title: Collagen cross-linking in keratoconus in Asian eyes: visual, refractive and confocal microscopy outcomes in a prospective randomized controlled trial.
abstract: To evaluate the safety and efficacy of collagen cross-linking (CXL) in the treatment of keratoconus. A prospective randomized sham-controlled clinical trial was undertaken and 43 eyes with moderate to severe keratoconus were randomized into two groups that is the treatment (n = 23) and the sham (n = 20) group. CXL was performed with riboflavin (0.1 in 20 % dextran) followed by UVA radiation (365 nm, 3 mW/cm(2), 30 min). In the sham group, only riboflavin was administered without UVA radiation. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity, intraocular pressure, corneal thickness, keratometry, endothelial count, confocal microscopy were evaluated at baseline and at 1 week, 1, 3, and 6 months. In cases where CXL was done, UDVA improved by mean 0.11 ± 0.06 logMAR units at 6 months (P = 0.01). The refractive cylinder and spherical equivalent decreased by mean of 0.62 D (P = 0.01) and 0.5 D (P = 0.19), respectively. Ultrasonic central corneal thickness decreased by mean 22.7 ± 10.3 μm (P = 0.01). The maximum and minimum keratometry decreased by mean of 1.2 ± 0.8 D (P = 0.01) and 0.83 ± 1.2 D (P = 0.39), respectively. The specular count and intraocular pressure did not show any significant change. In the sham group, no significant change was observed in any parameter. Confocal analysis showed that the epithelial healing was complete at 1 week after crosslinking. The sub-epithelial plexus showed loss of nerve plexus at 1 month, regeneration of nerve fibers which started at 3 months and was complete at 6 months. The anterior stroma showed loss of keratocytes with honeycomb oedema and apoptotic bodies till 3 months. The regeneration of keratocytes started at 3 months and was complete at 6 months of follow-up. Collagen cross-linking is an effective procedure to halt progression in keratoconus. The confocal microscopic changes correlate with the outcomes in the treatment and the sham groups.
authors.affiliation: Cornea and Refractive Surgery Services, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110026, India. namrata.sharma@gmail.com.
authors.forename: Namrata
authors.initials: N
authors.lastname: Sharma
authors.affiliation: Cornea and Refractive Surgery Services, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110026, India.
authors.forename: Kunal
authors.initials: K
authors.lastname: Suri
authors.affiliation: Cornea and Refractive Surgery Services, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110026, India.
authors.forename: Sri Vatsa
authors.initials: SV
authors.lastname: Sehra
authors.affiliation: Cornea and Refractive Surgery Services, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110026, India.
authors.forename: Jeewan S
authors.initials: JS
authors.lastname: Titiyal
authors.affiliation: Cornea and Refractive Surgery Services, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110026, India.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Sinha
authors.affiliation: Cornea and Refractive Surgery Services, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110026, India.
authors.forename: Radhika
authors.initials: R
authors.lastname: Tandon
authors.affiliation: Cornea and Refractive Surgery Services, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110026, India.|Centre for Eye Research Australia, University of Melbourne, Melbourne, VIC, Australia.|Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia.
authors.forename: Rasik B
authors.initials: RB
authors.lastname: Vajpayee
mesh_terms: D000293:Adolescent; D000328:Adult; D003094:Collagen / Q000378:metabolism; D003315:Cornea / Q000473:pathology; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D015603:Keratinocytes / Q000473:pathology; D007640:Keratoconus / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D018613:Microscopy, Confocal; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011446:Prospective Studies; D012030:Refractive Errors / Q000503:physiopathology; D012256:Riboflavin / Q000627:therapeutic use; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin
keywords: Collagen cross linking; Confocal microscopy; Keratoconus