[Effectiveness of topical anesthesia enhanced by sedation and analgesia for cataract surgery]

To compare the efficacy of topical anesthesia and retrobulbar anesthesia for cataract surgery by lens emulsification.

Two hundred sixty patients were randomized to two groups in this open clinical trial. Patients with cataracts that could not be treated by lens emulsification were excluded. Group I patients (n = 129) received 0.5% tetracaine drops and intravenous fentanyl and propofol, along with continuous sedation. Group II patients (n = 131) received 2% lidocaine in the retrobulbar space and hypnotic doses of intravenous propofol before retrobulbar injection. The anesthesiologist evaluated anesthesia negatively if SpO2 was 90% and either heart rate or blood pressure varied more than 20%. The ophthalmologist evaluated anesthesia negatively if the eye did not remain fixed in the center, if blepharospasm appeared or if the anterior chamber of the eye collapsed. The patient reported the intensity of any discomfort experienced on a six-point scale. Anesthesia was determined to be effective when favorable evaluations were given by both the anesthesiologist and the ophthalmologist and when no significant discomfort (first three points on the scale) was reported by the patient. The two treatment groups were compared using a single and multiple factor analysis.

Group II experienced significantly fewer instances of ineffective anesthesia than did group I (8 versus 22) and fewer negative evaluations by the ophthalmologists (7 versus 18). More patients in group I reported discomfort than in group II (46 versus 9), although most complaints were of slight discomfort. Multiple factor analysis showed that a patient in group I had 4.64 more chances of experiencing ineffective anesthesia.

Topical anesthesia is less effective than retrobulbar anesthesia for cataract surgery by lens emulsification.