We hear often from patients that many parts of the eye exam we perform, they have never been tested for before. While our testing may take more time, there are reasons we perform the tests we perform.
Pupil testing is an important test to insure the patient's pupils are responding properly. Some medications such as certain over-the-counter eye drops and anti-nausea medications can cause pupil dilation; however, dilated pupils can be a sign of more serious issues. Pupils that do not respond as expected can indicate a problem with the optic nerve or the brain, and may warrant additional studies such as an MRI or CT scan.
Color Vision Testing
A majority of genetic color vision deficencies are in males due to gene inhereitance. Color vision testing can also diagnose pathologies of the rods and cones of the retina. Most importantly, testing can diagnose new changes in optic nerve pathologies. The inability of the patient to see Red/Green vs. Yellow/ Blue can be helpful in making a diagnosis. An additional test, the red cap test, can be used to compare the color saturation of one eye vs. the other. It can be useful for comparing asymmetic optic nerve functionality or finding visual defects that may indicate brain tumors or aneurysms.
Eye alignment testing can be used to compare eye muscle alignment and posture at both distance and near. Testing can be used to identify reasons for eye fatigue, eye turn, or even double vision. Children should have eye alignment testing performed to identify delays in reading, increased eye fatigue, and/or poor reading performance.
Eye alignment abnormalities can be corrected with vision therapy, prism in glasses or by surgical means if necessary.
Anterior Segment Exam
The anterior segment exam allows the eye doctor to assess the front of the eye from cornea to lens using a microscope. Red eyes, inflammed eyes, dry eyes, and cataracts can be assessed on the anterior segment exam. A proper anterior segment evaluation scans from top and bottom lids to the ear and to the nose. Abnormalities from contact lens wear can be seen during the part of the exam including inflammation or even blood vessel growth (neovascularization) from overwear or sleeping in contact lenses.
Dilated Eye Exam
While cataracts can be viewed during the anterior segment exam, they are best viewed on a dilated eye exam. When the pupil is dilated, a more comprehensive view of the eye's lens exists. The doctor can grade the type of cataracts and the size of growth. During a dilated eye exam, the retina, macula, optic nerve, and blood vessels may be assessed. This part of the exam is where eye doctors look for changes due to Hypertension or Diabetes. The macula gives a patient central vision, and where we look for Macular Degeneration as a patient ages due to genetics, smoking, and UV damage from the sun. The optic nerve has an appearance like a doughnut and is the structure evaluated for Glaucoma. Additionally, because the nerve connects to the brain by way of the optic chiasm, the nerves could show changes due to brain tumors, Multiple Sclerosis, and even swelling of the brain.