Back to resultsExploring the Psychophysics of Keratoconus Using the Moorfields Acuity Chart (MACK)
Primary Purpose
Keratoconic Subjects
Status
Completed
Phase
Not Applicable
Locations
Study Type
Interventional
Intervention
Moorfields Acuity Chart
Sponsored by
About this trial
This is an interventional basic science trial for Keratoconic Subjects
Eligibility Criteria
Keratoconic subjects (50):
- Age 18-40 years.
- The presence of keratoconus in at least one eye.
- The absence of significant media opacities (e.g. cataract, corneal scarring).
- The absence of any other ocular pathology (e.g. glaucoma, diabetic retinopathy, uveitis).
- The absence of amblyopia in the test eye.
- No previous ocular surgery (e.g. corneal crosslinking, cataract surgery, etc.)
- Best corrected visual acuity better than or equal to 6/60 (1.0 logMAR).
- Pupil diameter ≥3 mm and ≤7 mm in normal room illumination.
Healthy subjects (30):
- Age 18-35 years.
- The absence of clinically significant keratoconus.
- The absence of significant media opacities. (e.g. cataract, corneal scarring).
- The absence of any other ocular pathology (e.g. glaucoma, diabetic retinopathy, uveitis).
- The absence of amblyopia in the test eye.
- No previous ocular surgery (e.g. corneal crosslinking, cataract surgery, etc.)
- Best corrected visual acuity better than or equal to 6/9 (0.1 logMAR).
- Pupil diameter ≥3 mm and ≤7 mm in normal room illumination.
Sites / Locations
Arms of the Study
Arm 1
Arm 2
Arm Type
Experimental
Experimental
Arm Label
Keratoconic subjects
Healthy subjects
Arm Description
Short clinical interview (Questions pertaining to ocular and systemic health, medications, family history and date of birth). (approx. 2 minutes) Visual acuity measurement using EDTRS chart at 4 m (approx. 4 minutes) Refraction: retinoscopy and subjective, at 4m (approx. 10 minutes) Anterior eye examination (approx. 4 minutes) Fundus examination using binocular indirect ophthalmoscopy or a standard ophthalmoscope - to screen for eye disease that is likely to affect visual ability in this study. (approx. 5 minutes) Corneal topography measurement with an Oculus Pentacam (Oculus Gmbh., Germany). (approx. 5 minutes) Two measurements of visual acuity will be made: Standard ETDRS logMAR acuity measurement (5 minutes) Vanishing Optotype logMAR acuity measurement (5 minutes)
Short clinical interview (Questions pertaining to ocular and systemic health, medications, family history and date of birth). (approx. 2 minutes) Visual acuity measurement using EDTRS chart at 4 m (approx. 4 minutes) Refraction: retinoscopy and subjective, at 4m (approx. 10 minutes) Anterior eye examination (approx. 4 minutes) Fundus examination using binocular indirect ophthalmoscopy or a standard ophthalmoscope - to screen for eye disease that is likely to affect visual ability in this study. (approx. 5 minutes) Corneal topography measurement with an Oculus Pentacam (Oculus Gmbh., Germany). (approx. 5 minutes) Two measurements of visual acuity will be made: Standard ETDRS logMAR acuity measurement (5 minutes) Vanishing Optotype logMAR acuity measurement (5 minutes)
Outcomes
Primary Outcome Measures
The relative difference in visual acuity measurement between subjects with and without keratoconus when examined with different types of visual acuity chart.
Secondary Outcome Measures
The relationship (if any) between optical imperfections (high order aberrations) and measurements of visual acuity when measured using different test chart designs.
Full Information
NCT ID
NCT02429609
First Posted
April 9, 2015
Last Updated
April 4, 2022
Sponsor
Moorfields Eye Hospital NHS Foundation Trust
1. Study Identification
Unique Protocol Identification Number
NCT02429609
Brief Title
Exploring the Psychophysics of Keratoconus Using the Moorfields Acuity Chart
Acronym
MACK
Official Title
Exploring the Psychophysics of Keratoconus Using the Moorfields Acuity Chart
Study Type
Interventional
2. Study Status
Record Verification Date
April 2022
Overall Recruitment Status
Completed
Study Start Date
April 15, 2015 (Actual)
Primary Completion Date
April 30, 2016 (Actual)
Study Completion Date
April 30, 2016 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Moorfields Eye Hospital NHS Foundation Trust
4. Oversight
Data Monitoring Committee
No
5. Study Description
Brief Summary
The measurement of visual acuity is made using black letters of varying size superimposed on a uniform white background. The objective is to determine the smallest letter, or optotype, that can be correctly identified. One limitation of current tests is the variability of measurements, this making it difficult for clinicians to determine if changes in visual acuity are related to ocular disease. This variability has been attributed to the design of current optotypes, in particular their differing legibilities. Our group has recently demonstrated that a new type of letter chart (Moorfields Acuity Chart), containing letters with a black core and a white border presented on a grey background, reduces the variability of visual acuity measurements. In this study the investigators wish to determine if changes in vision owing to keratoconus, a disease that causes the cornea to adopt an irregular shape, may be detected more easily using the Moorfields Acuity Chart compared with conventional letter charts.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Keratoconic Subjects
7. Study Design
Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Single Group Assignment
Model Description
This in a basic science exploratory study to examine the effect of keratoconus on visual acuity as measured using pseudo-high-pass filtered optotypes. The MAC will be compared with the standard charts currently used to monitor visual acuity (logMAR chart) and contrast sensitivity (Pelli-Robson). "Researcher effects" and "researcher bias" will be controlled by setting a written protocol for all testing procedures. Each procedure will be standardised and random checks will be made by the chief investigator on all anonymous record sheets. Neither the chief investigator nor the co-researchers will act as participants for this study.
