Corneal topography in Ehlers-Danlos syndrome

To assess the use of corneal topography in conjunction with slitlamp biomicroscopy and retinoscopy to diagnose keratoconus in a large group of patients with Ehlers-Danlos syndrome (EDS).

Kresge Eye Institute, Wayne State University, Detroit, Michigan, USA.

Thirty-six patients (72 eyes) with genetically typed EDS had slitlamp biomicroscopy, retinoscopy, and videokeratography with the EyeSys instrument. The presence or absence of slitlamp keratoconus findings was correlated to a presumptive diagnosis based on corneal topography using derived topographic indexes associated with keratoconus. These topographic indexes included central corneal power, (CCP), difference in CCP, inferosuperior asymmetry (I-S) value, and asphericity (Q). Axial and profile difference maps were generated and analyzed for findings suggestive of keratoconus.

In 72 eyes, no keratoconus was found using slitlamp biomicroscopy. No eye had an I-S value greater than 1.60 diopters (D), 2 eyes had a CCP greater than 46.50 D, and 2 eyes had a Q value less than -1.00. Eight of 36 pairs of eyes had an intereye CCP greater than 0.92 D. In both eyes of the patient with Q values less than -1.00 the profile difference maps were mildly abnormal.

Slitlamp biomicroscopy of the cornea was unremarkable in all patients. Only 1 patient had Q values and profile difference maps that were mildly suggestive of keratoconus. Even after adding topography to the examination, it appears that keratoconus in a known population of patients with EDS remains rare.