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 eye-lid 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 veloc-ity were calculated for the operated eye, and their values were then compared with those calculated for the con-tralateral, nonoperated eye.RESULTS: Data were obtained for 22 patients. Oper-ated 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 vis-its, 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 im-proved 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 base-line levels.(Am J Ophthalmol 2023;245: 81-85. (c) 2022 Elsevier Inc. All rights reserved.)