Epithelium-off
Photrexa with the KXL system removes the epithelium so riboflavin can penetrate. It was the only FDA-approved option until 2025.
Specialty contact lenses · Keratoconus
Keratoconus and Corneal Cross-Linking Catch progression, refer for CXL, restore vision with lenses.
Corneal cross-linking strengthens a thinning cornea and can halt keratoconus progression. Optometrists find the progression, co-manage the procedure and fit the specialty lenses that give patients usable vision before and after it.
2016First FDA-approved cross-linking therapy (Photrexa, epi-off)
Oct 2025FDA approval of Epioxa, epithelium-on
13+Epioxa age range: adults and children 13 and older
−1.6 DMean Kmax change at 1 year in the US keratoconus CXL trial
How it works
Riboflavin plus UVA light stiffens the stroma
Riboflavin drops saturate the cornea, then ultraviolet A light creates new collagen bonds. The goal is to stop the cornea from steepening further, not to restore normal shape.
Epithelium-on
Epioxa uses two riboflavin solutions with the O2n System and Boost Goggles and leaves the epithelium in place.
Who qualifies
Progressive keratoconus, documented by serial topography or tomography. Epioxa is labeled for adults and patients 13 and older.
Trial results
In the US multicenter trial, maximum keratometry fell 1.6 D at one year in treated eyes while control eyes kept progressing.
Common side effect
Corneal haze was the most frequently reported cross-linking adverse finding in that trial.
The optometrist's role
Most keratoconus patients are first seen by an optometrist. Early detection and timely referral protect vision.
- Map every suspicious cornea
- Document progression
- Fit lenses before and after CXL
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Screen
Topography or tomography on patients with unstable astigmatism, rising cylinder or poor best-corrected vision.
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Track
Compare serial maps on the same instrument to document progression for referral and payer requirements.
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Refer and co-manage
Send progressive cases to a corneal surgeon and manage the eye before and after the procedure as agreed.
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Rehabilitate vision
Scleral, hybrid, GP or custom soft lenses restore functional vision once the cornea is stable.
Patient counseling
What to tell patients
Keratoconus care is long term. Set expectations early.
Stop rubbing
Eye rubbing is strongly discouraged. Treat itch and allergy so patients are not tempted.
CXL halts, lenses correct
Cross-linking aims to stabilize the cornea. Most patients still need lenses for their best vision.
Keep follow-ups
Maps continue after treatment, and lens fits may need updating as the cornea settles.
Cross-linking options
FDA-approved corneal cross-linking
| Photrexa (Glaukos) | Riboflavin with the KXL system, epithelium removed; FDA approved 2016 |
|---|---|
| Epioxa (Glaukos) | Epioxa HD 0.239% and Epioxa 0.177% riboflavin solutions with the O2n System and Boost Goggles; epithelium on |
| Epioxa indication | Keratoconus in adults and pediatric patients 13 years and older |
| Epioxa availability | Glaukos expected US launch in the first quarter of 2026 |
| Key US trial | Hersh PS et al., Ophthalmology 2017: Kmax −1.6 D at 1 year in treated eyes |
| Who performs it | Ophthalmologists, typically corneal specialists, with optometric co-management |
Questions doctors ask
When should I refer for cross-linking?
When serial maps document progression. Referral criteria and timing are set with the treating surgeon.
Is epithelium-on cross-linking FDA approved?
Yes. Glaukos announced FDA approval of Epioxa in October 2025 for keratoconus in adults and patients 13 and older.
Can patients wear lenses after CXL?
Yes, once the surgeon clears it. Many need scleral or other specialty lenses for best vision.
Does CXL improve vision?
In the US trial, corrected and uncorrected vision improved on average, but the main goal is stopping progression.
Do keratoconus lenses earn the participation credit?
No. Contact lenses are excluded. Eligible OTC supplies such as scleral saline, ordered on VisionRescue.com through RescueLink, earn the 15% credit.
References
- Hersh PS, Stulting RD, Muller D, et al. United States multicenter clinical trial of corneal collagen crosslinking for keratoconus treatment. Ophthalmology. 2017;124(9):1259-1270. PubMed
- Glaukos announces FDA approval of Epioxa. Business Wire, October 20, 2025. Release
- American Academy of Ophthalmology. What is keratoconus? AAO
Be the keratoconus practice in your area.
Detection, co-management and lens fitting keep these patients with you for years.
Photrexa, KXL, Epioxa, O2n and Boost are trademarks of Glaukos. Review the full prescribing information before use. Individual results vary.