Eyelid Taping Alone Versus Taping With Lubricant Eye Drops for Perioperative Corneal Protection

Corneal abrasion is the most common perioperative ocular complication during non-ocular surgery under general anesthesia, with reported incidences of up to 44% in unprotected eyes. General anesthesia suppresses the orbicularis oculi muscle tone, blink reflex, Bell phenomenon, and lacrimal secretion, leaving the corneal surface vulnerable to exposure keratopathy. Hypoallergenic eyelid taping has become the standard preventive measure, reducing abrasion rates to less than 1%. However, many anesthesiologists additionally instill lubricant eye drops or ointments, despite limited evidence supporting this practice over taping alone.

Anesthesia duration is an independent and continuous risk factor for corneal injury, with each 10-minute increment associated with a 5% increase in risk (OR 1.05; 95% CI 1.03-1.07). Surgeries lasting 3 hours or more carry a 4.6-fold higher risk compared to shorter procedures. The present study focuses on the 30-minute to 3-hour window, which represents the majority of elective surgical caseloads and has not been directly studied with objective corneal outcome measures.

This is a prospective, randomized, assessor-blinded, two-arm parallel-group clinical trial conducted at Fatih Sultan Mehmet Training and Research Hospital, Department of Anesthesiology and Reanimation. Patients will be randomized using stratified block randomization (strata: age \<50 vs ≥50 years; anesthesia duration 30-90 vs 90-180 minutes) with randomly varied block sizes of 2, 4, and 6, generated via www.sealedenvelope.com and allocated through sequentially numbered opaque sealed envelopes.

Following anesthesia induction and loss of lid reflex, all patients will receive hypoallergenic surgical tape applied horizontally across the tarsal plate of both eyes. Patients in Group 1 (Tape Only) will receive no additional intervention. Patients in Group 2 (Tape + Drops) will receive preservative-free lubricant eye drops (carboxymethylcellulose 0.5%, single-dose vial) instilled into both conjunctival fornices prior to taping.

The primary outcome, corneal fluorescein staining score (NEI scale: 5 regions × 0-3, total 0-15 per eye), will be assessed by a blinded independent evaluator (assessor) at postoperative hour 1 in the post-anesthesia care unit. Secondary outcomes include: Schirmer I test (mm/5 min) and TBUT (seconds) measured preoperatively and postoperatively; patient-reported ocular symptom VAS scores (burning, stinging, blurred vision, each 0-10) at postoperative hours 2 and 24; conjunctival hyperemia score; and a cost-effectiveness analysis including material cost per patient and total projected institutional expenditure.

Sample size was calculated based on the primary binary outcome (NEI score \>0 vs. =0). Assuming a 25-30% incidence of any corneal staining in the tape-alone group and 10-12% in the tape-plus-drops group, with two-sided alpha of 0.05 and 80% power, a minimum of 74 patients per group is required. Adding 10% for dropout, the total sample size is 200 patients (100 per group), calculated using G\*Power 3.1.

The study will be conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. Written informed consent will be obtained from all participants prior to enrollment.

• Tear Film Break-Up Time (TBUT) [Срок оценки: Preoperative baseline and 1 hour after end of anesthesia]
• Schirmer I Test [Срок оценки: Preoperative baseline and 1 hour after end of anesthesia]
• Patient-Reported Ocular Symptom VAS Score [Срок оценки: 2 hours and 24 hours after end of anesthesia]
• Conjunctival Hyperemia Score [Срок оценки: 1 hour after end of anesthesia]
• Cost-Effectiveness Analysis [Срок оценки: At time of intervention (intraoperative)]