Corneas ideally remain clear and smooth, like the surface of an untroubled and unpolluted mountain lake. But sometimes fluid builds up inside the cornea, the clear surface that contributes to focus light onto the back of your eye, and you get a corneal edema. Sometimes bumps and lumps appear on the epithelium, the outermost of the cornea’s five layers, interfering with vision.
A small obstruction or corneal irregularity may be a nuisance at first, more an irritation than a health problem. Yet ignoring these minor annoyances occasionally makes them a hindrance to clear sight. (Find out more at Horizon’s cornea service page.)
A healthy cornea contains a delicate balance of water. An edema – a medical term for swelling – occurs when the water balance gets upset. Most people with such swelling have Fuchs’ dystrophy, a progressive degeneration of endothelial cells that line the backside of the cornea. Those cells pump fluid out of the cornea and into the eye all day long. We lose them as we age, and if enough die, the fluid can’t flow off.
You may have swelling and blurry vision in the morning that gets better during the day. Or you may see through a glare or misty haze all day. An eye doctor can fix this problem with an endothelial keratoplasty, stripping out diseased cells and implanting healthy ones. (The body seldom rejects a corneal transplant, because corneas don’t contain blood vessels like other tissue transplants.)
Other Corneal Irregularities
These issues, like corneal edema, usually have a genetic basis. They affect the epithelium, the outer layer that’s five to seven cells thick and measures slightly less than 10 percent of the thickness of the cornea. New cells get produced constantly, then sloughed off in the tear layer of the eye. And the entire epithelium turns over in about a week.
Most of the conditions affecting this layer are benign and can be treated with OTC remedies or by leaving your contact lenses out for a while. Dry eye, the most common of these as we age, causes tiny disruptions in the epithelial layer but responds to such treatments. However, paying no attention to pain or irritation could increase your chance of more serious corneal scarring.
Here Are Irregularities Worth Knowing About
Punctate keratitis occurs when small groups of cells die off on the corneal surface. It makes your eyes red, watery and light-sensitive, affecting their ability to refract light. You may also have a gritty or burning feeling. Occasionally, viruses and bacteria can be the underlying cause of punctate keratopathy which often require prescription treatments.
Epithelial basement membrane dystrophy
Epithelial basement membrane dystrophy happens when cells don’t adhere well to the corneal surface. They secrete a special collagen to strengthen that connection, but if they produce too much, the buildup looks like dots or fingerprint swirls. Lubrication or hypertonic saline drops help. A doctor could do a superficial keratectomy, an in-office procedure that smooths out the underlying surface of cells and slightly roughens the area, so new cells adhere properly.
Salzman’s nodular dystrophy
Salzman’s nodular dystrophy, raised areas often caused by pink eye, dry eye or previous illnesses, consists of irregular collagen deposited on the corneal surface. These may cause pain, but the real issue remains changes in astigmatism, especially in Caucasian women between 50 and 70. Lubrication and anti-inflammatory drops help here, too, or a superficial keratectomy can remove nodules and let healthy cells repopulate.
Pterygium and pinguecula
A pterygium appears as a fibrovascular tissue that grows from the side of the eye usually by the nose in a weblike or fan fashion. It can cause redness and irritation but also leads to scarring; if it grows right over the visual axis, serious distortion results. Pterygia usually happen to people who get too much UV exposure over time. They can be left alone if they’re purely cosmetic, or a surgeon can excise them. A pinguecula proceeds from the same cause and has the same remedy but takes the form of a thick yellowish patch on the white part of the eye.
Ocular surface squamous neoplasia or conjunctival intraepithelial neoplasia
An ocular surface squamous neoplasia or conjunctival intraepithelial neoplasia occurs when abnormal, dysplastic cells arrive from the conjunctiva, the white part of the eye. Patients generally get a progressive lesion that’s asymptomatic but can grow onto the corneal surface to cause vision problems and scarring.
A doctor who suspects a squamous cell carcinoma may do a biopsy, but those are rare in the eyes. The likelier procedure is to stain the eye and study the cornea in a slit-lamp exam. Topical drops may melt away these dysplastic cells, or a surgeon can remove the lesion. If it does turn out to be cancerous, it’s not likely to return or metastasize to other parts of the body.
To schedule a consultation at Horizon Eye Care, call 704-365-0555 Monday – Thursday, 8:00 a.m. to 5:00 p.m. and Friday 8:00 a.m. to 3:00 p.m.