Pin Point Anesthesia with 4% Lidocaine in Cataract Surgery

The increase of preoperative intraocular pressure by anesthetic is a troublesome problem in pin point anesthesia. In order to evaluate the efficacy of 4% lidocaine with less volume in pin point anesthesia 60 cataract surgeries were performed with different anesthetic dosage divided into 3 groups and compared preanesthetic with postanesthetic intraocular pressure and pain score(1; mild, 2; moderate, 3; severe). In the group 1(20 eyes), using 0.3ml of lidocaine, intraocular pressure change from preanesthesia to postanesthesia was 11.83+/-3.44mmHg to 12.19+/-3.27mmHg and there was no statistical significance(p=0.1025). In the group 2(20 eyes), using 0.4ml of lidocaine, intraocular pressure change was 11.53+/-3.22mmHg to 12.33+/-2.91mmHg and was statistically significant(p=0.0028). In the group 3(20 eyes), using 0.5ml of lidocaine, intraocular pressure change was 12.07+/-2.34mmHg to 13.41+/-2.51mmHg and was statistically significant(p=0.0000). Pain score in 3 groups were 1.60+/-0.17, 1.55+/-0.14, 1.35+/-0.11 and there was no statistical difference in 3 groups(p=0.5192). With these results, pin point anesthesia using 0.3ml of 4% lidocaine might be another useful local ocular anesthesia for the routine cataract operation.

Comparison on Preoperative Intraocular Pressure Elevation after Performing between Pin Point Anesthesia and Retrobulblar Anesthesia

The importance of the preoperative intraocular pressure cannot be overemphasized for cataract operation. We compared the preoperative intraocular pressure between the conventional retrobulbar anesthesia technique and the pin point anesthesia technique with different anesthetic dosage using tono-pen in 23 patients(41 eyes) divided into 4 groups. In the 1st group(10 eyes), after conventional retrobulbar injection was performed using 3ml of 2% lidocaine, digital massage was done for 10 minutes. In 2nd group(13 eyes), 2% lidocaine 1.0ml was injected into subtenon's space(true muscle cone) through the small hole in the superior temporal quadrant 8mm posterior to limbus using specially designed blunt, curved cannula without any method to decrease the intraocular pressure (pin point anesthesia). In the 3rd group(13 eyes), and 4th group(5 eyes), same procedure was performed as 2nd group using 0.75ml and 0.50ml of 2% lidocaine respectively. As a results, in 1st group, average intraocular pressure was decreased around 5.6mm Hg after digital massage. In the 2nd, 3rd, and 4th group, preoperative intraocular pressure increased by 2.2, 0.8, and 0.5mmHg. As comparison of three group of the pin point anesthesia, in the 2nd group, sometimes there were mild chemosis, in the 4th group, often discomfort, in contrast, in 3rd group there were no chemosis, pain or discomfort. As a conclusion we want to recommend a pin poit anesthesia using 0.75ml of 2% lidocaine for the routine cataract operation.