• Live sub-surface images at near-microscopic resolution
• Instant, direct imaging of tissue morphology
• No preparation of the sample or subject
• No ionizing radiation

Optical Coherence Tomography, or ‘OCT’, is a technique for obtaining sub-surface images of translucent or opaque materials at a resolution equivalent to a low-power microscope. It is effectively ‘optical ultrasound’, imaging reflections from within tissue to provide cross-sectional images.

Within the range of noninvasive three-dimensional imaging techniques that have been introduced to the medical research community, OCT as an echo technique is similar to ultrasound imaging. Other medical imaging techniques such as computerized axial tomography, magnetic resonance imaging, or positron emission tomography do not utilize the echo-location principle.

The technique is limited to imaging 1 to 2 mm below the surface in biological tissue, because at greater depths the proportion of light that escapes without scattering is too small to be detected. No special preparation of a biological specimen is required, and images can be obtained ‘non-contact’ or through a transparent window or membrane. It is also important to note that the laser output from the instruments is low – eye-safe near-infra-red light is used – and no damage to the sample is therefore likely.

Pattern electroretinography (pattern ERG) is a highly-advanced vision test that objectively measures how well your vision system is working. Information from this test will help your doctor diagnose various vision disorders, as well as better understand when changes in your visual function occur.

Corneal Pachymetry

Pachymetry is a simple, painless test that quickly measures the thickness of the cornea.

Why Measure Corneal Thickness?

• Pachymetry can tell doctors if the cornea is swollen.
• Medical conditions such as Fuch’s Dystrophy can increase fluid in the cornea and cause an increase in overall thickness. Even wearing contact lenses can sometimes cause significant corneal swelling. This may be difficult to see under the microscope. However, pachymetry will show a definite increase in thickness.
• Corneal thickness is extremely important in refractive surgical procedures such as LASIK. Knowledge of corneal thickness is important to determine if a person is a candidate for laser vision correction. Because part of the procedure includes removing tissue which will leave the corneal thinner, it is important to know exactly how much will remain. Some people may have a cornea that is just much thinner than normal. It does not cause problems or disease, but it could spell tragic vision loss if a refractive procedure is performed on someone whose cornea is extremely thin.
• Pachymetry has also become important in glaucoma care. Glaucoma is a disease in which eye pressure (intraocular pressure)can be elevated. Elevated eye pressure can cause nerve fiber loss in the retina which may result in blindness or decreased vision. Most methods involve a method of measuring eye pressure in which the instrument touches the cornea.
• Researchers discovered that corneal thickness can vary slightly in the population. Corneal thickness can influence the actual reading of the amount of pressure in the eye. Furthermore, the identification of central corneal thickness as an independent indicator of glaucoma risk by the Ocular Hypertensive Treatment Study (OHTS) has made corneal pachymetry an important part of glaucoma testing.

Corneal Pachymetry
Why is it important to have this test done?

• Contrast sensitivity is your ability to distinguish the foreground from the background. A contrast sensitivity test measures your ability to distinguish between finer and finer increments of light versus dark (contrast). This differs from common visual acuity testing in a routine eye exam, which measures your ability to recognize smaller and smaller letters on a standard eye chart.
• MContrast sensitivity is a very important measure of visual function, especially in situations of low light, fog or glare, when the contrast between objects and their background often is reduced. Driving at night is an example of an activity that requires good contrast sensitivity for safety.
• It is important to note that contrast sensitivity is a much more sensitive measure of real world vision. Even if you have 20/20 visual acuity, you can have eye or health conditions that may diminish your contrast sensitivity and make you feel that you are not seeing well.