INDICATORS OF PATIENT SUITABILITY FOR TOPICAL ANESTHESIA

Purpose: To determine whether a patient's suitability for phacoemulsif ication under topical anesthesia can be predicted preoperatively by th eir performance during tonometry and A-scan. Setting: Whipps Cross Hos pital Ophthalmology Department, London, England. Methods: Fifty consec utive patients who were considered suitable for phacoemulsification we re selected for the study. Using a scoring system we devised, observer s assessed the patients for the ease with which intraocular pressure a nd axial length were measured. These scores were compared with an asse ssment of how well they tolerated phacoemulsification under topical an esthesia. Correlation between the scores was measured with Spearman's rank correlation coefficient, Kendall's rank correlation coefficient, and the Goodman-Kruskal gamma statistic. Results: Phacoemulsification and posterior chamber intraocular lens implantation were completed in all patients. Statistical analysis showed that tonometry and A-scan sc ores correlated highly with surgery scores. Age was also a significant variable in predicting the surgery score. A significant discrepancy b etween tonometry and A-scan and surgery scores was found in only one p atient, and it was noted that he was one of the youngest patients in t he study. Conclusion: How well a patient performs during tonometry and A-scan was a good predictor of how well he or she tolerated having ph acoemulsification under topical anesthesia. The decision about type of anesthesia should, however, also involve other factors, including com munication, cooperation, and the age of the patient.