The effects of radiotherapy on the nasolacrimal system as evaluated by dacryoscintigraphy.

By utilizing 61 lacrimal scans, 26 patients who had received radiotherapy for inner canthus and lid lesions were evaluated. Results indicate that the membranous lacrimal passages are relatively immune to radiation therapy. Although dacryoscintigraphy did not delineate the anatomical features quite as well as contrast dacryocystography, it yielded very useful information about flow mechanisms and tear transit times. The study is rapid, simple, non-hazardous, and particularly helpful in documenting the status of the lacrimal drainage system before and after radiotherapy to the inner canthus region.