Diagnostic accuracy of an iPad application for detection of visual field defects.

BACKGROUND/OBJECTIVES: Tablet-based perimetry could be used to test for glaucomatous visual field defects in settings without easy access to perimeters, although few studies have assessed diagnostic accuracy of tablet-based tests. The goal of this study was to determine the diagnostic accuracy of iPad perimetry using the visualFields Easy application. SUBJECTS/METHODS: This was a prospective, cross-sectional study of patients undergoing their first Humphrey Field Analyser (HFA) visual field test at a glaucoma clinic in India. Participants underwent 24-2 SITA Standard HFA testing and iPad-based perimetry with the visualFields Easy application. Reference standards for both visual field loss and suspected glaucoma were determined by ophthalmologist review of HFA results and optic disc photographs. Receiver operating characteristic curves were constructed to assess diagnostic accuracy at various test thresholds. RESULTS: 203 eyes from 115 participants were included, with 82 eyes classified as moderate or worse glaucoma. iPad perimetry had an area under the receiver operating characteristic (AUROC) curve of 0.64 (95% CI 0.57 to 0.71) for detection of any visual field defect relative to HFA and an AUROC of 0.68 (0.59 to 0.76) for detection of moderate or worse glaucoma relative to ophthalmologist examination. At a set specificity of 90%, the sensitivity of iPad perimetry for detection of moderate or worse glaucoma was 35% (22-48%). CONCLUSIONS: iPad perimetry using the visualFields Easy application had inadequate diagnostic accuracy to be used as a screening tool for glaucoma in this South Indian population.

Comparison of Structural, Functional, Tonometric, and Visual Acuity Testing for Glaucoma: A Prospective Diagnostic Accuracy Study.

PURPOSE: To determine the diagnostic accuracy of potential screening tests for moderate to advanced glaucoma. DESIGN: Prospective diagnostic test accuracy study. PARTICIPANTS: The study enrolled a consecutive series of patients aged ≥50 years who presented to a glaucoma clinic in South India without ever having received automated visual field testing. METHODS: All participants underwent 8 index tests: OCT of the peripapillary retinal nerve fiber layer, optic disc photography, Moorfield's Motion Displacement Test (MDT), frequency doubling technique perimetry, noncontact tonometry, pneumatonometry, presenting visual acuity, and best-corrected visual acuity. Participants also underwent stereoscopic photographs and Humphrey visual fields, which were used by 2 ophthalmologists to arrive at the reference standard diagnosis of moderate to advanced glaucoma. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio. RESULTS: A total of 217 people were enrolled; 321 eyes from 180 participants had all tests performed. Of these, 127 eyes (40%) were classified as having moderate to advanced glaucoma. Among the 8 tests, OCT best optimized sensitivity (84%, 95% confidence interval [CI], 76-90) and specificity (75%, 95% CI, 68-81). Moorfield's Motion Displacement Test was the best perimetric test, with a sensitivity of 91% (95% CI, 85-96) and specificity of 53% (95% CI, 44-61). Pressure and vision tests were not sensitive (e.g., sensitivity of 16%, 95% CI, 9-23 for noncontact tonometry and 23%, 95% CI, 15-31 for best-corrected visual acuity). Moorfield's Motion Displacement Test identified 16 of 127 eyes (13%) with glaucoma that were not captured by OCT, but also had false-positive results in 65 of 194 eyes (34%) without glaucoma that OCT correctly classified as negative. CONCLUSIONS: OCT had moderate sensitivity and fair specificity for diagnosing moderate to advanced glaucoma and should be prioritized during an initial assessment for glaucoma.

Reproducibility of 5 Methods of Ocular Tonometry.

PURPOSE: To evaluate the agreement between Goldmann applanation tonometry (GAT; Haag-Streit, Bern, Switzerland) and several portable tonometers that could be used for glaucoma screening programs. DESIGN: Evaluation of a diagnostic test. PARTICIPANTS: Three hundred twenty-one eyes of 168 participants seeking treatment at the glaucoma clinic of a tertiary eye hospital in India. METHODS: Participants underwent intraocular pressure (IOP) measurement with GAT and 4 index tests: the Icare TA01i rebound tonometer (Icare USA, Raleigh, NC), a noncontact tonometer (NCT; Topcon CT-80; Topcon; Tokyo, Japan), a pneumatonometer (Model 30; Reichert Technologies; Depew, NY), and the Tono-Pen AVIA (Reichert Technologies). MAIN OUTCOME MEASURES: Estimates of reproducibility of IOP measurements between each index test and GAT, including the intraclass correlation coefficient (ICC) and the Bland-Altman 95% limits of agreement. RESULTS: The Icare showed the greatest agreement with GAT (ICC, 0.69; 95% confidence interval, 0.61-0.74), followed by the NCT (ICC, 0.65; 95% confidence interval, 0.58-0.71), the Tono-Pen (ICC, 0.51; 95% confidence interval, 0.43-0.59), and the pneumatonometer (ICC, 0.36; 95% confidence interval, 0.27-0.44). The pneumatonometer and Tono-Pen tended to overestimate IOP relative to GAT, with a mean difference of 3.4 mmHg (95% limits of agreement [LOA], -7.3 to 14.1 mmHg) for the pneumatonometer and 3.2 mmHg (95% LOA, -6.1 to 12.6 mmHg) for the Tono-Pen. In contrast, measurements from the Icare and NCT were on average within 1 point of those for GAT (mean difference, -0.4 mmHg [95% LOA, -8.4 to 7.6 mmHg] and -0.5 mmHg [95% LOA, -8.7 to 7.6 mmHg], respectively). CONCLUSIONS: The Icare and NCT both demonstrated good agreement with GAT across a wide range of IOPs and could be considered for glaucoma screening programs.