Oddone 2008.

Study characteristics
Patient Sampling	A series of consecutive normal and POAG participants from the population attending the glaucoma clinics were enrolled. Normal controls were people attending the outpatient clinics, spouses and friends of the recruited patients, or volunteers from the hospital staff. One eye per person was randomly selected.
Patient characteristics and setting	Sample size: 242 eyes of 242 participants enrolled; 236 included in the analysis (99 glaucoma,137 healthy controls). Age: glaucoma patients mean ± SD, 62.7 ± 11 years; controls 60.9 ± 13 years. Sex: 105 men (45 glaucoma, 60 controls) and 131 women (54 glaucoma, 77 controls). Country: Italy. Ocular comorbidities: no neuro‐ophthalmologic/retinal diseases, BCVA < 20/40, spherical refraction > ±5 D, cylinder refraction > ±3 D, uveitis, close angle by gonioscopy, ocular surgery or laser treatments, ocular trauma, rheumatologic systemic diseases and diabetes. Setting: University of Rome Tor Vergata, Rome;  University of Milan San Paolo, Milan; University of Genoa, Genoa. Spectrum of glaucoma severity: according to the VF defect severity: 42 eyes were at stage 1 (MD > ‐6 dB), 29 eyes at stage 2 (MD < ‐6 dB and > ‐12 dB), 28 at stage 3 (MD < ‐12 dB). Mean ± SD MD/CPSD on the VF test were respectively ‐3.74 ± 1.29 dB/4.67 ± 1.72 dB (stage 1), ‐8.35 ± 1.83 dB/7.5 ± 2.41 dB (stage 2), ‐18.07 ± 4.93/10.4 ± 2.88 dB (stage 3). Control participants: IOP < 22 mmHg and a normal VF test result.
Index tests	Confocal scanning laser tomography: HRT 3, software version 3.0 (Heidelberg Engineering GmbH, Dossenheim, Germany). After scanning, a contour line was manually placed around the ONH edge by 3 experienced investigators masked to the participant’s diagnosis. Only high‐quality images with acquisition sensitivity > 90% and a SD < 40 were considered acceptable. No author had conflict of interest.
Target condition and reference standard(s)	Manifest glaucoma: history of IOP > 24 mmHg in the hospital notes and glaucomatous VF defects (defined as GHT outside normal limits, MD and PSD outside 95% confidence limits and a cluster of at least 3 points with P < 0.05 in the pattern deviation plot, one of each with P < 0.01 affecting the same hemifield). Visual field testing: Humphrey Field Analyzer, 24‐2 SITA‐standard strategy (Carl Zeiss Meditec, Inc., Dublin, CA, USA). VF reliability criteria were not specified. Optic disc appearance was not part of the reference standard.
Flow and timing	The time interval between reference standard and index test was not reported. 268 participants were initially screened, 242 were enrolled. In 6 eyes (2.5%, 4 glaucoma and 2 controls) the GPS was unable to provide a classification, and were excluded from 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?	Yes
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?	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?		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?	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
Could the patient flow have introduced bias?		Unclear risk