Intraoperative Biometry - A Holy Grail? Trends In Modern Cataract Surgery

The purpose of this study was to determine if intraoperative aphakic biometry done for patients with mature or brown cataracts predicted better refractive outcomes than with patients undergoing only one set of preoperative biometry readings that utilised A scan readings.

This was done over a period of 4 months in a tertiary care center in New Delhi, India

98 patients were included in this study and evaluated thoroughly. The patients included were of cataracts with nuclear sclerosis grade >4 or mature cataracts where the preoperative biometry readings using the IOL master were variable. The axial length was then calculated using A scan immersion biometry. After entering all other values like the anterior chamber depth, lens thickness, and white-to-white measurements, the IOL power was calculated using Barett Universal II formula. Once phacoemulsification was done, the eye was left aphakic and wounds hydrated,and biometry was repeated with the IOL master in aphakic mode. A single surgeon performed all the surgeries and a  single type of monofocal IOL was inserted for all patients. 

The final refractive outcome of patients measured after 2 weeks of surgery was significantly better after measurement with intraoperative biometry in aphakic mode as compared to the biometry performed preoperatively. There were fewer refractive surprises, 98% patients achieved a target refraction within + 0.50 D using this method. 

In this day and age, patients undergoing cataract surgery deserve the best refractive outcome. Biometry in patients with dense nuclear cataracts is still a problem today, with frequent refractive surprises following cataract surgery, some even requiring IOL exchange. This procedure eliminated the need for any IOL exchange that would have been required for these errors.