Mechanism of tear flow after dacryocystorhinostomy and Jones' tube surgery
N. A. Nik, J. J. Hurwitz and H. C. Sang
In the 42 patients (84 eyes) in this study, 32 eyes had
dacryocystorhinostomy (DCR), 15 had Jones' tube insertions, and the
remaining 37 were considered controls. All patients were studied using
nuclear scanning with computer interfacing quantitative lacrimal
scintillography to determine the effects of blinking, respiration, and
gravity on their functioning. Tears flowed through DCR openings faster than
through the systems of normal patients. Patients with Jones' tubes
demonstrated slower flow than in normal patients. The effect of respiration
on tear flow was minimal, but blinking and lid function were important.
Patients with eyelid laxity may show decreased flow even if the DCR and
Jones' tubes are functional.
