Evidence map›Paper›PMID 30878226›Full record

Trial reportLancet (London, England)2019

Laser peripheral iridotomy for the prevention of angle closure: a single-centre, randomised controlled trial.

Mingguang He, Yuzhen Jiang, Shengsong Huang, Dolly S Chang, Beatriz Munoz, Tin Aung, Paul J Foster, David S Friedman

Registry-linked trialAbstract readRandomized Controlled Trial
PubMed Publisher
In one paragraph

Trial report in Lancet (London, England), 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04495491 (Prediction of the Degree of Angle Opening Distance in Patients With Primary Angle Closure Suspect After Laser Peripheral Iridotomy), which is not on this map. Cited by 123 papers, 5 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
123citing papers in PubMed, 5 pooled it
27.5field-weighted citation impact, top 1% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT04495491 unknown statusnot on this mapstarted 2020, after this paper: background citation

Prediction of the Degree of Angle Opening Distance in Patients With Primary Angle Closure Suspect After Laser Peripheral Iridotomy

Typeobservational_patient_registrySponsorZhongshan Ophthalmic Center, Sun Yat-sen UniversityRan2020 to 2021Enrolled200ConditionsGlaucomaArmspupillary block group, plateau iris group, mixing mechanism group
3 · Its place in the literature

Who cites it

123 citing papers in PubMed, 5 syntheses or guidelines pooled it, 252 citations in OpenAlex.

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  14. Computational study of DurystaDrug delivery and translational research · 2026
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  15. Longitudinal change in anterior chamber depth and its determinants: a median 4.9-year follow-up of 2,247 Japanese adults.Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie · 2026
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63 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

8 authors at 5 institutions in 5 countries.

Mingguang HeState Key Laboratory of Ophthalmology, Clinical Research Center, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China; Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia; National Institute for Health Research Biomedical Research Centre, Moorfields Eye Hospital, London, UK; UCL Institute of Ophthalmology, London, UK. Electronic address: mingguang_he@yahoo.com.
Yuzhen JiangNational Institute for Health Research Biomedical Research Centre, Moorfields Eye Hospital, London, UK; UCL Institute of Ophthalmology, London, UK.
Shengsong HuangState Key Laboratory of Ophthalmology, Clinical Research Center, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China.
Dolly S ChangDana Center for Preventive Ophthalmology, Wilmer Eye Institute and Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Beatriz MunozDana Center for Preventive Ophthalmology, Wilmer Eye Institute and Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Tin AungSingapore Eye Research Institute, Singapore National Eye Centre, Singapore Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Paul J FosterNational Institute for Health Research Biomedical Research Centre, Moorfields Eye Hospital, London, UK; UCL Institute of Ophthalmology, London, UK. Electronic address: p.foster@ucl.ac.uk.
David S FriedmanDana Center for Preventive Ophthalmology, Wilmer Eye Institute and Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Johns Hopkins University · USUniversity College London · GBMoorfields Eye Hospital · GBNational University of Singapore · SGSun Yat-sen University · CN

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundPrimary angle-closure glaucoma affects 20 million people worldwide. People classified as primary angle closure suspects have a higher but poorly quantified risk of developing glaucoma. We aimed to assess efficacy and safety of laser peripheral iridotomy prophylaxis against primary angle-closure glaucoma in Chinese people classified as primary angle closure suspects.

methodsIn this randomised controlled trial, bilateral primary angle closure suspects aged 50-70 years were enrolled at the Zhongshan Ophthalmic Center, a tertiary specialised hospital in Guangzhou, China. Eligible patients received laser peripheral iridotomy in one randomly selected eye, with the other remaining untreated. The primary outcome was incident primary angle closure disease as a composite endpoint of elevation of intraocular pressure, peripheral anterior synechiae, or acute angle-closure during 72 months of follow-up in an intention-to-treat analysis between treated eyes and contralateral controls. This trial is registered with the ISRCTN registry, number ISRCTN45213099.

findingsOf 11 991 screened individuals, 889 individuals were randomly assigned from June 19, 2008 (889 treated and 889 untreated eyes). Incidence of the primary outcome was 4·19 per 1000 eye-years in treated eyes compared with 7·97 per 1000 eye-years in untreated eyes (hazard ratio 0·53; 95% CI 0·30-0·92; p=0·024). A primary outcome event occurred in 19 treated eyes and 36 untreated eyes with a statistically significant difference using pair-wise analysis (p=0·0041). No serious adverse events were observed during follow-up.

interpretationIncidence of angle-closure disease was very low among individuals classified as primary angle closure suspects identified through community-based screening. Laser peripheral iridotomy had a modest, albeit significant, prophylactic effect. In view of the low incidence rate of outcomes that have no immediate threat to vision, the benefit of prophylactic laser peripheral iridotomy is limited; therefore, widespread prophylactic laser peripheral iridotomy for primary angle-closure suspects is not recommended.

fundingFight for Sight, the Sun Yat-Sen University 5010 Project Fund, Moorfields Eye Charity, and the National Natural Science Foundation of China.

Indexed as

Intraocular PressureAgedChinaFemaleGlaucoma, Angle-ClosureHumansIntention to Treat AnalysisIridectomyKaplan-Meier EstimateLasers, Solid-StateMaleMiddle AgedProphylactic Surgical Procedures

Identifiers

PMID30878226
OpenAlexW2922216742

What OpenQuestion holds

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Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.