The CLEI Center for Keratoconus
The CLEI Center of Keratoconus, founded in 2002, was the first dedicated subspecialty center for keratoconus in the nation and is world-renowned for its expertise. It led the FDA pivotal trial for the approval of corneal collagen crosslinking and continues to innovate and improve upon treatment techniques. The center also develops new specialty contact lenses for keratoconus. It offers state-of-the-art care, including diagnosis, therapy, specialty contact lenses, and advanced surgical procedures. The center’s collaborative approach ensures patients receive the best customized and comprehensive treatments to prevent disease progression and optimize vision.
Keratoconus Treatment
Are you looking for a keratoconus specialist near you? At CLEI, we offer an exhaustive evaluation using cutting-edge technologies to create a customized treatment plan for you, including specialty contact lenses, keratoconus surgery and genetic testing. Our center is a leader in keratoconus research and innovation, with doctors who have delivered thousands of academic lectures, published hundreds of peer-reviewed manuscripts, authored numerous academic book chapters, led multiple FDA clinical trials, written several books, and hold granted patents derived from our research. Trust in our unmatched experience, skill, and expertise for the most advanced treatment options available.
Keratoconus Vision
Understanding Vision from Normal Corneas versus Keratoconus and Irregular Corneas
Vision Simulations with Glasses Correction
Keratoconus Treatment at CLEI
We understand that keratoconus is more than a disease, it affects everything about your life. Every waking moment is a reminder of the disease. Our goal is to improve the quality of life for those affected by keratoconus. To do this we take a comprehensive approach to your treatment which we call Keratoconus 1,2,3.
Our approach to keratoconus treatment is comprehensive.
Step 1. Stop the progression of Keratoconus: Crosslinking
Since we began treating patients with crosslinking nearly in 2008 as part of our clinical studies, crosslinking has emerged as one of the most important advancements in keratoconus treatment. Corneal collagen crosslinking (CXL) halts the progression of keratoconus to maintain your vision and level of disease. Corneal crosslinking makes the cornea stronger and more resistant to disease progression. In this procedure, riboflavin (Vitamin B2) is administered in conjunction with ultraviolet A (UVA – 365nm) light. The interaction of riboflavin and UV causes a photobiologic reaction in the corneal leading to the formation of additional molecular bonds between collagen molecules and their supporting biological sugars. This results in the stiffening of the cornea, much like placing additional cables on a bridge will help to support it. At our center, we offer standard and specialty crosslinking.
Step 2. Improve the Keratoconus Topography: Keratoconus Surgery
Keratoconus causes a corneal shape deformation, leading to poor vision. The vision can be improved by having a procedure performed to improve corneal shape. This is part of the comprehensive management of keratoconus. and improved corneal shape will allow you to have a better quality vision in glasses and soft contact lenses and improve uncorrected vision to some extent. Our Center’s doctors are experts and innovators and will select the correct treatment to optimize your cornea and vision.
Step 3: Improving Keratoconus Vision: Keratoconus Contact Lenses & Other Keratoconus Surgeries
In keratoconus maximizing vision has the greatest impact on your quality of life. This can be achieved both surgical and non-surgically.
Specialty Contact Lenses Procedure
The process of designing a customized lens to meet the needs of the keratoconus patient starts with an advanced and in-depth evaluation. This evaluation guides the process of understanding which type of specialty contact lens will meet your individual needs. A multitude of different scans, impressions, and diagnostic lenses may be used in the design process. Once a lens type has been selected, our doctors will create a custom contact lens for you. This process generally involves several revisions or modifications to ensure the lens is ideally fit, eye health is maintained and vision is the best possible.
The Initial Evaluation
At the Cornea and Laser Eye Institute, patients undergo an advanced comprehensive ocular examination using sophisticated technologies to optimize results. Using this evaluation, your individual needs can be matched to the proper specialty contact lens to achieve the best outcome. This advanced ocular examination will typically take a few hours to complete. Once this baseline information is gathered, the lens design and fitting process can begin.
