NCT03841253

Brief Summary

This study sets out to evaluate the EpiMaster application software for use in predicting the refractive change induced by a trans-epithelial phototherapeutic keratectomy (TE-PTK) procedure in eyes with irregularly irregular astigmatism. If validation criteria are met during the observational phase, the software refractive prediction will be used to plan the refractive correction in TE-PTK treatments.

Trial Health

75
On Track

Trial Health Score

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

Enrollment
45

participants targeted

Target at P25-P50 for not_applicable

Timeline
31mo left

Started Aug 2019

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
active not recruiting

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

Study Progress73%
Aug 2019Nov 2028

First Submitted

Initial submission to the registry

February 12, 2019

Completed
3 days until next milestone

First Posted

Study publicly available on registry

February 15, 2019

Completed
6 months until next milestone

Study Start

First participant enrolled

August 1, 2019

Completed
8.6 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 1, 2028

Expected
8 months until next milestone

Study Completion

Last participant's last visit for all outcomes

November 1, 2028

Last Updated

February 12, 2026

Status Verified

February 1, 2026

Enrollment Period

8.6 years

First QC Date

February 12, 2019

Last Update Submit

February 10, 2026

Conditions

Corneal Astigmatism

Keywords

Trans-epithelial phototherapeutic keratectomyPTKTE-PTKCorneal epitheliumExcimer laser

Outcome Measures

Primary Outcomes (2)

  • The tendency of manifest sphere, cylinder and axis

    The correct tendency of manifest sphere, cylinder and axis should be achieved in 90% of cases, where tendency refers to: 1. The sign of the predicted and the post-operative sphere is equal for predicted sphere values greater than absolute value 0.50 D (confidence limit) 2. The sign of the predicted and the post-operative cylinder is equal (same cylinder format setting like e.g. plus cylinder format) for predicted cylinder values greater than absolute value 0.50 D (confidence limit) 3. The cylinder axis of the predicted and the post-operative cylinder do not deviate by more than ±45° for predicted cylinder values greater than absolute value 0.50 D (confidence limit) 4. In none of the cases the prediction in sphere and cylinder is more than absolute value 2.00 D off the post-operative values.

    3-12 months

  • Standard deviation of SEpostop-SEpredicted

    Standard deviation of SEpostop-SEpredicted at each follow-up time point (represents the scatter of the refractive outcome), where SEpredicted is the refractive outcome predicted by the EpiMaster application software.

    12 months

Study Arms (3)

Observational Phase 1

OTHER

A trans-epithelial PTK procedure will be performed using the MEL 90 excimer laser. The refractive outcome will be compared to the refractive change predicted by the EpiMaster application software. Data is collected prospectively.

Procedure: Trans-epithelial PTK

Observational Phase 1b

OTHER

A trans-epithelial PTK procedure will be performed using the MEL 90 excimer laser. The refractive outcome will be compared to the refractive change predicted by the EpiMaster application software. Data is collected retrospectively.

Procedure: Trans-epithelial PTK (retrospective data collection)

Treatment Phase 2

EXPERIMENTAL

If the transition criteria are met during the observational phase, the treatment phase will be initiated. A trans-epithelial PTK procedure will be performed using the MEL 90 excimer laser, including a refractive component according to the values determined using the EpiMaster application software.

Procedure: EpiMaster Application Software

Interventions

Trans-epithelial PTKPROCEDURE

The MEL 90 excimer laser will be used to ablate the corneal epithelium and stroma to a pre-defined depth, using the epithelium as a natural masking agent to smooth the stromal surface.

Observational Phase 1
Trans-epithelial PTK (retrospective data collection)PROCEDURE

The MEL 90 excimer laser will be used to ablate the corneal epithelium and stroma to a pre-defined depth, using the epithelium as a natural masking agent to smooth the stromal surface.

Observational Phase 1b
EpiMaster Application SoftwarePROCEDURE

The EpiMaster Application Software imports epithelial thickness data and corneal front surface topography data, and uses this to calculate the refractive change that would be induced by a trans-epithelial PTK treatment.

