Case of Progressive Keratoconus With Newly Diagnosed Pellucid Marginal Degeneration After Corneal Cross-Linking

Purpose:The purpose of this study was to document, to our knowledge, the first reported case of keratoconus progression accompanied with newly diagnosed pellucid marginal degeneration after corneal cross-linking (CXL).Methods:A novel case of further keratoconus progression plus development of pellucid marginal degeneration in the same eye after CXL was documented with supporting evidence from Scheimpflug and optical coherence tomography imaging.Results:A male patient was diagnosed with progressive keratoconus in the left eye and treated with CXL when aged 25 years. Although strongly cautioned not to rub his eyes, he admitted that he continued eye rubbing in association with atopic disease. At a follow-up examination 3.5 years after CXL, progressive keratoconus was detected and pellucid marginal degeneration was newly diagnosed in the left eye. The eye was retreated with CXL.Conclusions:This case illustrates that progressive keratoconus and pellucid marginal degeneration can occur in the same eye after CXL and demonstrates the deleterious effects that can develop with continued eye rubbing.