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# FDA Approves Avedro Keratoconus Therapy
- URL: https://www.fdaweb.com/fda-approves-avedro-keratoconus-therapy/
- Published: 2016-04-19T12:00:00.000Z
- Updated: 2026-09-14T20:55:43.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5135423

> FDA has approved an Avedro NDA for its Photrexa Viscous, Photrexa and the KXL System for corneal collagen cross-linking for treating progressive keratoconus. Photrexa Viscous and Photrexa are photoenhancers indicated for use with the KXL System in corneal collagen cross-linking. Keratoconus is a progressive thinning and distortion of the cornea. It causes the cornea to bulge from its normal symmetric domelike smooth optical shape, creating an abnormal curvature that changes the cornea’s optics, producing blurred and distorted vision that is difficult to correct with spectacle lenses. This can result in significant visual loss and may lead to corneal transplants.  
>  
> Approval was based on data from three prospective, randomized, parallel-group, open-label, placebo-controlled, 12-month trials conducted in the U.S. to determine the safety and effectiveness of Photrexa Viscous and Photrexa when used for performing corneal cross-linking in eyes with progressive keratoconus. In each study, patients had one eye designated as the study eye and were randomized to receive one of two study treatments (CXL or sham). “The cross-linked eyes showed increasing improvement in Kmax from month 3 through month 12,” the company says. “Kmax is defined as the maximum corneal curvature and measured in diopters (D). Progressive keratoconus patients had an average Kmax reduction of 1.4 D in Study 1 and 1.7 D in Study 2 at month 12 in the cross-linked eyes, while the untreated eyes had an average increase of 0.5 D in Study 1 and 0.6 D in Study 2 at month 12; the difference (95% CI) between the cross-linked and untreated groups in the mean change from baseline Kmax was -1.9 (-3.4, -0.3) D in Study 1 and -2.3 (-3.5, -1.0) D in Study 2.”