What is Keratoconus?
Keratoconus is the gradual thinning and bulging of your cornea, the clear front layer of your eye.
Someone with keratoconus has a cone-shaped cornea and may experience problems with their vision. The condition commonly affects both eyes, although one eye may be affected more than the other.
Keratoconus commonly affects young people (ages 15 to 25) and progresses over several years.
What Causes Keratoconus?
The cause of keratoconus is not well understood. Some eye experts have linked it to genetics.1
Other factors such as vigorous eye rubbing and atopy are also possible causes.
Atopy is an immune system problem that increases your vulnerability to allergic disorders.
Symptoms of Keratoconus
Some common signs of keratoconus are:
- Irregular astigmatism
- Distorted vision
- Glares and halos in bright light
- Sensitivity to light
- Eye irritation
- Headaches due to eye pain
During the early stages of keratoconus, you can enhance your vision with contact lenses or prescription glasses.
However, not everyone needs invasive surgery to manage their keratoconus.
According to one study, other non-invasive options, such as scleral lenses, can significantly reduce the need for surgery.3
Scleral lenses are contact lenses placed on the sclera (white of the eye) and enclose the cornea without touching it. This boosts vision and improves comfort by covering the bulging cornea.
Corneal changes due to keratoconus can make it difficult for the eye to focus even while using glasses or soft contact lenses.
If keratoconus is left untreated, permanent vision loss can occur.
Keratoconus Surgery Options
Different surgical procedures used to treat keratoconus are:
1. Corneal crosslinking
Corneal crosslinking is a new technique that uses a special eye drop and ultraviolet (UV) light to strengthen the cornea’s collagen fibers. The goal is to prevent further progression of keratoconus.
Strong collagen fibers stabilize the corneal tissue. They also reduce or eliminate the need for a transplant.
You’re a good candidate for corneal crosslinking if you:
- Have early-stage keratoconus
- Have a cornea that is not too thin
- Are between 15 and 25 years of age
- Are generally healthy and have no underlying health conditions
- Do not have any other eye diseases, such as cataracts
- Do not have any corneal scarring due to trauma or previous surgery
Corneal crosslinking is done in two ways:
1. Epithelium-off crosslinking
This involves corneal epithelium removal and uses riboflavin (vitamin B2) to help strengthen collagen fibers. Riboflavin provides a healthy environment for the formation of new, stiff, and strong collagen fibers.
2. Epithelium-on method.
Also known as transepithelial crosslinking, this procedure does not involve corneal epithelium removal. This prevents the risk of infection and discomfort.
Currently, only epithelium-off crosslinking performed with a Glaukos KXL System is FDA-approved. The recommended topical treatments used during surgery include Photrexa® Viscous and Photrexa®.4
The entire procedure should take around 1 to 2 hours. Afterwards, your surgeon will give you post-op care instructions to promote healing.
Your doctor may also include antibiotics and pain medication to prevent infection or discomfort after surgery.
Corneal crosslinking is very effective, with a 95% success rate. Few keratoconus patients experience vision changes after corneal crosslinking. If this occurs, you can seek a repeat procedure.
Some potential side effects and complications include:
- Eye infections
- Eye pain
- Corneal or epithelial damage
- Blurring vision (temporary)
- Delayed healing
- Corneal scarring
On average, corneal crosslinking costs about $2,500 to $4,000 per eye.
Insurance coverage is also available because the procedure is considered medically necessary.
Talk to your surgeon and insurance provider about the exact cost, as it may differ from one surgeon to the other.
2. Topography-guided conductive keratoplasty
Topography-guided conductive keratoplasty (CK) is a quick technique that uses radiofrequency energy to reshape irregular corneas.
It’s also valuable for the treatment of low hyperopia with or without astigmatism and presbyopia (age-related farsightedness).
CK takes 5 minutes or less to complete.
You’re a good candidate for topography-guided conductive keratoplasty (CK) if you:
- Are 40 years or older
- Measure between +0.75 and +2.50 diopters of correction
- Have lower than 0.75 diopters of astigmatism
- Have presbyopia (age-related farsightedness)
You’re not an ideal candidate if you:
- Are breastfeeding
- Have a history of keratitis
- Are immunocompromised
- Have eye diseases, such as dry eyes
- Have corneal scarring within the central optical zone
- Use a pacemaker (can be affected by radio waves)
The CK procedure is computer-guided. Your surgeon will create topographic images of your cornea by using special imaging technology. This helps individualize your treatment based on needs.
They will mark your visual axis with a device known as a Sinsky Hook. A marking tool is placed over the visual axis to mark the cornea in the areas to be treated.
Then, the keratoplast tip is inserted into the marked areas, which sends a mild radiofrequency energy into your cornea.
This action also gently heats the upper layer of the cornea, which causes it to shrink. The shrinkage enhances your cornea’s refractive power.
After the treatment, your surgeon will administer antibiotic drops in the area and place a soft contact lens on your eye to protect it as it recovers.
They will also give you post-operative care instructions to ensure proper healing.
Most people achieve a 20/40 vision or better immediately. Others take a few weeks to notice positive changes.
Common side effects include:
- Photophobia (sensitivity to light)
- Gritty feeling in your eyes that wears off with time
- Visual fluctuation
- Slight nearsightedness
- Corneal regression requiring a repeat procedure
Rare complications include:
- Corneal aseptic stromal necrosis
- Surgically induced astigmatism
The cost of topography-guided conductive keratoplasty (CK) will vary depending on your location, facility, and your surgeon’s experience.
Insurance does not cover it because it’s considered elective.
