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Home » What are Scleral Lenses and How Can They Help Me?

What are Scleral Lenses and How Can They Help Me?

Scleral Lens Q&A with Dr. Woo

Dr. Woo is a great advocate for the use of scleral lenses for the treatment of conditions such as keratoconus and severe astigmatism. We recently sat down with Dr. Woo to speak to her about what inspired her to get into scleral lenses and how they can help her patients see and feel better every day.

Dr. Woo, how did you get involved in scleral lenses?

When I was in school, I really thought I was going to go into macular disease. But during my third year in our contact lens clinic, there was a patient who had keratoconus and really could not see anything at all.

He didn’t have a job because he couldn’t see. He seemed really depressed, like anyone would if they can’t see very well. And then we ended up fitting him with a corneal gas permeable (GP) lens. Suddenly, he was able to see. I think it was like 20/30 or 20/40. And he was so excited that he could see again, you could see it in his face.

And from then I decided this is such an incredible part of optometry that I really want to look more into it. During my residency, I got lots of exposure to scleral lenses. So that’s kind of how I both got into it.

What’s so unique about scleral lenses?

Something unique about scleral lenses compared to other lenses is that they’re very large, sometimes measuring over 21 millimeters. For comparison, soft contact lenses that you wear are about 14 millimeters or 14.5 millimeters.

They also don’t touch the cornea at all. They pass over the cornea and rest on the sclera, the white part of the eye, which makes them very comfortable. They’re also very secure in the eye, so they don’t pop out, which is important. A lot of my patients go into scleral lenses because they’re frustrated that their corneal gas permeable lenses pop out.

Do scleral lenses require a specific type of saline solution?

Yes. Some patients don’t know that they have to use a special type of solution to fill the bowl of the lens. It’s very important to fill the bowl of the lens with something that does not have preservatives.

A lot of times patients will come in, and they’re filling the bowl of the lens with saline, but it’s not preservative free. That’s an issue because that solution can become toxic to the eye. There are many types of effective and valid solutions for scleral lenses. Currently, there’s scleral fill, there’s lacquer pure, there’s neutrophil, and there’s non-preserved saline.

The bottom line, though, is that you should only use solutions your doctor recommends. Using any other solution may cause serious complications that can lead to injury or infection.

Can small particles go inside the scleral lens, causing irritation?

This is one of the main reasons that people go into scleral lenses, because you don’t get that foreign body entrapment. If a foreign object, like dust or makeup, gets into the eye with a traditional disposable or GP contact lens, it can cause considerable irritation. You’ve got to take it out, rinse it off, put it back in your eyes, which are already irritated.

The beauty of scleral lenses is that you don’t get that because of how large it is, and how much it covers your eye.

What kind of patients can benefit most from scleral lenses?

If you have an extreme irregularity to your cornea, or maybe you’ve had a corneal transplant, you have really bad keratoconus, and so on, normal contacts won’t really work for you.

On the other hand, the size of scleral lenses, and the fact that they actually pass over the cornea without touching it, make them a perfect solution. They provide a smooth, rounded surface that replaces the warped corneal surface, and allow for really clear vision.

They’re also great if you have really severe dry eye as a result of a condition such as Sjogren’s syndrome or Stevens Johnson syndrome, because the lenses are filled with saline, which keeps the eyes hydrated all day.

We’ve also seen that they can help heal scratches and other damage to the cornea from conditions such as herpes simplex.

How often do scleral lenses need to be replaced?

Scleral lenses are made out of material that’s totally different from a soft lens. So it lasts a lot longer. They only need to be replaced when either your vision changes significantly, or your cornea changes such that the cornea is getting a little bit close to the lens, and we need to make a change. But other than that, if you take good care of them, and your vision is still the same and the fit looks good. You can keep them for as long as they last.

In general, lenses probably need to be changed about every year, though if they’re particularly well cared for, we’ve seen them last as much as five years.

How do you decide whether a patient is best in scleral lenses, rather than a different kind of lens?

Studies have come out that use data from our corneal mapping technology that are able to tell us whether a patient would be good with traditional corneal contacts, or whether they may be more successful with scleral lenses.

Many times, this has to do with the curvature and overall shape of the cornea. If the lenses require a great deal of customization to provide a comfortable fit and clear vision, scleral lenses are likely a good option.

Who are the best candidates for soft lenses, rather than hybrid, rigid gas permeable or scleral lenses?

I would put anybody in a soft contact lens, if their vision is still good with glasses. If you’re seeing well with glasses, you will see about the same in soft contact lenses.

Even with mild cases of keratoconus and similar conditions, soft lenses may still work, though it’s not likely to give the patient the best vision or comfort. I may keep somebody like this in a soft lens if they’re completely intolerant of any other lens, or if they don’t want to try something new or they’re kind of married to the idea of a soft lens.

What’s the best way to store an extra pair of scleral lenses not in use?

The best way is to actually store the lenses completely dry, and in a dry case, and put it somewhere kind of in a cold dark environment, like a cupboard or a drawer. If you store it in solution, you have to remember to replace the solution.

Why do scleral lenses work when glasses and soft contact lenses don’t?

When we’re speaking about conditions such as severe astigmatism or advanced keratoconus, the cornea is very uneven and warped. This causes light to be refracted in a strange way, resulting in double or blurry vision, along with other vision issues.

The problem with glasses is that, while the light is refracted properly through the lenses of the glasses, the moment the light passes through the warped cornea of the eye, it gets messed up again.

The issue with soft contact lenses is that they conform to the shape of the cornea very closely. If the shape of your cornea is the source of the problem, a lens that conforms to that same shape doesn’t help.

Scleral lenses offer a rigid surface that passes directly over the cornea, replacing the warped cornea with a lens that is smooth and well-rounded, offering a consistent refractive surface that results in clear vision.

What’s involved in an exam for scleral lenses?

To start out your scleral lens evaluation, your eye doctor will do a thorough history for you. Do you have any diseases that affect your vision? Are you just unhappy with your vision? You should let the doctor know what your issues are, and what your vision goals are. Maybe night driving is hard for you? Or you’re not very happy with your soft contact lenses? So just think of things that would make you happy as a patient as far as vision and comfort.

And then they’ll use advanced eye care and imaging equipment to get images and measurements of your eye. That kind of helps to also rule in or out certain candidates depending on eye conditions we may see.

Your eye doctor will likely try out some lenses with you based on the measurements they took, and gauge your level of comfort and visual clarity with each type. Once the best lenses are identified, your eye doctor can take proper measurements for customizing the lenses and move forward with ordering them for you.