MOUSSA FORMULA

Research Tools

Research Suite & Constant Optimiser

This powerful research tool allows for bulk processing of biometric data using a downloadable Excel template. It performs two main functions:

• Lens Constant Optimisation: Calculates optimised, zero-MPE (Mean Prediction Error) lens constants for various IOL formulas based on your postoperative refractive outcomes. Supported formulas for optimisation include: SRK/T, Hoffer Q, Holladay 1, Haigis (Single & Triple parameter), and the Moussa Formula.
• Bulk Refraction Prediction: Calculates the predicted postoperative refraction for your dataset using the optimised constants for the internal formulas, and includes comparisons against any user-provided formula predictions found in your spreadsheet.

The tool generates comprehensive output including detailed Excel spreadsheets and publication-quality figures analysing prediction errors and accuracy across different axial length groups.

Note: None of the data submitted via file upload is saved or stored on our servers after processing.

About the MOUSSA FORMULA

The MOUSSA FORMULA is a novel IOL power calculation formula developed by Mr. George Moussa. It utilizes a purely data-driven approach, derived from a complex mathematical expression trained using machine learning techniques on a large dataset of over 6,000 real-world eye measurements.

Unlike traditional vergence formulas that often rely on estimating effective lens position (ELP), the MOUSSA FORMULA directly predicts postoperative refraction using key biometric inputs including Axial Length, Keratometry, Anterior Chamber Depth, Lens Thickness (optional, calculated if missing), Age, and Gender.

Validation & Performance:

In independent validation studies involving diverse patient cohorts, the formula has demonstrated highly competitive accuracy:

• Testing on 769 eyes across two separate clinical centers, where full biometric data including Lens Thickness was available, showed the MOUSSA FORMULA achieved the lowest Mean Absolute Error (MAE), Standard Deviation (SD) of prediction error, and Root Mean Square Error (RMSE) compared to several other modern IOL calculation formulas.
• Further validation on approximately 400 eyes from a third center, where Lens Thickness was not available (and thus internally calculated by the formula), also confirmed its robust performance.

While potentially higher accuracy could be achieved by optimising multiple lens constants, a single optimisable Lens Factor (LF) is used in the online calculator and research suite for simplicity and easier integration with existing clinical frameworks and IOL constants databases.

This online calculator provides an interface to apply the formula for individual patient calculations and research purposes. Continuous validation and potential refinements based on larger datasets are ongoing.

Disclaimer: Users should always exercise clinical judgment and cross-reference results with established methods when making decisions for patient care.

Formula Version: 1.0

Contact

For questions regarding the MOUSSA FORMULA, feedback on this calculator, collaboration inquiries, or clinical consultancy, please contact:

Mr. George Moussa MBChB FRCOphth

Consultant Ophthalmic Surgeon
Sub-specialty: Vitreoretinal Surgery, Cataract Surgery
Special Interests: Refractive Outcomes, Artificial Intelligence & Data Science in Ophthalmology

With over 70 peer-reviewed publications and extensive experience in complex cataract and retinal surgery.

Clinical Affiliations:

• Manchester Royal Eye Hospital (MREH), Manchester University NHS Foundation Trust, Manchester, UK
• Newmedica Surgical Centre, Trafford Park, Manchester, UK

Email: gmeyeltd@gmail.com