Keratoconus-like topographic changes in keratoconjunctivitis sicca.

PURPOSE: To describe a case of inferior corneal steepening with a keratoconus-like pattern in a patient with nocturnal lagophthalmos and aqueous tear deficiency (ATD).

METHODS

Axial curvature mapping was performed with the Tomey TMS-2N videokeratoscopy instrument. Keratoconus-like topography patterns were identified with the Klyce Software package of this instrument.

RESULTS

Axial videokeratoscopy showed asymmetric inferior corneal steepening in the right eye. The surface regularity index (SRI), surface asymmetry index (SAI), and the simulated keratometric cylinder change (CYL) were 1.05, 5.05, and 0.75, respectively. The keratoconus screening indices were as follows for the right eye: Klyce/Maeda index of 95% similarity (clinical keratoconus interpreted) and Smolek/Klyce index of 23.09% severity (keratoconus suspect interpreted). Ultrasound pachymetric mapping showed a normal central corneal thickness. We found a similar topographic pattern of keratoconus in seven eyes of 74 dry eye patients who were previously evaluated with the Tomey TMS-2N.

CONCLUSION

Chronic ocular desiccation and aqueous tear deficiency can produce inferior corneal steepening and high astigmatism resembling keratoconus.