Right nomograms, instruments needed for ICL sizing
Key takeaways:
- Vault presents challenges when it comes to ICL sizing.
- Many nomograms are available to assist with sizing.
KOLOA, Hawaii — Measuring an eye for an ICL requires the right technology and formulas, according to a speaker at Hawaiian Eye 2025.
Helen K. Wu, MD, said the latest-generation EVO ICL (STAAR Surgical) has a lot of advantages but comes with challenges related to vault, which can be influenced by anatomy and the size of the ICL. Patients with low vault are at higher risk for complications such as cataract and decreased rotational stability, while patients with high vault are at higher risk for “pupillary block, endothelial cell loss, pigment dispersion, angle crowding and potentially glaucoma,” she said.
“The traditional method of sizing includes utilizing calipers for getting your white-to-white measurements,” she said. “More recent approaches utilize other imaging technologies, including biometry like IOLMaster (Zeiss), [ultrasound biomicroscopy] and anterior segment OCT to look at other structures within the eye.”
Wu said there are several nomograms available to calculate ICL sizing. However, none of them are perfect for all patients, and they depend on certain technology for measurements.
Existing formulas may need to be modified depending on the size of the ICL, and pupil diameter and movement may factor into vault measurements, she said. Additionally, surgeons should consider the demographics on which a particular nomogram is based.
Wu said surgeons need to pair the right nomogram with the right instrument. However, if they have multiple devices, using multiple formulas may be beneficial.
In her practice, Wu uses the STAAR Surgical Online Calculation & Ordering System nomogram combined with white-to-white measurements using Pentacam (Oculus).
“Hopefully in the future, machine learning and AI-based formulas will allow for better prediction of outliers,” Wu said.
Collapse
Wu HK. EVO-ICL: Sizing strategies for success. Presented at: Hawaiian Eye 2025; Jan. 18-24, 2025; Koloa, Hawaii.
Read more about