October 2014 Online Photo Diagnosis

October 2014 Online Photo Diagnosis

By Gregory W. DeNaeyer, OD, FAAO

Figure 1 shows the left cornea of a 46-year-old keratoconus patient who reported irritation with his current corneal GP lenses. His left corneal GP lens had a flat-fitting relationship and apical bearing (Figure 2), which resulted in significant epithelial erosion that was causing the patient’s discomfort. After evaluation and discussion, we successfully refit the patient into scleral contact lenses for both eyes. The scleral lenses provided 20/40 vision in each eye and improved his comfort.

Scleral lenses have an advantage in that they vault the cornea and avoid corneal compromise. Mechanical trauma secondary to a contact lens may be a factor in contributing to keratoconus progression1,2. With that in mind, it makes judicious sense to utilize scleral lenses when the best-fitting corneal GP lens has significant apical bearing that results in epithelial erosion. Alternatively, if scleral lenses are contraindicated, consider fitting patients with a piggyback system that protects their epithelium from mechanical friction secondary to a corneal GP lens.


1. DeNaeyer, G. Is Apical Bearing Acceptable when Fitting Keratoconus? Contact Lens Spectrum. 2011 Nov;26:20.

2. Kenney C, Brown DJ. The cascade hypothesis of keratoconus. Cont Lens Anterior Eye. 2003;26:139-146.