Investigations and Units

Ultrasound Biomicroscopy (UBM) is a new imaging technique that uses high frequency ultrasound to produce images of the eye at near microscopic resolution.

UBM gives clinicians higher-resolution digital images and video of the anterior segment of the eye behind the iris better than any other technology. This new capability is generating excitement among eyecare practitioners for its potential use in glaucoma and intra ocular lenses (IOL) patients and other common conditions and procedures.

The corneal specular microscope is a reflected-light microscope that projects light onto the cornea and images the light reflected from an optical interface of the corneal tissue, most typically the interface between the corneal endothelium and the aqueous humor. Depending on the instrument used, the projected light can be in the form of a stationary slit, a moving slit, or a moving spot and the optical design can either be non-confocal or confocal. Although specular microscopes have been used primarily to evaluate the corneal endothelium, the corneal epithelium and stroma as well as the crystalline lens can also be visualized and evaluated.

Normal corneal endothelium as photographed by specular microscopy. A quasi-regular array of hexagonal cells all having nearly the same area is seen.

These tests are done in partnership with El Borg lab.

Pathological specimen from a mass excised from the eye lid, conjunctiva, iris or other parts of the globe is described by our ophthalmologists and interpreted after being processed by the lab technicians.

The bacteriological studies for conjunctival smears or corneal scrapings  in cases of resistant conjunctivitis or corneal ulcer are essential, to prescribe the appropriate treatment. The smear is taken under sterile conditions by our ophthalmologists

Electrophysiological tests are non-invasive tools indispensable in many diagnostic dilemmas.
Being objective and reproducible they have a considerable prognostic role.

The neurophysiology unit of Bostan Diagnostic Center includes tests such as: EMG, EEG, BAEP, SSEP, VEP, ERG, EOG
Indications & Clinical applications of Electromyography (EMG) & Nerve conduction studies (NCS)

1. Myopathic Disorders
2. Neuropathic Disorders
3. Disorders of Neuromuscular Transmission
4. Extraocular muscle tests for synergistic or antagonistic movements to diagnose Duane retraction syndrome or paralytic squint

Indications & Clinical applications of Electroencephalography (EEG)

1. Epilepsy
2. Syncope
3. Vascular Lesions
4. Chronic Headache Syndromes that fail to respond to medical
   treatment
5. Tumors
6. Dementia
7. Metabolic Disorders
8. Head Trauma
9. Altered states of consciousness

When conventional spectacles can no longer help and surgery or medical treatment is not appropriate, or very prolonged, then it is time to consider low vision aids. These come in a bewildering array of strengths and designs. They range from simple hand-held lenses to electronic devices. Different ones are needed for different visual tasks.

The use of a low vision aid is dependent on many factors, the type of vision loss, the degree of loss, the patient’s light and glare needs, the ability of the patient to handle and operate the aid plus many other factors.

Your care should start with a low vision evaluation by our ophthalmologists who specialize in low vision rehabilitation. The low vision examination is not the same as the retinal or general eye examinations you might have experienced.

A Doppler ultrasound test uses reflected sound waves to evaluate blood as it flows through a blood vessel. It helps doctors evaluate blood flow through the major arteries and veins
It may be used to detect blood flow in carotid arteries and veins, also for ophthalmic artery and vein. This test helps to diagnose defective blood flow in the eye that affects the optic nerve or retinal functions.

During Doppler ultrasound, a handheld instrument (transducer) is passed lightly over the eye globe. The transducer sends and receives sound waves that are amplified through a microphone. The sound waves bounce off solid objects, including blood cells. The movement of blood cells causes a change in pitch of the reflected sound waves (called the Doppler effect). If there is no blood flow, the pitch does not change. Information from the reflected sound waves can be processed by a computer to provide graphs or pictures that represent the flow of blood through the blood vessels. These graphs or pictures can be saved for future review or evaluation.

