Purchase this article with an account.
P. M. Prahs, A. Walter, J. Hillenkamp, V. P. Gabel, R. Brinkmann, C. Framme; Selective Retina Therapy (SRT) in Patients With Geographic Atrophy Due to Age-Related Macular Degeneration. Invest. Ophthalmol. Vis. Sci. 2007;48(13):5100.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
For geographic atrophy (GA) due to age-related macular degeneration (AMD) so far there is no approved treatment option. Autofluorescence patterns usually reveal increased autofluorescence (AF) adjacent to the atrophic area indicating lipofuscin-laden RPE cells at a high risk for apoptosis. We examined a new therapeutic approach by selectively treating these RPE cells with SRT to stimulate neighboring cells to proliferate in order to reduce (or ideally stop) growth of the atrophic area.
So far, 4 patients with GA approved by angiography and AF were treated by SRT. Irradiation was performed using a prototype SRT laser (Med. Laser Center Luebeck GmbH, Germany: Nd:YLF laser; 527nm; 1.7µs pulse duration; 30 repetitive pulses at 100Hz, 200µJ pulse energy). Test lesions with increasing energy were applied at the lower arcade to determine the angiographic and ophthalmoscopic threshold radiant exposures. Treatment was then performed in the area of increased AF adjacent to the GA with energies within the therapeutic window (between angiographic and ophthalmoscopic threshold). After treatment laser induced RPE damage of the ophthalmoscopically invisible lesions was visualized and confirmed by fluorescein angiographic leakage.
In all patients the ophthalmoscopically invisible laser lesions became angiographically visible by leakage within the area of increased AF adjacent to the GA. During follow-up of 12 months in 2 patients the atrophic area still enlarged; however, RPE reaction was significantly different. Despite the fact that treatment energy was within the therapeutic window in both patients leading to selective RPE damage, in the first patient none of the laser lesions led to RPE atrophy whereas in the second patient all laser lesions caused RPE atrophy additionally to a slight enlargement of the initial GA.
In these patients SRT was not able to stop enlargement of GA due to AMD. However; the growth rates of the atrophic area with and without SRT have to be analyzed in more detail. Different RPE reactions after SRT seem to be possible. The reason for this is unclear and might depend on different subgroups of GA, which can be distinguished by AF patterns. An enlarged clinical trial is needed to further evaluate the effects of SRT in patients with GA.
This PDF is available to Subscribers Only