Laser compared to topical medicine as primary treatment for glaucoma in Africa

• Register: ISRCTN
• Last refreshed on: 5 January 2021
• Main ID: ISRCTN27208571
• Date of registration: 14/12/2015
• Prospective Registration: No
• Primary sponsor: University College London
• Public title: Laser compared to topical medicine as primary treatment for glaucoma in Africa
• Scientific title: To compare selective laser trabeculoplasty (SLT) with prostaglandin analogue as first line therapy in African Primary Open Angle Glaucoma (POAG) patients
• Date of first enrolment: 11/02/2014
• Target sample size: 571
• Recruitment status: Completed
• URL: http://isrctn.com/ISRCTN27208571
• Study type: Interventional
• Study design: Two centre randomised prospective trial (Treatment)
• Phase: Not Specified

Countries of recruitment

Kenya, South Africa

Contacts

• Name: Ian Murdoch

Key inclusion & exclusion criteria

Inclusion criteria:
1. Consent to inclusion and participation in trial
2. Characteristic glaucomatous changes in the optic disc. The presence of a focal or diffuse area of optic disc rim loss, so that the neuroretinal rim tissue in any quadrant is less than 5% of the disc diameter in that meridian. Extensive loss of neuroretinal rim tissue with marked optic disc cupping giving a cup disc ratio greater than 0.6
3. A measured intraocular pressure greater than or equal to 21 mmHg and less than or equal to 30mmHg on at least one visit before the time of entry into the study as measured by Goldmann applanation tonometry
4. Adequate visualization of angle structures (i.e. clear media and cooperative patient)
5. Black African patients

Exclusion criteria:
1. Unwillingness to participate in the study
2. Inability/unwillingness to give informed consent
3. Unwillingness to accept randomisation
4. Patient less than 20 years of age
5. Anterior segment neovascularisation
6. Past trauma to the eye or ocular adnexae
7. Retinal or optic nerve neovascularisation
8. Aphakia or pseudophakia
9. Previous ocular surgery Evidence of ocular disease other than glaucoma that might affect the measurements of IOP, assessment of visual function, visual field testing would likely require cataract surgery within 12 months of randomization on systemic medications known to ­IOP (e.g. steroids) Pregnancy or female of childbearing age who may be pregnant at time of treatment (LMP).
10. Anyone who is not Black African race


Age minimum:
Age maximum:
Gender: Both

Health Condition(s) or Problem(s) studied

Primary open-angle glaucoma
Eye Diseases
Primary open-angle glaucoma

Intervention(s)

After informed consent all patients undergo a standardised examination to establish baseline ocular function and findings. All patients receive counselling in glaucoma, the disease, what it means and the therapy. Each patient is then randomised (randomisation in London, contained in sealed opaque envelopes) to receive SLT or prostaglandin analogue therapy. Every effort is made to follow all patients according to a standardised protocol at a minimum of 3, 6 and 12 months. All therapeutic failures are followed closely to ascertain further management plans and subsequent therapeutic compliance. Follow-up is offered beyond 12 months.

Follow-up:
1. At 3 months: Patients will have a structured questionnaire relating to any adverse effects from the therapeutic interventions. They will receive an examination of visual function, external ocular structures and intraocular pressure in addition to the optic nerve head. Those with unacceptable topical/systemic side effects and those with partial or complete failure of IOP control (see outcomes) will have secondary therapy commenced in the form of timolol 0.5% or, if contraindicated, either brimonidine or oral acetazolamide)). The secondary therapy will either replace or be additive to the primary therapy depending on the initial response.
2. At 6 months: Patients will have a structured questionnaire relating to any adverse effects from therapeutic interventions. They will receive and examination of visual function, external ocular structures and intraocular pressure in addition to the optic nerve head. Those with unacceptable topical/systemic side effects and those with partial or complete failure of IOP control (see outcomes) will have secondary or tertiary therapy c

Primary Outcome(s)

Intraocular pressure reduction at one year. A reduction of 30% or more at one year is complete success and a reduction of 15-29% is partial success. In addition the proportion with an IOP less than 21, less than 17 and less than 14mmHg will be assessed as measured using Goldmann tonometry.

Secondary Outcome(s)

1. Visual function assessed as change in logMAR acuity
2. Progression of lens opacity assessed as change in LOCS III score
3. Reintervention rate- number experiencing reintervention during first year post commencement of therapy
4. Reintervention acceptance – number accepting reintervention during first year post commencement of therapy
5. Compliance – this is being assessed by weighing bottles prior to issuance and on return to the pharmacy for receipt of the next round of therapy (the difference in weight represents the number of drops administered from the bottle and will be compared to the number of doses that should have been taken during the period
6. Compliance via a questionnaire to both patients and clinician
7. Complications – number of adverse events during the first year of therapy

Secondary ID(s)

N/A

Source(s) of Monetary Support

International Glaucoma Association (UK)

Ethics review

Status:
Approval date:
Contact:

1. University College London Ethical Committee, 01/10/2014, ref: 5497/001 2. Biomedical Research Ethics Committee (BREC), 15/05/2012, ref: BFC107/11 3. Aga Khan University Faculty of Health Sciences Research Ethics Committee, 06/05/2013, ref: 2012/24

Results

• Results available: Yes
• Date Completed: 30/11/2018