Scleral Lenses for Terrien’s Marginal Degeneration
Understanding Terrien's Marginal Degeneration
Terrien's marginal degeneration causes the peripheral edge of your cornea to become thinner over time. The thinning usually starts in the superior part of your cornea, often in the upper nasal area, and can slowly spread around its edge. Your cornea remains clear, but the thinned areas may develop tiny blood vessels and a yellowish line at the edge of the affected zone.
The condition typically affects both eyes but may progress at different rates in each eye. The thinning happens very gradually, often over many years or even decades. Terrien's marginal degeneration is usually noninflammatory, though you may experience occasional irritation. If you develop significant pain or redness, we should evaluate you promptly to rule out other conditions.
As your cornea thins unevenly, it can develop an irregular shape rather than maintaining its normal smooth curve. This irregular shape bends light rays unevenly as they enter your eye, creating distorted images on your retina.
- Blurred vision that glasses cannot fully correct
- Increased astigmatism that changes over time
- Difficulty seeing fine details or reading small print
- Halos or distortion around lights, especially at night
This condition is rare and its exact cause remains unknown. It most commonly appears in men between the ages of 20 and 50, though women and people of any age can develop it.
Unlike some corneal conditions, Terrien's marginal degeneration does not seem to run strongly in families. We have not identified specific lifestyle factors or environmental exposures that increase your risk.
Many people with Terrien's marginal degeneration notice very gradual changes in their vision. Early on, you may simply find that your glasses prescription needs to be updated more frequently than before.
- Slowly worsening vision despite new glasses
- Increasing difficulty with night driving
- Eye irritation or a feeling that something is in your eye
- Occasional redness along the edge of your cornea
- Rare but serious: sudden sharp pain may signal a corneal perforation requiring emergency care
Why Scleral Lenses Are Recommended for Terrien's Marginal Degeneration
Regular eyeglasses work by bending light before it reaches your eye, but they cannot fully compensate for the irregular surface of a thinned cornea. When your cornea has an uneven shape, the light scattering happens right at the eye surface, and glasses worn inches away cannot correct this.
Standard soft contact lenses drape over your cornea and tend to conform to its irregular shape, so they also fail to provide clear vision. Smaller rigid gas permeable lenses may wobble or rest on the thinned areas, causing discomfort and unstable vision.
Scleral lenses are large, rigid gas permeable contact lenses that rest on the white part of your eye, called the sclera. Because they are larger than your cornea, they completely vault over the irregular corneal surface without touching it.
- The lens rests on the sclera, beyond the thinned corneal edge
- A smooth outer lens surface replaces the irregular corneal surface optically
- The rigid material holds its shape and provides crisp, stable vision
- Your cornea remains protected in the space beneath the lens
When we fit you with a scleral lens, we fill it with preservative-free saline solution before you place it on your eye. This creates a fluid reservoir between the back of the lens and your cornea.
The fluid layer fills in all the irregular valleys and peaks of your corneal shape, creating a smooth optical interface. This fluid cushion also keeps your cornea moist and comfortable throughout the day.
Scleral lenses offer advantages beyond vision correction alone. Because the lens vaults over your cornea without touching it, your eye surface stays continuously bathed in the saline reservoir. The lens also acts as a barrier against environmental irritants like dust, wind, and debris.
- Continuous moisture on the eye surface throughout the day
- Relief from dryness and irritation symptoms
- Stable vision that does not shift or blur with blinking
- Barrier protection from dust, wind, and other environmental factors
The Scleral Lens Fitting Process
Before we fit you for scleral lenses, our eye doctor will perform a thorough examination of your eyes. We check your overall eye health, measure your visual acuity, and look closely at the structure of your cornea.
Special imaging tests help us document the extent and location of corneal thinning. We also check for any signs of inflammation or other conditions that might affect your lens wear.
Corneal topography is an advanced imaging technique that creates a detailed three-dimensional map of your corneal shape. This computerized imaging shows us exactly where your cornea is thinned and how steep or flat different areas are.
- Precise measurements of your corneal curves and diameter
- Assessment of the scleral shape where the lens will rest
- Data used to design your custom lens parameters
- Baseline images to track changes over time
We typically start with diagnostic trial lenses based on your measurements. You will wear these lenses in our office while we evaluate the fit using a specialized microscope called a slit lamp.
We assess the fit after the lens has settled on your eye, typically after 20 to 30 minutes. Key checkpoints include adequate clearance over your cornea and limbal area, proper alignment of the lens edge on your sclera, minimal lens movement with blinking, and absence of blanching or excessive pressure. We may use advanced imaging such as optical coherence tomography to measure the fluid layer precisely if needed.
