Glossary of Terms

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 bullae become evident on the cornea as the swelling [edema] and fluid retention take place. In more advanced cases Bullae may rupture causing extreme 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. Can be left in for a number of days and is usually inserted and removed by the eye doctor

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 isn’t crystal clear and impedes vision.

cdfpubs.org

cdfpubs.org is a direct link to our literature request ordering system.

The Corneal Dystrophy Foundation

The Corneal Dystrophy Foundation is a US Tax Exempt Charitable Foundation of which Fuchs Friends is a part.

CHED

1. Congenital Hereditary Endothelial Dystrophy The eye situation presents either in infancy or young childhood with a cloudy cornea, sensitivity to light, tearing, and in some cases, nystagmus, rapid, involuntary movements of the eyes.
2. There is an autosomal recessively inherited type of CHED that usually presents at birth and is non-progressive.

Cornea Edema

Swelling of the cornea caused by the failure of the Cornea’s endothelial cells to prevent 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.

Descemethorexis Without Transplant;

Also Descemet’s Stripping Without Transplant. Spontaneous corneal clearing which may be combined with ROCK Inhibitor medication which encourages redistribution or repopulation of endothelial cells from the outer edge of the cornea towards the middle. This is experimental surgery at this time. Patients must be pre-qualified for this surgery.

Descement’s Layer

A thin, strong inner layer that also acts as a protective layer.

DLEK

Deep Lamellar Endothelial Keratoplasty An early transplant of the endothelial layer of the cornea.

DMEK

(Descemet’s Membrane Endothelial Keratoplasty) A partial corneal transplant which replaces only Descemet’s layer and the endothelium. The Donor graft has no stroma attached, resulting in an optically neutral transplant.

This is performed through a small (2.5mm) incision at the edge of the cornea. After the patient’s endothelium and Descemet’s Layer are removed, the donor tissue, previously loaded into a special glass insertion device, is injected into the anterior chamber.

Because of the thinness and fragility of the donor tissue, no instruments are permitted to touch the tissue except the especially designed/modified insertion device. Many Eye Banks are preparing donor tissue with an S stamped on the front side so the surgeon can see the side opposite the endothelium. The graft tissue is gently induced to open in the correct direction prior to inserting an air bubble behind the graft tissue. This causes it to press against the patient’s corneal stroma and bind to it.

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.

DSAEK (De-Sake)

Descemet’s Stripping Automated Endothelial Keratoplasty A partial corneal transplantwhich uses automated tissue preparation The Descemet’s Membrane and the Endothelial layer are stripped and donor tissue replaces it. Sometimes used interchangeably with DSEK.

DSEK

Descemet’s Stripping Automated Endothelial Keratoplasty – A partial corneal transplant replacing only Descemet’s layer, the endothelium and a small part of the stroma.

DSO

Descemet’s Stripping Only, also called Descemet’s Stripping Without Transplant – This is currently experimental surgery. The surgeon scrapes a 4 to 6 mm area in the center of the Endothelium to remove all cells in the area.  The patient may or may not experience a migration of healthy endothelial cells from the periphery of the endothelium to the center, repopulating the scraped area with healthy endothelial cells.  Since this is experimental there is no possible long term data about it and few documented studies..

DWEK

Descemetorhexis Without Endothelial Keratoplasty.  A different acronym for Descemet’s Stripping Only (DSO).  Please refer to DSO

EK

Endokeratoplasty The generic name for endothelial replacements such as DLEK, DSEK, DSAEK, DMEK, and DMAEK. Sometimes called Partial Transplant.

EBMD

Epithelial Basement Membrane Dystrophy.A condition in which the basement membrane of the cornea’s epithelial layer is faulty, not allowing a strong adhesion between the two. The resulting corneal erosions can lead to severe pain and decreased vision.

Edema

Swelling Evidenced in later stages of Fuchs’ when the endothelial cells can no longer help rid the cornea of fluid buildup.

ENDOKERATOPLASTY (EK)

A class of corneal surgery that involves removing and replacing the endothelial layer of the. See DSAEK, DMEK

Endothelium

The innermost layer consisting of specialized cells which pump excess fluid out of the cornea.

Eye Bank

An organization dedicated to recovering, testing, preserving and supplying Donor Tissue to surgeons who perform eye surgery.

Eye Bank Association of America

An organization that defines and publishes consistent standards of operations, quality and reporting necessary to ensure the safety of optical tissue the Eye Banks acquire, test, process and supply to Opthalmic Surgeons for surgery.

