Abstract
Abstract: :
Purpose: To study the differences in the clinical and demographic characteristics of keratoconus patients who needed penetrating keratoplasty (PK) verses those who did not need PK. Methods: All keratoconic eyes presenting to the Duke University Eye Center from January 1st, 1997 to December 31st, 2002 were reviewed. Eyes with previous corneal transplantation, eyes which had corneal transplants for reasons other than keratoconus and patients with only one visit during the study period were excluded from the analysis. A case–control study was performed. Cases were defined as eyes undergoing PK during the study period for keratoconus. Controls were defined as eyes that did not undergo PK during the study period. Results: 131 eyes with keratoconus were studied. 59 cases (history of PK) were compared to 72 controls (no history of PK). Groups were similar with respect to gender. Race, family history, diabetes mellitus, hypertension, asthma, smoking, and alcohol use were not associated with increased risk of progression to corneal transplant. Significant risk factors for PK in univariate analysis were vision worse than 20/40 (OR 3.2), astigmatism >10.0 D (OR 2.6), and average keratometry >55 D (OR 5.6). Multivariate analysis showed young age 21–30 years (OR 4.7) and average keratometry >55 D (OR 8.4) as significant risk factors. Conclusions: Young age may be an under recognized risk factor for progressive keratoconus. Visual acuity worse than 20/40 at presentation, large amounts of astigmatism and steep keratometry are clinical indicators of increased risk of progression to PK in keratoconus patients.
Keywords: keratoconus • clinical (human) or epidemiologic studies: risk factor assessment • cornea: clinical science