The Nallasamy formula was developed at University of Michigan's Kellogg Eye Center in the lab of Dr. Nambi Nallasamy. The Nallasamy formula leverages the latest machine learning techniques and data from the Sight Outcomes Research Collaborative (SOURCE) repository to generate highly accurate predictions of postoperative refraction after cataract surgery.

The Nallasamy formula outperforms other leading formulas and its performance is documented here: link to preprint. In particular, the Nallasamy formula was shown to outperform Barrett Universal II across short, medium, and long eyes. More detail regarding the performance of the Nallasamy formula can be found here: link to medrxiv paper.

The Nallasamy formula utilizes patient age, gender, axial length, keratometry, anterior chamber depth, central corneal thickness, lens thickness, and horizontal white-to-white distance to compute predictions of postoperative refraction. It is currently optimized for the Alcon SN60WF intraocular lens, but we expect to provide predictions for other IOLs in the near future.

Dr. Nallasamy is a cornea and cataract surgeon at Kellogg Eye Center whose lab develops machine learning tools to address clinically-related challenges using large datasets. Tingyang Li, a PhD student in Dr. Nallasamy's lab, has been instrumental in the development of the formula.

The formula provided here is the intellectual property of the Nallasamy Lab and the Regents of the University of Michigan. The calculator on this website is provided as is, and all responsibility for clinical decision-making relies solely with the treating physician.