EC Ophthalmology

Research Article Volume 17 Issue 5 - 2026

Implantable Collamer Lens Sizing in Eyes with Keratoconus

Colm McAlinden1, Mohamed Elalfy1,2,3, Islam A Mohalhal3, Hasan Naveed1 and Artemis Matsou1*

1Corneoplastic Unit and Eye Bank, Queen Victoria Hospital, East Grinstead, UK
2Department of Ophthalmology, Maidstone and Tunbridge Wells NHS Trust, Maidstone, UK
3Ophthalmology Department, Research Institute of Ophthalmology, Giza, Egypt

*Corresponding Author: Artemis Matsou, Corneoplastic Unit, Queen Victoria Hospital NHS Foundation Trust, Holtye Road, East Grin- stead, UK.
Received: June 15, 2026; Published: July 31, 2026



Aims/Background: The Implantable Collamer Lens (ICL) is an intraocular lens providing refractive correction for a large range of refractive errors. The aim of this study was to investigate the reasons for ICL removal/exchange and to identify cases with excessively high/low vault in patients with keratoconus.

Methods: A real-world chart review was undertaken to assess ICL sizing issues in terms of vault and rotation in patients with keratoconus. Additionally, cases in which the ICL was removed or exchanged were reviewed. The inclusion criteria included eyes with keratoconus that underwent phakic ICL surgery with an internal anterior chamber depth of ≥ 2.8 mm. The STAAR Surgical Online Calculation and Ordering System (OCOS) was reviewed to identify all orders placed between 2017 and 2023. The medical records of these orders were retrieved and reviewed.

Results: Fifty eyes of 39 patients were identified that matched the inclusion and exclusion criteria. Eleven patients had bilateral ICL surgery (on different dates), and 28 patients had unilateral ICL surgery. The mean age of patients was 38.2 (± 7.5) years. Thirteen patients were female and 26 patients were male. In terms of laterality, 27 right eyes and 23 left eyes were included. Two eyes had a low vault (≤ 100 μm), both remain under observation; two eyes had a high vault (≥ 1000 μm), one was removed and one remains under observation; three eyes had rotation/decentration issues, one required rotation and two required exchange for larger diameter ICLs; and one eye had a refractive surprise and the toric ICL was exchanged for a non-toric ICL.

Conclusion: In eyes with keratoconus, it would be prudent to expand pre-operative measurements in an effort to improve sizing issues identified, such as sulcus anatomy and lens rise. It is hypothesised that with additional pre-operative measurements and nomograms, ICL sizing can be improved in eyes with keratoconus.

Keywords: ICL; Keratoconus; Ectasia; Cornea; Vault; ICL Sizing

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Artemis Matsou., et al. “Implantable Collamer Lens Sizing in Eyes with Keratoconus”. EC Ophthalmology 17.5 (2026): 01-09.

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