Are routine preoperative medical tests needed with cataract surgery?: Study of visual acuity outcome

Purpose. The aim of this prospective randomized clinical trial was to investigate whether routine medical testing before cataract surgery reduced the rate of ocular surgical complications and to study its impact on visual acuity outcome. Methods. The study was carried out in an academic medical center in Brazil, at State University of Campinas, between 10 February 2000 and 10 January 2001. The scheduled cataract operations were randomly assigned to one of two groups: 1) to be preceded by routine medical testing (the "routine-testing group") or 2) not to be preceded by routine medical testing (the "selective-testing group"). If the patient was assigned to the selective-testing group, it was requested that no preoperative testing be performed unless the patient presented with a new or worsening medical problem that would warrant medical evaluation with testing. In the case of patients assigned to the routine-testing group, three tests were requested: a 12-lead electrocardiogram, a complete blood count, and measurements of serum glucose. Ocular surgical complications, preoperative and postoperative best-corrected visual acuity were recorded on a standardized form. Results. The sample of 1025 patients scheduled to undergo cataract surgery was comprised of 512 assigned to the routine-testing group and of 513 assigned to the selective-testing group. The two groups had similar proportions of operations canceled and not subsequently rescheduled, 2% in each group. The cumulative rate of ocular surgical complications was similar in the two groups, 20.5% in the routine-testing group and 19.3% in the selective-testing group (p = 0.624). The preoperative and the postoperative best-corrected visual acuity were similar in both groups (p = 0.999 in the former and p = 0.664 in the latter). Conclusions. The results of this study suggest that routine medical testing before cataract surgery did not reduce the rate of ocular surgical complications and did not influence visual acuity outcome.