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Randomized Controlled Trial
. 2021 Nov;9(11):e1589-e1599.
doi: 10.1016/S2214-109X(21)00348-X. Epub 2021 Oct 13.

Selective laser trabeculoplasty versus 0·5% timolol eye drops for the treatment of glaucoma in Tanzania: a randomised controlled trial

Heiko Philippin  1 , Einoti Matayan  2 , Karin M Knoll  3 , Edith Macha  3 , Sia Mbishi  3 , Andrew Makupa  2 , Cristóvão Matsinhe  4 , Vasco da Gama  5 , Mario Monjane  3 , Awum Joyce Ncheda  6 , Francisco Alcides Mulobuana  3 , Elisante Muna  3 , Nelly Fopoussi  7 , Gus Gazzard  8 , Ana Patricia Marques  9 , Peter Shah  10 , David Macleod  11 , William U Makupa  2 , Matthew J Burton  12
Affiliations
Randomized Controlled Trial

Selective laser trabeculoplasty versus 0·5% timolol eye drops for the treatment of glaucoma in Tanzania: a randomised controlled trial

Heiko Philippin et al. Lancet Glob Health. 2021 Nov.

Abstract

Background: Glaucoma is a major cause of sight loss worldwide, with the highest regional prevalence and incidence reported in Africa. The most common low-cost treatment used to control glaucoma is long-term timolol eye drops. However, low adherence is a major challenge. We aimed to investigate whether selective laser trabeculoplasty (SLT) was superior to timolol eye drops for controlling intraocular pressure (IOP) in patients with open-angle glaucoma.

Methods: We did a two-arm, parallel-group, single-masked randomised controlled trial at the Eye Department of Kilimanjaro Christian Medical Centre, Moshi, Tanzania. Eligible participants (aged ≥18 years) had open-angle glaucoma and an IOP above 21 mm Hg, and did not have asthma or a history of glaucoma surgery or laser. Participants were randomly assigned (1:1) to receive 0·5% timolol eye drops to administer twice daily or to receive SLT. The primary outcome was the proportion of eyes from both groups with treatment success, defined as an IOP below or equal to target pressure according to glaucoma severity, at 12 months following randomisation. Re-explanation of eye drop application or a repeat SLT was permitted once. The primary analysis was by modified intention-to-treat, excluding participants lost to follow-up, using logistic regression; generalised estimating equations were used to adjust for the correlation between eyes. This trial was registered with the Pan African Clinical Trials Registry, number PACTR201508001235339.

Findings: 840 patients were screened for eligibility, of whom 201 (24%) participants (382 eligible eyes) were enrolled between Aug 31, 2015, and May 12, 2017. 100 (50%) participants (191 eyes) were randomly assigned to the timolol group and 101 (50%; 191 eyes) to the SLT group. After 1 year, 339 (89%) of 382 eyes were analysed. Treatment was successful in 55 (31%) of 176 eyes in the timolol group (16 [29%] of 55 eyes required repeat administration counselling) and in 99 (61%) of 163 eyes in the SLT group (33 [33%] of 99 eyes required repeat SLT; odds ratio 3·37 [95% CI 1·96-5·80]; p<0·0001). Adverse events (mostly unrelated to ocular events) occurred in ten (10%) participants in the timolol group and in eight (8%) participants in the SLT group (p=0·61).

Interpretation: SLT was superior to timolol eye drops for managing patients with open-angle high-pressure glaucoma for 1 year in Tanzania. SLT has the potential to transform the management of glaucoma in sub-Saharan Africa, even where the prevalence of advanced glaucoma is high.

Funding: Christian Blind Mission, Seeing is Believing Innovation Fund, and the Wellcome Trust.

Translations: For the Kiswahili, French and Portuguese translations of the abstract see Supplementary Materials section.

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Conflict of interest statement

Declaration of interests GG reports personal fees from Alcon, Allergan, Belkin, Equinox, Genentech–Roche, Glaukos, Ivantis, Reichert, Sight Sciences, and from Thea; grants from Belkin, Santen, and from Thea; and non-financial involvement with the patient advocacy group GlaucomaUK, outside the submitted work; he is also a co-investigator on three other major SLT trials (LIGHT, COAST, and Belkin laser). All other authors declare no competing interests.

Figures

Figure 1
Figure 1
Trial profile SLT=selective laser trabeculoplasty. The full list of reasons for exclusion are provided in appendix 4 (p 3).
Figure 2
Figure 2
Kaplan-Meier curve of time to treatment failure Differences between the two intervention groups in time to an event was assessed with a Cox regression analysis using a shared frailty model to account for dependency between the two eyes. HR=hazard ratio. SLT=selective laser trabeculoplasty.
See this image and copyright information in PMC

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