Keratoconus Treatment Overview
We have seen great advances in keratoconus treatment in the past 5 years. Here we will discuss all of the current treatment methods along with their advantages and disadvantages. We have separated the treatment options into non-surgical and surgical keratoconus treatment options.
Non-Surgical Keratoconus Treatment Options
The vast majority of patients with keratoconus will never require surgery. In fact, for over 90% of patients with keratoconus non-surgical keratoconus treatment is all they will need.
Scleral Contact Lens Keratoconus Treatment
Treating keratoconus with scleral contact lenses has become the most popular and most successful option among keratoconus specialists. Here we will discuss why.
Lens Size Matters in Successful Keratoconus Treatment
Many people look at a scleral contact lens and assume because the lens is large it must be uncomfortable. Fortunately, for tens of thousands of keratoconus patients wearing scleral contacts, nothing could be further from the truth. A larger lens provides greater comfort. Better vision is also achieved with a larger lens. A scleral lens rests on the white part of the eye, which is called the sclera, and vaults over the cornea without touching it. Since scleral contacts place virtually all of their weight on the sclera they avoid the highly innervated cornea, which also greatly improves comfort.
Better Stability and Customization with Scleral Contacts
The custom scleral contacts used by Dr. Driscoll, the keratoconus specialist at Total Eye Care allows for customization of multiple sections of the lens in each quadrant. This degree of customization allows him to achieve better vision and comfort for his patients. Patients report these are the most comfortable keratoconus lenses they have worn.
Pros/Cons of Scleral Contact Lenses
The biggest advantage to scleral contacts is clearly their best of class vision and comfort. On the other hand, the biggest disadvantage to scleral contact lenses is they are more challenging to fit. Therefore, there are relatively few doctors with significant experience fitting scleral contact lenses. Dr. Driscoll has over 25 years experience in treating patients with keratoconus. He primarily sees patients with keratoconus at Total Eye Care in Colleyville. You can reach the Colleyville office at (817) 416-0333.
Gas Permeable Contact Lenses
Gas Permeable or RGP keratoconus lenses were the mainstay of keratoconus treatment for decades. RGP keratoconus lenses are relatively small, typically ranging in size from 8.0 to 9.6 mm in diameter. This is in contrast to scleral contacts which usually range from roughly 14.5 to 19.0mm. There are numerous brands of gas permeable contact lenses, the most popular of which is the Rose K lens. Other commonly fit RGP keratoconus lenses are the TruKone and YamaKone Lenses. Keratoconus RGP lenses vary from traditional gas permeable contacts by having an enhanced central zone which is much steeper than traditional gas permeable lenses.
Pros/Cons of Gas Permeable Keratoconus Lenses
RPG lenses give good vision and are widely available. Each lens is custom made; therefore, they are highly customizable. However, because of their small size and the fact they move a couple millimeters with each blink poor comfort is a common complaint. Traditional gas permeable lens places their entire weight on the cornea, which is highly innervated, contributing to poor comfort. Lens movement with blinking may also cause fluctuating vision.
Hybrid Contact Lenses
A hybrid contact lens marries a small gas permeable lens (about 6mm diameter) to a soft contact lens skirt. Hybrid contact lenses are among the easier keratoconus lenses to fit thus we see a wide range of eye doctors fitting them. There are relatively few fitting options with hybrid lenses which makes the fitting process easier than other customizable lenses. The relative ease of fitting; however, comes at a price since hybrid contacts are not customizable. SynergEyes hybrid lenses are best suited to less complex keratoconus cases. Vision is usually reported as satisfactory and comfort is good. SynergEyes, Ultrahealth, and ClearKone are all names of hybrid lenses used in keratoconus treatment.
Pros/Cons of Hybrid Lenses
The advantage of hybrid lenses is their high availability, having a large network of doctors fitting them. High cost, sometimes less than optimal vision, and poor durability are the biggest disadvantages to hybrid lenses. While the soft skirt improves the comfort of a gas permeable lens it also presents a weak point. The junction where the soft skirt is bonded to the gas permeable lens is a weak point and often separates. At Total Eye Care, our keratoconus specialists find patients report better vision and consistently better comfort with scleral contact lenses.
Keratoconus Treatment with Soft Contact Lenses
Soft contact lenses are the least common non-surgical keratoconus treatment. There are a couple of reasons for this. Poor vision and very limited options to customize the fit is why we don’t see many keratoconus doctors fit soft keratoconus contact lenses. Soft lenses do a poor job of correcting high degrees of both regular and irregular astigmatism. Typically soft contact lenses provide poor visual acuity. Soft keratoconus lenses are comfortable because they are thick and large. While soft keratoconus contacts are relatively comfortable they still fall short of mainstream contacts.
Pros/Cons of Soft Keratoconus Contact Lenses
Keratoconus specialists rarely use soft keratoconus lenses for effective keratoconus treatment since they only provide acceptable results in the simplest cases. A soft contact lens’ advantage is that it provides acceptable comfort. The disadvantage of soft keratoconus lenses is high cost, poor vision for most patients, and limited manufacturers. It usually takes 3 to 4 weeks to accept delivery of these types of lens. There are much better options available with better comfort and visual acuity.
Surgical Keratoconus Treatment Options
Corneal Collagen Cross Linking Keratoconus Treatment
Corneal Collagen Crosslinking with Riboflavin keratoconus treatment, sometimes referred to as C3R, involves bathing the cornea with a solution of riboflavin, then exposing the cornea to UV light after the riboflavin has sufficiently penetrated the cornea. Cross linking is one of the newest surgical keratoconus treatments. Cross linking for keratoconus was approved by the FDA in 2016. The UV light activated riboflavin greatly increases the connections between the collagen fibers (cross linking). The increased connections between the collagen fibers increases the strength of the cornea. This increased strength tends to stabilize the cornea, often stopping further corneal steepening.
