Topography Versus Non-Topography-Guided PRK With CXL in Keratoconus

Topography Versus Non-Topography-Guided Photorefractive Keratectomy With Corneal Cross-Linking Variations in Keratoconus

To our knowledge, this study is one of the first to compare the visual results of non-topography-guided and topography-guided photorefractive keratectomy (PRK) applying sequential and simultaneous corneal cross-linking (CXL) treatment for keratoconus. Considering recent advances in cross-linking and imaging in keratoconus, the outcomes of this study can lead us to several non-invasive algorithm management options.

Interventional and comparative prospective study: Sixty-nine eyes (38 patients) suffering from keratoconus (stages 1-2 Amsler-Krumeich classification) were divided into four groups. The four groups underwent topography- and non-topography-guided PRK with sequential and simultaneous CXL. The main outcome measures were pre- and postoperative uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (CDVA), manifest refraction, contrast sensitivity, and keratometry.

Inclusion criteria

• age 34 (range from 34 to 41)
• stable corneal topography and refraction for at least six months
• estimated residual bed thickness of >410 µm

Exclusion

• presence of macular or retinal disease,
• dry eye
• history of recurrent corneal erosions
• anterior segment abnormalities
• unstable refractive error
• post-surgically residual stromal bed thickness of under 350 mm
• autoimmune disease
• collagen vascular disease
• immunosuppressive therapy or current use of systemic corticosteroids
• diabetes mellitus
• pregnancy
• lactation