BIOMICROSCOPIC SIGNS AND DISEASE SEVERITY IN KERATOCONUS

The Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Survey represents the largest sample of clinic-based keratoconus patients to date. Data were collected at 38 clinical centers on 1,579 keratoconus patients. This article reports demographic variables, ages, self-repo rted ages at diagnosis, keratometry, slit-lamp findings, systemic dise ase, family history of keratoconus, and best spectacle-corrected and c ontact lens-corrected visual acuity of this sample group. The average age of this clinic-based sample group was 37 years (range 10-89 years) , with 84% between 20 and 49 years old. Thirteen percent of patients h ad unilateral keratoconus, defined as unilateral corneal irregularity. More advanced disease (steeper average keratometric reading) was asso ciated with a greater likelihood of Vogt's striae, Fleischer's ring, a nd/or corneal scarring. Fifty-eight percent of the eyes in this group of patients had greater than or equal to 20/40 visual acuity with mani fest refraction. Penetrating keratoplasty was reported in 12.3% of eye s. This prospective survey identifies the association between the pres ence of Vogt's striae, Fleischer's ring, and/or corneal scarring and i ncreasing steepness, as measured by keratometry.