Photorefractive Keratectomy for Severe Anisometropia and Isoametropia Associated With Amblyopia

NCT03610997 | Terminated DMC

• 1 other identifier: H-6604
• Study Type: interventional
• Target: 200
• Locations: 1 country
• Sites: 1

Brief Summary

Photorefractive keratectomy (PRK) with excimer laser has been used successfully to treat myopia, hyperopia, and astigmatism in adults for over 35 years. Children with high refractive errors that go untreated will develop severe amblyopia. PRK can normalize high refractive errors and potentially improve the visual acuity in affected children. The purpose of this study is to investigate whether children with high anisometropia or isoametropia with amblyopia that are nonresponsive to standard therapy and receive PRK develop better longterm visual acuity.

Conditions

High Myopia; Amblyopia Isometropic; Amblyopia Bilateral; High Astigmatism; Anisometropia; Hyperopia

Outcome Measures

Primary Outcomes (1)

• Visual acuity

  Snellen equivalent

  10 years

Secondary Outcomes (2)

• Refractive error

  10 years

• Corneal clarity

  10 years

Study Arms (1)

Photorefractive keratectomy

OTHER

The children will undergo PRK in the affected eye(s) using previously derived formulas for PRK.

Procedure: Photorefractive keratectomy

Interventions

Photorefractive keratectomy PROCEDURE

Photorefractive keratectomy

Eligibility Criteria

• Age: 2 Years - 17 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Children aged 2 to 17 with significant anisometropia or isoametropia and amblyopia that have failed traditional treatment for at least 6 months.
• Anisometropic group:
• The anisometropia must be at least 3.00 diopters.
• The amblyopic eye best corrected visual acuity must be at least 2 lines worse than the fellow eye in verbal children
• Isoametropic group
• Myopia must be at least -4.00 diopters in both eyes
• Hyperopia must be at least +4.00 diopters in both eyes
• Astigmatism must be at least +2.50 diopters in both eyes.

You may not qualify if:

• History of significant corneal abnormality that, in the investigator's opinion, may limit visual rehabilitation.
• History of known collagen disorder
• History of known corneal ectasia
• History of previous herpes simplex keratitis
• Corneal thickness of less than 450u

Sponsors & Collaborators

• Baylor College of Medicine: lead

Study Sites (1)

Texas Children's Hospital

Houston, Texas, 77030, United States

Location

MeSH Terms

Conditions

Anisometropia; Hyperopia

Interventions

Photorefractive Keratectomy

Condition Hierarchy (Ancestors)

Refractive Errors; Eye Diseases

Intervention Hierarchy (Ancestors)

Corneal Surgery, Laser; Laser Therapy; Therapeutics; Ablation Techniques; Surgical Procedures, Operative; Keratectomy; Refractive Surgical Procedures; Ophthalmologic Surgical Procedures

Study Officials

• Evelyn Paysse, MD

  Baylor College of Medicine

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Ophthalmology and Pediatrics

Model Details: Photorefractive Keratectomy

Study Record Dates

• First Submitted: July 19, 2018
• First Posted: August 2, 2018
• Study Start: January 1, 2001
• Primary Completion: September 1, 2024
• Study Completion: September 1, 2024
• Last Updated: December 8, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)