Flattening of the cornea after collagen crosslinking for keratoconus

• Published in: Journal of cataract and refractive surgery Vol. 37; no. 8; pp. 1488 - 1492
• Main Authors: Koller, Tobias, MD, Pajic, Bojan, MD, Vinciguerra, Paolo, MD, Seiler, Theo, MD, PhD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.08.2011; Elsevier
• Subjects: Adolescent; Adult; Biological and medical sciences; Child; Cohort Studies; Collagen - metabolism; Cornea - metabolism; Cornea - pathology; Corneal Topography; Cross-Linking Reagents; Diseases of cornea, anterior segment and sclera; Female; Follow-Up Studies; Humans; Keratoconus - drug therapy; Keratoconus - metabolism; Male; Medical sciences; Middle Aged; Ophthalmology; Photosensitizing Agents - therapeutic use; Prospective Studies; Riboflavin - therapeutic use; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery of the eye and orbit; Tomography, Optical Coherence; Ultraviolet Rays; Visual Acuity; Young Adult; Eye disease; Cornea; Treatment; Keratoconus; Surgery; Collagen; Keratopathy; Ophthalmology; Anterior segment disease
• ISSN: 0886-3350; 1873-4502
• DOI: 10.1016/j.jcrs.2011.03.041

Purpose To identify preoperative parameters that may predict flattening of the keratoconic cornea after collagen crosslinking (CXL). Setting Institut für Refraktive und Ophthalmo-Chirurgie (IROC), Zurich, Switzerland. Design Cohort study. Methods Patients with verified progressive primary keratectasia received standard corneal CXL. Factors such as corrected distance visual acuity (CDVA) and Scheimpflug tomography (Pentacam) were used to follow the evolution from preoperatively to 12 months after CXL. Statistical analysis included U tests and Spearman rank correlation tests to detect risk factors for flattening of the keratoconus. Results The study enrolled 151 eyes of 151 patients; more than 80% completed the 12-month follow-up. The flattening rate (flattening of the maximum curvature >1.00 diopter [D]) was 37.7%. A preoperative maximum keratometry (K) reading of more than 54.00 D was identified as the only significant risk factor for this effect (odds ratio, 1.88; 95% confidence interval, 1.01-3.51). A restriction to corneas with a maximum K value greater than 54.00 D would have resulted in a significant flattening in 51% of the cases. Conclusions Statistically significant flattening occurred during 1 year after CXL in more than 50% of cases when the preoperative maximum K reading was more than 54.00 D. None of the other preoperative parameters evaluated (eg, age, sex, diagnosis, CDVA, corneal shape factors) had a statistically significant impact on corneal flattening after CXL. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.