Preventing Errors in IOL Calculation, Selection, and Insertion
The A-scan transducer is typically calibrated before use each day. Several scans are performed on each patient, and the measurements should cluster around a value, with a variance no greater than 0.2 mm. Both eyes are typically checked, especially if the first eye measures longer or shorter than anticipated. The difference in axial length between the eyes is usually no greater than 0.3 mm, unless there is a refractive or other anatomical reason. The patient name and K-readings, as well as AL and white-to-white measurements, are confirmed and documented. The lens power and the manufacturer’s model number are also specified. Lenses and their powers for placement in the capsular bag, sulcus, or anterior chamber angle are selected.
All this information, including the IOL calculations, should be double-checked by the surgeon on the day of surgery, and the implants located, verified, and set aside preoperatively. In the operating room, a “time-out” is performed with the entire surgical team before the procedure begins to confirm the patient’s identity, the operative eye, the procedure, and the IOL to be implanted.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.