title: Biomicroscopic signs and disease severity in keratoconus. Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study Group.
abstract: 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 variable, ages, self-reported ages at diagnosis, keratometry, slit-lamp findings, systemic disease, family history of keratoconus, and best spectacle-corrected and contact 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 had unilateral keratoconus, defined as unilateral corneal irregularity. More advanced disease (steeper average keratometric reading) was associated with a greater likelihood of Vogt's striae, Fleischer's ring, and/or corneal scarring. Fifty-eight percent of the eyes in this group of patients had > or = 20/40 visual acuity with manifest refraction. Penetrating keratoplasty was reported in 12.3% of eyes. This prospective survey identifies the associates between the presence of Vogt's striae, Fleischer's ring, and/or corneal scarring and increasing steepness, as measured by keratometry.
authors.affiliation: School of Optometry, University of California at Berkeley 94720-2020, USA.
authors.forename: K
authors.initials: K
authors.lastname: Zadnik
authors.forename: J T
authors.initials: JT
authors.lastname: Barr
authors.forename: M O
authors.initials: MO
authors.lastname: Gordon
authors.forename: T B
authors.initials: TB
authors.lastname: Edrington
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002921:Cicatrix / Q000209:etiology; D003316:Corneal Diseases / Q000209:etiology; D005260:Female; D006306:Health Surveys; D006801:Humans; D007640:Keratoconus / Q000150:complications / Q000473:pathology* / Q000601:surgery; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014792:Visual Acuity