Phase-Specific And Time-Dependent Alterations In Blink Kinematics Following Cataract Surgery: A Prospective Analysis Of Closing And Opening Dynamics

To evaluate time-dependent, phase-specific changes in blink kinematics after uncomplicated cataract surgery using high-speed frame-by-frame analysis and to assess the impact of surgery duration and eyelid speculum opening on postoperative blink dynamics.

Zonguldak Bulent Ecevit University, Ophthalmology Department, Zonguldak, Türkiye

Twenty-one patients undergoing unilateral cataract surgery were prospectively evaluated preoperatively and at postoperative day 1(POD1), week 1(POW1), and month 1(POM1). Blink recordings were obtained using a smartphone camera(240 fps) positioned directly in front of the patient for 3 minutes. The central 1-minute segment was analyzed frame-by-frame using Kinovea software to quantify blink rate(BR), mean closing velocity(MCV), and mean opening velocity(MOV). Changes(Δ) were calculated relative to baseline. Temporal changes were assessed using the Friedman test with Bonferroni-adjusted post-hoc analysis. Spearman correlation was used for secondary analyses.

The mean age was 64.43±6.69 years. At baseline, MCV was 65.93±22.31 mm/s, MOV was 25.62±5.56 mm/s, and mean BR was 9.5±3.63 blinks/min. Mean surgery duration was 9.14±0.85 minutes, and mean eyelid speculum opening was 1.58±0.10 cm. MCV showed a significant time-dependent alteration (ΔMCV: −18.22±23.82 at POD1, −0.14±21.41 at POW1, −10.29±27.33 at POM1; χ²(2)=7.714, p=0.021), with a significant difference between POD1 and POW1 (p<0.001). MOV did not change significantly over time (p=0.180). BR demonstrated marked temporal fluctuation (ΔBR: 1.17±6.62 at POD1, 6.83±4.49 at POW1, 0.17±1.92 at POM1; χ²(2)=21.462,p<0.001). Surgery duration and speculum opening showed no significant association with any blink parameter (all p>0.05). 

Cataract surgery induces phase-selective and time-dependent alterations in blink mechanics, with early reduction in closing velocity while opening dynamics remain preserved. This phase-specific pattern suggests differential involvement of the periocular musculature, particularly affecting the closing mechanism. The transient fluctuation in blink rate may indicate that mechanical factors contribute to early alterations in blink closing dynamics. These findings may be related to mechanical effects associated with longer eyelid speculum use and its duration, and further evaluation across a wider range of surgical durations is warranted.