What does the FDT measure?

What does the FDT measure?

PURPOSE: Frequency Doubling Technology (FDT) perimetry is a novel perimetric test that provides rapid screening (45 to 60 seconds) and full-threshold (4 to 5 minutes) testing for detection of vision loss.

What is a FDT screening?

The original FDT perimeter threshold testing utilizes a four-reversal staircase procedure known as the modified binary search algorithm (MOBS). In this way, contrast is decreased if the stimulus is detected at a higher level, or contrast is increased until a stimulus is detected.

What is Humphrey FDT?

Description. The Humphrey® FDT Perimeter uses Frequency Doubling Technology to provide a clinically verified, fast and affordable means of detecting early visual field loss. The FDT is the ideal visual field screening device because it conducts supra-threshold testing in only 40 seconds per eye.

What is FDT and retinal imaging?

The FDT is an instrument designed for fast and effective screening of visual field loss. It can determine if you have lost the ability to see in a specific viewing area (i.e. a segment of your peripheral vision or central vision).

What is FDT perimetry?

The Frequency Doubling Technology (FDT) perimeter is a portable, relatively inexpensive instrument designed for fast and effective detection of visual field loss1. This instrument (Welch Allyn, Skaneateles, N.Y., and Carl Zeiss Meditec, Dublin, Calif.)

What is perimetry in ophthalmology?

​Perimetry is the systematic measurement of visual field function (the total area where objects can be seen in the peripheral vision while the eye is focused on a central point). The two most commonly used types of perimetry are Goldmann kinetic perimetry and threshold static automated perimetry.

How do you read a Humphrey visual field test?

The dBs tested by the Humphrey analyzer range between 0 and 50 dB (0 is the brightest and 50 is the dimmest). A value of 0 means the patient could not see the brightest target, and a 50 means the dimmest target was seen.

What are the three types of Ophthalmic imaging?

In the past two decades eye care has seen the emergence of three major technologies for diagnostic imaging of the posterior segment of the eye: Scanning Laser Polarimetry (SLP), Confocal Scanning Laser Ophthalmoscopy (CSLO), and Optical Coherence Tomography (OCT).

What is a MAC eye test?

The Amsler grid is a tool that opticians use to detect vision problems resulting from damage to the macula (the central part of the retina) or the optic nerve. The damage may be caused by macular degeneration or other eye diseases, so the Amsler grid is useful in detecting these problems.

How accurate is Amsler grid?

The pooled sensitivity of studies assessing the Amsler grid was 0.78 (95% confidence intervals; 0.64–0.87), and the pooled specificity was 0.97 (95% confidence intervals; 0.91–0.99).

How do you do Goldmann perimetry?

Goldmann perimetry and Automated perimetry. For either test, you sit in front of a concave dome and stare at a target in the middle. You press a button when you see small flashes of light in your peripheral vision. With Goldman testing, the flashes are controlled and mapped out by the examiner.

What is the most accurate test for visual field loss?

Amsler grid: This is a printed image of a grid with a dot in the center. The patient is asked to look at the dot, one eye at a time, and note whether the grid lines surrounding the dot appear distorted, faded, or partially missing. This test is most often used to detect central visual field defects.

What are the different types of visual field tests?

Six types of visual field tests

• Confrontation visual field test.
• Automated static perimetry test.
• Kinetic visual field test.
• Frequency doubling perimetry.
• Electroretinography.
• Amsler grid: A basic visual field test for central vision.

What is Sita standard?

The Swedish Interactive Thresholding Algorithm (SITA) Standard was developed for the Humphrey Field Analyzer (HFA; Carl Zeiss, Meditec) in the 1990s and allows VF testing to be performed in about half the time taken by older full-threshold strategies,5-7 with no significant decrease in precision.

What are the types of perimetry?

There are two major types of perimetry. Kinetic perimetry involves the detection of moving targets and static perimetry involves the detection of a stationary target.