Ectatic disorders associated with a claw-shaped pattern on corneal topography

Am J Ophthalmol. 2007 Jul;144(1):154-156. doi: 10.1016/j.ajo.2007.02.032.

Abstract

Purpose: To identify clinical findings associated with claw-shaped patterns on corneal topography.

Design: Retrospective, observational case series.

Methods: Forty eyes (26 patients) with classic claw-shaped patterns on corneal topography were identified from 3,993 Orbscan II records. They were subclassified into three groups: Group 1 (pellucid marginal degeneration [PMD] or PMD suspect); group 2 (keratoconus or keratoconus suspect); and group 3 (ectasia). The refractive and topographic indices of groups 1 and 2 were compared.

Results: There were nine eyes (six patients) in group 1, 27 eyes (18 patients) in group 2, and four eyes (two patients) in group 3. The mean radii of maximal anterior (2.96 mm) and posterior (3.06 mm) elevation in group 1 were significantly greater than those of group 2 (1.89 mm; P = .018 and 1.72 mm; P = .022, respectively).

Conclusions: The claw-shaped pattern on corneal topography is not diagnostic of PMD; it is also seen in keratoconus.

MeSH terms

  • Cornea / pathology*
  • Corneal Dystrophies, Hereditary / diagnosis*
  • Corneal Topography*
  • Dilatation, Pathologic / diagnosis
  • Humans
  • Keratoconus / diagnosis*
  • Retrospective Studies