Eyelid Blink Lagophthalmos and Blinking Velocity Changes After External Transcutaneous Dacrocystorhinostomy: A Prospective Study

Purpose: To investigate the changes in eyelid blinking dynamics after external dacryocystorhinostomy (DCR). Design: Prospective before-and-after study with follow-up. Methods: Patients undergoing external DCR surgery for primary acquired nasolacrimal duct obstruction were observed using high-speed videography that recorded eyelid blinking of both eyes for a total duration of 4 minutes at a rate of 120 frames per second. These recordings were taken before the surgical procedure, on postoperative day 3, and then at 1 week, 1 month, and 3 months after the DCR surgery. A total of 3 random blinks were selected and isolated from each video recording for data analysis. For each blink, lagophthalmos and eyelid blinking velocity were calculated for the operated eye, and their values were then compared with those calculated for the contralateral, nonoperated eye. Results: Data were obtained for 22 patients. Operated eyes showed large postoperative lagophthalmos on postoperative day 3, with a mean of 56.58% ± 52.63% of the palpebral fissure height. Gradual improvement of the lagophthalmos occurred over the next follow-up visits, and reached a mean of 31.24% ± 36.71% at follow-up visit 3 months postoperatively. The velocity of eyelid blinking showed a significant reduction for the operated eyes, with gradual improvement over 3 months. Conclusions: Postexternal DCR eyelid blinking changes included significant blink lagophthalmos with decreased velocity of eyelid blinking which gradually improved over the 3-month follow-up period. A longer follow-up period may be required to confirm if eyelid blinking lagophthalmos and velocity will return to baseline levels.