Ophthalmic Optics Terminology Flashcards
25% of ABO Prep Test
Cornea
A transparent layer that covers the pupil and iris, allowing light to pass through the eye.
Astigmatism
An irregularly shaped cornea causing blurred vision or multiple images.
Bullous/Bullae
Having to do with blisters. In later stages of Fuchs’ corneal dystrophy, the Blullae become evident on the cornea as the swelling and fluid retention take place. Bullae could rupture causing immense pain.
Bandage Lens
A contact lens inserted in the eye when the epithelial (outer) layer is injured or tender from a surgical procedure, to protect the cornea while healing. (Removed and Placed by an optometrist)
Cataract
As we age, our natural crystalline lens becomes cloudy and makes it difficult to see. A cataract is NOT a growth on the lens but the fact that the lens is no longer clear.
CHED
Congenital Hereditary Endothelial Dystrophy. Cloudy cornea, sensitivity to light, and tearing. In some cases: nystagmus, rapid, involuntary movements of the eyes.
Cornea Edema
Swelling of the cornea caused by the failure of the cornea’s endothelial cells to precent other ocular fluids from invading the cornea.
DALK
DALK is a partial-thickness cornea transplant procedure that involves selective transplantation of the corneal stroma, leaving the native Descemet membrane and endothelium in place.
Diopter
A unit of measurement that helps determine how much a lens should be altered to bend or refract light rays to achieve correct focus.
Descement’s Layer
A thin, strong inner layer that also acts as a protective layer.
DLEK
Deep Lamellar Endothelial Keratoplasy. An early transplant of the endothelial layer of the cornea.
Dry Eye
Dry Eye can result from a number of causes, both physical and environmental. In Fuchs’ patients it is not uncommon to have symptoms post-surgery. Some factors which cause dry eye include lack of blinking, aging, dry climates, windy conditions, surgery or trauma to the eye. Remedies can be warm ompresses, various eye drops or gels, using a humidifier.
Edema
Swelling evidenced in later stages of Fuchs’ when the endothelial cells can no longer help rid the cornea of fluid buildup.
Endothelium
The innermost layer consisting of specialized cells which pump excess fluid out of the cornea.
Floaters
Particles of various sizes floating within the eyeball’s vitreous fluid. They are often blood droplets from minor hemorrhaging when the fluid pulls away from the eyeball.
Graft
The portion of tissue from a donor’s cornea which is transplanted into the eye of a recipient in a partial or full transplant.
Guttata
Corneal guttata are droplet-like accumulations of non-banded collagen on the posterior surface of Descemet’s membrane where no endothelial cells are visible. This is a telltale symptom of Fuchs’ Corneal Dystrophy.
Pachymeter
Instrument for measuring the thickness of the cornea. It is used as an evaluative tool of contact lens wear, detection of Glaucoma, and monitoring corneal edema.
Prism
Placed in the lens of eyeglasses to help people with double vision, positional correction or convergence correction.
Refraction
An eye exam which measures a person’s prescription for eyeglasses or contact lenses. In US measurements (20/20) shows what a person actually sees and compares this to what a person with normal vision should see at 20 feet. In metric countries it is 6/6 (6 meters).
Slit Lamp
A lamp with a narrow beam of intense light used to examine individual layers of the cornea .
Speculum
A device which keeps the eye open during an examination or surgery.
Stroma
The thickest layer of the cornea, consisting of water, collagen fibers and other connective tissue components that give the cornea its strength, elasticity and clarity.
