‘Pseudokeratectasia’ Due To Epithelial Basement Membrane Dystrophy: Role Of Corneal Tomography And Epithelial Mapping

To discuss the role of corneal tomography and epithelial thickness mapping in a case of epithelial basement membrane dystrophy (EBMD) mistakenly diagnosed as keratoconus

Cornea and Refractive Services of Advanced Eye Centre, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India

A 30-year-old female presented with complaints of blurred vision OU. Based on corneal topography she was diagnosed as keratoconus elsewhere and referred to our tertiary care cornea services for cross-linking. Slit lamp biomicroscopy showed ‘map,’ ‘dot’ and ‘fingerprint’ epithelial lesions in the pupillary area. Scheimpflug based corneal tomography revealed central corneal steepening bilaterally in axial scan, with anterior elevation on Belin Ambrosio Enhance Ectasia Display. However, posterior corneal tomography showed no abnormality with normal corneal thickness. A clinical diagnosis of EBMD was made which was corroborated by epithelial mapping showing increased thickness in the areas of the epithelial lesions and the areas of maximum steepening on front surface topography.

Meticulous slit lamp biomicroscopy and appropriate use of imaging modalities, can help differentiate conditions simulating ectasia from true corneal ectatic disorders.