Comparing the Fit and Performance of Scleral Lenses With Oval and Circular Limbal Zones

Scleral lenses are large, rigid contact lenses that rest on the white part of the eye and arch over the cornea. They are commonly used to improve vision in people with eye conditions like keratoconus or corneal scarring, but are increasingly popular among people with high prescriptions or dry eyes due to the comfort and clarity they provide. While these lenses offer many benefits, fitting them properly can be difficult, especially over the limbus, the border between the clear front surface of the eye and the white part of the eye. This area is home to important stem cells that help keep the eye healthy. Most lenses today are designed to fit the limbus as if it were perfectly round, but new research shows the limbus is actually more oval-shaped. When scleral lenses do not match this shape, they may press too hard in some areas or leave too much space in other areas of the limbus, potentially causing discomfort or long-term eye health problems. This study will test whether lenses designed with an oval-shaped limbal zone provide a better fit and greater comfort than traditional round designs. To do this, advanced eye imaging and computer modelling will be used to measure the limbus and customize scleral lens design for each participant. All lenses used in the study are already approved and available in Canada. The results may help improve lens comfort and safety for people who rely on scleral lenses every day.

NCT Number	NCT07288658
Lead Sponsor	University of Waterloo Collaborators: Fighting Blindness Canada, Canadian Optometric Education Trust Fund (COETF)
Conditions	Limbus Corneae
Enrollment	7 participants
Start Date	2026-01-13
Primary Completion	2026-03-18 (estimated)
Study Completion	2026-03-18 (estimated)
Updated on ClinicalTrials.gov	2026-05-05