“Everything You Want to Know About Keratoconus” was the title of The Eye & Ear Foundation’s February 5th webinar.
The first presenter was Gaurav Prakash, MD, Assistant Professor of Ophthalmology at the University of Pittsburgh School of Medicine. He is a clinician scientist with vast experience in the field of corneal disorders and refractive surgery and specializes in keratoconus and corneal ectasia.
He shared a story of despair and hope: A 19-year-old who presents with frequent headaches, an inability to drive in the dark, and who can barely manage to drive during the day. They need new glasses every six months. Each visit shows them worsening.
“This is more common than we think,” Dr. Prakash said. He showed a slide that depicted what this patient’s vision is like. It is blurry, has doubling and haziness even with glasses. There is no meaningful vision. He can still see what is in the room but cannot make his way through.
He has a disease called keratoconus (conical cornea) which can affect 1:150 to 1:1000 depending on the part of the world you belong to, demographics, and family history.
Keratoconus Presentation
- Onset when young
- Frequent change of glasses
- Can have high incidence
- Night vision is worse
- Progressive, sometimes relentless
Basic Information
The cornea is the window of the eye, like the windshield of a car. A normal cornea is shaped like a soccer ball. Keratoconus causes irregular thinning and bulging of the cornea, like a football.
A major result is poor quality of vision due to irregular astigmatism.
Keratoconus is not a new disease. More cases are seen now because they were picked up earlier. There is a valid argument for treating this disease early, as it is progressive and will not revert back again.
Change in Treatment
Two decades ago, if a young patient with early keratoconus walked in the room, the physician would have said, “I have bad news!” The options were glasses/contact lens or a corneal transplant. In the most likely scenario, if the patient asked if the disease would keep on progressing, the answer was yes. If the patient asked if they would need a transplant, the answer was “likely yes.”
Now, if this same patient walked in the room, the physician would say, “I have bad news, but we can take care of it!” Instead of a corneal transplant, an option is cross linking. The answer to progression would be, “No, we can likely stabilize it.” The answer to a transplant would be, “No, in the majority of cases.”
Keratoconus is a chronic disease that worsens with age, Dr. Prakash said.
Three Different Parts
If keratoconus is divided into three different parts, the first would be pre-clinical. This involves microscopy, genetics, family history, and ethnic factors. The next stage is early changes, which mean peripheral changes, borderline topography, and night symptoms. The third stage is late changes, with obvious topography and clinical signs.
“The aim is to work in the first two stages and improve pickup as we have a treatment now to stabilize progressive keratoconus,” Dr. Prakash said.
Screening
Step one is to suspect the condition based on symptoms like worsening haloes and glare at night, worsening night vision, double vision, change in astigmatism, frequent change in glasses, and frequent eye rubbing.
The gold standard for testing is corneal topography. Topography is a detailed analysis of cornea beyond the central cornea. Keratoconus starts outside the central cornea most frequently. Basic testing such as refraction/keratometry can miss it.
Treatment Options
Anatomical progression management is the first stage, in which risk factors like eye rubbing, obstructive sleep apnea, and allergies are reduced. The patient is monitored yearly until 40 years of age, and later based on pathology/risk factors. Corneal cross linking is done if the condition is worsening.
What is cross linking? Riboflavin mediated cross linking is a catalytic process that shifts the weak cornea to a safer biomechanical level. The outpatient procedure only takes an hour. Eye drops are put in and then UV light (not laser) is used to cross link the cornea.
Post cross linking, if vision with glasses is good, then glasses are given. If there is a lot of double vision or the patient does not want glasses, there is a treatment called ICL (implantable collamer lenses), also known as phakic IOLs.
Another treatment option is vision management. In early keratoconus, glasses/normal contact lenses are used. If moderate to advanced, then a specialized (scleral) contact lenses is used.
If a patient has an intolerance to contact lens, poor vision with contact lens, or advanced keratoconus with scarring, then a corneal transplant is the treatment option. It can be partial or full thickness based on the scenario and is called a keratoplasty. It is an invasive treatment but the success rate is fairly good.
