Spectacles for correcting irregular astigmatism in patients with keratoconus
| ISRCTN | ISRCTN15964758 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN15964758 |
| IRAS number | 282471 |
| Secondary identifying numbers | UoL001582, IRAS 282471, CPMS 49194 |
- Submission date
- 13/03/2023
- Registration date
- 28/03/2023
- Last edited
- 03/04/2023
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Eye Diseases
Plain English Summary
Background and study aims
Keratoconus occurs when the cornea (front surface of the eye) thins and bulges outward into a cone shape, causing blurred vision. This study aims to create spectacle lenses that correct irregular astigmatism for keratoconic patients. As advanced keratoconic patients find difficulty in their daily life when they cannot wear their contact lenses, this study will be a step towards developing spectacles that can maintain a reasonable visual acuity. The study addresses the visual side effects of the resultant distortion with the development of spectacle lenses that can correct non-orthogonal astigmatism. This is not possible with current spectacle lens manufacturing techniques, leaving patients with this condition entirely dependent on contact lenses, or in severe cases, corneal transplants, to achieve reasonable visual acuity.
Who can participate?
Keratoconus patients aged 18 years and over
What does the study involve?
Visual acuity is measured at a single visit with no follow-up.
What are the possible benefits and risks of participating?
Participation has no direct benefit, and risks are minimal as it is like trying a pair of glasses.
Where is the study run from?
Royal Liverpool University Hospital
When is the study starting and how long is it expected to run for?
July 2021 to December 2022
Who is funding the study?
1. Fight for Sight (UK)
2. Keratoconus Group (UK)
Who is the main contact?
Dr Ahmed Abass, amfabass@liverpool.ac.uk
Contact information
Principal Investigator
Department of Mechanical, Materials and Aerospace Engineering
School of Engineering, University of Liverpool
Brownlow Hill
Liverpool
L69 3GH
United Kingdom
 ORCID ID |
0000-0002-8622-4632 |
|---|---|
| Phone | +44 (0)151 794 5229 |
| a.abass@liverpool.ac.uk |
Study information
| Study design | Prospective controlled observational study |
|---|---|
| Primary study design | Observational |
| Secondary study design | Cross sectional study |
| Study setting(s) | Hospital |
| Study type | Treatment |
| Participant information sheet | Not available in web format, please use the contact details to request a participant information sheet |
| Scientific title | Spectacles for correcting irregular astigmatism in keratoconic patients |
| Study hypothesis | An earlier analytical study indicated that the higher the degree of non-orthogonal astigmatism the larger the benefit to the patient’s visual acuity (Abass, Lopes et al. 2019). This study will assess this prediction and identify those candidates who stand to benefit most from using non-orthogonal lenses. Those candidates will be identified based on their topography power maps. As conventional topographers’ software packages are measuring orthogonal astigmatism only, a special custom-built MATLAB code will be developed to locate the non-orthogonal astigmatism axes and determine if the patient is a good candidate for this treatment. |
| Ethics approval(s) | Approved 08/07/2021, London - Bromley Research Ethics Committee (Temple Quay House, 2 The Square, Temple Quay, Bristol, BS1 6PN, UK; +44 (0)2071048118, +44 (0)2071048140, +44 (0)2071048016; bromley.rec@hra.nhs.uk), ref: 21/PR/0561 |
| Condition | Keratoconus |
| Intervention | Visual acuity is measured at a single visit with no follow-up. |
| Intervention type | Device |
| Pharmaceutical study type(s) | |
| Phase | Not Applicable |
| Drug / device / biological / vaccine name(s) | |
| Primary outcome measure | Visual acuity in LOGMAR at refraction (using both letters and lines) measured at a single visit |
| Secondary outcome measures | 1. Keratometry measured using a keratometer at a single visit 2. Corneal thickness measured using a Pentacam tomographer at a single visit 3. Corneal profile measured using a Pentacam tomographer at a single visit 4. Aberrometry measured using an aberrometer at a single visit |
| Overall study start date | 08/07/2021 |
| Overall study end date | 31/12/2022 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | Both |
| Target number of participants | 15 |
| Total final enrolment | 15 |
| Participant inclusion criteria | Keratoconus patients aged 18 years and over |
| Participant exclusion criteria | 1. Patients unable to fixate on a target 2. Patients under 18 years old 3. Patients with other ocular diseases 4. Pregnant patients 5. Patients with a corneal scar or fibrosis |
| Recruitment start date | 15/02/2022 |
| Recruitment end date | 30/06/2022 |
Locations
Countries of recruitment
- England
- United Kingdom
Study participating centre
Liverpool
L7 8YA
United Kingdom
Sponsor information
University/education
Research Support Office
2nd Floor Block D Waterhouse Building
3 Brownlow Street
Liverpool
L69 3GL
England
United Kingdom
| Phone | +44 (0)151 794 8739 |
|---|---|
| sponsor@liverpool.ac.uk | |
| Website | https://www.liverpool.ac.uk/ |
"ROR" |
https://ror.org/04xs57h96 |
Funders
Funder type
Charity
Private sector organisation / Trusts, charities, foundations (both public and private)
- Alternative name(s)
- Fight for Sight
- Location
- United Kingdom
No information available
Results and Publications
| Intention to publish date | 31/12/2023 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Published as a supplement to the results publication |
| Publication and dissemination plan | The results of this study will be published in a research paper |
| IPD sharing plan | The datasets generated and/or analysed during the current study will be published as a supplement to the results publication. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| HRA research summary | 28/06/2023 | No | No |
Editorial Notes
03/04/2023: Internal review.
28/03/2023: Trial's existence confirmed by the London - Bromley Research Ethics Committee.
