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Updated: Feb 12, 2026
Three Different Protocols of Corneal Collagen Crosslinking in Keratoconus: Conventional, Accelerated and Iontophoresis
Published on: November 12, 2015
Prospective, randomized contralateral eye study of accelerated and conventional corneal cross-linking in pediatric
1Department of Ophthalmology, Faculty of Medicine, Cairo University, Kasr Al Aini, Manial, Cairo, 11451, Egypt. drsjesus3@hotmail.com.
Insights
Both conventional and accelerated cross-linking (CXL) effectively treated pediatric keratoconus, improving vision and reducing corneal steepness. Neither CXL protocol showed disease progression over three years.
Area of Science:
- Ophthalmology
- Corneal Surgery
- Biomedical Engineering
Background:
- Pediatric keratoconus is a progressive corneal ectasia.
- Cross-linking (CXL) is a standard treatment to halt progression.
- Comparing CXL protocols in pediatric patients is crucial for optimizing outcomes.
Purpose of the Study:
- To compare the efficacy of conventional versus accelerated riboflavin-ultraviolet A (UVA) cross-linking (CXL) in pediatric keratoconus.
- To evaluate visual acuity, corneal topography, and aberrations after CXL.
Main Methods:
- Prospective randomized contralateral eye study involving 34 pediatric patients (9-16 years old).
- Conventional CXL: 30 min UVA (3 mW/cm²). Accelerated CXL: 5 min UVA (18 mW/cm²).
- Total energy delivered was 5.4 J/cm²; follow-up was 3 years.
Main Results:
- Both groups showed significant improvement in uncorrected (UCVA) and corrected distance visual acuity (CDVA) at 12 months.
- Accelerated CXL demonstrated statistically significant better UCVA and CDVA compared to conventional CXL at 12 months.
- No significant differences were observed in wavefront aberrations, corneal astigmatism, or endothelial cell density between groups.
Conclusions:
- Both conventional and accelerated CXL are effective in treating pediatric keratoconus.
- Accelerated CXL may offer faster visual recovery.
- No keratoconus progression was observed in either group over 36 months.
Purpose:
To compare the outcomes of two different cross-linking (CXL) protocols, in pediatric keratoconus eyes.
Materials And Methods:
In this prospective randomized contralateral eye interventional study, 68 eyes of 34 patients, 9-16 years old, underwent CXL and enrolled between October 2011 and October 2013. Group A represents conventional riboflavin-ultraviolet A (UVA)-induced CXL with 30 min of exposure to UVA irradiation of 3 mW/cm2. Group B represents accelerated cross-linking with 5 min of continuous UVA irradiation of 18 mW/cm2. In either group, total energy delivered was adjusted to 5.4 J/cm2. Follow-up of all patients was accomplished throughout the postoperative 3 years, and the data from the preoperative, 12, 24, and 36 months visits were analyzed and compared in both groups. Uncorrected visual acuity, corrected distance visual acuity, steepest keratometry (Kmax), corneal astigmatism (simulated K), total wavefront aberrations, central corneal thickness (CCT), corneal densitometry, manifest refraction spherical equivalent, and endothelial cell density (ECD) were evaluated at baseline, 12, 24, and 36 months post-CXL.
Results:
At 1-year assessment, the mean value of UCVA, CDVA, and Kmax showed a statistically significant difference between both groups, without any documented change in the variables throughout the remaining follow-up (1-3-year) period. Twelve months postoperatively, mean LogMAR UCVA and CDVA were (0.11 ± 1.60) and (0.03 ± 1.60), respectively, in accelerated CXL group, compared to conventional CXL group values of (0.20 ± 1.00) and (0.06 ± 1.22), showing a statistically significant difference (P < 0.05). Mean Kmax in accelerated CXL group (45.47 ± 0.44) showed a statistically significant difference (P < 0.05) compared to conventional CXL group (46.41 ± 1.59) at 12 months post-CXL. On the other hand, wavefront aberrations, simulated K, corneal densitometry, ECD, and CCT changes showed nonstatistically significant difference in conventional CXL group, compared to accelerated CXL group (P > 0.05) throughout the follow-up course.
Conclusions:
Both conventional and accelerated CXL improved UCVA and CDVA, attenuated disease progression, and reduced corneal steepness and wavefront aberrations at 1, 2, and 3 years postoperatively. In no case did keratoconus progress over the 36-month follow-up.
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