Manual Debridement Vs Phototherapeutic Keratectomy in the Treatment of Corneal Basement Membrane Dystrophy

September 26, 2024 updated by: Samir Jabbour, Centre hospitalier de l'Université de Montréal (CHUM)

Comparison of Efficacy and Safety Between Manual Debridement and Phototherapeutic Keratectomy (PTK) in the Treatment of Corneal Basement Membrane Dystrophy

Of the few comparisons made in the existing literature, the results of PTK are comparable to those documented for manual debridement (MD). However, the shorter length of follow-up in patients with MD may have underestimated the associated complications. Our study, therefore, aims to offer a comparison between these two techniques to clarify the choice of effective treatment with a good safety profile.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Epithelial Basement Membrane Dystrophy (EBMD) affects the anterior cornea, impacting about 2% of the population. EBMD is characterized by alterations and duplications of the basement membrane, a tissue layer that connects the epithelium to the underlying eye tissue. Dysfunction of the basement membrane prevents proper adhesion of the overlying epithelium, leading to recurrent corneal erosions. Additionally, tissue protrusions infiltrate the epithelium, creating surface irregularities that cause symptoms like blurred vision and irregular corneal topographies. This abnormal proliferation results in microcysts and corneal irregularities resembling fingerprints and maps. These surface irregularities can be observed in optical coherence tomography (OCT) images showing epithelial thickening. Non-invasive medical treatments are the first line of therapy, including lubricating drops and hypertonic solutions to protect the ocular surface and promote epithelial adhesion. For corneal erosions, soft contact lenses are used to aid healing. Surgical interventions such as manual debridement and phototherapeutic keratectomy (PTK) are required in refractory cases. These are also indicated for patients preparing for cataract surgery to optimize preoperative corneal measurements and postoperative optical outcomes. Manual debridement (MD), a technique since 1952, involves scraping off the irregular epithelium to allow a new layer to form. Some surgeons use 20% ethanol on the cornea before scraping with a blade or sponge, preserving the basement membrane. This method is simple, cost-effective, and has an 85% success rate in treating recurrent corneal erosions. However, recurrence rates are up to 24%, with the first recurrence typically within six months. Corneal opacities can form between 7 and 41 days post-procedure. Over the past two decades, PTK has become increasingly used for anterior corneal pathologies, including EBMD. PTK uses a 193nm excimer laser to break molecular bonds between cells on the epithelial surface. It is considered a more reliable, safe, and precise alternative to manual debridement, completely obliterating the basement membrane and potentially reducing recurrence rates. Success rates without recurrence range from 46% to 100%, with minimal complications. Unlike manual debridement, PTK may induce a hyperopic shift, which stabilizes within a year. Corneal erosions and pain recur at about 13% over an average of 9.7 months. Comparative studies between these two methods are scarce, and more data is needed to favor one technique over the other. Limited comparisons suggest PTK results are comparable to manual debridement, though shorter follow-ups in MD patients may underestimate associated complications. Our study aims to compare these techniques to describe the efficacy and safety of both treatments.

Study Type

Interventional

Enrollment (Estimated)

25

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Canada
    • Quebec
      • Montreal, Quebec, Canada, H2X 3E4
        • Centre Hospitalier de l'Universite de Montreal (CHUM)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patient over 18 years of age;
  • Ability to give free and informed consent
  • At least 1-year follow-up possible
  • Patients with bilateral basal membrane corneal dystrophy who are symptomatic (recurrent corneal erosions, visual disturbances) and are candidates for bilateral surgery.

