The cornea is the clear window at the front of the eye that covers the coloured iris and the pupil. Light is focused while passing through the cornea to form a clear image on the retina. The healthy cornea is transparent. If the cornea is abnormal, damaged or diseased, it may become swollen or scarred, resulting in blurred vision or glare.
Keratoconus is a condition affecting the shape of cornea. A healthy eye is more spherical in shape, allowing an image to come into focus clearly. A cornea with Keratoconus bulges outward because it is weak, creating a cone-like shape and consequently, blurred or distorted vision (even with glasses or contact lenses). Keratoconus is a disease that normally affects both eyes. In most people, Keratoconus begins during their teenage years and progresses at varying rates until stabilizing in their 30s or 40s. Excessive eye rubbing has also been implicated as a causative factor. Current treatments for Keratoconus include glasses, contact lenses and Collagen Cross-linking and in later stages of the disease a corneal transplant.
A Pterygium is a wedge-shaped growth of thickened tissue that extends from the inside corner of the eye, over the cornea towards the pupil margin. A Pterygium may grow large enough to cause redness, irritation or blurred vision and therefore require surgical intervention.
Other corneal conditions affecting the corneal include Fuch's Endothelial Dystrophy and Lattice Dystrophy, corneal scarring from injury, Herpes Simplex Virus (Shingles), Conjunctivitis, and Keratitis.
PHOTOTHERAPEUTIC KERATECTOMY (PTK)
PTK is a surgical technique that uses excimer laser to reshape and restore the cornea. This is a safe and effective procedure that treats corneal surface diseases and scars.
A corneal transplant removes the damaged part of the cornea and replaces it with healthy donor tissue. There are different types of corneal transplant surgery. Penetrating Keratoplasty is performed when the entire cornea needs to be replaced whereas Lamellar Keratoplasty is performed when only part of the cornea requires replacing.