On average, CK costs about $1,500 to $2,000 per eye.
3. Penetrating keratoplasty (corneal transplant)
Penetrating keratoplasty (PK) is a century-old procedure and the most commonly performed eye transplant.
It treats corneal problems that affect visual acuity, such as keratoconus.
The PK procedure involves the complete removal of a damaged section of the cornea. This follows replacing it with a healthy one from a donor.
In some cases, the cornea may be artificial bundled with the donor tissue (keratoprosthesis).6
Although PK is a common eye surgery, it’s only recommended in severe and advanced cases.
The risk of permanent vision loss makes keratoconus a serious condition.
Considering a five-year prognostic study, the graft survival rate of penetrating keratoplasty is around 74%.7
A significant improvement of PK is deep anterior lamellar keratoplasty or DALK.
You’re a good candidate for PK if you have:
- A thin, cone-shaped cornea (keratoconus)
- A corneal injury
- Unhealthy corneal tissue due to ulcers or sores
Before the procedure, your surgeon will conduct a comprehensive examination of your cornea to determine if PK will work for you.
To avoid infections, you’ll also have to use antibiotic eye drops a day before PK.
During surgery, your surgeon will administer anesthesia to ease discomfort and a sedative to keep you calm.
Using a device known as a trephine, your surgeon will then make a full-thickness incision in your cornea and safely remove the damaged section.
Next, they’ll replace your cornea with a healthy one from a donor.
The PK procedure typically takes about 30 minutes to an hour.
Your doctor will likely give you an eye shield to protect your healing cornea for a few days. Post-op care instructions to promote recovery will also be provided.
Some risks and side effects include:
- Corneal stromal graft rejection
- Glaucoma (increased eye pressure)
- Clouding of the eye lens
- Swollen cornea
- Retinal detachment
- Corneal scarring
If PK is considered medically necessary, private coverage or medicare will cover some of the costs. You may still have to pay out of pocket for things like specialty and hospital copays.
On average, PK costs about $1,500 to $2,500 per eye.
4. Deep anterior lamellar keratoplasty (DALK)
DALK is a procedure for advanced keratoconus. It reduces the risk of transplant rejection and is more complex than PK.
Unlike PK, DALK involves partial removal of the affected corneal stroma and replacing it with a healthy donor.
This surgical procedure preserves Descemet’s membrane and endothelium.8 These are two layers of the cornea that lie underneath the corneal stroma.
If Descemet’s membrane and endothelium are left intact, the wound is less delicate and less prone to transplant rejection.
A study found that DALK patients have a graft survival rate of over 90%.9
You’re an ideal candidate for DALK if you have:
- A corneal injury
- Unhealthy corneal tissue due to ulcers or sores
The DALK procedure is similar to penetrating keratoplasty except it preserves the endothelium and Descemet’s membrane.
The donor cornea has the endothelium-Descemet’s membrane removed. Then the graft is placed within the recipient’s membrane.
The graft is secured with stitches, which can be removed post-surgery.
The procedure usually takes about an hour or less.
Some risks and side effects include:
- Perforation of the Descemet’s membrane during surgery10
- Graft rejection (rare compared to PK)
- Corneal swelling
- Infection in the healing area
- Posterior scarring
The DALK procedure costs roughly $13,000 for an outpatient procedure and about $28,000 for an inpatient procedure.
The cost may vary based on your location, facility, and the surgeon’s experience. Also, insurance will likely cover most of the cost.
What is the Best Surgery for Keratoconus?
The best surgery will slow or stop the progression of keratoconus and fix your vision problem with minimal discomfort, risk, or complications.
Your doctor will determine what works best for your situation after your initial examination.
It’s important to seek medical attention if your cornea bulges forward or if you experience eye pain, blurry vision, and/or other visual disturbances.
Keratoconus is a progressive condition. Early intervention requires less-invasive techniques. How well you care for your eyes after surgery will also affect the outcome.
Make sure you follow your doctor’s post-surgery guidelines, too.
Schedule a follow-up visit at least 24 to 48 hours post-surgery and frequently after, as directed. Your surgeon should monitor the healing process closely.
Preparing for Keratoconus Surgery
How you prepare for keratoconus surgery depends on the specific procedure you will undergo.
However, there are general rules for most eye surgeries. These include:
- Stop using your prescription eyeglasses or contact lenses a few days or weeks before surgery
- On the day of the surgery, do not use eye makeup, such as mascara, eyeliners, or fake eyelashes, as they can breed bacteria
- Don’t wear perfume or after-shave
- Eat a light meal and drink fluids beforehand
- Prepare reliable transportation to and from surgery, as you’ll have impaired vision immediately after
- Follow your doctor’s instructions carefully and discuss any concerns beforehand to ensure you’re ready for the procedure
Alternative Treatment Options
Here are some of the best alternatives to keratoconus surgery:
Eyeglasses or soft contact lenses
These correct vision issues in early keratoconus.
Gas permeable contact lenses (GP lenses)
The smooth, uniform refracting surface of GP lenses replaces the uneven curvature of the cornea, improving comfort and visual acuity.
Intacs are plastic, arc-shaped corneal implants placed in the cornea to restore its shape.
These are hard contact lenses placed on soft ones to improve comfort.
Hybrid contact lenses
These have a rigid center with a soft ring on the edges to increase comfort.
Scleral contact lenses
These are contacts placed on the sclera (white of the eye). They cover the cornea without contact to enhance comfort and improve visual acuity.
These are specially designed through 3D imaging to match the exact impression of your sclera. They fix corneal irregularities.
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