[Eye neoplasms].

AIMS: The effect of transpupillary thermotherapy (TTT) on human choroidal melanomas was investigated by means of histopathology. METHODS: Before enucleation TTT was performed in 11 eyes with a xenon are photocoagulator with a red filter or a diode laser at 810 nm. The exposure time was 1 minute; the estimated temperature at the top of the tumour was about 65 degrees C. RESULTS: Seven of 11 tumours developed necrosis to a maximum depth of 3.9 mm with a sharp demarcation between the necrotic and the viable part of the tumour. The depth correlated with penetration of heat into the tumour. Scattered small haemorrhages in the transitional zone between the necrotic and the viable part of the tumour were observed in three eyes but large haemorrhages were absent. Ocular media were not affected owing to the low rate of absorption of radiation at 810 nm. TTT did not cause significant scleral damage. Intrascleral tumour cells with a viable appearance were observed in one eye, where the tumour was almost totally necrotic. CONCLUSION: Results show that TTT has potential as a conservative therapeutic treatment for choroidal melanomas.

Choroid Neoplasms↗

PubMed1997

Lack of correlation between the location of choroidal melanoma and ultraviolet-radiation dose distribution.

Ocular melanomas arise from the choroid. The results of our study of a total of 92 ocular melanomas would indicate that there is no preferential location for tumors on the eye. We estimated the ultraviolet (UV) radiation dose distribution using data available in the literature. We then compared tumor location and UV-radiation dose distribution. UVC and UVB do not reach the choroid, and UVA is filtered by the cornea and the lens. Only a small percentage of the incoming rays reach the posterior and inferior part of the retina, but none reach the superior and anterior part of the eye. We concluded that it is therefore very unlikely that UV-radiation exposure is responsible for choroidal melanoma.

Choroid Neoplasms↗