Glossary

Always under construction - Please let me know if you think of a term that isn't here!

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A
Acanthamoeba	A free living amoeba, which can be found in tap water, making contact-lens wearers particularly susceptible to infection. It has been known to cause keratitis and sometimes, in extreme cases, blindness. Curing the infection can be difficult. Prevention is better than cure.
Aquasil	Type of material used to make rigid contact lenses. The inner side is "softer" than a typical RGP lens.
Astigmatism	A visual defect in which the unequal curvature of one or more refractive surfaces of the eye, usually the cornea, prevents light rays from focussing clearly at one point on the retina, resulting in blurred vision.
Atopic	Allergic (e.g. hayfever, dust)
B
Binding	Where the lens "sticks" to the eye
C
CONCTGP	Condition Of Not Contributing To Glossary Page!!!!!!!! If you have any suggestions for terms on here, please email webmaster@keratoconus-group.org.uk
Cornea	Transparent part of the front of the eye. It's the cornea to blame if you suffer from Keratoconus.
Corneal Graft	A transplant of eye tissue to replace the cornea
D
DALK	Deep Anterior Lammelar Keratoplasty. A form of corneal transplant where only the central section of cornea (the stroma) is replaced by the donor's tissue. Often, the front epithelium is replaced also; if it isn't, the host's own cells re-grow to form a new epithelium.
Diopter	Measurement of optical acuity
E
Endothelium	The back layer of the cornea. The endothelial cells job is to keep the cornea free of the fluid inside the eye.
Epicon lens	New contact lens for KC
F
Fenestrations	Holes in a (scleral) contact lens
G
GPC	Giant papillary conjunctivitis (GPC) presents as multiple large, white bumps on the inside of the upper eyelids. These bumps then rub against the upper edge of the contact lens, causing significant irritation
Graft	Another name for a transplant (where it concerns the cornea)
H
Hydrogel	Type of soft lens
Hydrops	Corneal hydrops is a condition commonly associated with advanced Keratoconus, in which a deep layer of the cornea, known as Descemet's membrane, ruptures. The cornea then swells resulting in significantly reduced, blurred, and often foggy vision. The corneal swelling usually resolves over a period of 6 to 8 weeks without any specific treatment, however, visual acuity may be permanently reduced as a result of associated corneal scarring.
I
Intacs	Form of surgery where semi-circular devices are implanted into the cornea. They are used to help correct poor vision.
Iris	Coloured part of the eye
K
KC	Keratoconus
KCH	Kent & Canterbury Hospital
Keratoconjunctivitis Sicca	The medical term for dry-eye syndrome.
Keratoplasty	The transplantation of a button of a donor cornea to a living person. Penetrating Keratoplasty (PK) replaces a full thickness of cornea; Deep Lamellar Keratoplasty (DALK) replaces a partial thickness.
M
Moorfields	The London Eye Hospital. The London NHS centre of excellence.
P
Photophobic	Extreme sensitivity to light
Piggyback	Method of wearing contact lenses where a soft lens is worn underneath an RGP
PMMA	Polymethylmethacrylate. The old-fashioned rigid clear plastic material that non gas permeable contact lenses were made from.
PRK	A form of laser surgery - see Wikipedia's entry
Pupil	Dark part of eye that adjusts (dilates) to light level
R
Refraction	Where an optician checks your vision by using a series of different lenses, each lens refracts (bends) light in a different manner. Commonly known simply as the sight test.
Rejection	The worst-case scenario with a corneal transplant. This can usually be reversed in the early stages using steroid drops.
Retina	The back surface of the eye, on which an image is formed.
RGP	Rigid Gas Permeable
S
Sclera	White of the eye
Scleral lenses	Lenses which cover the white of the eye
Sjögren's syndrome	The medical term for an autoimmune condition where "dry-eye is accompanied by dry mouth and dyspareunia/ vaginal dryness. It is associated with rheumatoid arthritis.
SoftPerm	Hard contact lens with soft skirting. A fusion of a hard RGP and a soft contact lens.
T
Topography	A 3D map of the cornea surface
Transplant (of the cornea)	Surgical procedure where the central part of the cornea is removed, and replaced with a healthy cornea from a recently-deceased donor. Also referred to as Keratoplasty.