NCT02613780

Brief Summary

Keratoconus is a bilateral, progressive corneal degenerative disorder that often leads to significant visual deterioration over time. Corneal collagen crosslinking with riboflavin (CXL) was developed as a treatment to halt the progression of keratoconus and thus negate the need for corneal transplantation. However, the treatment alone has little impact in terms of improving visual function. Photorefractive keratectomy (PRK) is the application of an excimer laser to treat a patient's refractive error, therefore decreasing the dependence on spectacles or contact lenses for improved vision. Corneal collagen crosslinking combined with photorefractive keratectomy has been explored to partially correct the refractive error in keratoconic patients, whilst simultaneously stabilizing the corneal changes. Recently, the iDesign® Advanced WaveScan Studio (iDesign system; Abbot Medical Optics; Santa Ana, CA) has been launched as the most advanced high-resolution aberrometer. It is capable of mapping highly aberrated corneas for wavefront-guided laser procedures, and represents an important technological advance in treating corneal disease. The purpose of this single center, prospective pilot study is to assess the safety and efficacy of combined wavefront-guided PRK and CXL in patients with early keratoconus using the iDesign® aberrometer. Results of this pilot study will be used to provide sample size estimates for an extension of the study, which aims to determine whether sequential or same day procedure leads to better outcomes.

Trial Health

35
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
24

participants targeted

Target at below P25 for phase_3

Timeline
Completed

Started Jan 2016

Typical duration for phase_3

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

November 17, 2015

Completed
8 days until next milestone

First Posted

Study publicly available on registry

November 25, 2015

Completed
1 month until next milestone

Study Start

First participant enrolled

January 1, 2016

Completed
1 year until next milestone

Primary Completion

Last participant's last visit for primary outcome

January 1, 2017

Completed
2 years until next milestone

Study Completion

Last participant's last visit for all outcomes

January 1, 2019

Completed
Last Updated

December 14, 2015

Status Verified

December 1, 2015

Enrollment Period

1 year

First QC Date

November 17, 2015

Last Update Submit

December 11, 2015

Conditions

Outcome Measures

Primary Outcomes (1)

  • Improvement in best-corrected visual acuity at followups

    Best-corrected visual acuity (BCVA) will be measured in logMAR. Preoperative BCVA will be compared to BCVA postoperatively and at followups over 1 year using paired t tests.

    1 year

Secondary Outcomes (1)

  • Intraoperative and postoperative complications

    1 year

Study Arms (2)

Sequential group

ACTIVE COMPARATOR

Photorefractive keratectomy will be performed 12-18 months after participants had crosslinking

Procedure: CrosslinkingProcedure: Photorefractive keratectomyDevice: iDesign® Advanced WaveScan Studio

Simultaneous group

ACTIVE COMPARATOR

Photorefractive keratectomy and crosslinking will be performed on the same day

Procedure: CrosslinkingProcedure: Photorefractive keratectomyDevice: iDesign® Advanced WaveScan Studio

Interventions

CrosslinkingPROCEDURE

corneal collagen crosslinking with riboflavin

Sequential groupSimultaneous group
Sequential groupSimultaneous group

Used to map wavefront aberration in planning photorefractive keratectomy

Sequential groupSimultaneous group

Eligibility Criteria

Age21 Years - 60 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64)

You may qualify if:

  • Group 1:
  • \. Patients with confirmed diagnosis of keratoconus in Krumeich stage 1 or 2 who have received crosslinking 12-18 months prior, with follow up of at least 12 months
  • Group 2:
  • Diagnosis of keratoconus confirmed based on clinical examination findings and corneal topography
  • Evidence of progression of keratoconus occurring over the last 12 months defined as:
  • i. An increase of maximum keratometry reading by 1 diopter or more (≥ 1 D), or ii. Evidence of clinical progression
  • Age between 21 and 60 years
  • Eyes satisfying all of Krumeich stage 1 or 2 criteria listed below i. Stage 1: eccentric corneal bulging, myopia, and/or astigmatism \<5 D and corneal radius ≤48 D, no corneal opacities ii. Stage 2: myopia and/or astigmatism \>5 D and \<8 D and/or corneal radius ≤53 D, no central opacities, pachymetry ≥400 μm

You may not qualify if:

  • Age less than 21 years, or older than 60 years
  • Pregnant, or planning to become pregnant, or breastfeeding
  • Past history of Herpes Simplex Keratitis or corneal surgery (other than crosslinking)
  • Thin Cornea (\<425 microns)
  • Other corneal disease, corneal scarring
  • History of chemical burns to the cornea or known healing problems
  • Known allergy to Riboflavin (vitamin B2)
  • If patient suffers from nystagmus or any other condition that would render it difficult for the patient to hold a steady gaze
  • Very advanced corneal ectasia (beyond Krumeich stage 2)
  • Poor visual potential
  • Vitamin C supplements within 1 week of the procedure
  • Lenticular changes (cataracts)
  • Programmed PRK treatment exceeding 50 microns in tissue depth

Contact the study team to confirm eligibility.

Sponsors & Collaborators

MeSH Terms

Conditions

Keratoconus

Interventions

Photorefractive Keratectomy

Condition Hierarchy (Ancestors)

Corneal DiseasesEye Diseases

Intervention Hierarchy (Ancestors)

Corneal Surgery, LaserLaser TherapyTherapeuticsAblation TechniquesSurgical Procedures, OperativeKeratectomyRefractive Surgical ProceduresOphthalmologic Surgical Procedures

Central Study Contacts

Setareh Ziai, MD, FRCSC

CONTACT

Study Design

Study Type
interventional
Phase
phase 3
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

November 17, 2015

First Posted

November 25, 2015

Study Start

January 1, 2016

Primary Completion

January 1, 2017

Study Completion

January 1, 2019

Last Updated

December 14, 2015

Record last verified: 2015-12