Tag Archives: Eye Health

Eye Health: Why Corneal Transplants Are Rising

At one time, replacement parts for the eyes must have seemed unimaginable. Nowadays, if the inner lens of the eye becomes clouded by a cataract, a routine surgery to swap it out with a new artificial lens restores vision.

But what happens if the outer lens of the eye (the cornea) becomes damaged or diseased? You can have that replaced, too. “It’s not as common as cataract surgery, but many people get corneal diseases after age 50 and may need a corneal transplant,” says Dr. Nandini Venkateswaran, a corneal and cataract surgeon at Harvard-affiliated Massachusetts Eye and Ear.

More than 49,000 corneal transplants occurred in 2021 in the US, according to the Eye Bank Association of America.

What is the cornea?

The cornea is a dome of clear tissue at the front of each eye, covering the iris and pupil, that acts as a windshield that protects the delicate eye apparatus behind it, and focuses light onto the retina, which sends signals that the brain turns into images (your vision).

You need this combo of windshield and camera lens to focus and see clearly. But many things can go wrong within the five layers of tissue that make up the cornea. That can make it hard to see and rob you of the ability to read, drive, work, and get through other activities in your day.

How does damage to the cornea occur?

It may stem from a number of causes:

  • Injuries, such as a fall. “Falls are a big reason for people to come in with acute eye trauma. The cornea can be damaged easily if something pokes it,” Dr. Venkateswaran says.
  • Previous eye surgeries. “Especially for adults who’ve had several eye surgeries — such as cataract and glaucoma surgeries — the inner layers of the cornea can become damaged and weakened with age,” she adds.
  • Illness. Problems like severe corneal infections, or genetic conditions such as Fuchs’ endothelial dystrophy, can cause vision loss.

What are the options for treating corneal damage?

Cornea treatment depends on the type of problem you have and the extent of the damage. “It’s a stepwise approach. Sometimes wearing a specialty contact lens or using medications can decrease swelling or scarring in the cornea,” Dr. Venkateswaran says.

Technology: How AI Is Helping To Cure Blindness

Eye Health: Cataracts

Cataracts involve the lens of the eye which is located just back of the cornea.

The lens is composed of evenly aligned collagen fibers which are progressively damaged  by ultraviolet light as we age. Cataracts cause clouding of the lens and reduce visual acuity, as well as causing a stiffening and rigidity of the lens which keeps it from changing shape for close-up activities like reading.

If you live long enough, cataracts are almost inevitable and the main decision is when to get them corrected. With intraocular lenses, the operation has few downsides.

The halo around oncoming headlights disturbed my night driving, and was a major reason for me to get my cataracts removed.

I used to require glasses all the time, and took them off to read. Now I wear no glasses, and even reading is possible without glasses, since one of my eyes has a  -1.5 diopter cylindrical  astigmatism.  You can ask for one Intraocular lens to be slightly nearsighted, if you wish to avoid needing reading glasses.

I prefer to use my corrective glasses to read, however.

—Dr. C.

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Eye Infections: What Is Herpetic Keratitis?

Herpetic Keratitis is a viral infection of the transparent, frontmost part of the eye, the  cornea.

Herpes 1 or 2  when rubbed into the eye from a cold sore, or contacted from somebody else with herpes, will often affect the cornea. The use of corticosteroid eyedrops or ointment will allow the disease to spread faster.

The symptoms are pain and redness of the eye and are a medical emergency, needing prompt treatment by your doctor to prevent scarring and blindness.

Antiviral eyedrops, such as valacyclovir, are used to treat ophthalmic herpes.

A related condition is ophthalmic zoster, caused by the varicella zoster virus. The VZ virus will produce chickenpox in unimmunized people, go into dormancy in the nervous system, and then resurface, if immunity wanes, as shingles. If the shingles occurs in the ophthalmic division of the trigeminal nerve, affecting the skin near the eye, the cornea  will often be involved. Ophthalmic zoster is also treated by antiviral eyedrops.

The varicella zoster virus is closely related to the herpes simplex virus, and is a member of the same nasty family of viruses.

—Dr. C.

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Eye Diseases: Keratoconus – Causes And Symptoms

Keratoconus involves the cornea, the front most part of the eye, which becomes thin, and then can bulge out in ways that make correction with glasses difficult. It usually involves both sides although one side is worse. When it occurs only in one eye and not regularly followed, it can be difficult to diagnose and treat properly.

In keratoconus, there is a thinning of the cornea caused by collagen deterioration. This can be usually detected by an ophthalmologist with his slit lamp, which is a low magnification microscope.

Vision loss is always distressing, but arguably is even worse when it afflicts young people in the process of developing their identity, and interferes with schoolwork.

Keratoconus is usually begins in adolescence, progresses over 10 to 20 years, and stabilizes in the third decade of life.

There are a number of treatments depending upon the severity of the condition. In the beginning glasses suffice. Later on, a hard scleral contact lens can be used. There are treatments aimed at cross linking the corneal collagen and strengthening it. The worst cases require a corneal transplant.

The most important thing is to go promptly to a good eye doctor, preferably an ophthalmologist.

–Dr. C

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Eye Health: ‘Cheater’ Glasses Vs Prescription

If you can go the over-the-counter route, here are some tips.

  • Find the right power. Reading glasses will have signs or stickers noting their power. In most cases, they range from +1 to +4 diopter, in increments of +.25. Look for what matches your prescription. If you don’t have a prescription, try the lowest power (+1) first.
  • Test-drive the glasses. If you’ve brought reading material with you, try reading it at a comfortable length. (Many eyeglass displays have an eye chart, too, to test the glasses.) Try different powers until you can read clearly at a distance that’s most comfortable for you.
  • Go big the first time. While there are many styles and colors to choose from, you may want to start your reading glass journey with a bigger pair of specs. Larger lenses offer more of a “sweet spot” where the prescription is. It’s easier to use a smaller lens once you get used to wearing glasses.

Eye ‘Floaters’: Posterior Vitreous Detachment

This eye condition usually won’t threaten your vision or require treatment. But it can sometimes signal a more serious, sight-threatening problem. So it’s best to be checked by an ophthalmologist (a specialist who treats eyes) right away.

How can you tell that your vitreous may have detached? By a sudden increase in floaters — those small, typically harmless shapes that drift across your field of vision as you move your eyes.

“Vitreous detachments are pretty common,” says professor of ophthalmology at Cleveland Clinic Lerner College of Medicine Rishi P. Singh, MD. “When you see these new floaters, it’s best to have them evaluated and, specifically, to have a dilated eye examination performed by an ophthalmologist.”

Dementia: Age-Related Eye Diseases Increase Risks

DR. C’S JOURNAL: AMBLYOPIA

Amblyopia is an example of how the body suppresses or gets rid of activity that is not used. Amblyopia “ex anopsia” is the leading cause of poor vision in children, and the most common reason is a “lazy eye”. If the eyes do not work together for binocular vision, the weaker of the two eyes has suppressed development and eventually eyesight is lost.

I have a friend who was going in the pilot training, it was found to lack good depth perception, and could not proceed. He now complains occasionally of double vision, and may be an example of the suppressed eye with lack of binocular vision.

I have a muscle in balance which causes a rotation of my eye so that it’s hard to fuse on a horizontal linear object. I was probably able to fuse  when I was younger and avoid this loss of vision in the weaker eye.

So be on the alert for a squint, or wandering eye in children. Get them in early for treatment, the earlier the better, and it must take place before age 5 to 7.

—Dr. C.

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