A systematic review «Ervin AE, Boland MV, Myrowitz EH ym. Screening for...»1 was conducted through October 6, 2011 and existing databases were screend to identify relevant systematic reviews. The quantity, quality, and consistency of the body of available evidence was assesses for answering the question ‘What is the predictive value of screening tests for open-angle glaucoma?’
One systematic review (Burr et al., 2007) addressed the diagnostic test accuracy of candidate screening tests for the detection of OAG. Burr et al. (2007) conducted a diagnostic test accuracy review of candidate diagnostic and screening tests for OAG. Highly sensitive systematic electronic searches were undertaken by December 2005. The investigators included 40 studies totaling more than 48,000 participants 40 years of age and older and those at high risk for the development of OAG based on demographic characteristics or comorbidities. The focus was on studies of participants likely to be encountered in a routine screening setting. The primary reference standard was confirmation of OAG at followup examination. Also considered was diagnosis of OAG requiring treatment. No studies were at low risk of bias. A small subset of eight studies was judged to have higher quality.
After the Burr et al. 2007 systematic review, 4,960 studies were identified, of which 83 studies addressing the accuracy of screening tests were eligible «Burr JM, Mowatt G, Hernández R ym. The clinical ef...»2. The sensitivity of standard automated perimetry (SAP) was higher than Goldmann tonometry, similar to the Heidelberg retina tomograph (HRT), and lower than disc photos or frequency doubling technology (FDT) visual field testing. The specificity of SAP was higher than disc photos and FDT, similar to HRT, and lower than Goldmann tonometry. Some comparisons of tests could not be performed due to variability in populations and reported thresholds. No other studies were identified.
68 % of studies were at high risk of spectrum bias (not representative of those who would receive the test in practice). 6 % had differential verification bias (different reference standards). The candidate test were interpreted without knowledge of reference standard in only 29 % of studies. 48 % of the studies did not include an explanation of withdrawals from the study, and 46 % of the studies reported the number of uninterpretable test results. Only 3 of 83 studies included a population-based sample
Humphrey Visual Field Analyzer (HFA) - Evidence From Primary Studies
Ten studies examined the diagnostic accuracy of the HFA. Of these, six examined HFA Short Wavelength Automated Perimetry; two tested HFA-SAP, (SAP)-SITA, and HFA SAP-Full Threshold (FT); four examined HFA-SITA-Standard; and one tested the HFA SITA-Fast protocol. The HFA Short Wavelength Automated Perimetry testing protocol (the most frequently reported) included 25 to 286 participants with glaucoma and 22 to 289 healthy volunteers across the six included studies. Sensitivity across all comparisons and cutoffs for the mean deviation ranged from 25.9 to 83 percent. Specificity ranged from 80 to 95.2 percent. Cutoff points ranged from -5.42 to -11.06 dB.
SAP Suprathreshold Test - Evidence From Burr et al., 2007
Nine studies, including the Baltimore Eye Survey and the Blue Mountains Eye Study, examined the SAP suprathreshold test. Although the sensitivity and specificity were similar for the Baltimore and Blue Mountains studies, there was significant heterogeneity among the included studies. The range in sensitivity was 25 to 90 percent; the range in specificity was 67 to 96 percent.
SAP Threshold Test -Evidence From Burr et al., 2007
Among the five studies analyzed for SAP threshold, both Humphrey 30-2 and 24-2 threshold and Octopus 500 were evaluated. The pooled sensitivity was 88 percent, and specificity was 80 percent for the common cutoff point. (The definition of the common cutoff point differed by included study, but is defined in Burr et al.)