A feasibility study of different types of laser to treat glaucoma in Nigeria
| ISRCTN | ISRCTN25405808 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN25405808 |
| Secondary identifying numbers | Proj. No. 1373 |
- Submission date
- 05/03/2021
- Registration date
- 11/03/2021
- Last edited
- 08/10/2024
- Recruitment status
- No longer recruiting
- Overall study status
- Ongoing
- Condition category
- Eye Diseases
Plain English summary of protocol
Background and study aims
Glaucoma is a group of eye diseases that result in damage to the optic nerve and cause vision loss. Laser treatment has become one of the first-line treatments for patients with glaucoma around the world. Selective laser trabeculoplasty (SLT) has been found to be effective in reducing intraocular pressure (fluid pressure inside the eye) around the world and in a few studies in Africa, but it is relatively expensive. The aim of this study is to assess the effectiveness of SLT and other types of laser treatment, namely micropulse trabeculoplasty (MLT) and micropulse transcleral laser treatment (mTLT), in patients in Nigeria. This is a feasibility study and may lead to the design of a larger trial if the effectiveness of the lasers is established.
Who can participate?
Patients aged 18 and over with uncomplicated open-angle glaucoma and residual vision, living within 200 km of the study centre
What does the study involve?
Participants are randomly allocated to one of three treatment options where the ophthalmologist decides that laser is the treatment indicated for that patient. Treatment success is measured after 1 year.
What are the possible benefits or risks of participating?
The benefit will be the preservation of vision by reducing intraocular pressure, avoiding the need for topical medication which is often unavailable or non-affordable and has low compliance. Risks are minimal as the laser doesn't cause destructive tissue damage. There may be some pain or mild inflammation which is routinely treated. In rare cases there may be complications leading to reduction or loss of vision.
Where is the study run from?
Abubakar Tafawa Balewa University (ATBU) Teaching Hospital (Nigeria)
When is the study starting and how long is it expected to last?
December 2018 to October 2025
Who is funding the study?
Velux Foundation (Switzerland)
Who is the main contact?
Dr Mohammed Abdull
abdullmm@atbu.edu.ng
Contact information
Scientific
ATBU Teaching Hospital
Bauchi
PMB 0117
Nigeria
 ORCID ID |
0000-0003-1577-9291 |
|---|---|
| Phone | +234 (0)8037420779 |
| abdullmm@atbu.edu.ng |
Study information
| Study design | Randomized parallel trial |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised parallel trial |
| Study setting(s) | Hospital |
| Study type | Treatment |
| Participant information sheet | ISRCTN25405808_PIS.docx |
| Scientific title | Laser treatment for glaucoma in Nigeria: a feasibility study of four different treatment modalities to provide data to design randomised controlled trials |
| Study objectives | In Nigeria, where there are estimated to be 1.2 million adults aged ≥40 years with glaucoma, there is a considerable body of evidence which suggests that a high proportion of patients with glaucoma present with very advanced disease, but acceptance of trabeculectomy and compliance with topical medication are very low. Patients are, however, more likely to accept laser treatment. There is, therefore, an urgent need to identify which is the most cost-effective form of laser treatment in this setting. The results of this evaluation will provide data that can help guide the design of randomized controlled trials comparing interventions for glaucoma in Sub-Saharan Africa. |
| Ethics approval(s) | Approved 15/02/2021, London School of Hygiene and Tropical Medicine (LSHTM) ethics and research committee (London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E7HT, UK; tel not known; ethics@lshtm.ac.uk), ref: 22040 Approved 09/12/2020, Abubakar Tafawa Balewa University Teaching Hospital Bauchi research and ethics committee (Abubakar Tafawa Balewa University Teaching Hospital, Hospital Road, Bauchi, Nigeria; +234 (0)8035044243; cchama1960@gmail.com), ref: 0048/2020 |
| Health condition(s) or problem(s) studied | Glaucoma |
| Intervention | The researcher plan to use an online website to perform the randomisation (Sealedenvelope, https://www.sealedenvelope.com) in real time for each patient. All patients recruited to the study will be randomised to either of the following three interventions in one or both eyes: 1. Selective laser trabeculoplasty (SLT) 2. Micropulse laser trabeculoplasty (MLT) 3. Micropulse transscleral laser treatment (mTLT) If after a repeat treatment the IOP is not controlled they will be treated with transcleral diode laser cyclophotocoagulation (TDLC) |
| Intervention type | Procedure/Surgery |
