Diagnostic testing
Most patients who come into our clinic will have diagnostic testing at some point prior to seeing their ophthalmologist. We recommend that our glaucoma patients are monitored more closely so we can evaluate their vision and maintain the health of their eyes. If you have glaucoma or are a glaucoma suspect we will schedule special diagnostic tests for you through out the year.
Visual Fields
A visual field test maps out what your world looks like to you. It measures the area of vision, or how wide of an area your eye can see. The visual field shows changes that are not noticed by the patient until the damage is severe. Glaucoma is often called “The Sneak Thief of Sight” because it usually is a painless process that mostly affects the peripheral, or side vision, first. It is important when taking this test that you concentrate on the fixation light in the center and press the button when the blinking test light is seen with your side vision. If you move your eyes to follow or look for the blinking lights, it decreases the reliability of the test and the ability of your doctor to monitor your disease. Areas that appear gray or black on the test results reflect areas in your vision that are blurred or missing. If your glaucoma remains uncontrolled, these areas will get darker and larger. This makes visual field testing a very important part in managing your glaucoma so we can detect the changes before you will.
Optical Coherence Tomography (O.C.T.)
Optical Coherence Tomography (OCT) is a non-invasive diagnostic instrument that uses low coherent interferometry with near-infrared light to perform high-resolution cross-sectional images of the retina. OCT is comparable to ultrasound imaging, except that is uses light instead of sound. These scans present an image of the tissue layers within the retina and can be differentiated and their thickness measured. The OCT is commonly used for glaucoma and macular degeneration and can usually be done without pupil dilation, but is commonly done during the annual exam. The test takes approximately 5-10 minutes for both eyes.
Optos retinal imaging
An Optos is a diagnostic imaging device that captures an ultra-wide field image of your retina, approximately 200°. To have your Optomap taken, you simply look into the device with one eye (like looking through a hole in a fence). You will see a colored target that may shift between blue, green or red. The technician will help align your head in the optimal position and when ready will capture an image of your retina. Under normal circumstances pupil dilation is not necessary, but your eye care practitioner will decide if it is needed.
Orthoptic evaluation
An orthoptist specializes in the non-surgical treatment of visual disorders such as amblyopia, strabismus and diplopia. The orthoptist is the front line in the assessment and diagnosis of these disorders, and works with the ophthalmologist in formulating and implementing treatment plans.
Corneal Topography
Corneal topography provides us with a detailed description of various curvature and shape characteristics of the cornea. This information is very helpful for the illustration of corneal astigmatism and detection of corneal pathologies. Corneal topography is also a useful pre-operative test to assess the corneal curvature when selecting an intraocular lens implant prior to cataract surgery.
Refraction
If your vision is not 20/20, “refraction” is the process of putting lenses in front of your eye to see if lenses can bring your vision to 20/20. You look at a chart, usually 20 feet away, or in a mirror that makes things look like they’re 20 feet away. You’ll look through a tool called a phoropter. It lets the technician move lenses of different strengths in front of your eyes. You will then be asked if things look clear or blurry. Your answers give the technician your prescription for your glasses. The test will also help the technician spot presbyopia, hyperopia, myopia, and astigmatism.
Colour deficiency testing
There are different types of colour blindness but the most common is known as ‘red-green color blindness.’ Colour blindness (also called colour vision deficiency), is a condition in which the retinal cone cells respond to light differently than normal. People with colour blindness can usually still see colours but have colour confusions or see certain pairs of colours so similarly that they cannot tell them apart. The most widely used screening test for colour blindness is the Ishihara Vision Test. The Ishihara Vision Test consists of a booklet, each page containing a circular pattern comprising many dots of various colours, brightness and sizes. The seemingly random coloured dots are arranged in such a fashion that a person with normal colour vision will see a single-digit or two-digit number within the array of dots. But a colour-blind person will either be unable to see a number or will see a different number than the one seen by a person with normal colour vision.
Optical Biometry (A-scan)
Optical biometry is the current standard for intraocular lens (IOL) power calculations. Optical biometry is a highly accurate non-invasive automated method for measuring the anatomical characteristics of the eye, including the axial length, keratometry and anterior chamber depth. Here at New West Eyes, we have a specially trained Certified Ophthalmic Medical Technologist who performs these critical measurements prior to your cataract surgery.