Dacryocystography

A computed tomography (CT) scan of the orbit is an imaging method that uses x-rays to create detailed pictures of the eye sockets (orbits) and eyes (globes).

How the Test is Performed:
A special dye, called contrast, may be injected into your hand or forearm before the test starts. Contrast can highlight specific areas inside the body, which creates a clearer image.

You will be asked to lie on your back a narrow table that slides into the center of the CT scanner. Only your head is positioned inside the CT scanner.

You may be allowed to rest your head on a pillow, but this must be done before the scan begins. It is very important that once your head is in place, you do not move it during the test. Movement causes blurred images.

Once inside the scanner, the machine’s x-ray beam rotates around you. (Modern “spiral” scanners can perform the exam in one continuous motion.)

Small detectors inside the scanner measure the amount of x-rays that make it through the part of the body being studied. A computer takes this information and uses it to create several individual images, called slices. These images can be stored, viewed on a monitor, or printed on film. Three-dimensional models of organs can be created by stacking the individual slices together.

Generally, complete scans take only a few minutes.

How to Prepare for the Test:
Remove dentures, any jewelry, and anything metal.
If contrast is used, you may be asked not to eat or drink anything for 4-6 hours before the test.
Some people have allergies to IV contrast and may need to take medications before their test in order to safely receive this substance.

How the Test Will Feel
Contrast given through an IV may cause a slight burning sensation, a metallic taste in the mouth, and a warm flushing of the body. These sensations are normal and usually go away within a few seconds.

Why the Test is Performed
This test is helpful for diagnosing diseases that affect the following areas:

• Blood vessels
• Eye muscles
• Eyes
• Nerves supplying the eyes (optic nerves)
• Sinuses

An orbit CT scan may also be used to detect:

• Abscess (infection) of the eye area
• Hard-to-see fractures of the eye socket
• Foreign object in the eye socket

Corneal topography is a process for mapping the surface curvature of the cornea, similar to making a contour map of land. The cornea is a clear membrane that covers the front of the eye and is responsible for about 70 percent of the eye’s focusing power. To a large extent, the shape of the cornea determines the visual ability of an otherwise healthy eye. A perfect eye has an evenly rounded cornea, but if the cornea is too flat, too steep, or unevenly curved, less than perfect vision results.

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.

How does corneal topography work?

The corneal topographer is made up of a computer linked to a lighted bowl that contains a pattern of concentric rings. The patient is seated in front of the bowl with his or her head pressed against a bar while a series of data points are generated on a placido disk, which has been projected on the cornea. Computer software digitizes these data points to produce a printout of the corneal shape, using different colors to identify different elevations.
The procedure itself is painless and brief. It is a non-contact examination that photographs the surface of the eye using ordinary light. The greatest advantage of corneal topography is its ability to detect conditions invisible to most conventional testing.

Anterior segment OCT (Ocular Coherence Tomography) involves the measurement of a series of cross sections of the anterior segment of eye, including the cornea, iris, angle, and lens.

Optical Coherence Tomography, “OCT” for short. OCT is a non-invasive technology used for imaging the retina, the multi-layered sensory tissue lining the back of the eye. OCT is the first instrument to allow doctors to see cross-sectional images of the retina, is revolutionizing the early detection and treatment of eye conditions such as macular holes, pre-retinal membranes, macular swelling and even optic nerve damage.

Similar to CT scans of internal organs, OCT uses the optical backscattering of light to rapidly scan the eye and describe a pixel representation of the anatomic layers within the retina. Each of these ten important layers can be differentiated and their thickness can be measured.

Knowing the normal thickness of a healthy retinal layer, the ophthalmologist can then distinguish a multitude of retinal diseases and conditions.
In 2007, OCT was named one of the top 10 medical innovations expected to improve healthcare.

For certain conditions, such as age-related macular degeneration and cystoid macular edema, the 45 second OCT procedure is able to reduce or eliminate the need for fluorescein angiography for some patients.