Binocular Visual Function Changes After Corneal Collagen Cross-linking in Patients With Keratoconus

Area of Science:

• Ophthalmology
• Corneal Surgery
• Vision Science

Background:

• High-order aberrations (HOAs) significantly impact visual and stereoacuity in keratoconus.
• Corneal collagen cross-linking (CXL) effectively reduces HOAs in keratoconus patients.
• The effect of CXL on stereopsis in keratoconus has not been previously evaluated.

Purpose of the Study:

• To assess changes in binocular visual performance in keratoconus patients.
• To evaluate the impact of corneal collagen cross-linking (CXL) on stereopsis.
• To correlate HOA reduction with improvements in binocular vision after CXL.

Main Methods:

• 30 keratoconus patients underwent standard Dresden protocol epi-off CXL.
• Pre- and post-operative assessments included visual acuity, corneal tomography, and stereopsis tests (Lang, TNO).
• Stereopsis tests were conducted with spectacle correction 6 months after CXL.

Main Results:

• Stereopsis significantly improved post-CXL, with more patients achieving a positive Lang test (53.3% vs 20%) and improved TNO stereoacuity.
• A subgroup of patients (46.7%) showed a clinically significant improvement in TNO stereoacuity, correlating with a reduction in total root mean square values.
• No significant changes were observed in cover test or Irvine test results post-CXL.

Conclusions:

• Keratoconus patients experiencing reduced HOAs after CXL demonstrate significant improvements in stereoacuity.
• CXL is a viable treatment for enhancing binocular visual function in keratoconus.
• Reduction in HOAs following CXL is linked to improved stereopsis.