The Value of Central Corneal Curvature and Central Corneal Thickness in the Clinical Diagnosis of Marfan Syndrome

Abstract

Purpose:: To explore the clinical utility of central corneal curvature and central corneal thickness in the diagnosis of Marfan syndrome.

Methods:: Retrospective chart review of 211 patients referred to look for ocular manifestations of Marfan syndrome (MS). Patients were examined for ectopia lentis and had keratometry and central corneal pachymetry (CCP). Patients were categorized in into MS or normal groups per the Ghent criteria based on clinical examinations from medical genetics, ophthalmology and cardiology. Patients in whom MS could not be diagnosed or ruled out were categorized as inconclusive. Those with other connective tissue diseases were excluded from the study. T test was performed on the keratometry and CCP values, supposing non-homoscedastic distributions in the Marfan syndrome and normal groups.

Results:: There were 62 patients in the MS group, 98 patients in the normal group and 41 patients in the inconclusive group. 10 patients were excluded from the study because of another connective tissue disorder. 49 of 62 MS patients (79%) had ectopia lentis. Keratometry was available for 110 eyes and CCP was available for 113 eyes in the MS group. In the normal group, keratometry was available for 147 eyes and CCP was available for 144 eyes. The mean age of the MS group was 22.3 yrs vs 19.3 yrs in the normal group (p = 0.23). MS group had significantly lower keratometry and CCP than normal, 40.81 diopters (MS) vs 43.32 diopters (normal), p = 4.02 X 10^-19, and 543.45 nm (MS) vs 564.19 nm (normal), p = 9.12 X 10^-6. In MS patients without ectopia lentis, these values were 41.51 diopters (p = 0.00026 vs normal) and 542.00 nm (p = 0.0011 vs normal) respectively. In inconclusive patients with either ectopia lentis or aortic root dilation, these values were 42.39 diopters (p = 0.016 vs normal) and 537.71 nm (p = 0.0011 vs normal) respectively.

Conclusions:: There was a highly significant difference in keratometry between MS and normal patients. A diagnosis of MS should be strongly considered in patients with one non-ocular major criterion and keratometry less than 41 diopters. Although the corneas in MS patients were thinner than that of normal patients, most readings were still in the normal range. Therefore, our data does not support the utility of using corneal thickness in the clinical diagnosis of Marfan syndrome. Longitudinal follow up of inconclusive patients should provide more definitive predictive value of corneal curvature in the clinical diagnosis of Marfan syndrome.

Keywords: cornea: clinical science • genetics