- Corneal Staining
A piece of blotting paper containing the dye will be touched to the surface of your eye. You will be asked to blink. Blinking spreads the dye around and coats the “tear film” covering the surface of the cornea a blue light is then directed at your eye. Any problems on the surface of the cornea will be stained by the dye and appear green under the blue light.
- Endothelial cell count
Corneal endothelial microscopy involves the use of a specular microscope to visualize the cornea and perform an endothelial cell count. The cornea consists of several layers, including the epithelium, stroma, and single-celled endothelium. The endothelium is the most posterior layer, interfacing with the aqueous humor of the anterior chamber of the eye.
Gonioscopy describes the use of a goniolens (also known as a gonioscope) in conjunction with a slit lamp or operating microscope to gain a view of the iridocorneal angle, or the anatomical angle formed between the eye’s cornea and iris. The importance of this process is in diagnosing and monitoring various eye conditions associated with glaucoma.
- IOP measurements: sitting and supine
Between the cornea and the lens, which is located behind the cornea, there is a clear fluid that helps keep the eye healthy. If there is too much pressure or fluid in the eye, the optic nerve can become damaged. This can result in decreased vision.Intraocular pressure (IOP) varies significantly during the wake–sleep cycle It is known that a simple postural change from upright to recumbent elevates IOP, because of the hydrostatic responses in the episcleral venous pressure and the distribution of body fluid.
The pachymeter is an instrument that measures the thickness of the cornea. 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.
Measurement of the diameter or width of the pupil of the eye.
- Slit lamp assessments
The slit lamp is an instrument consisting of a high-intensity light source that can be focused to shine a thin sheet of light into the eye. It is used in conjunction with a biomicroscope. The lamp facilitates an examination of the human eye, which includes the eyelid, sclera, conjunctiva, iris, natural crystalline lens, and cornea. The binocular slit-lamp examination provides stereoscopic magnified view of the eye structures in detail, enabling anatomical diagnoses to be made for a variety of eye conditions.
- Visual Acuity
Visual Acuity is a quantitative measure of the ability to identify black symbols on a white background at a standardized distance as the size of the symbols is varied. It is the most common clinical measurement of visual function. In the term “20/20 vision” the numerator refers to the distance in feet from which a person can reliably distinguish a pair of objects.
- Visual Field examinations
The visual field refers to the total area in which objects can be seen in the side (peripheral) vision while you focus your eyes on a central point. The exam can be performed using different methods and equipment.