About Corneal Cross-Linking
Among corneal conditions that may lead to vision loss, early diagnosis of keratoconus is highly important. In particular, the progression of keratoconus, which can advance rapidly between ages 10 and 20, Corneal Cross-Linking can be halted with the corneal cross-linking method.
After cross-linking treatment, which makes the cornea tighter and stronger, patients can return to daily life in a short time while preserving visual health.
What is Cross-Linking?
Corneal cross-linking is a safe procedure aimed at increasing the number of cross-links between collagen fibers in the cornea using riboflavin drops and ultraviolet-A light which makes the cornea stronger and more resistant. This combination increases tissue durability and slows the course of progressive corneal diseases such as keratoconus.
Which Conditions Is It Used For?
Primarily preferred to halt keratoconus progression, cross-linking can also be safely applied in similar corneal weakening conditions:
- Keratoconus and pellucid marginal degeneration (PMD): In patients with rapidly progressive corneal thinning, tissue stability can be preserved.
- Post-excimer laser ectasia: Tissue weaknesses that appear after surgery are strengthened.
- Protective use in patients with thin corneas: It can be used as a combined protocol to reduce the risk of ectasia developing before excimer laser procedures.
How Is Cross-Linking Applied?
The procedure is performed in operating-room conditions and consists of two main stages. After local anesthetic drops are instilled, the eye is sterilized and kept open with a blepharostat.
- Epithelial preparation: The central corneal epithelium, approximately 8.5-9 mm in diameter, is gently removed, and corneal thickness is then measured.
- Riboflavin application: The stroma is saturated by instilling riboflavin solution every two minutes for 20 minutes.
- Thickness check: At the second measurement, the thinnest point of the cornea must be at least 400 microns; once this threshold is confirmed, the UV‑A irradiation stage begins.
- UV-A irradiation: Cross-link strengthening is completed with UV irradiation lasting 3-30 minutes. In the standard protocol, a 30-minute application is preferred especially in rapidly progressive keratoconus cases under 18 years of age.
What is Keratoconus?
Keratoconus, is a progressive thinning and steepening of the cornea, the frontmost layer of the eye. It usually starts during adolescence and may progress into the 30s. This condition can cause a significant decline in visual quality and irregular astigmatism.
Keratoconus symptoms
Changing eyeglass prescription
Frequent prescription changes and increasing astigmatism.
Reduced visual quality
Inability to achieve full visual clarity even with glasses.
Night-vision problems
Light scattering and difficulty driving at night.
Eye itching
Persistent eye rubbing can worsen the condition.
Cross-linking treatment process
Epithelium-on
(Epi-on)
Next-generation transepithelial protocols with high comfort and a short recovery period.
Pre-Procedure Preparation
Special drops are applied to increase riboflavin absorption.
Iontophoresis
Uniform distribution to deep tissue is achieved within minutes.
UV Irradiation
Cross-links are strengthened with low-dose UV-A.
Fast Recovery & Minimal Pain
Epithelium-off
(Epi-off)
A gold-standard method with proven long-term outcomes in halting keratoconus progression.
Debridement
The delicate epithelial layer is temporarily removed.
Saturation
Riboflavin is absorbed directly into the stromal layer.
Activation
UV is applied to achieve maximum biomechanical resistance.
Maximum Effect & Gold Standard
Which method is suitable for you?
After corneal thickness and stage analysis, your doctor will determine the most appropriate option.
Riboflavin Application
By instilling vitamin B2 (riboflavin) drops onto the cornea, the tissue is made sensitive to UV light.
- Tissue Preparation
- Vitamin Support
UV Irradiation Application
Ultraviolet-A light forms new cross-links between corneal collagen fibers, strengthening the tissue.
- Disease Control
- Corneal Strengthening