Masking
None (Open Label)
Allocation
Non-Randomized
Enrollment
80 (Actual)
8. Arms, Groups, and Interventions
Arm Title
Keratoconic subjects
Arm Type
Experimental
Arm Description
Short clinical interview (Questions pertaining to ocular and systemic health, medications, family history and date of birth). (approx. 2 minutes)
Visual acuity measurement using EDTRS chart at 4 m (approx. 4 minutes)
Refraction: retinoscopy and subjective, at 4m (approx. 10 minutes)
Anterior eye examination (approx. 4 minutes)
Fundus examination using binocular indirect ophthalmoscopy or a standard ophthalmoscope - to screen for eye disease that is likely to affect visual ability in this study. (approx. 5 minutes)
Corneal topography measurement with an Oculus Pentacam (Oculus Gmbh., Germany). (approx. 5 minutes)
Two measurements of visual acuity will be made:
Standard ETDRS logMAR acuity measurement (5 minutes)
Vanishing Optotype logMAR acuity measurement (5 minutes)
Arm Title
Healthy subjects
Arm Type
Experimental
Arm Description
Short clinical interview (Questions pertaining to ocular and systemic health, medications, family history and date of birth). (approx. 2 minutes)
Visual acuity measurement using EDTRS chart at 4 m (approx. 4 minutes)
Refraction: retinoscopy and subjective, at 4m (approx. 10 minutes)
Anterior eye examination (approx. 4 minutes)
Fundus examination using binocular indirect ophthalmoscopy or a standard ophthalmoscope - to screen for eye disease that is likely to affect visual ability in this study. (approx. 5 minutes)
Corneal topography measurement with an Oculus Pentacam (Oculus Gmbh., Germany). (approx. 5 minutes)
Two measurements of visual acuity will be made:
Standard ETDRS logMAR acuity measurement (5 minutes)
Vanishing Optotype logMAR acuity measurement (5 minutes)
Intervention Type
Device
Intervention Name(s)
Moorfields Acuity Chart
Primary Outcome Measure Information:
Title
The relative difference in visual acuity measurement between subjects with and without keratoconus when examined with different types of visual acuity chart.
Time Frame
9 months
Secondary Outcome Measure Information:
Title
The relationship (if any) between optical imperfections (high order aberrations) and measurements of visual acuity when measured using different test chart designs.
Time Frame
9 months
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
35 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Keratoconic subjects (50):
Age 18-40 years.
The presence of keratoconus in at least one eye.
The absence of significant media opacities (e.g. cataract, corneal scarring).
The absence of any other ocular pathology (e.g. glaucoma, diabetic retinopathy, uveitis).
The absence of amblyopia in the test eye.
No previous ocular surgery (e.g. corneal crosslinking, cataract surgery, etc.)
Best corrected visual acuity better than or equal to 6/60 (1.0 logMAR).
Pupil diameter ≥3 mm and ≤7 mm in normal room illumination.
Healthy subjects (30):
Age 18-35 years.
The absence of clinically significant keratoconus.
The absence of significant media opacities. (e.g. cataract, corneal scarring).
The absence of any other ocular pathology (e.g. glaucoma, diabetic retinopathy, uveitis).
The absence of amblyopia in the test eye.
No previous ocular surgery (e.g. corneal crosslinking, cataract surgery, etc.)
Best corrected visual acuity better than or equal to 6/9 (0.1 logMAR).
Pupil diameter ≥3 mm and ≤7 mm in normal room illumination.
12. IPD Sharing Statement
Learn more about this trial
Exploring the Psychophysics of Keratoconus Using the Moorfields Acuity Chart
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