Clinical Trial: Adapted Fluence Settings for Corneal Collagen Cross-linking in Mild to Moderate Progressive Keratoconus

Study Status: Active, not recruiting
Recruit Status: Active, not recruiting
Study Type: Interventional

Official Title: Adapted Fluence Settings for Corneal Collagen Cross-linking in Progressive Mild to Moderate Keratoconus Aged 18 to 30

Brief Summary: the purpose of this study is to compare the efficacy and safety of a new method of corneal cross-linking that uses UV-A irradiation intensity of 9mW/cm2 for 7 minutes to well-known Accelerated corneal cross-linking (9 mW/cm2 UV-A irradiation for 10 minutes)

Detailed Summary:

This study is a Prospective interventional clinical trial comparing two groups of mild to moderate progressive keratoconic patients; Control group will be treated with routine accelerated protocol of corneal cross-linking, while exposure time will be decreased in the experimental group.

we considered two groups of patients in our study:

  • Group 1 (experimental): Exposure to 7 minutes at 9 mW/cm2 = 3.78 J/cm2
  • Group 2 (controls): Exposure to 10 minutes at 9 mW/cm2 = 5.4 J/cm2

All demographic data of patients, their uncorrected distance visual acuity (UCDVA), corrected distance visual acuity (BCDVA), sphere and cylinder refraction, keratometry readings (k1 and k2) and other topographic parameters of the patients before the procedure and at every follow up visit will be recorded.

Corneal hysteresis and resistance factor will be checked by Ocular response analyzer before surgery and will be rechecked at 6 month follow up.

Intraoperative pain will also be recorded based on the visual analog scale (VAS + FACES pain scale) immediately after the completion of surgery.

Confocal microscopy will be used to evaluate changes in corneal stromal collagen fibers and keratocytes following cross-linking at 3 and 6 and 12 month post op period.

All procedures will be done by a single surgeon. We will use topical anesthesia by tetracaine followed by mechanical epithelial debridement at a radius of 9 millimeters. Then riboflavin 0.1% combined with dextran 20 % will be instilled every 3 minutes for 25 minutes. A short irrigation o
Sponsor: Tehran University of Medical Sciences

Current Primary Outcome:

  • keratometric values on pentacam measured by Javal keratometer [ Time Frame: one year ]
  • best corrected visual acuity [ Time Frame: one year ]
  • uncorrected distant visual acuity [ Time Frame: one year ]


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • clinical refraction [ Time Frame: one year ]
  • endothelial cell count [ Time Frame: one year ]


Original Secondary Outcome: Same as current

Information By: Tehran University of Medical Sciences

Dates:
Date Received: August 6, 2014
Date Started: August 2014
Date Completion: February 2016
Last Updated: July 22, 2015
Last Verified: July 2015