Frequency doubling technology and confocal scanning ophthalmoscopic optic disc analysis in open-angle glaucoma with hemifield defects

Purpose: To evaluate the potential of frequency doubling technology for det ecting early glaucomatous damage. Patients and Methods: Forty-nine eyes of 49 patients with open-angle glauco ma with visual field defects only in one hemifield according to the Humphre y Field Analyzer 30-2 program were included. Forty-five healthy patients we re also included as control subjects. In each patient, frequency doubling t echnology with the threshold N-30 program and optic disc analysis using the Heidelberg Retina Tomograph was performed. Frequency doubling technology t est results and the Humphrey Field Analyzer test results were compared. Opt ic disc parameters corresponding to the hemifield designated intact by the Humphrey Field Analyzer were compared between the eyes in which the hemifie ld was normal by frequency doubling technology and those in which the hemif ield was abnormal. Results: Forty-one percent of the 49 hemifields designated intact by the Hu mphrey Field Analyzer were abnormal based on frequency doubling technology, whereas 98% of the 49 hemifields designated defective by the Humphrey Fiel d Analyzer were abnormal and 12% of the 90 hemifields designated intact by the Humphrey Field Analyzer were abnormal in healthy patients. The percenta ge of the hemifields designated abnormal by frequency doubling technology w as significantly higher than that in healthy patients (P < 0.001). The rim volume was significantly smaller in eyes with abnormal results based on fre quency doubling technology than in eyes with normal results (P < 0.05, pair ed t test, with Bonferroni correction for multiple comparison). Conclusion: Frequency doubling technology can detect glaucomatous damage ea rlier than conventional static perimetry can.