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

Keratoconus Clinical Trial

Official title:

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

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT02507362
• Other study ID #: ERC/S/9341
• Status: Active, not recruiting
• Phase: Phase 1/Phase 2
• First received: August 6, 2014
• Last updated: July 22, 2015
• Start date: August 2014
• Est. completion date: February 2016

Study information

• Verified date: July 2015
• Source: Tehran University of Medical Sciences
• Contact: n/a
• Is FDA regulated: No
• Health authority: Iran: Ministry of Health
• Study type: Interventional

Clinical Trial 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)

Description:

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 of the surface with BSS (to avoid a layer of riboflavin on the cornea during irradiation) will be performed. Corneal thickness will be determined by ultrasound pachymetry. If needed, hypoosmolar solution will be used to swell the cornea over 400 µm. If 400 µm cannot be reached, then irradiation will not be performed. Then we will irradiate the eye by the UV A light source 5cm away from the eye with a light intensity of 9 mW/cm2 for 10 minutes in control group and 7 minutes in experimental group and riboflavin will be instilled after 5 minutes for further in both groups, followed by a short irrigation of the surface with BSS (to avoid a layer of riboflavin on the cornea during irradiation).

After the procedure we will apply a bandage contact lens for 5- 7 days and will prescribe topical betamethasone every 6 hours for 2 weeks, tapered to TDS, BID and HS weekly for a total duration 5 weeks. A topical antibiotic drop (Oftaquix every 6 hours) will be used for the first week.

Patients will be followed up at day 1, day 6, 1 month, 3 months and 6 months and 12 months after surgery.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 40
• Est. completion date: February 2016
• Est. primary completion date: December 2015
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 30 Years

Eligibility

Inclusion Criteria:

• Mild to moderate progressive KCN (Grade I and II) based on Amsler-krumeich classification; progression is defined as the old fashioned way in the lack of a consensus for more modern methods that is increase of > 1D of Kmax readings within 12 months

• Age> 18 y, and <35 years

• Kmax lower than 58 D

• Signing informed consent form

Exclusion Criteria:

• Any other ocular disease

• Corneal scar

• History of hydrops

• Any other ocular surgery including previous CCL, corneal inlay or keratorefractive surgery

• Inability to complete follow up schedule

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Keratoconus

Intervention

Radiation:
• adjusted corneal collagen cross-linking
UV-A irradiation for 7 minutes
• accelerated corneal collagen cross-linking
UV-A irradiation for 10 minutes

Drug:
• riboflavin 0.1% combined with dextran 20 %
after mechanical epithelial removal riboflavin drop will be instilled every 5 minutes for 30 minutes and then instillation will be continued during irradiation

Procedure:
• epithelial debridement
corneal epithelium will be removed by a cottons swab

Locations

Country	Name	City	State
Iran, Islamic Republic of	Farabi eye hospital	Tehran

Sponsors (1)

Lead Sponsor	Collaborator
Tehran University of Medical Sciences

Country where clinical trial is conducted

Iran, Islamic Republic of, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	corneal thickness		one year	No
Other	corneal hysteresis		one year	No
Other	corneal resistance factor		one year	No
Other	intraoperative discomfort and pain	Visual Analog scale	up to 1 hour	No
Primary	keratometric values on pentacam measured by Javal keratometer		one year	No
Primary	best corrected visual acuity		one year	No
Primary	uncorrected distant visual acuity		one year	No
Secondary	clinical refraction		one year	No
Secondary	endothelial cell count		one year	Yes