Opthalmoscope

An opthalmoscope is used to examine the retina and vitreous. Ophthalmoscopy aids visualization of the inside of the back of the eye including the retina, optic disc, choroid and blood vessels. It is often part of a routine eye examination. A direct opthalmoscope is used for viewing the central retina. It is hand-held and powered with a light source. The instrument has to be adjusted constantly to focus on different structures within the eye. The light can be intense and disturbing. An indirect ophthalmoscope aids in examining the entire retina. This instrument is attached to the doctor's head and allows a clear view of the retina with a special lens. The patient may feel uncomfortable due to the intense light and pressure from the instrument. Opthalmoscopy is useful in detecting any changes in the retina due to diseases such as eye disease, diabetes, arteriosclerosis, high blood pressure or macular degeneration. Cataracts and other eye problems can be detected with an opthalmoscope.

The patient's eyes are dilated so as to allow a good view of the insides of the eye. Some patients develop allergic reaction, vomiting, nausea and dizziness. This test is conducted in a darkened room where the patient is asked to look ahead at a distant spot. The eyes must be held steady without blinking. The opthalmoscopy procedure may take just about 5 - 10 minutes.

Tonometry

Tonometry test is a diagnostic test to measure the intraoccular pressure (IOP). When the tonometry test measures the pressure inside the eye, it can help in detecting glaucoma. Ensure that you take off your contact lenses. Do not wear tight clothing around the neck as it can lead to increased pressure inside the eye. Do not smoke a few hours prior to the tonometry test. The tonometry test is also conducted in cases of head or eye surgery and hyphema.

When the pressure builds up within the eye due to improper drainage, it can cause permanent damage to the ooptic nerve. Tonometry is done as part of routine eye examination to check for glaucoma. Anesthetic eyedrops are used to numb the eye before using the tonometer. In the applanation method of testing intraoccular pressure, a paper stained with fluorescein is placed to the side of the eye thereby staining the front of the eye. The tonometer is then brought close to the cornea for testing. Here the intraoccular pressure is measured by the amount of weight that is needed to flatten the cornea. This type of tonometry test can also be conducted with a pencil-like instrument, which will give instant digital measurement. The air puff method of conducting tonometry is a non-contact one where a puff of air is blown at your eye and change in the light reflected from the cornea is measured to arrive at the intraoccular pressure. This method is preferred for children and persons who have undergone LASIK surgery.