The Lens Design and Fitting Process
During your initial evaluation, the lens design process will begin. Just like a fingerprint, each eye has its own unique contour. There is even a significant difference in the shape when comparing the 2 eyes of the same individual. Specialty contact lenses are tailored to your individual eyes’ anatomy, physiology, and visual needs. From the lens materials, physical lens parameters, and optics, the process aims to determine and create lenses to achieve these three goals; improved vision, ample comfort, and optimum health. There are several techniques used in the process of designing your lenses.
Diagnostic Set Design
The classic way to fit and design specialty contact lenses is by using a diagnostic contact lens set. A series of lenses with varying curvatures are placed on the eye. The lens’s alignment is evaluated, and during the design process, modifications to the lenses are made based on the observations and eye performance. At the Cornea and Laser Eye Institute, our doctors have over 100 different diagnostic contact lens sets at their disposal. In contrast, the average practitioner may have 1 or 2 diagnostic sets.
Scan-Based Design
An additional approach is scan-based specialty contact lens design. Using highly specialized devices to scan the ocular shape, this data is used to create a digital model of the eye. Our doctors have access to all the devices capable of capturing this data, while the average
practitioner will not have access to these devices. Once this model is created, we will use specialized computer-aided design software to create a lens unique to your eye’s contour.
Corneal cross-sections from a tomographer, used to create a 3d model to build a custom scleral lens, ortho-k lens, or other specialty contact lens.
Impression-Based Design
An impression of the cornea and ocular surface. This ocular impression will be 3D scanned and used to create a model of the eye and then create a custom scleral lens, corneal gp lens or other specialty contact lens.
Another approach is the technique of ocular impressions. Using a specialized gel, an impression of your eye is obtained. This impression is then 3D scanned, creating a digital model of the eye. Using this model and highly specialized computer-aided design programs, completely bespoke lenses can be created. Our center has been a pioneer in this technique. The first to perform it in the northeastern United States and is the only doctor trained to do so in New Jersey. Less than 0.1% of practitioners worldwide are trained in this technique.
Once the initial visit is complete, your individualized specialty contact lenses will be fabricated. The lenses will typically take 2-3 weeks before they arrive in the office for the final verification process before being dispensed.
Derived Specialty Contact Lenses
Both are custom made scleral lenses derived from diagnostic fitting, scan based, or impression based data. Both lenses lead to a successful result. Though the examples above are of scleral lenses, these scan and impression data derived lenses can be applied to other lens types such as custom soft lenses, hybrid lenses, and corneal GP lenses
Keratoconus Contact Lenses
Types of Specialty Contact Lenses for Keratoconus and Irregular Corneal Conditions
Most patients are familiar with standard soft lenses. These lenses are mass-manufactured in a process called cast molding. The lens parameters are generally limited to fit the average shape, size, and power needs of a normal eye. Though they are highly successful for most individuals with uncomplicated corneas and average refractive errors, those patients with moderate to advanced corneal irregularity commonly experience difficulty. However, individuals with mild corneal irregularity and refractive error within the normal parameters, a standard soft lens may achieve a satisfactory outcome.
Unlike their mass-produced counterparts, custom soft lenses are not limited to the typical parameter constraints of the normal corneal population. Custom soft lenses are lathe-cut and can be produced in an extensive range of base curve radii, diameters, materials, and nearly endless refractive powers. Some of these lenses can have a cosmetic or prosthetic option added, which can be useful to improve cosmesis and to reduce glare. Additionally, lens thickness can be significantly increased to create a pseudo-rigidity, which can mask corneal irregularity. Success of these lenses depends on the severity of the irregularity. For individuals who are unable to tolerate corneal GP lenses, custom soft lenses may provide adequate vision and improved levels of comfort.
Corneal GP lenses are the classic choice to mask corneal surface irregularities and to improve visual acuity. These lenses are also referred to a hard lenses, rigid lenses and RGP (rigid gas permeable) lenses. Using corneal GP lenses on a cornea that has very minor irregularity is similar to fitting them for refractive correction on a normal cornea. However, fitting corneal GPs becomes increasingly difficult as the corneal surface becomes more irregular. Success of these lenses depend greatly on the severity and location of the corneal irregularity. Many patient whom have had difficulty with GP lenses in the past generally have irregularity that is too severe to be successful with this type of lens. These lenses are lathe-cut and can be produced in an extensive range of base curve radii, diameters, materials, and nearly endless refractive powers. When fitting a corneal GP lens, precision of fit is of the utmost importance to maintain the corneal integrity and lens comfort. Additionally GP lenses have proven useful in deciding if surgical intervention may be beneficial.
