NCT06312163

Brief Summary

The goal of this Prospective, single-site, cohort study is to validate rigid gas permeable corneal contact lens (RGP) designs for keratoconus derived from combining the data from corneal topography scans and contact lenses ordered in patients with keratoconus (KC) attending a UK tertiary NHS Hospital contact lens clinic. The main questions it aims to answer are:

  • Does a Scheimpflug topography derived RGP contact lens design for keratoconus have the equivalent overall contact lens fit as the patients' own lens?
  • Is the number of trial lenses required to fit a patient is reduced compared to standard practice?
  • Is the time taken to fit a contact lens is reduced compared to standard practice?
  • Is there user acceptance of the new lens?
  • Are the Axial ege lift (AEL) changes clinically significant? There will be 3 work packages WP1: For each participant data collection will take place over two visits.
  • Visit 1: Pentacam topography scans and optimal 'virtual' lens selection will take place. • • Visit 2: Participants are fitted with 4 contact lenses (i) the optimal lens design as specified by the virtual fitting module, (ii) a contact lens with a clinically significant step flatter AEL (iii) a contact lens steeper in axial edge lift (AEL) (iv) the participant's own contact lens. Each CL fit will be assessed with slit lamp photography according to the standardised method proposed by Wolffsohn et al. (2013), Anterior segment OCT MS39) (CSO Hansom Instruments, UK) and best-corrected visual acuity with each lens design using high-contrast logMAR . WP2. Participants will attend one appointment where a traditional lens fit, and a lens fitted using the topography guided 'virtual' module will be undertaken (with the fitting method selected for each eye randomised). For each fitting method the total fitting time will be measured and the total number of trial contact lenses used. Patients will be invited to complete a questionnaire that probes their satisfaction of this process. WP3. Clinicians not involved in the study will be invited to examine a demo version of the virtual fitting module and complete the validated system usability scale tool.

Trial Health

87
On Track

Trial Health Score

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

Enrollment
120

participants targeted

Target at P50-P75 for all trials

Timeline
Completed

Started Jun 2022

Geographic Reach
1 country

1 active site

Status
completed

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

Trial Relationships

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Study Timeline

Key milestones and dates

Study Start

First participant enrolled

June 6, 2022

Completed
1.5 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 15, 2023

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 15, 2023

Completed
3 months until next milestone

First Submitted

Initial submission to the registry

March 8, 2024

Completed
7 days until next milestone

First Posted

Study publicly available on registry

March 15, 2024

Completed
Last Updated

March 15, 2024

Status Verified

March 1, 2024

Enrollment Period

1.5 years

First QC Date

March 8, 2024

Last Update Submit

March 8, 2024

Conditions

Keratoconus

Keywords

rigid gas permeable contact lens

Outcome Measures

Primary Outcomes (1)

  • Rigid gas permeable contact lens fit

    The CL fit will be assessed through (i) slit lamp photography according to the standardised method proposed by Wolffsohn et al. (2013), (ii) slit lamp video of lens movement following blink in the primary position and horizontal version movements, and (iii) Anterior segment OCT MS39) (CSO Hansom Instruments, UK).

    18 months

Secondary Outcomes (3)

  • The changes in contact lens fit from increased and decreased Axial Edge lift

    18 months

  • Best corrected Visual Acuity

    18 months

  • Clinician Usability Assessment

    18 Months

Study Arms (2)

ARM1

The contact lens to be investigated in this study (Scheimpflug topography derived corneal RGP contact lens design)

Device: The contact lens to be investigated in this study (Scheimpflug topography derived corneal RGP contact lens design). A CE (UKCA) marked class 2 medical devices.

Arm2

The patient's own corneal RGP lens - CE (UKCA) marked class 2 medical devices.

Device: The contact lens to be investigated in this study (Scheimpflug topography derived corneal RGP contact lens design). A CE (UKCA) marked class 2 medical devices.

Interventions

The contact lens to be investigated in this study (Scheimpflug topography derived corneal RGP contact lens design). A CE (UKCA) marked class 2 medical devices.DEVICE

The participants will be fitted with (i) the optimal lens design as specified by the virtual fitting module, in addition to (ii) lenses that are one clinically significant step (0.12 mm) flatter and (iii) steeper in axial edge lift (AEL).

ARM1Arm2

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)
Sampling MethodNon-Probability Sample
Study Population

Patients with keratoconus (KC) attending Moorfields contact lens clinics

You may qualify if:

  • \- WP1:
  • (a) Presence of keratoconus in either eye
  • (b) Currently using a rigid gas permeable contact lens correction
  • (c) Male or female, aged 18 years or older
  • (d) The absence of significant media opacities
  • (e) No ocular pathology other than keratoconus
  • (f) Ability to understand nature/purpose of the study and to provide informed consent
  • (g) Ability to follow instructions and complete the study
  • (h) Ability to speak English
  • WP2:
  • (a) Presence of keratoconus in both eyes
  • (b) Male or female, aged 18 years or older
  • (c) The absence of significant media opacities
  • (d) No ocular pathology other than keratoconus
  • (e) Ability to understand nature/purpose of the study and to provide informed consent
  • +8 more criteria

You may not qualify if:

  • \- WP1:
  • (a) Any systemic disease likely to affect visual performance
  • (b) Any ocular disease that may affect visual performance, other than keratoconus
  • (c) Hearing impairment sufficient to interfere with hearing instructions
  • (d) Poor understanding of English language and/or alphabet
  • (e) Any condition which, in the investigator's opinion, would conflict or otherwise prevent the participant from
  • complying with the required procedures, schedule, or other study conduct.
  • (f) Not currently using a rigid gas permeable contact lens or a contraindication to this
  • (g) A history of corneal graft surgery (keratoplasty) in the eye under investigation.
  • (h) A recent history (in preceding 12 months) of corneal abrasions in the designated study eye
  • (i) A recent history (in preceding 1 month) of corneal cross linking for keratoconus
  • WP2:
  • (a) Any systemic disease likely to affect visual performance
  • (b) Any ocular disease that may affect visual performance, other than keratoconus
  • (c) Hearing impairment sufficient to interfere with hearing instructions
  • +12 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Moorfields Eye Hospital NHS Foundation Trust

London, EC1V 2PD, United Kingdom

Location

MeSH Terms

Conditions

Keratoconus

Condition Hierarchy (Ancestors)

Corneal DiseasesEye Diseases

Study Design

Study Type
observational
Observational Model
COHORT
Time Perspective
PROSPECTIVE
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

March 8, 2024

First Posted

March 15, 2024

Study Start

June 6, 2022

Primary Completion

December 15, 2023

Study Completion

December 15, 2023

Last Updated

March 15, 2024

Record last verified: 2024-03

Locations

GB(1)