Diode-light transillumination for ophthalmic plaque localization around juxtapapillary choroidal melanomas.

Purpose: An evaluation of plaque-mounted diode-light transillumination (DLT) for localization of episcleral plaques beneath juxtapapillary tumors.

Methods And Materials: Two patients scheduled for radiotherapy for juxtapapillary melanomas were offered DLT as an additional method of ophthalmic plaque localization. Plaques were constructed by affixing 4 non-heat producing, light-emitting diodes with their apertures flush with the episcleral outer surface of the plaque's rim. Bio-implantable epoxy was used to encapsulate the electronic components. Then the plaques were loaded with 103Pd seeds. After the eye-plaques were sewn to the episclera covering the base of the intraocular tumors; the diode-lights were illuminated, viewed and recorded. Photodocumentation of the relative position of the 4 lights around tumor's base was obtained in both cases.

Results: Digital images of plaque-mounted diode retro-transillumination were obtained. No evidence of diode-light toxicity was noted. Both tumors were found to be covered by the ophthalmic plaques.

Conclusion: Juxtapapillary tumors are often difficult or impossible to visualize with standard transillumination techniques and have been associated with poor local control rates. We have developed plaque-mounted DLT in an effort to improve ophthalmic plaque localization. Retrobulbar transillumination was viewed by indirect ophthalmoscopy and recorded with video-imaging. This technique provides unique photographic documentation of episcleral plaque localization beneath juxtapapillary tumors.