, Bressler NM (2007) The long-term natural history of geographic atrophy from age-related macular degeneration: enlargement of atrophy and implications for interventional clinical trials. Ophthalmology 114(2):271–277CrossRefPubMedGoogle Scholar