Scotopic contrast sensitivity and glare after accelerated corneal cross-linking

Area of Science:

• Ophthalmology
• Corneal Surgery
• Vision Science

Background:

• Keratoconus is a progressive corneal disease.
• Accelerated corneal cross-linking (CXL) is a treatment option.
• Assessing visual function changes post-CXL is crucial.

Purpose of the Study:

• To evaluate one-year changes in scotopic contrast sensitivity (CS) and glare after accelerated CXL.
• To compare outcomes between CXL-treated eyes and unoperated controls.

Main Methods:

• A non-randomized clinical trial included 30 eyes in the CXL group and 30 in the control group.
• Scotopic CS was measured at various spatial frequencies (SFs) under low light conditions (0.5 lux).
• Measurements were taken at baseline, six months, and 12 months post-treatment.

Main Results:

• Accelerated CXL reduced corrected scotopic CS at SFs of 7.1 and 15 cycles per degree (cpd) compared to controls (p=0.010 and p=0.007, respectively).
• These reductions were more pronounced in patients with better baseline corrected CS.
• Changes in uncorrected CS and glare were not significantly different between groups and were related to baseline values.

Conclusions:

• Accelerated CXL can negatively impact high-SF scotopic corrected CS in keratoconus patients with good baseline vision.
• Uncorrected CS and glare are primarily influenced by pre-operative measurements one year after CXL.
• The 18 mW/cm² protocol may affect specific aspects of visual function under low-light conditions.