State-of-the-Art Testing and Measurement Equipment

Our medical office is equipped with the latest, state-of-the-art examination, testing and measurement equipment. This enables Dr. Harmon and his staff of experienced professionals to provide you with the best diagnosis and care available. Following are descriptions of some of the examinations that are routinely performed. Some of these exams may require dilation of the pupils with drops. All of the exams are non-invasive and painless and provide detailed information about your eyes that will be discussed with you during your visit.

The Slit Lamp Examination

The slit lamp is a microscope with a high-intensity light source. The slit lamp allows the doctor to examine the various structures within the anterior chamber of your eye (the sclera, conjunctiva, iris, lens, and cornea) under high magnification. With special lenses, the structures in the “back portion of the eye” (vitreous, retina, optic nerve) can also be examined. The term “slit” is used because the beam of light on this device is adjustable (from a wide beam to a thin slit of light), making it possible for the doctor to visualize the various parts of the eye in different ways.

The Visual Field Examination

For the Visual Field exam, you sit in front of a concave dome and stare at a central target within the dome. A computer-driven program flashes small lights at different locations within the dome's surface, and you press a button when you see the small lights in your peripheral vision. Your responses are compared to age-matched controls to determine the presence of defects within the visual field.

The test will detect any loss of peripheral vision and provide a map of that loss which will be helpful in diagnosing the cause.

Humphrey Automated Perimeter

Determining and monitoring the visual field are crucial aspects of the detection and management of glaucoma. By monitoring the patient’s visual field, doctors are monitoring whether or not vision is being lost. In glaucoma, it is the peripheral (side) vision that is most commonly affected first. Loss of peripheral vision can go unnoticed at the early stages. In fact, loss of peripheral vision can often go undetected until significant glaucoma damage is present. Currently, the state-of-the-art visual field test is the Humphrey automated perimeter.

Short Wavelength Automated Perimetry (SWAP)

SWAP is performed on the Humphrey visual field machine (perimeter) and is the so-called blue-on-yellow test. This test shows the patient blue stimuli (dots of light) on a yellow background. For a patient to detect these blue dots on a yellow background, specific cells that are usually damaged very early in the development of glaucoma must function. It is these specific cells that are being tested in SWAP. The SWAP test is more sensitive in early glaucoma than late and can detect visual field loss before it would be detected with a standard white –on-white test. It is believed that SWAP may be able to detect visual field loss related to glaucoma as early as 5 years before damage is seen with standard white-on-white perimetry.

The Heidelberg Retinal Tomography (HRT) Examination

The HRT scans your eye with a beam of light, producing a topographical or surface image of the eye's optic disc, and then measures the key structures known as cup, rim and retinal nerve fiber layer. The instrument then stores each patient's images, and on a follow-up visit the device checks for signs of statistical change that are presented to the clinician as signs of a possible disease progression. This enables the clinician to make a better decision on a course of therapy.

Optical Coherence Tomography (OCT)

OCT produces cross-sectional images of the retina. This technology allows accurate measurements of the retinal nerve fiber layer, the optic disc, and the macula (the center of the retina and the surrounding area that provide you with the sharpest central vision). OCT is a valuable tool in the evaluation of glaucoma and macular disorders.

IOLMaster

The IOLMaster is used for biometric measurement and preoperative computation of intraocular lens (IOL) power. Non-contact Optical Coherence Biometry revolutionizes measurement of the ocular axis and sets new standards for speed and accuracy. IOLMaster technology makes possible exact measurement of visual axis length. Its accuracy is not affected by high ametropia, pupil size or state of accommodation. The integrated OD/OS sensor eliminates the risk of confusing right and left eye data.

• Precise axial length measurements

• Non-contact optical biometry

• Multiple operators, same measurement results

• Improved refractive results through personalized IOL constants

• Performance, simplicity, efficiency – the IOLMaster provides all biometric parameters required for IOL power calculation in a natural, user-friendly sequence in a single location