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Refractive Treatment of Early Keratoconus

Primary Purpose

Keratoconus

Status

Unknown status

Phase

Phase 3

Locations

Study Type

Interventional

Intervention

Crosslinking

Photorefractive keratectomy

iDesign® Advanced WaveScan Studio

About this trial

This is an interventional treatment trial for Keratoconus

Eligibility Criteria

21 Years - 60 Years (Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

Group 1:

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

Exclusion Criteria:

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

Sites / Locations

Arms of the Study

Arm 1

Arm 2

Arm Type

Active Comparator

Arm Label

Sequential group

Simultaneous group

Arm Description

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

Photorefractive keratectomy and crosslinking will be performed on the same day

Outcomes

Primary Outcome Measures

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.

Secondary Outcome Measures

Intraoperative and postoperative complications

Number of patients with unexpected complications, as well as the type of complication will be collected over 1 year of followups.

Full Information

NCT ID

NCT02613780

First Posted

November 17, 2015

Last Updated

December 11, 2015

Sponsor

Ottawa Hospital Research Institute

Collaborators

Abbott Medical Optics

1. Study Identification

Unique Protocol Identification Number

NCT02613780

Brief Title

Refractive Treatment of Early Keratoconus

Official Title

iDesign Aberrometer for the Refractive Treatment of Early Keratoconus

Study Type

Interventional

2. Study Status

Record Verification Date

December 2015

Overall Recruitment Status

Unknown status

Study Start Date

January 2016 (undefined)

Primary Completion Date

January 2017 (Anticipated)

Study Completion Date

January 2019 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title

Sponsor

Name of the Sponsor

Ottawa Hospital Research Institute

Collaborators

Abbott Medical Optics

4. Oversight

Data Monitoring Committee

Yes

5. Study Description

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.

Detailed Description

The purpose of this pilot study is to assess the visual outcomes of combined wavefront-guided PRK and CXL in Krumeich stage 1 and 2 keratoconic eyes. The investigators will be conducting a prospective study at the University of Ottawa Eye Institute. A total of 24 patients will be enrolled in the study divided into two groups: Group 1: PRK performed12-18 months after CXL; Group 2: PRK performed or on the same day as CXL Participants will be followed at regular intervals for 1 year and information regarding visual, refractive, keratometric and higher order aberration outcomes will be collected. The researchers aim to investigate the safety and efficacy of combined wavefront guided PRK and CXL. Results of this pilot study will used to provide estimates for sample size calculation for an extension of the study, which aims to determine whether sequential or same day procedure leads to better outcomes.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study

Keratoconus

7. Study Design

Primary Purpose

Treatment

Study Phase

Phase 3

Interventional Study Model

Parallel Assignment

Masking

None (Open Label)

Allocation

Non-Randomized

Enrollment

24 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title

Sequential group

Arm Type

Active Comparator

Arm Description

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

Arm Title

Simultaneous group

Arm Type

Active Comparator

Arm Description

Photorefractive keratectomy and crosslinking will be performed on the same day

Intervention Type

Procedure

Intervention Name(s)

Crosslinking

Intervention Description

corneal collagen crosslinking with riboflavin

Intervention Type

Procedure

Intervention Name(s)

Photorefractive keratectomy

Intervention Type

Device

Intervention Name(s)

iDesign® Advanced WaveScan Studio

Intervention Description

Used to map wavefront aberration in planning photorefractive keratectomy

Primary Outcome Measure Information:

Title

Improvement in best-corrected visual acuity at followups

Description

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.

Time Frame

1 year

Secondary Outcome Measure Information:

Title

Intraoperative and postoperative complications

Description

Number of patients with unexpected complications, as well as the type of complication will be collected over 1 year of followups.

Time Frame

1 year

10. Eligibility

Sex

All

Minimum Age & Unit of Time

21 Years

Maximum Age & Unit of Time

60 Years

Accepts Healthy Volunteers

Eligibility Criteria

Inclusion Criteria: Group 1: 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 Exclusion Criteria: 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

Central Contact Person:

First Name & Middle Initial & Last Name or Official Title & Degree

Setareh Ziai, MD, FRCSC

ziaieye@gmail.com

12. IPD Sharing Statement

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Refractive Treatment of Early Keratoconus

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