Selective laser trabeculoplasty for glaucoma in sub-Saharan Africa
Authors: Michael Xiangchen Fu
Journal: The Lancet Global Health (2022)

Heiko Philippin and colleagues have done a novel and consolidated randomised controlled trial (RCT), which confirmed their hypothesis that selective laser trabeculoplasty (SLT) has superior efficacy to timolol eye drops in managing intraocular pressure in patients with open-angle glaucoma in sub-Saharan Africa.1Philippin H Matayan E Knoll KM et al.Selective laser trabeculoplasty versus 0·5% timolol eye drops for the treatment of glaucoma in Tanzania: a randomised controlled trial.Lancet Glob Health. 2021; 9: e1589-e1599Summary Full Text Full Text PDF PubMed Scopus (7) Google Scholar Their finding is crucial, since glaucoma prevalence in sub-Saharan Africa is higher than that in any other world region, with few treatment options.2Steinmetz JD Bourne RRA Briant PS et al.Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the Right to Sight: an analysis for the Global Burden of Disease Study.Lancet Glob Health. 2021; 9: e144-e160Summary Full Text Full Text PDF PubMed Scopus (328) Google Scholar As an RCT comparing SLT versus timolol eye drops, the authors have used a robust study design. For example, patients (instead of eyes) were randomly allocated to receive either SLT or eye drops. Randomised allocation of patients eliminated a potential crossover effect, which occurred in the Glaucoma Laser Trial when eyes were randomised for treatment.3Glaucoma Laser Trial Research GroupThe Glaucoma Laser Trial (GLT) and glaucoma laser trial follow-up study: 7. Results.Am J Ophthalmol. 1995; 120: 718-731Summary Full Text PDF PubMed Google Scholar Adverse events were well explained and accounted for, and the possibility of various confounders that could have influenced observed differences between groups was also considered. However, there is no record of the length of time for which timolol eye drops were previously taken by participants, nor any record of other eye drops that patients might have taken before the trial. These are possible confounders that might have influenced the study's results, thus including these variables in the Article's table 2 would have strengthened the quality of this study. Furthermore, this study's 12-month follow-up period is insufficient, since glaucoma is a long-term condition. The LiGHT trial showed fluctuations in health-related quality of life (HRQoL) scores over their 36-month follow-up, with 81 [25·8%] of 314 patients having unsuccessfully controlled intaocular pressure without additional eye drops at 36 months following SLT.4Gazzard G Konstantakopoulou E Garway-Heath D et al.Selective laser trabeculoplasty versus eye drops for first-line treatment of ocular hypertension and glaucoma (LiGHT): a multicentre randomised controlled trial.Lancet. 2019; 393: 1505-1516Summary Full Text Full Text PDF PubMed Scopus (200) Google Scholar The eye drops group also needed more treatment escalations over the 36-month trial. With a longer follow-up period, more knowledge would be attained regarding longitudinal HRQoL, number of trabeculotomy escalations, intraocular pressure, and visual field progression. In addition, the effects of SLT on later eye drop use, and potential long-term effects of SLT on trabecular meshwork function, could be known. Thus, a follow-up of at least 36 months in this trial would be beneficial in answering these further questions. In conclusion, this well designed study has provided important evidence regarding the feasibility of SLT for open-angle glaucoma. However, to confirm these findings and to introduce SLT into clinical practice in sub-Saharan Africa to transform open-angle glaucoma management, a multicentre RCT with a longer follow-up period and larger sample group is recommended. This online publication has been corrected. The corrected version first appeared at thelancet.com/lancetgh on May 24, 2022 This online publication has been corrected. The corrected version first appeared at thelancet.com/lancetgh on May 24, 2022 I declare no competing interests. Selective laser trabeculoplasty versus 0·5% timolol eye drops for the treatment of glaucoma in Tanzania: a randomised controlled trialSLT 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. Full-Text PDF Open AccessSelective laser trabeculoplasty for glaucoma in sub-Saharan Africa – Author's replyWe would like to thank Michael Fu for his correspondence on our Article.1 Fu suggests that the study could be further strengthened by reporting the duration of timolol eye drop application and the use of other eye drops before enrolment as possible confounders. As we describe in our study, timolol eye drops are the most affordable and accessible medical treatment option in the region but their long-term application is often hampered, which was also reflected in our study.1–3 Before enrolment, of 382 eyes included in the trial, 208 had previously received timolol, 17 eyes had received other glaucoma eye drops only, nine eyes had received eye drops that were not related to glaucoma, we did not know whether 18 eyes had received any eye drops, and 130 eyes had received no previous eye drops. Full-Text PDF Open AccessCorrection to Lancet Global Health 2022; 10: e334Fu MX. Selective laser trabeculoplasty for management of glaucoma in sub-Saharan Africa. Lancet Global Health 2022; 10: e334—In this Correspondence, the corresponding author's middle name was omitted. This has been corrected as of May 24, 2022. Full-Text PDF Open Access