Subconjunctival anaesthesia using cocaine or mepivacaine for cyclocryotherapy in advanced glaucoma

Abstract

Retro- or peribulbar anaesthesia are the standard procedures for cyclodestructive surgery. Because these methods of anaesthesia may further compromise optic nerve function, especially in advanced glaucoma, subconjunctival anaesthesia was evaluated as an alternative procedure in cyclocryotherapy. 1. To evaluate the current methods of anaesthesia a questionnaire was sent to all University Eye Clinics in Germany in 2001. 2. A prospective, consecutive study concerning cyclocryotherapy in advanced glaucoma was started using subconjunctival anaesthesia with 5 % cocaine or, alternatively, 2 % mepivacaine in 25 eyes of 25 patients in each group. Pain during cyclocryotherapy was recorded using a 10-point rating-scale (1 = no pain to 10 = intolerably severe pain) and adverse events were also recorded. 1. 88.6 % of the University Eye Clinics in Germany replied to our questionnaire. In 2001 cyclocryotherapy was performed in 80.6 % of the University Eye Clinics in Germany (Tübingen not included), 16.1 % among them solely used cyclocryotherapy for the treatment of advanced glaucoma. 2. Using 5 % cocaine for subconjunctival anaesthesia - 92 % of patients experienced no pain and 8 % of patients reported very mild pain during cyclocryotherapy. One patient reported nausea, 4 patients mouth dryness. After anaesthesia with mepivacaine - 80 % experienced no pain, 12 % very mild pain, and 8 % mild pain. There were no systemic side effects. Most of the patients experienced no pain during cyclocryotherapy using subconjunctival anaesthesia with cocaine or mepivacaine. Therefore, risks and side effects of retro- or parabulbar anaesthesia can be successfully avoided by this simple modification.