For patients experiencing reduced comfort or minor epitheliopathy with a best-fit corneal GP, a PB lens system can be utilized. This approach uses a GP lens to improve visual acuity, while the underlying soft lens provides corneal protection, cushioning the cornea from the GP lens and improving comfort. The PB lens system may be best utilized when other options have failed and GP lens is the appropriate first lens option. Patients may be apprehensive to adopt this modality due to the perceived difficulty of wearing and caring for two lenses. Daily disposable standard soft lenses can be used to as the cushion to simplify care. On occasion a custom soft lens option, such as a cosmetic/prosthetic soft lens or a soft lens with a central excavation (allowing the GP lens to rest in a depression in the soft lens surface), can be used to improve cosmesis, reduce glare, or improve lens centration.
Candidates for refractive lens exchange are generally older than 40 years of age when one requires glasses to read, work on the computer, and possibly for distance as well. In some cases, patients have a prescription that is not ideally treated with blended vision LASIK. This procedure is performed one eye and a time in an ambulatory surgery center. Surgery on the second eye is usually performed two weeks after the first eye is complete. The amount of time it takes to see an improvement in vision varies. Most patients see better and can return to work within a few days.
Hybrid lenses utilize a GP center with a soft lens edge, so they have characteristics of both GP and soft lenses. Various hybrid lens designs exist, with multiple geometries to accommodate a mild to moderate corneal irregularity. The GP portion of the lens can be modified to align with or vault over the corneal irregularity while the soft skirt an aids in adjusting lens movement, tear exchange, and lens centration and can also influence alignment of the GP portion of the lens. Hybrids can produce improved vision and comfort over corneal GPs in cases of lens decentration and lens intolerance. Of note, quality of life is similar with corneal GP, soft, and hybrid lenses. Hybrid lenses are filled with saline prior to lens application and because of the soft edge special attention to the force of lens application to avoid issues with lens wear.
When corneal irregularity is extreme, scleral lenses are preferred over other lens designs. These lenses vault over the cornea, aligning with the sclera and overlying conjunctiva (white of the eye). Scleral lenses can overcome nearly any corneal irregularity and should be considered as an option prior to referral for corneal transplantation. Individuals who have keratoconus and who otherwise would have undergone corneal transplantation secondary to contact lens failure can achieve success with these lenses. These lenses are can be designed with an abundance of unique modifications. Advanced fitting techniques can include impression based and scan based design. These lenses are lathe-cut and can be produced in an extensive range of shapes, diameters, materials, and nearly endless refractive powers. In addition, highly customizable optics such as wavefront guided, higher order aberration correcting optics can be added in some lenses.
In some cases vision with scleral lenses, though improved, may still have some residual blur. This residual blur is caused by higher-order aberrations. These higher-order aberrations are responsible for doubled, overlapped, ghosted vision with glare, flare, starburst and halos. In these cases, the addition of highly customized wavefront-guided, higher-order aberration-correcting scleral lenses can further improve your vision.
Vision Simulations of Traditional Scleral Lenses & Wavefront Guided Scleral Lenses
These optics are considered High Definition optics as the clarity is improved over traditional optics. Our doctors were the first to use this technology in the North East United States and is currently the only doctor trained to do so in the state of New Jersey. Our research has found these lenses provide an average 50% percent reduction in aberrations and 1 or more lines of visual acuity improvement over traditional scleral lenses.
Scleral lenses and scleral devices are specially designed to rest on the conjunctiva and underlying sclera, the “white” of the eye, and vault over the entire corneal surface.
The cornea focuses light and when diseases, such as keratoconus, trauma or surgery distorts its shape it also distorts vision. The cornea is also one of the most sensitive tissues in the body and the one most damaged by dry eye and ocular surface disease. By vaulting over the cornea, the lens masks the irregular shape. The space created between the cornea and the back surface of the device is filled with fluid. In ocular surface disease, this fluid reservoir acts as a “tear bandage” which bathes the corneal surface to provide comfort, protection, and healing for people with diseases that affect the ocular surface. This therapeutic use can rehabilitate the cornea and prevent further damage caused by various diseases.
