Most lacrimal duct obstructions are total, unilateral and located in Krause's valve, study finds

Lacrimal duct obstructions typically block the entire duct, are unilateral and are located in Krause's valve, according to a retrospective study of 1,000 eyes.

Fabiano C. Francisco of Federal University in Rio de Janeiro, Brazil, and colleagues reviewed diagnoses of 500 patients treated at a single center in Brazil. They reported their results in the January issue of the British Journal of Ophthalmology.

According to Dr. Francisco and colleagues, 121 patients were men and 379 were women. Ages ranged from 2 to 93 years. The authors found 352 cases of duct obstruction — 298 unilateral and 54 bilateral. Obstructions blocked the whole duct in 378 cases and were partial in 28 cases, the authors said.

The majority of obstructions were found at Krause's valve; women were significantly more likely to have obstructions there. Men were more likely have obstructions in Hasner's valve, the authors said.