IDEA #4EY0MG Instrument For Blindness Treatmentcaused By The Age Related Macula Degeneration

INSTRUMENT FOR BLINDNESS TREATMENT CAUSED BY THE AGE RELATED MACULA DEGENERATION V. V. Molebny, Institute of Biomedical Engineering of the Academy of Technological Sciences of Ukraine Vascular disorders in retina are very common causes of severe and often irreversible loss of vision. In age-related macula degeneration (AMD), abnormal blood vessels grow beneath the macula – the central part of the retina. They leak and bleed, causing disturbance of central vision. Later, the light-sensitive retinal cells (photorecep- tors) degenerate, and scar tissue grows in the mac- ula. This causes a blind spot in the center of vi- sion. Current treatments for vascular disorders in retina include laser surgery and laser therapy to eliminate the crucial influence of abnormal blood vessels. Sophisticated laser-based technologies are in use today: laser photocoagulation, photody- namic therapy (PDT), and transpupillary laser thermotherapy (TTT). Unfortunately, none of them can solve the problem of adequate dosage of the irradiation, that is an extremely critical matter. The Institute of Biomedical Engineering of the Academy of Technological Sciences of Ukraine has developed several technologies, ena- bling multi-channel on-line control of the proce- dure of the transpupillary thermotherapy, based on the changes of the topography of the eye bottom, and on the level and dynamics of blood flow as well as its oxygenation during tissue heating Fig. 1. Zone of control: reference (red) and scanning (blue) beams Temperature difference between treated and untreated zones achieves 10°C and more. The growth of temperature of the irradiated tissue leads to dimension changes, and thus to the changes of the topography of the eye bottom. We use the phase-difference dual-beam interferometry is along scanned where the reference beam is kept in a reference posi- tion without scanning. A second, frequency-shifted beam trajectory, crossing the treated and untreated zones of the eye bottom (V. Molebny. Proc. SPIE, Vol. 5086, 2003). Changes in phase structure are analyzed to have an estimate on thermal processes in the retina. On eye model, sensitivity to profile variation of the order of 0.1 μm has been achieved. a The blood flow is controlled through the Doppler shift measurement. Level of blood oxygenation and its dynamics is controlled by a spe- cially developed technology of multispectral infra- red sensing which excludes eye media backscattered light. , normalized | h | , 1 a b 1.0 0.8 0.6 0.4 0.2 0 - 6 -4 -2 0 2 4 6 x, mm Fig. 2. Normalized height across the scanned area for two positions of the retina model: a - initial position; b - shifted 5 μm forward The developed are the prototypes of the con- trol channels. Contact details: Prof. Molebny V. V. (380 68) 364-4969 molebny@gmail.com Mrs. Zheltovska T. V. (380 44) 526-5443 Academy of Technological Sciences of Ukraine 42, Acad. Glushkov Prospect 03187 Kiev, Ukraine ats@immsp.kiev.ua