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Abstract #16935 Published in IGR 9-1
Performance of frequency-doubling technology perimetry in a population-based prevalence survey of glaucoma: the Tajimi study
Iwase A; Tomidokoro A; Araie M; Shirato S; Shimizu H; Kitazawa Y; Tajimi Study GroupOphthalmology 2007; 114: 27-32
OBJECTIVE: To evaluate the performance of frequency-doubling technology (FDT) perimetry in a population-based glaucoma prevalence survey. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Participants older than 40 years randomly selected from the population of Tajimi City. METHODS: Each participant underwent screening ophthalmic examinations including a visual field test using FDT with the C-20-1 screening protocol. A diagnosis of glaucoma was determined by glaucoma specialists with another detailed visual field test using the Humphrey Field Analyzer (HFA; Humphrey Instruments, San Leandro, CA) with the 30-2 Swedish interactive threshold algorithm standard protocol and stereoscopic disc photographs. MAIN OUTCOME MEASURES: The ratios of reliable FDT results and the sensitivity and specificity for detecting glaucoma in a general population. RESULTS: Of 5784 eyes of 2892 participants (age range, 40-92 years; refractive error, -23 to 11 diopters) in whom FDT was performed in both eyes, reliable results (≤ 33% fixation loss and ≤ 33% false-positive errors) were obtained in 5707 eyes (98.7%), including 2871 right eyes (99.3%) and 2836 left eyes (98.1%) with a significant bilateral difference (P < 0.001, chi-square test). The rate of reliable FDT results did not differ between men and women (P = 0.81) but decreased with age. In 5582 eyes with reliable FDT results, FDT showed 1 or more abnormal points in the visual field in 502 eyes (9.0%), including 388 (7.3%) of 5295 normal eyes, 19 (16.4%) of 116 eyes of glaucoma suspects, and 95 (55.6%) of 171 eyes with definite glaucoma. The sensitivity and specificity values for detecting definite glaucoma were 55.6% and 92.7%, respectively. The positive and negative predictive values were 18.9% and 98.5%, respectively. In further analyses stratified with the mean deviation (MD) of the HFA, the sensitivities were 32.1%, 48.4%, 73.7%, and 96.6% for detecting definite glaucoma with an MD of more than -2 dB, an MD of -2 dB or less and more than -5 dB, an MD of -5 dB or less and more than -8 dB, and an MD of -8 dB or less, respectively. CONCLUSIONS: In a population-based glaucoma screening study, FDT perimetry with the C-20-1 screening protocol was reliably performed in more than 98% of participants. The sensitivity for detecting glaucomatous visual field damages, especially early damage, was not sufficiently high, whereas the specificity was high.
Dr. A. Iwase, Department of Ophthalmology, Tajimi Municipal Hospital, Tajimi, Japan
Classification:
6.6.3 Special methods (e.g. color, contrast, SWAP etc.) (Part of: 6 Clinical examination methods > 6.6 Visual field examination and other visual function tests)