Most patients need several fitting appointments to achieve the optimal lens design. We may modify the lens curvature, diameter, or other parameters until the fit is just right.
Once we have determined your final lens design, we will train you on proper lens handling. Inserting and removing scleral lenses requires a different technique than smaller lenses.
- How to fill the lens with preservative-free saline
- Positioning the lens on your eye while looking down
- Using a small plunger tool for safe removal
- Checking the lens for debris or damage before insertion
- What to do if an air bubble gets trapped under the lens
Daily Care and Long-Term Management of Your Scleral Lenses
Proper daily cleaning and disinfection keep your lenses clear and safe to wear. Following the correct steps reduces your risk of eye infections and other complications.
- Always wash and dry your hands thoroughly before handling your lenses
- Clean each lens by rubbing it gently with the recommended rigid gas permeable cleaning solution, then rinse thoroughly
- Store lenses in fresh disinfecting solution overnight for the full time specified on the label
- Discard used solution daily and never top off old solution with new solution
- Never use tap water, saliva, or preservative-free saline for cleaning or disinfection
Each morning, remove your lenses from their storage case and rinse them with the recommended rinsing solution. Fill the bowl of the lens completely with preservative-free saline solution before placing it on your eye.
- Use only preservative-free saline to fill the lens bowl
- Check that no air bubbles are trapped under the lens after insertion
- If you see a bubble, remove the lens and reinsert it
- Never fill the lens bowl with tap water or any solution containing preservatives
Do not sleep or nap in your scleral lenses unless our eye doctor has specifically prescribed overnight wear for a medical reason and is monitoring you closely for it. Sleeping in lenses increases the risk of serious complications.
If fogging or clouding occurs during the day, remove your lenses, clean and rinse them as directed, refill the bowl with fresh preservative-free saline, and reinsert them.
Your lens case needs regular care to prevent contamination and infection. After you insert your lenses each morning, empty the case completely and rinse it with the recommended disinfecting solution, not with saline.
Wipe the inside of the case and let it air dry with the caps off on a clean, dry surface or paper towel. Avoid using tissues that may shed lint. Replace your lens case monthly to every three months, or sooner if it becomes cracked, cloudy, or damaged. We may recommend specific cleaning or disinfecting solutions designed for rigid gas permeable and scleral lenses.
Regular follow-up appointments are essential even when your lenses feel comfortable and your vision seems stable. We need to check that your lenses still fit properly and that your eyes remain healthy.
During follow-up visits, we examine your cornea for any signs of stress or inflammation and verify that the lens is not putting pressure on thinned areas. We also update corneal topography periodically to track any progression of the condition. Most patients need visits every three to six months initially, then annually once everything is stable.
Scleral lenses do not last forever. Deposits can build up on the lens material over time, and small scratches may develop that affect vision or comfort.
- Most scleral lenses need replacement every one to two years
- Replace lenses sooner if they become cloudy, scratched, or warped
- Changes in your corneal shape may require a new lens design
- Keep a backup pair in case of loss or damage
Recognizing Problems and Knowing When to Seek Care
Even a well-fitted scleral lens may need occasional adjustments. If you notice any changes in comfort or vision quality, contact our office for an evaluation.
- Vision that becomes blurry or unstable during the day
- An increase in redness that does not resolve after lens removal
- Difficulty wearing your lenses for as many hours as before
- New awareness of the lens on your eye
- Fogging or clouding that develops after a few hours of wear
While scleral lenses are safe for most patients when cared for properly, it is important to understand potential complications so you can recognize warning signs early.
- Microbial keratitis, a serious eye infection that requires urgent treatment
- Corneal abrasion or surface scratches from improper handling or debris under the lens
- Corneal swelling or hazy vision from inadequate oxygen or excessive lens wear time
- Midday fogging from debris or protein buildup in the fluid reservoir
- Redness from poor fit, suction effects, or limbal compression where the lens edge presses on tissue
- Allergic or toxic reactions to lens care solutions
Minor irritation can sometimes occur with contact lens wear, but certain symptoms require prompt attention. Stop wearing your lenses immediately if you develop any worrisome signs.
Call our office the same day if you notice increased light sensitivity, mucus discharge, persistent pain, or vision changes that do not improve after removing your lenses. These symptoms could indicate an infection or other problem that needs treatment.
Some symptoms signal serious problems that need emergency care. A painful red eye while wearing contact lenses combined with light sensitivity or decreased vision should be treated as a medical emergency. Do not resume lens wear until you have been examined and cleared by our eye doctor.
