Combined collagen crosslinking treatments for keratoconus.

The landscape of keratoconus treatment has changed profoundly since the introduction of corneal collagen crosslinking (CXL). A decade ago, a newly diagnosed keratoconus patient could expect a treatment plan that involved gradual escalation from spectacle correction to contact lens wear, perhaps followed by an attempt to improve contact lens tolerance or spectacle acuity with intrastromal corneal ring segments (ICRS) and then, for some patients, keratoplasty. This path is beset with frustrations for patients and clinicians alike. Contact lens intolerance, multiple fitting attempts, and temporal gaps in visual function while waiting for special-order lenses are a few of the difficulties faced by patients who would otherwise be enjoying some of the healthiest and most productive years of their lives. Keratoconus carries the additional burden of significant medical expenses that are often passed along as out-of-pocket expenses because of inconsistent insurance coverage for ICRS and contact lenses. When patients do reach the point of keratoplasty, they are often disappointed by the discrepancy between their post-transplant vision and the expectation that transplantation will “cure” their disease and reverse all the optical distortion that makes keratoconus a leading cause of impaired vision-related quality of life. Not long ago, disease progression was accepted as an inevitability for predisposed patients, and one that could be addressed only post facto. Crosslinking has fundamentally altered this former truth. Originally envisioned for stabilizing early disease, CXL is increasingly used across the spectrum of keratoconus severity and in combination with other therapies. Questions about who to treat, when to treat, how to treat, and why to treat are increasingly important given the dizzying number of possible treatment combinations. In their prospective study of staged ICRS, CXL, and toric phakic intraocular lens (pIOL) implantation, Coşkunseven et al. (pages 722–729.) report impressive refractive and visual results while providing a unique opportunity to study the incremental effects of each treatment not afforded in studies of simultaneous procedures. The 14 eyes treated in the study demonstrated very high myopia with a mean spherical equivalent (SE) refractive error of 16.40 diopter (D) and a range up to 22.50 D. Study eyes also had steeper corneas (mean keratometry value was 60.57 D) than those in most CXL studies, and progression of at least 0.75 D was required prior to initiation of treatment. In such