[Improvement of optical system for better visibility and intensity of radiation during transpupillary thermotherapy].

PURPOSE

Coagulation is the most serious complication of transpupillary thermotherapy(TTT) for choroidal neovascularization (CNV). To detect coagulation quickly, it is important to have good visibility of the fundus during exposure. With the existing laser optical system using a half mirror, the fundus image is dim, and coagulation is difficult to detect. We have improved the laser optical system for TTT. The purpose of this study was to improve the optical system and to estimate the usefulness of our new system compared with the current optical system.

METHOD

We exchanged the half mirror used in the existing TTT optical system to a split mirror. The illumination intensities were measured and the visibility of fundus images were compared.

RESULTS

Illumination intensity was increased by means of the split mirror of the slit-lamp for the TTT laser optical system. The fundus image became brighter and clearer.

CONCLUSIONS

Improvement of the optical system was useful for safe and effective treatment of cases of CNV with an indication for TTT.