A custom scleral lens made by a scan or impression based design technique. Notice the unique shape of the lens, designed to fit the exact nuances of the cornea or ocular surface. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.
Scleral lenses can be a great option for those with irregular corneas and ocular surface disease. Many times these lenses are the only option for patients with severe disease and often times can delay or prevent the need for surgical intervention. Occasionally standard scleral lenses will be unsuccessful due to the complex shape of the eye. In those cases custom scleral lenses and prosthetic scleral devices become the best option.
Our doctors work extensively with these devices and has helped suffering patients from all over the world. He has been instrumental in developing advanced technology, fitting techniques and lens designs. Custom made scleral lenses, whether derived from diagonic fitting, software driven, scan based or impression based data, all can lead to a successful result. As an expert in these techniques, our doctor determines which approach will be best so he can create a custom scleral lens or device to meet your individual needs.
A variety of custom made scleral lenses, each is made to mimic the ocular shape of the patient’s eye. Note no 2 lenses are the same just as no 2 eyes are the same. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.
The classic way to fit and design scleral lenses is by use of a diagnostic contact lens set. A series of lenses with varying curvatures are placed on the eye. The alignment of the lens is evaluated and during the design process modifications to the lenses are made based on the observations and on eye performance. The majority of diagnostic designs have simplified parameter options, which can limit the design process. Scleral lens design software can remove these restrictions, allowing for more customized lenses to be made. Several custom scleral lenses or scleral devices, such as a PROSE device, use these powerful software programs allowing our doctors to create more customized of lenses.
Example of software used to design lenses. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.
Various derived shapes. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.
Another design approach uses highly specialized devices to scan the ocular shape. This shape data is used to create a 3 dimensional digital model of the eye. Once this model is created our doctors will use a specialized computer aided design software to create a lens unique to the contour of the eye.
3 different profilometers at CLEI. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.
Scans from a profilometer, used to create a 3d model to build a custom scleral lens. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.
Another approach is the technique of ocular impressions. Using a specialized gel, a impression of the eye is obtained. This impression is the most accurate depiction of your eye possible and is then 3D scanned, creating a digital model of the eye. Using this model and multiple highly specialized computer aided design programs a completely bespoke scleral lens, such as a EyePrintPro device, can be created.
Our doctors has been a pioneer in this technique. The first to perform it in the North East United States and is currently the only doctors trained to do so in the state of New Jersey. Less than 0.1% of practitioners in the world are trained on this technique.
An impression of cornea and ocular surface, this will be 3D scanned and used to create a model of the eye which custom scleral lens is designed. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.
An impression being 3D scanned, a model lens derived, and a custom scleral lens manufactured. Image by John D. Gelles, O.D. Copyright © 2020 by the Cornea and Laser Eye Institute. All Rights Reserved.
Genetic Testing for Keratoconus
Understanding Genetics and Keratoconus
If the last time you learned about genetics was in biology class, you’re not alone. To best understand genetic testing it’s important to revisit the basics.
There are two main categories of genetic diseases: Monogenic and Polygenic. Monogenic disease is simple, if you have the gene you have the disease. It’s a yes or no. A well-known example of this is cystic fibrosis.
Polygenic disease is more complex, no individual gene is responsible for the disease, rather, it is a collective of genes associated with a disease. If you have more genes associated with the disease, you have a higher genetic risk of the disease. These genetic factors interact with environmental factors to cause the disease. Polygenic diseases are associated with several or lots of genetic variances. Keratoconus is a polygenic disease. Other examples of polygenic diseases include hypertension and diabetes.
Genetic tests help to guide personalized, precise, medicine. If a patient is identified with a high genetic risk for keratoconus, then our doctor will prescribe more frequent follow-up, recommend avoiding or treating environmental factors, such as treating ocular allergies and stopping eye rubbing, and may initiate earlier intervention with treatments such as crosslinking. These treatments if initiated at the earliest onset of the disease can slow the trajectory of the disease, preventing advanced disease.
