The Dundee University Scottish Keratoconus study: demographics, corneal signs, associated diseases, and eye rubbing

Eye (Lond). 2008 Apr;22(4):534-41. doi: 10.1038/sj.eye.6702692. Epub 2007 Jan 19.


Aim: To investigate and correlate the corneal, refractive, topographic and familial characteristics of a large cohort with keratoconus.

Methods: Prospective observational study of 200 consecutive patients presenting with keratoconus during the 4 year-period 1997-2000. Subjects were examined at enrolment and at a final review. Data were collected on demographic characteristics, referral route, symptoms, refractive correction, eye rubbing, family history, medical history, slit-lamp biomicroscopic corneal signs, and computerized corneal topography.

Results: Mean age at enrolment was 30.9+/-10.4 (range, 12.2-72) years (N=200, 62.5% male, 93% white Caucasian) with a 5% family history of keratoconus. Atopic diseases included asthma (23%), eczema (14%), and hay fever (30%). Only 9% wore contact lenses before referral. Mean follow-up was 1004 days +/-282 (range, 390-1335) and 9.7+/-8.9 (range, 1.1-60) years from diagnosis. The mean simulated K1 corneal power at enrolment was 51.74+/-5.36 (range, 42.59-67.32) D and 88.5% exhibited bilateral keratoconus. Fifty-three (15%) topographically confirmed cones exhibited no clinical corneal signs at presentation. At enrollment, 56% had a pachymetry <0.480 mm increasing to 77% at final review. Forty-eight percent of subjects reported significant eye rubbing and there was a highly statistically significant difference (two sample t-test P=0.018) between keratoconus and control groups. TMS-2 axial corneal power was strongly associated with corneal scarring and age at diagnosis. The size of the scarring effect was 2.2 D (95% confidence interval (CI) 1.34, 3.06).

Conclusions: This study provides an overview of a large population with keratoconus highlighting presenting features and clinical and topographic progression over a 4 year-period.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Asthma / complications
  • Corneal Topography
  • Eczema / complications
  • Female
  • Humans
  • Keratoconus / diagnosis*
  • Keratoconus / epidemiology
  • Keratoconus / etiology*
  • Keratoconus / pathology
  • Keratoplasty, Penetrating
  • Male
  • Middle Aged
  • Physical Stimulation / adverse effects*
  • Prospective Studies
  • Rhinitis, Allergic, Seasonal / complications
  • Risk Factors
  • Scotland / epidemiology