Vision is most commonly graded by the size of letters which can be seen on the test chart (for example 6/6 or 20/20 is regarded as “normal” vision), but sight is much more nuanced than black letters on a white test chart. In addition, some zones of the central vision are often more damaged than others, creating problems reading without affecting the eye chart testing result. Perimetry tests different areas around central vision and assesses the sensitivity to decreasing light intensity. Macula microperimetry is an essential way to identify poor macular function, to monitor the rate of deterioration and potentially help improve reading ease.
To perform this test, the patient sits in front of a computer screen with a central target and presses the button when they detect a spot of light. This test takes approximately 10 minutes and is stress free, but does require some concentration. Macula microperimetry is very similar to standard perimetry assessing for diseases such as glaucoma, but standard perimetry tests the peripheral vision, whereas macula microperimetry provides much more detail of central or macula function.
The advantage of the MAIA (Centervue Macular Integrity Assessment) unit is that the computer software tracks eye movement so that the same retinal areas are tested, providing accurate monitoring of any visual deterioration or improvement in each specific tested area.