What Does the Future Hold?
The second presenter was Vishal Jhanji, MD, FRCS (Glasgow), FRCOphth, FARVO, Professor of Ophthalmology at the University of Pittsburgh School of Medicine. He is a corneal specialist and a clinician scientist by training, and the current president of the Eye and Contact Lens Association.
“Fortunately, in that story from despair to hope, we are moving towards certain hopeful things in the near future,” Dr. Jhanji said. “Everyone who comes to the clinic is helping us just by being a patient at the Vision Institute helping us understand this disease better. Every time you come in, we do certain things. We take images and think about treatment modalities. Some of you are kind enough to participate in ongoing clinical trials as well.”
Glasses and contacts improve vision but do not alter the course of keratoconus, he added.
Why do we not see older patients with keratoconus? An article from 25-30 years ago addressed this question, explaining that the most common reason unfortunately is because they probably die sooner due to their poor vision. They get into trouble, accidents, falls, etc. Over the past 10 years, however, things have changed drastically.
Dr. Jhanji showed a photo of a patient who had a cornea transplant. The center of the cornea was changed, but the rim was still keratoconic. The disease cannot be rid of completely. In the early 80s, people started to realize that if patients have transplant surgery done at a really early age, they have the rest of their lives for keratoconus to progress further in the rim. These patients are difficult to treat, but the new contact lens designs have been game changers.
Donor Cornea
The U.S. has an abundance of donor cornea tissue. Doctors Prakash and Jhanji trained in India, where the wait for transplant can be up to two years. In China and Hong Kong, the wait can be up to 3-3.5 years sometimes. In countries like the U.S. and Australia, it is only a few days.
“If you look at data from around the globe, there’s only one donor cornea for 70 people,” Dr. Jhanji said. That means looking for options where physicians can provide good vision to patients without a cornea transplant. Collagen cross linking is one way to slow down or stop disease progression.
Understanding the Pathophysiology
Dr. Jhanji said there is work with collaborators in southern China where they are trying to take imprints of the corneal epithelium to understand the physiology and how inflammation affects the cornea and leads to exacerbation of the disease in these patients.
There is also work being done to make cross linking better and more effective. There are patients who cannot get it done because their corneas are too thin. They also might not find out they have keratoconus for multiple reasons. Maybe they are living in a place where there is no access to a keratoconus specialist. They may have been told all their lives that they were born with poor vision and that is how it is. “When they come to us, the cornea is very thin and cross linking doesn’t work very well or it’s not FDA approved for a very thin cornea,” Dr. Jhanji said. It is a work in progress trying to make cross linking more accessible to these patients.
Dr. Gary Yam, Dr. Jhanji’s colleague at Pitt, is working with Dr. Rizwan from Michigan Tech University on certain modalities to see if they can potentiate the thin corneas that are already there in keratoconus. Perhaps there is a modality in which the thickness of the cornea is increased so cross linking or a transplant are not needed.
Pediatric Keratoconus
Very few people realize that keratoconus can affect every age group.
Dr. Jhanji said Dr. José-Alain Sahel, Chair of Ophthalmology, worked hard to get a cross linking unit for the Children’s Hospital cornea department before getting one for the adult side. “It was worth it,” he added. “We treat a lot of patients with keratoconus in a younger population. The progression of the disease is very fast in some of these patients. Some would need retreatment if they receive cross linking. Visual rehabilitation is very difficult. It is hard to put a large contact lens on a kid’s eye. There are also associated complications. We have a very very able team of doctors that take very good care of these patients.”
Global Down Syndrome Foundation
Something close to Dr. Jhanji’s heart is the Global Down Syndrome Foundation. Certain diseases are associated with a high prevalence of keratoconus, and down syndrome is probably very close to the top of the list. There are patients in their 20s and 30s who were born with down syndrome and have never had a proper eye exam. By the time they come to Dr. Jhanji, it is sometimes too late to do anything. He just started working with this foundation to make sure there is a pathway for these patients to be seen by a specialist early in the course of the disease to make sure any important eye diseases are not missed.