While cross linking is most beneficial to younger patients, whom are more likely to experience unstable keratoconus, this keratoconus treatment can also help patients of any age experiencing unstable keratoconus. In addition to increasing corneal strength, some patients will experience a slight flattening of the cornea.
Cross Linking and Scleral Contact Lenses
Most patients that undergo cross linking still require further keratoconus treatment with scleral or gas permeable contact lenses to achieve their best vision. In this case, corneal cross linking is done first and then 1 to 2 months after the cross linking keratoconus treatment the patient is fit with scleral contact lenses.
Who are the Best Candidates for the Cross Linking Keratoconus Treatment
The best candidates for the cross linking keratoconus treatment are those keratoconus patients experiencing progressive steepening of their cornea. Keratoconic progression is best evaluated with corneal topography readings taken and evaluated over time. If the cornea is stable then it is usually best to stay with more conservative keratoconus treatment options since there is nothing to be gained with cross linking yet the potential surgical risks remain.
Pros/Cons of Corneal Collagen Cross Linking
Corneal cross linking has a good safety profile. The most common complaint was pain for up to a couple days following the procedure. Approximately 25% reported this pain as severe while 45% reported no pain. When keratoconus specialists treat keratoconus with cross linking the progressive steeping was stopped in about 98% of patients. Corneal haze lasting over 6 months was reported in less than 2% of patients.
Penetrating Keratoplasty (Corneal Transplant)
Approximately 5% of patients with keratoconus will benefit from a corneal transplant. Corneal transplant surgery involves replacing the patient’s cornea with a donor cornea (picture on the left). Some surgeons may perform a modified version of a corneal transplant called the DALK (Deep Anterior Lamellar Keratoplasty). Rather than replace the entire cornea, the DALK procedure only replaces the outer layers of the cornea leaving the inner layers intact.
Penetrating Keratoplasty vs DALK
If the decreased visual acuity is primarily due to scarring through all of the layers of the cornea or the innermost layer (Descemet’s membrane) is affected then a full corneal transplant is often the keratoconus treatment of choice. Most often, however; the corneal scarring is only found in the outer layers of the cornea. If this is the case then the DALK procedure can be considered.
When is Corneal Transplant Surgery Considered?
Corneal transplants are only recommended in a few situations. The most common reasons where corneal transplants are used in keratoconus treatment are;
- Severe scarring or distortion results in unacceptable visual acuity even after keratoconus treatment with scleral or gas permeable contact lenses
- Frequent episodes of corneal hydrops
We consider corneal transplant surgery as a viable keratoconus treatment option when other, more conservative treatment options fail to give a sufficient improvement in visual acuity. This is usually due to corneal scarring or corneal edema. Patients considering a corneal transplant have usually tried at least some of the other keratoconus treatments on this page and experienced an unsatisfactory outcome. Since the corneal transplant replaces the diseased cornea with new tissue a better optical surface is achieved. The new, clearer cornea results in better vision after surgery. After corneal transplant surgery, many patients will be able to further enhance their vision with gas permeable or scleral contact lenses.
Pros/Cons of Corneal Transplant Surgery
- irregular astigmatism – usually correctable with scleral or rigid contact lenses
- corneal graft rejection (approx 3% to 30% depending on the procedure and the study)
- complicates the fitting of contact lenses
Intacs® Intrastromal Corneal Ring Segments
Intacs®, intrastromal corneal ring segments, were approved for keratoconus treatment in 2004. Previously, Intacs® segments were used to treat low amounts of myopia (under -3.00). As a treatment for low myopia, Intacs® corneal implants were a market failure since LASIK provided better, more consistent results with a lower complication rate. While Intacs® are approved for treating astigmatism and myopia related to moderate to mild keratoconus their success rate is low. Intacs® is the least popular and least successful keratoconus treatment listed here.
Intacs® Surgical Procedure
The surgical procedure to implant an Intacs® corneal ring segment is rather tedious. It involves creating a tunnel at half the depth of the cornea just outside of the pupil. Once this tunnel is made the plastic corneal ring segment is inserted into the tunnel. In some cases, a ring segment is placed on each side of the pupil, and in others, only one ring segment is used (as in the photo above).
Pros/Cons of Intacs® Intrastromal Corneal Ring Segments
Few keratoconus specialists offer Intacs® as a keratoconus treatment since they don’t typically improve the patient’s vision. The theory is good, raise the peripheral cornea up to create a more uniformly curve corneal surface. In practice, the peripheral cornea is raised up; however, the mid-peripheral cornea does not get raised up. This causes the cornea to have a high center, where the central cone is located, a lower middle area and then an elevated periphery (area under the ring segment). The patient is essentially left with a “moat” around the central cone. It is very difficult to successfully fit traditional gas permeable contact lenses on patients with intrastromal corneal ring segments. Scleral contact lenses, while more challenging to fit on a patient with corneal ring segments than a patient that has not had the surgery, offer much better success rates.
Keratoconus Treatment Options Review
There are many keratoconus treatment options available today. It can be a complicated and confusing process to determine the best course of action. That is why we offer a free consultation to help patients sort out the different choices of keratoconus treatment options available today. We can advise you on all of the treatments available including medically necessary contact lenses as well as the surgical options. In some cases, you may benefit from both, in which case we will coordinate the entire process for you. Our comprehensive keratoconus treatment services allow us to assist patients in all phases of the condition. If you would like to set up a free consultation with Dr. Driscoll please call us at (817) 416-0333 or you can schedule your free consultation online. We look forward to helping you.