GA Diagnosis

GA Diagnosis

Retinal Imaging

Currently GA can only be effectively diagnosed with a full dilated eye exam, involving retinal imaging techniques. The examination is typically undertaken in a specialist ophthalmology clinic. Several retinal imaging techniques are used, usually in combination, to diagnose GA and monitor GA progression.

Functional Tests

The standard ‘functional’ vision test that people are familiar with is the visual acuity test, which checks how well you see the details of a letter or symbol from a specific distance. However, GA is generally a slowly progressing disease and the early stages are typically not associated with a loss in central visual acuity. The visual acuity test is thus not adequate to detect functional deficits experienced by people with GA. Alternative assessments of visual function are needed in order to identify deterioration of visual function that occur before the loss of foveal function; several functional tests are being investigated in patients with GA.

Patient-Reported Outcome (PRO)

These measures are designed to gain the patient’s insights into the impact of a disease on different aspects of their everyday quality of life, including physical, mental, and social functioning. Two PRO instruments (questionnaires) are mainly used to collect information from patients with AMD:

Functional Reading Independence (FRI) Index11

7-item questionnaire that evaluates the effect of GA on a patient’s ability to independently perform reading activities.
FRI index score has been shown to be sensitive to GA lesion size as well as changes in GA lesion size over time.
This instrument is publicly available through Mapi Research Trust

25-item Visual Function Questionnaire (VFQ-25)12

Developed by the National Eye Institute, the 25-item (question) instrument measures the influence of visual dysfunction on functional aspects (e.g. reading the newspaper).
This questionnaire has not been widely used in the GA patient population.