A relatively new technology, called preferential hyperacuity perimetry (PHP) allows eye doctors to detect progression in AMD sooner than with the Amsler grid. The key to the best outcome for treatment of wet AMD is early diagnosis and treatment. The ForeseeHome™ AMD Monitor by Notal Vision has received Section 510 (k) clearance from the U.S. Food and Drug Administration (FDA)
The standard practice of patient self-monitoring with the Amsler grid can be useful if patients carefully follow their doctor's instructions for using the grid. However, studies show that many patients have a hard time adhering to the regimen. In addition, evidence shows that in the early stages of conversion to wet AMD, the brain can "correct" distortions in what the eye actually sees when looking at the grid. This means that by the time the patient actually perceives that the lines appear curved, vision loss has already occurred, thus compromising the effectiveness of the Amsler test.
"When left unchecked for as little as three months, wet AMD can cause severe vision loss," said Dr. Yair Alster, the developer of the Foresee PHP device. "PHP technology represents a positive step forward in monitoring macular degeneration, and can result in vision-saving outcomes for patients."
In studies, PHP testing has been shown to correctly detect indicators of wet AMD more than 80 percent of the time, representing a significant improvement over the Amsler grid. The device works by mapping defects within a patient's visual field. The non-invasive and easy-to-perform test analyzes patients' responses to images flashing on a computer screen. The response patterns are recorded and analyzed, then compared to a database to produce a report that tells the eye care specialist the location of defects in the macular area. Once these defects are identified, the doctor can perform additional tests to verify the diagnosis and begin proper treatment.
Most doctors recommend at-risk patients with intermediate, dry AMD have this diagnostic test performed four times a year. For additional information about the Foresee PHP, visit www.foreseephp.com.