Risk calculation in polygenic diseases such as keratoconus is complex. Researchers have identified 75 genes associated with keratoconus, discoveries that enabled Avellino to develop the AvaGen Genetic Eye Test, which screens for thousands of variants on those 75 genes and provides a risk assessment based on those findings.
AvaGen Genetic Eye Test is a major breakthrough in understanding a patient’s risk of keratoconus. It provides risk scores for both symptomatic and asymptomatic keratoconus patients. The results are presented as a simple score, 0 to 100, which breaks down into low, moderate, or high risk. Our doctors were involved with the original development of the test.
Both genetic and environmental factors contribute to the development of keratoconus. An example of environmental factors impacting the development of keratoconus is eye rubbing. Does this mean all people that rub their eyes will develop keratoconus? No, and this is where genetics play a role. For a person with high genetic risk, eye rubbing compounds and increases the risk for keratoconus development.
The test is simple. It is performed in-office with a cheek swab, also known as a buccal swab, which collects a small number of cells from the inner cheek.
Patients with a diagnosis of keratoconus should consider having their family members, especially their children, tested.
What is Keratoconus?
Keratoconus, one of the more obscure and less widely known eye diseases, occurs in about one out of every 725 individuals and is one of the more difficult eye diseases to diagnose. Keratoconus eye disease is caused by the weakening of the collagen tissue that makes up the cornea. The cornea begins to stretch and thin as the collagen gets weaker, resulting in a loss of the cornea’s normal dome shape.
Biologically and structurally, the cornea is made up of bands of collagen called lamellae which are “glued” together by natural biologic sugars called glycosaminoglycans or GAG’s. The cornea’s collagen and microstructure are abnormal in keratoconus, causing a weakness of the corneal, which then leads to corneal distortion and related visual problems.
It is a progressive condition which, aside from distorting the cornea’s natural optics, can also lead to scarring and other problems. The presentation and impact of keratoconus can vary widely from person to person. In its earliest stages, keratoconus often masquerades as astigmatism or nearsightedness, two of the more common eye conditions. Often, it is only after numerous unsuccessful attempts at vision correction with glasses or soft contact lenses that keratoconus is diagnosed.
Keratoconus is typified by corneal thinning and biomechanical instability. This may be caused by abnormalities in the normal collagen structure of the cornea. Collagen is the main structural component of the cornea. Collagen is a molecule that is typically very strong. For example, it makes up most of the structure of the tendons and ligaments of your muscles and bones. The cornea is made of pancakes (or lamellae) of collagen tissue in a complex array. In keratoconus, the collagen lamellar architecture may be abnormal. There may also be abnormal enzymes that degrade the collagen and reduce the collagen in the KC cornea. In addition, the cells of the cornea (keratocytes) may not be normal, contributing to the thinning and instability of the keratoconic cornea. The linkages of the collagen molecules, collagen lamellae, and corneal sugars to one another may also be weak in keratoconus. For instance, “anchoring fibrils” which normally lock the collagen pancakes to the front of the cornea, on Bowman’s layer, may be abnormal. This may allow the collagen pancakes to slide on one another and exacerbate KC progression. Because of this, it is important that the keratoconus patient does not rub his/her eyes in order to avoid mechanical shearing of the collagen pancakes. Finally, inflammation may also play a role in keratoconus. Reactive oxygen species, or oxygen free radicals, may damage the corneal cells and collagen structure, and lead to keratoconus progression. Because of this, avoiding and treating eye inflammation (for instance, eye allergies) also may be important for the patient with KC.
Keratoconus Symptoms
Detecting keratoconus eye disease can be challenging as its initial symptom is often a minor blurring of vision or gradual deterioration in vision that cannot be easily corrected. Keratoconus symptoms include:
- Blurred or distorted vision
- Increased sensitivity to light and glare
- Glare and halos around lights
- Frequent changes in eyeglass or contact lens prescriptions
- Difficulty seeing at night or in low light conditions
- Eye redness or swelling
- Eye strain or fatigue
- Headaches or migraines
What Causes Keratoconus?
The actual cause of keratoconus is unclear. It may have a genetic, inheritable component. However, in many patients there are no family members with the disease. Similarly, most children of KC patients do not have keratoconus, but they should be checked in early adolescence for signs of KC because early management can prevent the progression of the condition over time.