Treatment Phase 2

Eligibility Criteria

Age21 Years - 70 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Patient presents with topographic irregularly irregular astigmatism and associated quality of vision issues, where TE-PTK would be a more effective treatment than topography-guided ablation or other therapeutic treatment options.
  • Medically suitable for corneal laser refractive surgery.
  • Calculated residual stromal thickness ≥250 µm.
  • Subjects should be 21 years of age or older.
  • Contact lens wearers must stop wearing their contact lenses one week per decade of wear before baseline measurements in case of hard contact lenses and one week before baseline measurements in case of soft contact lenses.
  • Patient will be able to understand the patient information and willing to sign an informed consent.
  • Patient will be willing to comply with all follow-up visits and the respective examinations.

You may not qualify if:

  • Patient not being able to tolerate local or topical anesthesia
  • Autoimmune diseases
  • Sicca syndrome, dry eye
  • Herpes viral (herpes simplex) infections
  • Herpes zoster
  • Diabetes
  • Pregnant or nursing women (or who are planning pregnancy during the study)
  • Patients with a weight of \> 135 kg
  • Any residual, recurrent or acute ocular disease or abnormality of the eye, e.g.
  • Cataract
  • Suspected glaucoma or an intraocular pressure \> 21 mm of Hg
  • Corneal disease
  • Corneal thinning disorder, e.g. keratoconus,
  • Pellucid marginal corneal degeneration
  • Dystrophy of the basal membrane
  • +9 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

London Vision Clinic

London, W1G 7LA, United Kingdom

Location

Related Publications (5)

  • Reinstein DZ, Archer TJ, Gobbe M. Refractive and topographic errors in topography-guided ablation produced by epithelial compensation predicted by 3D Artemis VHF digital ultrasound stromal and epithelial thickness mapping. J Refract Surg. 2012 Sep;28(9):657-63. doi: 10.3928/1081597X-20120815-02.

    PMID: 22947295BACKGROUND

  • Reinstein DZ, Archer TJ, Gobbe M. Improved effectiveness of transepithelial PTK versus topography-guided ablation for stromal irregularities masked by epithelial compensation. J Refract Surg. 2013 Aug;29(8):526-33. doi: 10.3928/1081597X-20130719-02.

    PMID: 23909779BACKGROUND

  • Reinstein DZ, Archer TJ, Dickeson ZI, Gobbe M. Transepithelial phototherapeutic keratectomy protocol for treating irregular astigmatism based on population epithelial thickness measurements by artemis very high-frequency digital ultrasound. J Refract Surg. 2014 Jun;30(6):380-7. doi: 10.3928/1081597X-20140508-01.

    PMID: 24972404BACKGROUND

  • Guglielmetti S, Kirton A, Reinstein DZ, Carp GI, Archer TJ. Repair of Irregularly Irregular Astigmatism by Transepithelial Phototherapeutic Keratectomy. J Refract Surg. 2017 Oct 1;33(10):714-719. doi: 10.3928/1081597X-20170721-04.

    PMID: 28991341BACKGROUND

  • Reinstein DZ, Archer T. Combined Artemis very high-frequency digital ultrasound-assisted transepithelial phototherapeutic keratectomy and wavefront-guided treatment following multiple corneal refractive procedures. J Cataract Refract Surg. 2006 Nov;32(11):1870-6. doi: 10.1016/j.jcrs.2006.07.016.

    PMID: 17081871BACKGROUND

MeSH Terms

Conditions

Astigmatism

Condition Hierarchy (Ancestors)

Refractive ErrorsEye Diseases

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Model Details: Phase 1 will be observational comparing the software predicted refractive change to the observed refractive change. Data will be collected prospectively. Phase 1b will be observational comparing the software predicted refractive change to the observed refractive change. Data will be collected retrospectively. Phase 2 will use the software predicted refractive change to plan the refractive component of the treatment.
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

February 12, 2019

First Posted

February 15, 2019

Study Start

August 1, 2019

Primary Completion (Estimated)

March 1, 2028

Study Completion (Estimated)

November 1, 2028

Last Updated

February 12, 2026

Record last verified: 2026-02

Data Sharing

IPD Sharing
Will not share

Participant data will not be shared with other researchers.

Locations

GB(1)