Congdon 1996.

Study characteristics
Patient Sampling	Cross‐sectional study. Participants, aged 40 years and above, were invited for screening. Data from both eyes were included in the analysis.
Patient characteristics and setting	Sample size: 562 participants. Age: mean (SD) 59.2 ± 11.8 years. Sex: 312 (55.6%) female. Setting: community. Country: Taiwan. Ethnicity: East Asian. Exclusions: none reported.
Index tests	LACD: modified van Herick grading method used; Grades 3 or 4 termed ‘deep’, Grade 2 ‘narrow’; Grade 1 ‘critically narrow’. Cut‐off values were < 25% and > 25% to ≤ 50%. Flashlight: oblique handlight illumination using three grades: critically narrow (nasal shadow > 1/2 the distance from limbus to pupillary axis); narrow (1/4 to 1/2); or deep (< 1/4). Cut‐off values used were critically narrow (grade 1) and narrow (grade 2).
Target condition and reference standard(s)	The ACA was graded by Zeiss 4‐mirror dynamic gonioscopy. If no trabecular meshwork was seen in 1 or more quadrants (≥ 90 degrees), an overall grade of 'narrow' was given. A grade of ‘critically narrow’ was given to eyes that were ‘closed’ in two or more quadrants (≥ 180 degrees). The authors defined PACG as 'one or both eyes graded as narrow or critically narrow by gonioscopy who had one or more of the following: intraocular pressure (IOP) greater than 18 mmHg, a rise in IOP greater than or equal to 8 mmHg on dark‐prone provocative testing, or past acute attack with an iridectomy already performed. The optic disc and visual field could be normal or abnormal.'
Flow and timing	562 participants were recruited, 503 participants were included in the analysis for LACD and 352 for the flashlight test. For the flashlight, the numbers were smaller than the LACD as handlight testing of all participants was started one month after the study had begun. The index test and reference standard were conducted on the same occasion. There were no uninterpretable test results or exclusions reported.
Comparative
Notes	Conflict of interest: no conflict of interest statement provided. Van Herick Grade 2 is a modified version of the original van Herick grade. For both van Herick and flashlight grade 1 and grade 2 was compared to a critical narrow and narrow angle respectively on gonioscopy.
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Yes
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Yes
Could the selection of patients have introduced bias?		Low risk
Are there concerns that the included patients and setting do not match the review question?			Low concern
DOMAIN 2: Index Test (LACD)
Were the index test results interpreted without knowledge of the results of the reference standard?	Unclear
If a threshold was used, was it pre‐specified?	Yes
Could the conduct or interpretation of the index test have introduced bias?		Unclear risk
Are there concerns that the index test, its conduct, or interpretation differ from the review question?			Low concern
DOMAIN 2: Index Test (Scheimpflug photography)
DOMAIN 2: Index Test (AS‐OCT)
DOMAIN 2: Index Test (SPAC)
DOMAIN 2: Index Test (Flashlight)
Were the index test results interpreted without knowledge of the results of the reference standard?	Unclear
If a threshold was used, was it pre‐specified?	Yes
Could the conduct or interpretation of the index test have introduced bias?		Unclear risk
Are there concerns that the index test, its conduct, or interpretation differ from the review question?			Low concern
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	Yes
Were the reference standard results interpreted without knowledge of the results of the index tests?	Unclear
Could the reference standard, its conduct, or its interpretation have introduced bias?		Unclear risk
Are there concerns that the target condition as defined by the reference standard does not match the question?			Low concern
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard?	Yes
Were all patients included in the analysis?	Unclear
Did all patients receive a reference standard	Yes
Could the patient flow have introduced bias?		Unclear risk