This study is conducted to evaluate the effects of preoperative oral pregabalin on postoperative pain and analgesic requirements in patients undergoing DCR surgery. The primary outcome is to compare pain scores by visual analogue scale (VAS). Secondary outcomes are the time of first analgesic request, the total analgesic requirements during the postoperative 24 hours, the incidence of PONV, in addition to effect on hemodynamic parameters between the two groups.

External dacryocystorhinostomy (DCR) is still considered the golden standard for lacrimal surgery. It is a bypass technique which creates an anastomosis between the lacrimal sac and the nasal mucosa through a bony ostium via an external skin incision. External DCR can be completed under either local or general anesthesia. It is a painful surgical procedure that involves intra- and extra-ocular dissection, with a high prevalence post-operative nausea and vomiting (PONV). So, it is necessary to ensure a stress-free peri-operative period with adequate pain relief and a low incidence of PONV after DCR surgery.

Pregabalin is a lipophilic gamma-amino-butyric acid (GABA) analogue that binds to the voltage-gated calcium channels. It reduces the excitability of the dorsal horn neurons after tissue damage. It has anticonvulsant, anxiolytic and sleep-modulating properties. It was shown to be effective in several models of neuropathic pain, incisional injury, and inflammatory injury.

Preoperative administration of pregabalin is supposed to be a promising technique of enhancing postoperative pain control and reduction in postoperative opioid consumption.

This study is a prospective randomized double-blind clinical trial included 100 ASA I and II patients of both sex with age between 18 and 65 years old, who are planned for elective DCR surgery under general anesthesia in Mansoura University ophthalmology center. Informed written consent is obtained from all subjects in the study after ensuring confidentiality. Details of the anesthetic technique and the study protocol are clarified to the entire involved cases. Patients are randomly assigned to two equal groups according to computer-generated randomization schedule.

A prospective analysis of the collected data is performed using the Statistical Package for the Social Sciences (SPSS) program for Windows (version 22). All data are considered statistically significant if P value is ≤ 0.05.

Inclusion Criteria:

• American Society of Anesthesiology (ASA) I and II patients.
• Scheduled for DCR surgery.

Exclusion Criteria:

• Patient' refusal of consent.
• Mental, psychological or neurological disorders.
• Patients with history of drug or alcohol abuse.
• History of know sensitivity to the used drugs.
• Bleeding or coagulation diathesis.
• Obese patients (body mass index (BMI) < 35).
• Pregnancy and lactation.