During general anesthesia, the eye's natural protective reflexes are suppressed, which can lead to corneal drying and injury. To prevent this, anesthesiologists routinely tape the eyelids closed. In many centers, lubricant eye drops are also applied in addition to taping, but whether this adds meaningful protection is unclear.This study will compare two approaches to eye protection during general anesthesia lasting 30 minutes to 3 hours: eyelid taping alone versus eyelid taping combined with lubricant eye drops. Two hundred adult patients undergoing elective, non-eye surgery in the supine position will be randomly assigned to one of the two groups.The main outcome is corneal surface damage measured by a standardized fluorescein staining score (NEI scale, 0-15) assessed by a blinded evaluator one hour after surgery. Secondary outcomes include tear film stability (TBUT), tear production (Schirmer test), patient-reported eye symptoms at 2 and 24 hours after surgery, and a cost-effectiveness analysis comparing the two approaches.If taping alone proves equally effective, routine use of lubricant eye drops may be unnecessary, reducing costs without compromising patient safety.

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.

Inclusion Criteria:

• Age 18 to 75 years
• ASA physical status I or II
• Scheduled for elective non-ocular surgery under general anesthesia
• Expected anesthesia duration between 30 and 180 minutes
• Supine surgical position
• Ability to provide written informed consent

Exclusion Criteria:

• Preoperative corneal epithelial defect, keratitis, conjunctivitis, conjunctival hyperemia, or chemosis
• Known ocular surface disease (dry eye syndrome, Sjögren syndrome, rheumatoid arthritis, systemic lupus erythematosus, or other systemic conditions associated with ocular surface involvement)
• Use of topical or systemic medications known to affect tear production within the past 30 days
• History of ocular surgery or ocular trauma
• Contact lens use
• Planned head and neck surgery
• Prone or lateral decubitus surgical position
• Patients requiring rapid sequence induction
• Inability or refusal to provide written informed consent

The primary outcome (NEI corneal fluorescein staining score) is assessed by an independent evaluator who is blinded to group allocation throughout the study. Participants are blinded to group assignment as the intervention is applied under general anesthesia. The treating anesthesiologist (care provider) is not blinded due to the nature of the intervention.