The Amsler Grid is typically a hand-held card that consists of a white background on which a black grid is printed with a black dot in the center. The test is often administered in the doctor’s office but may be utilized by patients at home for self monitoring. The test requires the patient to focus on the black dot with one eye noting if there are any abnormalities in the lines such as waviness or missing sections. The test is used to check the health of the retina (macula). It is commonly used to detect macular degeneration or to monitor the progression of the disease or the success of treatment.
A specialized camera is used to photograph the back of the eye including the macula, retina, optic nerve, blood vessels and any abnormalities. These photos are used to document the progression of diseases such as macular degeneration, diabetic retinpathy, and glaucoma.
Eye angiography uses specialized cameras to examine the back of the eye, especially the health of the blood vessels in the retina. Fluoroscein angiography (FA) is the most common type performed. Indocyanine green (ICG) is another type of dye used to image the retina. Both are specialized dyes that are injected into a vein in the patient’s hand or arm. The dye circulates through the patient’s blood stream outlining the vessels in the back of the patient’s eye. Pictures are taken in a timed sequence as the dye circulates. This allows the retinal specialist to diagnose eye diseases such as age-related macular degeneration, diabetic retinopathy and many other less common diseases.
Optical Coherence Tomography
Optical Coherence Tomography (OCT) is a painless diagnostic test that uses low-energy laser light to create cross-sectional images of the retina and the optic nerve. It is also able to measure retinal thickness. This test is used to diagnose retinal conditions such as macular degeneration and other conditions that cause fluid to accumulate under the retina. OCT is also used as a way to monitor the health of the retina to determine if a particular treatment method being used is successful.
Ultrasound uses sound waves to visualize retinal structures when the view into the eye through the pupil is obscured by cataract formation, vitreal blood or corneal opacities. The test may also be used to measure the size of tumors located in the back of the eye.
Visual Field Testing
This diagnostic test is used to measure and document a patient’s peripheral vision. This test usually requires the patient to focus on a fixed target while responding to points of light by pressing a button. The test can be used to monitor changes in the peripheral vision caused by specific diseases such as glaucoma but may also used to assess the neurological function of the retina, optic nerve and brain.