Routine Preoperative Testing Before Cataract Surgery

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Schein OD, Katz J, Bass EB, et al. The value of routine preoperative medical testing before cataract surgery. N Engl J Med 2000; 342:168-75.


CLINICAL QUESTION: Does routine medical testing before cataract surgery reduce the rate of perioperative complications?

BACKGROUND: Although routine medical tests (serum chemistries, complete blood counts, and electrocardiograms) are commonly ordered before elective surgery, their value is questionable. This study prospectively analyzes the usefulness of routine medical testing before cataract surgery.

POPULATION STUDIED: Patients aged older than 50 years presenting to one of 9 clinical centers for elective cataract surgery were enrolled (18,189 patients and 19,557 cataract surgeries). Study centers included private, academic, and community-based hospitals. Exclusion criteria were minimal; only patients who did not speak English or Spanish, who were scheduled for general anesthesia, who had a history of a myocardial infarction in the preceding 3 months, or who had routine preoperative medical testing 28 days before enrollment were excluded.

STUDY DESIGN AND VALIDITY: This is a randomized prospective trial. Patients were given a letter to take to their primary care physician that explained the study and whether the physician was to order routine tests. One group had a battery of routine preoperative tests, and the other did not. All patients had a complete history taken and a physical examination performed before surgery. Adverse medical events were recorded on the day of surgery (intraoperative) and for 1 week following surgery (postoperative). Each adverse event was independently documented by 2 investigators and confirmed in a blinded fashion. This study is elegant in design and execution. Patient representativeness and generalizability were addressed in the study design, and crossovers were appropriately analyzed by intention to treat. The authors were specific in their aim to maximize the generalizability of their results.

OUTCOMES MEASURED: The primary outcomes measured were recorded as adverse events. These included myocardial infarction/ischemia, congestive heart failure, arrhythmia, hypertension, hypotension, cerebral infarct/ischemia, bronchospasm, respiratory failure, hypoglycemia, diabetic ketoacidosis, and oxygen desaturation.

RESULTS: Only 5.9% of the patients crossed over from one group to another, and most of those were from routine testing to no testing. There was no difference between the rates of intraoperative events in the routine testing (19.2 events per 1000 operations) and the no-testing (19.7 events per 1000 operations) groups. There was also no significant difference between the rates of postoperative events in the routine testing (12.6 events per 1000 operations) and no-testing (12.1 events per 1000 operations) groups. Subgroup analyses revealed no benefit of routine testing among groups stratified according to age, ethnicity, sex, or health status.


Routine preoperative medical testing before elective cataract surgery does not improve patient outcomes but does increase the cost of care. It contributes nothing that cannot be elicited by a careful medical history and physical examination. This confirms the age-old dictum: Do not order a test unless you know what you are going to do with the result. In this situation, physicians should rely less on technology and more on clinical skills.

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