Frequency doubling technology (FDT) perimetry is based on a flicker illusion created by counterphase flickering of a low spatial frequency sinusoidal grating at a high temporal frequency. [1] . This phenomenon essentially creates an image that …

The Frequency Doubling Technology (FDT) perimeter is a portable, relatively inexpensive instrument designed for fast and effective detection of visual field loss 1.

The Humphrey FDT Perimeter uses Welch Allyn Frequency Doubling Technology to provide a clinically verified, fast and affordable means of detecting early visual field loss. The perimeter is the ideal glaucoma screening device because it conducts supra-threshold testing in only 35 seconds per eye.

While white-on-white standard automated perimetry (SAP) remains the reference standard for evaluation of visual field (VF) in glaucoma, there is evidence supporting that frequency-doubling technology (FDT) perimetry performs as well as, if not better than, SAP for detection of glaucomatous VF defects. 1 - 7 However, less is known about the role ...

FDT and Humphrey Matrix perimetry have been shown to be effective in the detection, evaluation, and follow-up of glaucomatous visual field loss.

本研究旨在找出倍频技术视野检查（FDT）与标准自动视野检查（SAP）在检测视野（VF）损伤方面的差异的意义，并评估早期SAP-FDT差异的相关因素。 青光眼。 该横断面研究包括早期青光眼患者（MD优于-6.0分贝，96只眼）。

2022年6月17日 · This study aimed to find out the significance of the difference between FDT perimetry and SAP in terms of the detected visual field (VF) damage, and evaluate associated factors to SAP–FDT ...

Frequency-doubling technology seems to be a clinically feasible VF method for evaluating young children older than approximately 8 years of age. The reliability indices, MD, test duration, and the reproducibility of the VF test were found to be highly correlated with age, in such a way that these parameters all improved with increasing age.

Importance: While standard automated perimetry (SAP) remains the reference standard for evaluation of visual field (VF) defects in glaucoma, this study demonstrates that frequency-doubling technology (FDT) perimetry is effective in monitoring visual field progression and may detect the onset of visual field defects earlier than SAP.

Aim: To evaluate the effect of cataract surgery on frequency doubling technology (FDT) perimetry in patients with co-existing cataract and glaucoma. Methods: In this consecutive prospective cohort study 27 patients with open angle glaucoma scheduled for cataract extraction alone or combined with trabeculectomy were enrolled.