Macular phototoxicity after corneal cross-linking

Area of Science:

• Ophthalmology
• Corneal Surgery
• Retinal Imaging

Background:

• Keratoconus is a progressive eye condition affecting corneal shape.
• Corneal collagen cross-linking (CXL) is a treatment to halt keratoconus progression.
• Potential effects of CXL on the macula are not fully understood.

Purpose of the Study:

• To evaluate vascular, structural, and functional changes in the macula after ultraviolet A (UVA)-riboflavin-mediated CXL.
• To assess the safety and potential side effects of CXL on the macula.

Main Methods:

• Seventeen eyes of patients aged 16+ with keratoconus underwent CXL.
• Evaluations included visual acuity, refractive error, OCT, fluorescein angiography, autofluorescence, and mfERG before and after CXL.
• The treated eye served as its own control.

Main Results:

• No significant changes in best-corrected visual acuity (BCVA) or central macular thickness (CMT) were observed post-CXL.
• Multifocal electroretinography (mfERG) showed statistically significant increases in P1 latency and decreases in P1 amplitudes in several rings.
• Increased P1 latency correlated with increased CMT, suggesting a mild subclinical effect.

Conclusions:

• CXL treatment for keratoconus may induce minor, subclinical changes in macular function and thickness.
• These changes were not associated with vascular abnormalities, reduced BCVA, or reported symptoms.
• The observed mfERG and OCT alterations appear to be transient and mild side effects of the CXL procedure.