MAIA is a non‐mydriatic, near infrared, line scanning laser ophthalmoscope which incorporates a high frequency eye tracker and an automated macular perimeter to determine threshold sensitivity and fixation characteristics.

The MAIA software, with its normative database and statistical analysis module, is designed to identify the normal, age‐related, decrease in sensitivity and differentiate it from the pathological changes associated with macular degenerations and other retinal diseases.

ADVANTAGES OF SLO IMAGING

By using a line scanning laser ophthalmoscope (LSLO) to continuously image the retina, the light reflected by the out‐of‐focus layers does not degrade the quality of the image. The sharp constrast of the SLO image is due to its confocal properties.

EYE TRACKER

The role of the eye tracker is to compensate for the patient’s ocular movements during testing to ensure that point‐to‐point correspondence exists between the stimulus and the measured retinal location during the test and on subsequent tests.

The eye tracker also quantifies a patient’s fixation characteristics: the extent of the area covered by fixation points is a measure of fixation stability, while the location of the gravitational center of the fixation points with respect to the fovea is an indication of fixation location.

These indices aid in the determination of stable, relatively unstable or unstable fixation patterns.

The automated eye tracker is fast, accurate and robust.

It locks onto the entire fundus image and captures fixation changes 25 times per second during testing.

Live images of the retina are processed to “track” anatomical landmarks over the entire image and quantify the corresponding eye movements observed during the test procedure.

The software also identifies the Preferred Retinal Locus (PRL) – a retinal position that identifies

the patient’s preferred fixation site. This is the location around which the perimetric stimuli will be projected.

MICROPERIMETRY

Following eye‐tracking based position corrections, perimetric stimuli are automatically projected in random order using either a supra‐threshold or a 4‐2 threshold strategy to accurately measure macular threshold sensitivity at predefined retinal locations over the central 10° of the retina using a standard Goldmann III stimulus size.

Background luminance is 4 asb; stimulus dynamic range is 36 dB and maximum luminance is 1000 asb. Measured values areaveraged and compared with the age‐adjusted average for normals.

The average macular threshold, along with other variables, serves for the calculation of the macular integrity index, a statistical parameter derived by comparison with normative data that describes the likelihood of threshold values to significantly differ from normal values.

MAIA permits the differentiation of normal age-related loss of macular sensitivity from pathological (disease state) changes that require treatment.

It provides a first step in retinal disease management, enabling us to test macular function and to follow sequential changes of retinal disease and/or treatment over time.

This will allow us to improve our diagnosis and treatment of our patients by detecting disease changes earlier than conventional testing.