INVESTIGATIONS INTO DYNAMICS OF THE ACCUMULATION OF PHOTODITASINE GEL IN THE EYE WITH THE USE OF RADIOISOTOPES

The present study on the dynamics of the accumulation of photoditasine gel in the eyeball with the use of radioisotopes was carried out on the in vivo rabbit model. The photoditasine gel labeled with 99Te was administered into the conjunctival sac of the animals, with the time of exposure being 15, 30, and 60 minutes. The maximum accumulated dose amounting to 23 ± 1.0 counts/cell was documented in the experiments with the exposure time of 15 min. Observations of the dynamics in the accumulation of radiolabeled photoditasine within 15 and 30 min after the end of exposure revealed the progressive reduction of its concentration in the eyeballs of all the animals. It is concluded that the highest efficiency of photodynamic therapy appears to be achieved within 15 minutes after the administration of the photosensitizing agent into the conjunctival sac when it is accumulated in the greatest quantity.