OCT is an acronym for “Optical Coherence Tomography”. This state-of-the-art instrument is used to analyze the anatomic structure of the optic nerve head, or disc, and the retina. This instrument and the tests it can perform are very useful for the evaluation of the optic nerve and macula to diagnose conditions such as thinning of the optic nerve, macular holes, epi-retinal membranes, cystoid macular edema, central serous choroidopathy and diabetic retinopathy.
The test itself is quick and painless and involves a noninvasive/noncontact scan of the internal structures of the eye. The data is generated via optical backscattering of light and produces cross sectional images of the retina and the optic nerve head. This sophisticated technology boasts extremely high micrometer-resolution that generates a three dimensional image. As a result, OCT testing allows for the layers of the retina to be isolated and differentiated, thus determining the thickness of the retina.
OCTs are able to provide a snap-shot in time. Comparison of past and present OCTs allows for monitoring of small changes over time. For this reason, OCT testing has proved to be a vital tool when evaluating such conditions as glaucoma and macular changes.
The intraocular pressure is measured through a technique called, tonometry. This measurement is quantified in millimeters of mercury (mm Hg); “normal” eye pressure is considered to be within the range of 10-21 mm of Hg. That being said, an ideal intraocular pressure is different for each individual. Some patients are able to tolerate a higher eye pressure while others cannot. Your eye doctor will be able to determine what target eye pressure is appropriate for you.
Humphrey Visual field
Digital Retinal Photography
Digital Retinal photography is the latest technology used in vision care. This new technology allows us to look directly at the retina with a high resolution camera. Images of the eye are analyzed by the doctor helping them in determining if there are any signs of high blood pressure, diabetes, cataracts, glaucoma, congenital anomalies, along with many other eye diseases. Pictures are then shared and explained to the patient. Your doctor will compare these photos to previous photos during your annual eye exam; if further evaluation is necessary your doctor may take more comprehensive photos to export and email to referring doctors for further analysis.
An autorefractor is a computer-controlled instrument used during an eye exam to provide an objective measurement of a person’s refractive error and prescription for glasses or contact lenses. This is achieved by measuring how light is changed as it enters a person’s eye. The automated refraction technique is quick, simple and painless. The patient takes a seat and places their chin on a rest. One eye at a time, they look into the instrument at a picture inside. Several readings are taken which the instrument averages to form a prescription. No feedback is required from the patient during this process.
Within seconds an approximate measurement of a persons’ prescription can be made by the instrument and printed out. It is used to provide the starting point for our optometrist in subjective refraction tests and is particularly useful when dealing with non-communicative people, such as young children or those with disabilities.
Pachymetry gives the doctor the ability to catch and begin treatment for problems such as glaucoma and ocular hypertension before they cause permanent damage. It is useful in monitoring the progression of certain disorders that cause the cornea to become thickened (or filled with water), resulting in a loss of vision. A pachymeter is a device that uses ultrasound to determine the thickness of the cornea. A pachymetry reading for a normal eye is 550 microns. When this number is significantly above or below the norm, it indicates that a patient’s corneal thickness is abnormal. Pachymetry is also an essential measurement prior to the refractive surgical procedure, LASIK. During LASIK, the surgeon must remove tissue from the cornea and, therefore, pachymetry is important to be certain that the cornea will retain enough central tissue thickness to prevent ectasia, an abnormal “bowing” of thin corneas.
Glaucoma is the leading cause of preventable blindness in the U.S with over 67 million people worldwide affected. Yet, approximately 2 million Americans are unaware they have the disease and still others will be diagnosed only when it is too late to save their vision. Glaucoma, often called the “silent thief of sight,” has no noticeable symptoms and no cure.
Precise measurement of the entire eye, from the cornea to the retina, is key to achieve best IOL prediction accuracy in state-of-the-art cataract surgery. The Lenstar is the first optical biometer on the market providing the surgeon with all measurements necessary to take full advantage of the latest IOL prediction methods. Lenstar’s unique dual zone keratometry provides highly accurate measurement of corneal astigmatism and axis location 4), the key parameters for precise planning of toric IOL.
The purpose of corneal topography is to produce a detailed description of the shape and power of the cornea. Using computerized imaging technology, the 3-dimensional map produced by the corneal topographer aids an ophthalmologist in the diagnosis, monitoring, and treatment of various visual conditions.