Central corneal thickness not related to refractive error, axial length

Central corneal thickness is not a surrogate marker for abnormal scleral or laminar thickness as an independent cause of increased glaucoma risk, according to a study. The authors add it is also unrelated to refractive error or axial length.

Cristiano Oliveira, MD, and colleagues studied 140 eyes of 140 patients who had no previous history of intraocular surgery. Mean patient age was 57 years old, and mean refractive error was –1.3 D, with a range of +2.7 D to –6.3 D.

Surgeons measured axial length, central corneal thickness (CCT) and scleral thickness via ultrasound. The scleral thickness was measured independently on radial ultrasound biomicroscopy by two masked observers at scleral spur and 2 mm and 3 mm posterior to the spur.

There was a positive correlation between CCT and the scleral spur, but not among CCT and either posterior measurements, refractive error or axial length.

This study is published in the June issue of Journal of Glaucoma.