Indicators of patient suitability for topical anesthesia

To determine whether a patient's suitability for phacoemulsification under topical anesthesia can be predicted preoperatively by their performance during tonometry and A-scan.

Whipps Cross Hospital Ophthalmology Department, London, England.

Fifty consecutive patients who were considered suitable for phacoemulsification were selected for the study. Using a scoring system we devised, observers assessed the patients for the ease with which intraocular pressure and axial length were measured. These scores were compared with an assessment of how well they tolerated phacoemulsification under topical anesthesia. Correlation between the scores was measured with Spearman's rank correlation coefficient, Kendall's rank correlation coefficient, and the Goodman-Kruskal gamma statistic.

Phacoemulsification and posterior chamber intraocular lens implantation were completed in all patients. Statistical analysis showed that tonometry and A-scan scores correlated highly with surgery scores. Age was also a significant variable in predicting the surgery score. A significant discrepancy between tonometry and A-scan and surgery scores was found in only one patient, and it was noted that he was one of the youngest patients in the study.

How well a patient performs during tonometry and A-scan was a good predictor of how well he or she tolerated having phacoemulsification under topical anesthesia. The decision about type of anesthesia should, however, also involve other factors, including communication, cooperation, and the age of the patient.