IOLzero: A Web Application for Calculations, Outcomes Tracking and Optimization in Cataract Surgery

Abstract

INTRODUCTION: Cataract surgery results can be improved by a data-driven approach: outcome tracking (visual acuity, residual refraction, and complications) as well as optimization (formulas, constants, SIA, ...). Most health record systems in ophthalmology are not tailored to these specific tasks. Alternative software tools that implement some of these analyses are usually commercial in nature and/or locked to a specific biometer analysis pipeline. Many of these calculations are complex and error prone and some of them even impossible to replicate in standard spreadsheets. This hinders the adoption of outcome tracking and optimization by many cataract surgeons worldwide.

MATERIAL AND METHODS: Development of a free web application, named IOLzero (available at https://iolzero.com), using a Python backend, optimized for both desktops, tablets and smartphones. The web application is seamlessly updated with new tools, IOLs and biometers. The surgeon can define his default preferences (preferred incisions, IOL models, formulas, ...). All analysis and calculations follow literature standards, which are properly referenced. Patient identifying data is processed locally (never leaves the browser), ensuring privacy. Individual case data can be exported to conventional text-based electronic health records by user-defined templates. All data can be exported to spreadsheets for further analysis by the surgeon.

RESULTS AND DISCUSSION: The “Patients” module implements a cataract focused registry with preoperative biometry, surgical details, and a final post-operative evaluation. The “Analysis” module can evaluate clinical outcomes (visual acuity, complications, and residual re- fractive errors), formula comparison (prediction errors with graphical evaluation), formula opti- mization (A- constant optimization and mean target optimization for unpublished formulas) and SIA calculation (by laterality, incision type and location). Auxiliary calculators for IOL calcula- tion (SRK/T, Holladay 1, Haigis and HofferQ), Wang-Koch optimization for axial myopia, Cooke- modified axial length for sum-of-segments approximation, second eye refinement, pediatric IOL calculator, multi-device keratometry vectorial averaging, sulcus power adjustment, among other tools, are also available on IOLzero.

CONCLUSION: We believe IOLzero is a valuable tool for cataract surgeons interested in improving their results by a systematic process of data analysis and optimization, while not being locked down to a commercial solution or a specific biometer.