| Primary outcome measure | Success defined as intraocular pressure (IOP) at or below target (21 mmHg) on no IOP-lowering medication (complete success) or IOP at target on one or more medication (qualified success), measured at 1 year |
| Secondary outcome measures | Clinical: 1. Change in IOP (mmHg) at 12 months as a percentage of baseline IOP levels, measured using an Icare tonometer 2. Complications following the first, and subsequent laser treatment if needed, measured by a list and frequency of complications for each laser type after treatment or at follow up points: 1 week, 1, 2, 6 and 12 months 3. Number of individuals requiring repeat laser for each laser type expressed as a percentage, measured using records of repeat treatments at the end of the study 4. Pain score subjectively measured on a scale of 1-5 where 1 = pain and 5 = extreme pain, recorded immediately after each treatment 5. Visual loss (reduction of VA to <3/60 Snellen equivalent), attributable to glaucoma progression or other causes measured at 12 months Non-clinical: 1. Recruitment rates: the proportion of eligible patients who consent to take part measured at the end of the study 2. Uptake of first and (where indicated) second or third laser treatments: the proportion of eligible patients who agreed to have the laser treatment measured at the end of the study 3. Follow up rates: the proportion of patients who return for follow up at 12 months 4. Patient-reported outcome measures (POEM) measured using a standard POEM questionnaire at 1 week after the first treatment |
| Overall study start date | 17/12/2018 |
| Completion date | 31/10/2025 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | Both |
| Target number of participants | 480 |
| Key inclusion criteria | 1. Age ≥18 years 2. Diagnosis of primary open-angle glaucoma (ISGEO category 1 & 2)(41) or Disc Damage Likelihood Scale (DDLS) grades 5-10 3. IOP >21 mmHg with or without glaucoma medication 4. Visual acuity better than 3/60 in eye(s) to be treated 5. Patient lives within 200 km of the hospital, for ease of follow up |
| Key exclusion criteria | 1. Visual acuity ≤3/60 due to glaucoma or other ocular pathology 2. DDLS <5 3. History of glaucoma surgery or laser 4. Evidence or history of uveitis, trauma or neovascularisation, aphakia 5. Opaque cornea 6. Angle grading <Shaffer 2 7. Patient unable to give informed consent |
| Date of first enrolment | 14/04/2021 |
| Date of final enrolment | 30/04/2025 |
Locations
Countries of recruitment
- Nigeria
Study participating centre
Hospital Road
Off Yandoka Street
Bauchi
PMB 0117
Nigeria
Sponsor information
University/education
Keppel St
London
WC1E 7HT
England
United Kingdom
| Phone | +44 (0)209958832 |
|---|---|
| clare.gilbert@lshtm.ac.uk | |
| Website | http://www.lshtm.ac.uk |
"ROR" |
https://ror.org/00a0jsq62 |
Funders
Funder type
Charity
Private sector organisation / Trusts, charities, foundations (both public and private)
- Alternative name(s)
- Velux Foundation
- Location
- Switzerland
Results and Publications
| Intention to publish date | 14/10/2026 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Available on request |
| Publication and dissemination plan | The protocol will be available but not published. The researchers plan to present their results at the World Ophthalmology Congress (WGC), The Ophthalmological Society of Nigeria (OSN) annual conference, the International Society of Geographical and Epidemiologic Ophthalmology (ISGEO), The West African College of Surgeons annual conference and sister teaching hospitals in Nigeria. |
| IPD sharing plan | Anonymised data collected can be shared with the consent of Dr Abdull Mohammed Mahdi, Professor Clare Gilbert and Dr Winnie Nolan. The full extent of what can be shared and for what will be determined by the group upon request. Dr Abdull Mohammed Mahdi will be the contact person at abdullmm@atbu.edu.ng. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | 01/04/2021 | No | Yes |
Additional files
- ISRCTN25405808_PIS.docx
- Uploaded 01/04/2021
Editorial Notes
08/10/2024: The following changes were made to the trial record:
1. The recruitment end date was changed from 14/04/2023 to 30/04/2025.
2. The overall end date was changed from 14/04/2024 to 31/10/2025.
3. The plain English summary was updated to reflect these changes.
15/07/2022: The following changes have been made:
1. Recruitment resumed on 25/04/2022.
2. The recruitment end date has been changed from 14/04/2022 to 14/04/2023.
3. The overall trial end date has been changed from 14/10/2022 to 14/04/2024 and the plain English summary updated accordingly.
4. The intention to publish date has been changed from 14/10/2023 to 14/10/2024.
01/04/2022: Due to damage to the SLT laser machine, recruitment for this study has been paused.
01/04/2021: The participant information sheet has been uploaded.
08/03/2021: Trial's existence confirmed by Velux Stiftung.
