Cross-Linking,Eye Exam,Eye Health,Keratoconus,What's New

Keratoconus is a progressive corneal disorder that typically begins in adolescence or early adulthood in which the cornea – normally clear and dome-shaped, becomes thinner and protrudes into a cone-like profile. This irregular shape of the cornea affect the way light enters the eye, leading to irregular astigmatism and visual impairment. As a result, individuals with Keratoconus will often experience blurred vision, heightened light sensitivity, and reduced night vision. Although its exact cause is not fully understood, factors such as genetic predisposition, chronic eye rubbing, and environmental influences may contribute to its development. Emerging new evidence suggests that low-grade, chronic inflammation may also contribute to the weakening of the corneal structure, specifically the breakdown of corneal collagen thereby promoting corneal ectasia.1

Although vitamin D is best known for its role in bone health, it is also a powerful immuno-modulator with anti-inflammatory properties. Proper vitamin D levels may help modulate systemic immune function and, as a result, could slow the progression of corneal ectasia seen in Keratoconus.2 It is important to note, however, that Keratoconus is a multi-factorial disorder; low vitamin D is likely one piece of a much larger puzzle.

Clinical Insights: Vitamin D Supplementation in Keratoconus

A recent pilot study published in the American Journal of Ophthalmology examined the effects of vitamin D supplementation in a group of adolescent patients with Keratoconus.3 In this 12-month study, 40 patients aged between 12 and 19—all with documented vitamin D deficiency and varying degrees of corneal thinning — took vitamin D supplements for six months. Their Best Corrected Visual Acuity (BCVA), maximal keratometry (Kmax), and the thinnest corneal thickness were closely monitored, along with periodic blood tests.

The results were promising:

  • Corneal Stability: In about 65% of the subjects, the progression of Keratoconus measured by Kmax was less than one diopter over the 12-months observational period and corneal thickness remained stable.
  • Molecular Changes: Blood tests revealed an increase in vitamin D binding proteins—the main transporters of vitamin D in blood—while markers of inflammation and platelet activation decreased.

These findings suggest that maintaining optimal vitamin D levels may help stabilize the cornea by reducing systemic inflammation and slowing collagen degradation—a key factor in the progression of Keratoconus.


This suggests that adequate vitamin D levels might help modulate systemic inflammation, ultimately reducing the cascade of events that contribute to collagen degradation and the progression of corneal ectasia.

Practical Tips for Keratoconus Patients at North Toronto Eye Care

Whether you are at risk of Keratoconus or have already been diagnosed with Keratoconus, consider these actionable tips:4

  • Avoid Eye Rubbing: Eye rubbing can worsen Keratoconus by further thinning the cornea. If you experience itchy eyes, please consult our doctors for anti-histamine eye drops or preservative-free artificial tears.
  • Attend Follow-up Visits!: Keratoconus is most likely to progress in teenage years to 20s but can still progress beyond this point. Timely check-ups include assessments of vision, refraction, and detailed corneal imaging (topography and tomography) that help track subtle changes in the cornea’s shape and thickness. This is critical for diagnosing progression for timely intervention regardless of whether you have received cornea stabilizing treatment corneal cross-linking (CXL).
  • Ask Our Doctors on Treatment Options to match Your Visual Needs:
    • LASIK is not recommended for individuals with Keratoconus as it can further weaken the cornea.
    • Topography-guided PRK is a laser correction that can be done just prior to the corneal stabilizing treatment corneal collagen cross-linking (CXL). This laser procedure aims to reduce the irregularity of the cornea and astigmatism but not fully correct the refractive error.
    • Specialty Contact Lenses such as corneal Rigid Gas Permeable Lenses or Scleral Lenses provides clear vision by providing a smooth optical surface that mitigates corneal irregularities. This may be an excellent option for Patients with Keratoconus after receiving the corneal stabilizing treatment corneal collagen cross-linking (CXL).
For More Information on Keratoconus Treatment Options

By combining these lifestyle changes with state-of-the-art medical guidance, you can play an active role in preserving your vision.

Keratoconus is a challenging condition that affects many individuals worldwide by distorting the cornea and impairing vision. As research evolves, vitamin D emerges as a potential valuable non-invasive adjunct approach to stabilize the cornea in young patients facing this condition.

Staying informed about the latest ophthalmology research and incorporating proactive lifestyle choices can make a real difference in eye health. Proactively seek out new approaches to vision care for a clearer, brighter tomorrow.

References

  1. Lasagni Vitar RM, Fonteyne P, Knutsson KA, Bertuzzi F, Galli L, Rama P, Ferrari G. Vitamin D Supplementation Impacts Systemic Biomarkers of Collagen Degradation and Copper Metabolism in Patients With Keratoconus. Transl Vis Sci Technol. 2022 Dec 1;11(12):16. doi: 10.1167/tvst.11.12.16. PMID: 36580321; PMCID: PMC9804020.
  2. https://www.reviewofoptometry.com/news/article/vitamin-d-shown-to-stabilize-keratoconus-in-adolescent-patients
  3. Bartolomeo N, Pederzolli M, Palombella S, Fonteyne P, Suanno G, Tilaro G, de Pretis S, Borgo F, Bertuzzi F, Senni C, De Micheli M, Bandello F, Ferrari G. The effects of Vitamin D on Keratoconus progression. Am J Ophthalmol. 2025 Apr 15:S0002-9394(25)00186-2. doi: 10.1016/j.ajo.2025.04.009. Epub ahead of print. PMID: 40245974.
  4. https://eyesoneyecare.com/resources/managing-progression-in-keratoconus