Performance of the 24-2-5 frequency doubling technology screening test: a prospective case study

Abstract

Aim: To evaluate the performance of the frequency doubling technology (FDT) 24-2-5 screening test by comparison with the established N-30-5 FDT screening test for detection of glaucoma. Method: A prospective random sample of individuals referred for possible glaucoma were tested with FDT screening tests 24-2-5 and N-30-5 using the Humphrey Matrix perimeter in addition to standard clinical examination relevant to glaucoma detection. Discriminatory power, reliability and test time of these tests were assessed and compared. The case definition for glaucoma was made by patient according to the established clinical diagnosis. Results: Of 63 referred eligible individuals, 53 (84%) were recruited. Sensitivity and specificity for the N-30-5 screening test was 78 and 85% respectively, compared with 83% and 75% for the 24-2-5 with areas under a receiver operator characteristic curve being 0.87 and 0.92. Differences between these indices were not statistically significant. For a specificity of 95%, sensitivity values were 76% and 56% for the 24-2-5 and N-30-5 respectively. Mean (standard deviation) test duration for the FDT 24-2-5 and N-30-5 screening tests were 111 (13) and 39 (10) seconds respectively (p,0.001). A total of 19 subjects (36%) produced unreliable test results in one or both eyes when tested with the 24-2-5 screening test compared with 5 subjects (9%) with the N-30-5 (p,0.0005). Conclusion: Minimal discriminatory power differences existed between the two screening tests evaluated, with both screening tests exhibiting high discriminatory power for detection of individuals with glaucoma. More individuals produced unreliable results on the 24-2-5 screening, which also took longer to perform.

Risk factors for open‐angle glaucoma with normal baseline intraocular pressure in a young population: the Korea National Health and Nutrition Examination Survey

“…The specificity of the FDT screening mode is approximately 85-100%, and the sensitivity is about 78-92% for detecting glaucoma. 33,34 In the Tajimi study, the sensitivity and specificity of the FDT screening mode for detecting glaucoma were 55.6% and 92.7%. 35 Therefore, the FDT screening mode is most appropriate for population-based screening where false-positive outcomes need to be minimized.…”

Development of Visual Field Screening Procedures: A Case Study of the Octopus Perimeter

“…Note that some screening procedures have altered the stimulus level after the first presentation, 8 but we did not explore these variants. Rather, we kept the stimulus level constant at any given location set to either the population's 0.5%, 1%, 2%, or 5% sensitivity levels (brightest) of age-matched normal observers for that location.…”

Burden of Undetected and Untreated Glaucoma in the United States

“…Visual field data were used to identify a glaucomatous visual field defect (GVFD), which was defined as an abnormal visual field based on the 2-2-1 algorithm as described above. 17 The GVFD status (defect, no defect, no visual field test) was matched with glaucomatous optic neuropathy (GON) status (probable GON, possible GON, no GON) to reach a classification of definite, probable, possible, or no glaucoma based on the Rotterdam Eye Study criteria. 4 Persons were excluded from the analysis if they had pathologies that had the potential to provide alternative explanation for any optic neuropathy.…”