Materials and Methods: Twenty-eight patients with bilateral diffuse diabetic macular oedema who were resistant to previously applied grid laser photocoagulation were recruited into the study. Each patient underwent intravitreal injection of 4 mg triamcinolone acetonide under topical anesthesia for one eye and subconjunctival anesthesia for the other eye by using 4% lidocaine. Patients were asked to grade the pain they experienced during administration of both anesthesia and intravitreal injection by using 4-point pain scale: from 0=no pain to 3=severe pain. Complications developed during both procedures were also recorded.

Results: Of 28 patients 15 were female and 13 were male. Mean age was 59 (44-71 years). Intravitreal injection was performed successfully in all patients. The mean pain score experienced during subconjunctival injection of lidocaine was 0.78, whereas no anesthesia related pain was reported in topical group. The mean pain score experienced during intravitreal injection was 1.64 in topical and 0.85 in subconjunctival group (p<0.001). There was no statistically significant difference between scores of topical (0.32) and subconjunctival (0.25) groups according to the eye movements observed during injection (p>0.05). Nine eyes (32%) developed subconjunctival haemorrhage after subconjunctival injection, whereas no anesthesia related complication developed in topical group. Subconjunctival haemorrhage was also observed in 5 eyes (18%) in topical group and in 11 eyes (40%) in subconjunctival group (p>0.05) after intravitreal injection.

Conclusion: Although both topical and subconjunctival anesthesias provide adequate anesthesia for intravitreal injection, subconjunctival injection of lidocaine appears to be more effective than topical administration. Nevertheless, subconjunctival injection is more painful than topical application and leads to subconjunctival haemorrhage in some eyes. Therefore, topical anesthesia may be more suitable for daily practice. Subconjunctival anesthesia may be used in cases of relatively painful eyes such as endophtalmitis and early postoperative eyes. Keywords : Intravitreal injection, topical anesthesia, subconjunctival anesthesia.