Begum 2014b.

Study characteristics
Patient Sampling	Retrospective, cross‐sectional study. 295 eyes were randomly selected (after the exclusion of eyes with poor index or reference‐test quality results) from 678 eyes of 382 patients referred for glaucoma evaluation to a tertiary care clinic.
Patient characteristics and setting	Sample size: 295 eyes (68 with perimetric glaucoma, 62 with preperimetric glaucoma and 165 normal control eyes). Age: perimetric glaucoma median (IQR), 56 (48, 61) years; preperimetric glaucoma median (IQR), 54 (41, 62) years; controls, 54 (41, 63) years. Sex: not reported. Ethnicity: not reported. Setting: L V Prasad Eye Institute, Banjara Hills, Hyderabad, Andhra Pradesh. Country: India. Ocular comorbidities: patient with any media opacities that prevented good‐quality optic disc photographs and other imaging tests, and any retinal (including macular) or neurologic disease other than glaucoma, were excluded. Spectrum of glaucoma severity: the median (IQR) mean deviation and PSD on the VF test were ‐9.1 (‐14.8, ‐4.8) and 8.2 (3.7, 10.5) respectively, for perimetric glaucoma, ‐2.3 (‐3.9, ‐0.9) and 1.8 (1.5, 2.2) respectively, for preperimetric glaucoma. Control participants: non‐glaucomatous optic discs appearance and normal VF result.
Index tests	Optical coherence tomography: RTVue (Optovue Inc, Fremont, CA, USA), software version 5.1.0.90. GCC scanning protocol was used for imaging the macula. Only well‐centred images with a signal strength index of ≥ 30 were used for analysis. The authors declared no conflict of interest.
Target condition and reference standard(s)	Manifest perimetric glaucoma: glaucomatous optic disc (defined as the presence of focal or diffuse neuroretinal rim thinning, localised notching, or nerve fibre layer defects and glaucomatous) and glaucomatous VF result (defined as the PSD < 5% and GHT outside normal limits). Visual field test: Humphrey Field Analyzer, model 750i (Zeiss Humphrey Systems, Dublin, CA, USA), with the SITA‐standard programme. The VFs were considered reliable if the fixation losses, false‐positive and false‐negative response rates were < 20%. A single observer masked to the optic disc classification, SD‐OCT findings and the other eye status, graded all VFs. Optic disc evaluation: stereoscopic optic disc photographs using digital fundus camera (FF 450 plus with VISUPAC 4.2.2; Carl Zeiss Meditec Systems GmbH, Pirmasens, Germany). Optic disc photograph was evaluated independently by 2 experts masked to the clinical details of the patients.
Flow and timing	42 eyes with unreliable VFs, 7 eyes with poor quality disc photographs and 18 eyes with poor OCT images quality, were excluded from the analysis. So, fewer than 10% of the patients enrolled were excluded. Index test and reference standard were performed on the same day.
Comparative
Notes	None.
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?	Unclear
Did the study avoid inappropriate exclusions?	Yes
Could the selection of patients have introduced bias?		Unclear risk
Are there concerns that the included patients and setting do not match the review question?			Low concern
DOMAIN 2: Index Test (All tests)
If a threshold was used, was it pre‐specified?	Yes
Were imaging test's quality assessed?	Yes
Were any conflict of interest avoided	Yes
Could the conduct or interpretation of the index test have introduced bias?		Low 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?	Yes
Could the reference standard, its conduct, or its interpretation have introduced bias?		Low 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
Did all patients receive the same reference standard?	Yes
Were all patients included in the analysis?	Yes
Did all patients receive a reference standard	Yes
Could the patient flow have introduced bias?		Low risk