Serum melatonin levels following enucleation and transpupillary thermotherapy in patients with choroidal melanoma

Purpose: To study serum melatonin levels in patients with choroidal melanoma preoperatively and following enucleation and transpupillary thermotherapy. Methods: Forty patients with preoperative choroidal melanoma were included in the study. Of these, 15 patients underwent enucleation (group 1) and 25 patients received transpupillary thermotherapy (group 2). A further 20 patients without melanoma acted as age-matched controls. Serum melatonin levels were determined 1 day preoperatively, and at the first and sixth months postoperatively using ELISA. Results: Preoperative serum melatonin levels were highest in group 2 followed by group 1, but this was not statistically significant compared to controls. Postoperatively, a constant decrease of serum melatonin was observed in both groups after the first month, which reached statistical significance at the sixth month (P = 0.003). Also, a significant regression in tumour thickness was documented in group 2 (P = 0.003). Three patients in group 1 developed hepatic metastases. Conclusions: Patients with choroidal melanomas had higher levels of serum melatonin compared to individuals without tumours. Smaller tumours were associated with more elevated melatonin levels compared to larger tumours. Serum melatonin levels fell considerably following enucleation and transpupillary thermotherapy.