Accelerated Corneal Cross Linking Procedure Improves Vision, Reduces Keratometry Values

Keratoconus of eye
Macro eye photo.
The accelerated corneal cross-linking procedure reduced all measured keratometry parameters, but only the reduction in corneal thickness at the thinnest point was statistically significant in both the adult and pediatric cohorts.

The accelerated corneal cross-linking (ACXL) (9 mV/cm2 for 10 minutes) procedure improves best corrected visual acuity (BCVA) in adults and children and has a slight tendency toward more flattening in adults 1 year after treatment, according to research published in Journal Français d’Ophtalmologie. 

Researchers retroscopically collected data from 64 right eyes of 64 participants who underwent AXCL. They stratified patients into 2 groups based on age: a pediatric group (n=32, mean age 13.50±3.05 years, 56.3% girls) and an adult group (n=32, mean age 23.58±4.37 years, 40.7% women). The team obtained BCVA, maximum keratometry (Kmax), sim K1, sim K2, corneal thickness at the thinnest point (thCT), and corneal astigmatism (CA) measurements at baseline and 1-year follow up.  

The team noted the presence of stage 1, stage 2, and stage 3 keratoconus in 37.5%, 34.3%, and 28.2% of eyes in the pediatric cohort, respectively. They observed stage 1 keratoconus in 40.6% of participants, stage 2 in 34.3%, and stage 3 in 25.1% of eyes in the adult group.  

Investigators report a significant improvement in BCVA (Children: 0.59±0.40 to 0.54±0.39 logMAR, P =.033; Adults: 0.49±0.34 to 0.39±0.29 logMAR, P =.001) and a significant decrease in thCT (Children: 449.5±49.1 to 422.9±45.4 µm; Adults: 452.5±43.5 to 425.8±46.8 µm; P <.001 for both) in both groups at 1 year follow up. The team also noted significantly reduced Kmax, sim K1 and sim K2 values in the adult group at 1-year follow up (P =.005, P =.025, and P =.011, respectively). After comparing the values obtained at follow-up between the 2 groups, the team determined that the simK1 value was significantly lower in the adult group (P =.022).

Keratoconus exhibits different characteristics in the pediatric and adult age group in terms of the progression and severity of the disease,” according to the researchers. “Keratoconus has a more progressive and severe course in pediatric patients. Stabilization of the disorder as soon as possible is of great importance in this age group in terms of providing better visual function and decreasing the need for a future keratoplasty.”

Study limitations include a retroscopic nature, single center design, small sample size, and the absence of spherical equivalent data. 

Reference

Berhuni M, Ozturkmen C. Comparison of accelerated corneal cross- linking for progressive keratoconus in pediatric and adult age groups: one-year results. J Fr Ophtalmol. Published online June 23, 2022. doi:10.1016/j.jfo.2022.02.002