ICL Education
Learning resources for ICL sizing, vault prediction, and EVO Visian Implantable Collamer Lens surgery. Start with the free EVO ICL Workshop from Refractive Foundations below.
EVO ICL Workshop — free online course from Refractive Foundations
Covers Basics and Overview, Selecting ICL Power, ICL Sizing, and Off-Label ICL Use. Taught by Hirabayashi, Virdi, Nasser, Waite, and Parkhurst — including Matt Hirabayashi MD (co-founder of ICL Fit).
About ICL Sizing and Vault Prediction
Implantable Collamer Lens (ICL) surgery — most commonly the EVO Visian ICL from STAAR Surgical — is a refractive procedure in which a phakic intraocular lens is placed between the iris and the natural crystalline lens to correct myopia, hyperopia, and astigmatism. Unlike LASIK or SMILE, ICL surgery is additive and reversible, and it preserves the cornea entirely.
The single most important variable in ICL surgery is lens size selection. An undersized ICL produces a low post-operative vault (the distance between the back of the ICL and the front of the natural lens), which can rub on the crystalline lens and accelerate cataract formation. An oversized ICL produces a high vault, which can crowd the iridocorneal angle and raise intraocular pressure, with risk of pigment dispersion or angle closure. The clinically accepted ideal vault is typically 250–750 μm, with most surgeons targeting around 500 μm.
Traditional ICL sizing relies on white-to-white (WTW) measurement and a manufacturer nomogram, but WTW is a rough proxy for the actual sulcus-to-sulcus distance where the lens haptics rest. Modern sizing approaches use Pentacam Scheimpflug tomography and other anterior segment imaging to capture anterior chamber depth, angle-to-angle distance, crystalline lens rise, and other geometric features that more accurately predict post-operative vault. ICL Fit is an AI-driven nomogram that takes Pentacam scan data as input and outputs an optimal lens size recommendation along with a predicted vault, helping refractive surgeons reduce sizing errors and improve outcomes for EVO ICL patients.
Topics Covered in the Workshop
- Basics and Overview — what the EVO ICL is, FDA indications, candidate selection
- Selecting ICL Power — power calculation and contact lens over-refraction technique
- ICL Sizing (Intro) — fundamentals of sizing the EVO ICL for optimal vault
- Off-Label ICL Use — expanded indications and considerations