[Low dosage radiotherapy of subfoveal neovascularizations in age related macular degeneration. Results after 6 weeks and 6 months].

AIM OF THE STUDY

The aim of this pilot study is to test the effect of low dose radiation on classic and occult subfoveal neovascular membranes (SNVM) in age-related macular degeneration.

METHODS AND PATIENTS

From November 1993 through to May 1995 the macula of the affected eye was irradiated with 5 Gy for 12 patients and with 8 Gy for 34 patients. The radiotherapy was done ambulatorily by a linear accelerator 6 MeV during 4 consecutive days with daily 1.25 Gy and 2 Gy respectively. A "half beam technic" was used to protect the lens. Before the treatment, 6 weeks and 6 months later different parameters of the visual acuity were measured and a simultaneous Fluo- and ICG-angiography was done.

RESULTS

In the 5 Gy group, all the planned controls were done for 11 patients. 9 membranes were classic and 2 occult. After 6 months the vision in the distance remained the same in 7 cases, was better in 2 cases and worse in 2 cases. The size of the membrane increased in 10 cases and remained unchanged in 1 case. In the 8 Gy group, all the planned controls were done for 29 patients. 12 membranes were classic and 17 occult. The vision in the distance remained the same in 17 cases, was better in 4 cases and worse in 8 cases. The size of the membrane increased in 12 cases and there was no change in 17 cases.

DISCUSSION AND CONCLUSION

Exact comparisons between the 5 Gy and 8 Gy group are not possible because of the different composition of these groups. In no case were we able to note a reduction of the size of the membrane. Concerning the visual acuity, our results are better than the spontaneous evolutions described in the literature. Meanwhile, affirmations about possible stabilisation of the visual acuity are too early. A further study which is being done in our hospital may possibly bring new information.