FCD

Fuchs’ Corneal Dystrophy – Fuchs’ (pronounced Fooks) An eye disease in which cells lining the inner surface of the cornea [endothelial] slowly start to die off. The disease usually affects both eyes.

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.

Fuchs’ Friends®

Fuchs’ Friends an online support community of The Corneal Dystrophy Foundation.

Full Corneal Transplant

See Penetrating Keratoplasty.

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.

Hyperopic Shift (Hyperopia}

A change in vision toward far-sightedness. May be caused by eye injury, age or eyesurgery that changes the shape of the cornea or the distance between the cornea and the retina’s surface..

IOL

Intraocular Lens In cataract surgery a man-made product is used as lens replacement.

IOP

Intraocular Pressure The fluid pressure inside the eye. Pressure is measured by a Tonometer which, with numbing drops, touches the eye briefly. It is usually done at every eye doctor visit. The greatest risk factor with high pressure is glaucoma. Steroid drops can increase the IOP.

Kerato…

A prefix meaning cornea.

Keratoplasty

Any corneal surgery that removes and replaces all of or one or more layers of the Cornea

Microkeratome

A precision instrument with an oscillating blade. it is used for cutting the corneal tissue in both the donor graft and the patient during DSAEK.

Myopic Shift (MYOPIA)

A change in vision toward near-sightedness. May be caused by eye injury, age or eye surgery that changes the shape of the cornea or the distance between the cornea and the retina’s surface

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.

Partial Corneal Transplants

There are two major types, DALK for the front layers of the cornea; Endokeratoplasty (EK) a generic term for transplanting the back layer of the cornea. Refer to DMEK and DSAEK for specifics.

Penetrating Keratoplasty (PK)

The original full corneal transplant. All layers of the cornea are removed. A similar section (button) is removed from a donor’s eye and held in place with anchor stitches with a running stitch around the periphery.

Phaco-Emulsification

An ultrasonic technique using instruments which allows the cataract-affected lens to be liquefied and removed by suction during cataract surgery.

PLK

Posterior Lamellar Keratoplasty, also known as deep lamellar endothelial keratoplasty (DLEK).

PK

Penetrating Keratoplasty A corneal transplant which replaces the patient’s full thickness cornea with a donor cornea. Rarely used today for Fuchs’.

Prism

Placed in the lens of eyeglasses to help people with double vision, positional correction or convergence correction.

PRK Or LASIK

Photorefractive Keratectomy and Laser Assisted Keratectomy. Laser surgery used to correct vision: near-sighted, far-sighted, or astigmatism.

Pseudophakic Bullous Keratopathy

A post-operative condition that can occur as a complication of cataract surgery and intraocular lens placement.

PTK

Phototherapeutic Keratectomy. One of the latest advances in eye care for the treatment of corneal dystrophies, corneal scars, and certain corneal infections.

PVD

Posterior Vitreous Detachment. One possibility for seeing flashes and floaters. Needs to be checked out by your eye doctor.

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).

Remission

Remission is either the reduction or disappearance of the signs and symptoms of a disease.

[1] The term may also be used to refer to the period during which this reduction occurs.

[2] A remission may be considered a partial remission or a complete remission.

Rigid Gas Permeable (RGP)

RGPs are made of a highly gas-permeable hard plastic that allows oxygen to reach the cornea. They are designed to create a space between the prosthetic device and the eye that is filled with sterile saline. The liquid remains in the reservoir, providing constant lubrication by bathing the eye in a pool of artificial tears.

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.

T

Corneal Transplant A ‘shorthand’ abbreviation for a transplant formerly used a great deal on FF.

Tonometer

Instrument used for the test of Intraocular Pressure (IOP) inside the eye.

Toric Lens

A lens with different optical power and focal length in two orientations perpendicular to each other. … Such a lens behaves like a spherical lens combined with a cylindrical lens. Toric lenses are used primarily in intraocular lenses, eyeglasses and contact lenses to correct astigmatism.

Trab

Trabeculectomy. a surgical procedure to treat Glaucoma by making a ‘port’ in theeye to allow excess Intraocular Pressure (IOP) to be reduced.

Triple

A surgery where a cataracted natural lens is removed, an Intraocular Lens (IOL) replaces the natural crystalline lens and a corneal transplant is performed.

YAG

(Synthetic) Yttrium Aluminum Garnet laser used to perform a Posterior Capsulotomy, a simple procedure performed some time after cataract surgery if an uneven surface or cloudiness of vision occurs after cataract surgery, which removes the posterior surface of the lens sack from the path of light to the retina.