Laser eye surgery glossary
E
Ectasia
A progressive corneal thinning and bulging.
Emmetropes
People who have no refractive error.
Emmetropia
The ophthalmic term for a perfect refractive state - no nearsightedness, farsightedness or astigmatism. Further reading
Endothelium
The innermost layer of the cornea. The endothelium is one cell layer thick (5-10 microns) and provides hydration balance to maintain the cornea's transparency. The endothelium serves three main purposes it regulates the stroma's water content, provides a barrier to ingress of several constituents of the aqueous humor, and actively transports glucose. Further reading
Enhancement
A secondary laser eye surgery procedure performed after the initial one in an attempt to achieve better visual acuity.
Epithelial ingrowth
A complication of LASIK laser eye surgery wherein epithelial cells grow underneath the corneal flap.
Epithelium
The outermost layer of cells of the cornea. Six cells thick (20 microns), the epithelium is the eye's first defense against infection. Further reading
EXCIMER
EXCited diMER - The type of laser used in laser eye surgery. Further reading
Eye drops
Drugs administered to the eye in drop form. Further reading
Eye-pressure test
A standard eye test that determines the fluid pressure inside the eye. The test is called tonometry. Increased pressure within the eye is a possible sign of glaucoma and must be treated to avoid blindness.
