Purpose. To evaluate the efficacy and clinical practicability of topical anesthesia in comparison with retrobulbar anesthesia for penetrating trabeculectomy.

Methods. The prospective single-surgeon clinical interventional trial included 20 consecutive patients, who were randomly distributed into a topical anesthesia group (n=10) and a retrobulbar anesthesia group (n=10). In the topical anesthesia group, patients received preoperatively oxybuprocaine 0.4% eye drops and cocaine hydrochloride eye drops 10%. The patients of the retrobulbar group received 5 ml mepivacaine 2% injected into the retrobulbar space. To assess intraoperative pain, each patient was asked immediately after surgery to quantitate his/her pain using a 10-point pain rating scale.

Results. The topical anesthesia group and the retrobulbar anesthesia study group did not vary significantly in duration of surgery (21.5-3.37 min vs 20.2-4.46 min, P=0.31), preoperative intraocular pressure (32.2-14.62 mmHg vs 30.6-12.33 mmHg, P=0.22), postoperative intraocular pressure (8.0-4.47 mmHg vs 9.12-3.13 mmHg, P=0.64), subjective pain score by the patient (2.25-1.23 relative units vs 2.33-1.08 relative units (P= 0.71), and practicability score by the surgeon (2.24-1.76 vs 2.56-1.58, P=0.82).

Conclusions. In view of its clinical feasibility and its minimally invasive character, topical anesthesia may be an option for penetrating trabeculectomy.