- Sudden severe pain in or around your eye, especially during or after lens wear
- Rapid decrease in vision that does not improve after lens removal
- Visible white or cloudy spot on your cornea
- Heavy discharge, pus, or matted eyelashes upon waking
- Intense light sensitivity with tearing and inability to open your eye
If you break or lose a lens, do not try to wear a lens from an old prescription or borrow lenses from someone else. An improperly fitted scleral lens can damage your cornea.
Contact our office as soon as possible to order a replacement. We keep your lens parameters on file so we can quickly order a new lens with the same specifications. This is one reason why we recommend having a backup pair of lenses.
Alternative and Additional Treatment Options
In very early Terrien's marginal degeneration, glasses may still provide acceptable vision if the corneal irregularity is minimal. Some patients wear glasses for short tasks at home and reserve their scleral lenses for work or driving.
Glasses can also serve as a backup option on days when you cannot wear your contact lenses due to eye irritation or illness. We can prescribe the best possible glasses correction for your corneal shape, though it may not give the same clarity as scleral lenses.
While scleral lenses are the most commonly recommended option for Terrien's marginal degeneration, other specialty lens designs may be considered in specific cases. Smaller rigid gas permeable lenses sometimes work in early disease if the thinning is very localized.
Hybrid lenses, which have a rigid center with a soft outer skirt, offer another alternative for some patients. Custom soft lenses designed for irregular corneas or piggyback lens systems, where a soft lens cushions a rigid lens on top, may also be options in select situations. We may consider these alternatives if you have difficulty handling larger scleral lenses or if your eye shape makes scleral lens fitting challenging.
Terrien's marginal degeneration progresses slowly, but regular monitoring helps us detect any changes early. We track your condition with periodic corneal topography and careful examination of the thinned areas.
- Baseline imaging at diagnosis and then yearly or as needed
- Measurement of corneal thickness in the affected areas
- Assessment of any new blood vessel growth
- Early detection of complications like neovascularization
Most people with Terrien's marginal degeneration do well with scleral lenses and never need surgery. However, in rare cases where the cornea becomes dangerously thin or at risk of perforation, surgical options may be considered.
Procedures such as tectonic lamellar grafting, including crescentic lamellar keratoplasty, can strengthen very thin areas by reinforcing them with donor tissue. In cases where perforation has occurred or is imminent, emergency surgical repair may be necessary. Our eye doctor will work closely with a corneal specialist if your condition reaches this advanced stage, though this is uncommon with proper monitoring and care.
Frequently Asked Questions
Most patients can safely wear scleral lenses for 12 to 16 hours per day once they adapt to them. Some people wear them for the entire time they are awake, while others prefer shorter wearing times. We will help you determine a wearing schedule based on your comfort, your tear production, and how your eyes respond during follow-up visits.
Scleral lenses do not treat or slow down the progression of Terrien's marginal degeneration itself. They correct the vision problems caused by the irregular corneal shape and protect your cornea from environmental stress. The condition may still progress slowly over time, which is why we monitor you regularly and may need to adjust your lens fit as your cornea changes.
Scleral lens fitting is more complex and time-intensive than standard contact lens fitting, so the fees are typically higher. Costs vary depending on how many fitting visits you need and the complexity of your lens design. Many medical insurance plans provide some coverage for medically necessary contact lenses like sclerals when glasses cannot adequately correct your vision, but coverage varies widely among plans.
Scleral lenses are excellent for sports and active lifestyles because they fit securely on your eye and rarely dislodge. Many athletes prefer them over glasses or smaller contacts. You should wear protective eyewear for contact sports or activities with a risk of eye injury, just as you would if you were not wearing lenses. Remove your lenses before swimming, showering, or any water exposure due to infection risk.
Replacement timing depends on lens condition and how your eyes respond over time. Variables include how well deposits clean off, whether scratches develop, and whether your corneal shape remains stable. We will examine your lenses at each visit and recommend replacement when we see signs of wear, typically every one to two years. If your corneal thinning progresses, you may need a redesigned lens with updated parameters rather than just a replacement of the same design.
Getting Help for Scleral Lenses for Terrien's Marginal Degeneration
If you have been diagnosed with Terrien's marginal degeneration or are experiencing vision changes that glasses no longer correct, we encourage you to schedule an evaluation with our eye doctor. We can assess whether scleral lenses are right for you and guide you through every step of the fitting and adaptation process to help you achieve the clearest, most comfortable vision possible.