Exclusion Criteria:

  • Patient under 18 years of age;
  • History of ocular infection with herpes simplex virus.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Manual debridement
Manual debridement is a technique that has existed since 1952 and whose objective is to remove the irregular epithelium by scraping with an instrument, thus allowing the formation of a new superficial layer. Some surgeons use 20% ethanol which they apply to the cornea to debride it before using a blade or sponge to complete the procedure. In this technique, the basement membrane is preserved. This method is still used being simple and cost effective. Its effectiveness in the treatment of recurrent corneal erosions is demonstrated by a success rate estimated at 85%. Thus, it is one of the methods of treating epithelial basement membrane dystrophy. However, the recurrence rate associated with manual debridement is up to 24%, and the average duration before a first recurrence is estimated at 6 months. The formation of corneal opacities was recorded between 7 and 41 days following the intervention.
Procedure: Manual debridement
Traditional technique which consists of scraping off the irregular epithelium to allow a new layer to form.
Experimental: Phototherapeutic keratectomy
Over the past two decades, phototherapeutic keratectomy (PTK) has become an increasingly used approach for the treatment of several anterior corneal pathologies, including epithelial basement membrane dystrophy. This technique consists of directing a 193nm excimer laser towards the epithelial surface in order to break the molecular bonds between cells. PTK appears to be a more reliable, safe and precise alternative to manual debridement. Unlike manual debridement, PTK completely obliterates the basement membrane which would promote a reduction in the recurrence rate according to some experts. Thus, the success rate without recurrence has been estimated between 46 to 100% by certain studies and the associated complications are minimal.
Procedure: Phototherapeutic keratectomy
New technique which has been increasingly used and which consists of a 193nm excimer laser that breaks molecular bonds between cells on the epithelial surface.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The recurrence rate of corneal basement membrane dystrophy
Time Frame: Day 1, week 1 and months 1, 3, 6, 12 and 24 months
Evaluated with slit-lamp morphological findings (maps, "fingerprint" lines, epithelial microcysts), imaging results including OCT (thickened basement membrane and epithelial irregularities) and patient symptoms (redness, pain, photophobia, associated with erosions).
Day 1, week 1 and months 1, 3, 6, 12 and 24 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Corneal haze formation assessed by a corneal haze gradation scale
Time Frame: 1, 3, 6, 12 and 24 months

0: Clear with no opacity seen by any method of microscopic slit-lamp examination.

0.5: Trace or faint haze seen only by indirect, broad tangential illumination.

  1. Haze of minimal density seen with difficulty with direct or diffuse examination.
  2. Mild haze easily visible with direct focal slit lamp illumination.
  3. Moderate opacity that partially obscured details of iris.
  4. Severe opacity that completely obscured the details of intraocular structures.
1, 3, 6, 12 and 24 months
Contrast sensitivity with the CSV-1000 Contrast Sensitivity chart with glare
Time Frame: 1,3,6,12 and 24 months
Standardized contrast sensitivity test.
1,3,6,12 and 24 months
Patient comfort using the Wong-Baker FACES pain scale
Time Frame: Day 1, week 1, month 1, month 3, month 6 and month 12
0 = no hurt; 2= hurts a little bit; 4=hurts little more; 6=hurts even more; 8=hurts whole lot; 10=hurts worst
Day 1, week 1, month 1, month 3, month 6 and month 12
Post-operative complications
Time Frame: Day 1, week 1, month 1, month 3, month 6 and month 12
Post-operative complications include persistent epithelial deficits, formation of subepithelial corneal opacities, infectious keratitis, reactivation of herpes simplex virus, scarring, and corneal infiltrates.
Day 1, week 1, month 1, month 3, month 6 and month 12
Best corrected distance visual acuity (BCVA)
Time Frame: 1,3,6,12 and 24 months
This is the visual acuity measured using an eye chart. To achieve best possible visual acuity, corrective lenses are used.
1,3,6,12 and 24 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Centre hospitalier de l'Université de Montréal (CHUM)

Investigators

  • Principal Investigator: Samir Jabbour, MD,CM,FRCSC, Centre Hospitalier de l'Universite de Montreal (CHUM)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2024

Primary Completion (Estimated)

October 1, 2026

Study Completion (Estimated)

October 1, 2026

Study Registration Dates

First Submitted

September 26, 2024

First Submitted That Met QC Criteria

September 26, 2024

First Posted (Actual)

October 1, 2024

Study Record Updates

Last Update Posted (Actual)

October 1, 2024

Last Update Submitted That Met QC Criteria

September 26, 2024

Last Verified

September 1, 2024

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2024-12106

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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