Schrems 2010.

Study characteristics
Patient Sampling	Healthy participants, ocular hypertensive and glaucoma (preperimetric and perimetric) patients were recruited from the Erlangen Glaucoma Registry (a clinical registry for cross‐sectional and longitudinal observation study of patients with open‐angle glaucoma or glaucoma suspect).
Patient characteristics and setting	Sample size: 386 participants (95 perimetric glaucoma, 89 preperimetric glaucoma, 145 ocular hypertensive, 57 controls). Age: preperimetric glaucoma mean ± SD, 55.7 ± 11.3 years; perimetric glaucoma mean ± SD 56.4 ± 11.2 years; ocular hypertensive mean ± SD 53.9 ± 12years; controls 49.9 ± 13 years. Sex: 179 men (30 preperimetric glaucoma,56 perimetric glaucoma, 76 OHT, 17 controls) and 207 women (59 preperimetric glaucoma, 39 perimetric glaucoma, 69 OHT, 40 controls) Country: Germany. Ocular comorbidities: no ocular diseases other than glaucoma,BCVA < 16/40, spherical refraction > ±8 D, diabetes. Setting: Department of Ophthalmology, University of Erlangen‐Nuremberg, Schwabachanlage, Erlangen. Spectrum of glaucoma severity: mean ± SD MD/PSD on the VF test were ‐0.37 ± 1.3/2.48 ± 1.72 dB, for preperimetric glaucoma; ‐6.26 ± 5.26/32.6 ± 28.8 dB for perimetric glaucoma; 0.44 ± 1.4/2.19 ± 1.88 dB for OHT. Control participants: normal VFs and normal clinical examination.
Index tests	Scanning laser polarimetry: GDx VCC (Carl Zeiss Meditec Inc, Dublin, CA, USA). A score ≥ 7 was the minimum standard for good‐quality scans in this study. No author had conflict of interest.
Target condition and reference standard(s)	Manifest perimetric glaucoma: IOP > 21 mmHg, abnormal appearance of the optic disc (unusually small neuroretinal rim area in relation to the optic disc size and cup/disc ratios being higher vertically compared with horizontally or notching, or localised/diffuse RNFL loss) and glaucomatous VF defects (defined by a reproducible reduction in sensitivity of at least 10 dB in a cluster of ≥ 2 contiguous locations and/or a deterioration of at least 5 dB in a cluster of ≥ 3 contiguous locations with at least one of those with ≥ 10 dB), with open angle by gonioscopy. Manifest preperimetric glaucoma: IOP > 21 mmHg, glaucomatous optic disc appearance without any corresponding VF loss. OHT: IOP > 21 mmHg, with normal optic disc appearance and VF test result. Visual field test: No details were reported about how VF testing was conducted. Optic disc evaluation: 15° colour photographs (Zeiss telecentric fundus camera, Germany). The analyses were independently performed by 2 glaucoma specialists.
Flow and timing	The time interval between reference standard and index tests was not reported. All participants recruited were included in the analysis.
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?	Unclear
Was a case‐control design avoided?	No
Did the study avoid inappropriate exclusions?	Yes
Could the selection of patients have introduced bias?		High risk
Are there concerns that the included patients and setting do not match the review question?			High
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?	Unclear
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?	Unclear
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?		Unclear risk