Translated and utilized with permission of the Danish Keratoconus association.
Keratoconus is a corneal disease. The disease causes visual impairment but not total blindness. There are various aids and treatments to help keep the disease controlled.
The cause of keratoconus is largely unknown. Keratoconus is most common in younger years. The development of the disease differs between individuals and can also be different between the eyes. In most cases, patients who have keratoconus disease have it in both eyes.It is not known how many people suffer from keratoconus in Iceland, but about 5000 people have been diagnosed with the disease in Denmark or 0.09% of the population. If those numbers are used to predict the disease in Iceland, it can be estimated that around 290 individuals have the disease, which in most cases is not hereditary.
What is a Keratoconus?Keratoconus is a corneal disease and can significantly affect the eyesight. The cornea distorts in a certain way and consequently is not as equal in terms of thickness and shape. As a result, the vision is impaired and the patient can become more symptomatic and visual disturbances are greatly increased.Keratoconus develops differently between patients and between the eyes. Thus, the disease for example can be very significant in one eye but almost not present in the other. The corneal changes can occur in a short period of time, even in a few months and evolve for up to 20 years and then abruptly stop.
The diagnosisThe diagnosis is based on topography of the cornea. This study shows the shape and thickness of the cornea, and it is then possible to detect the cones and severity. This study is the basic prerequisite for diagnosis and control of keratoconus disease.In the mildest cases, it may be difficult to determine whether keratoconus is involved. If your glasses change significantly or glasses do not fully adjust your eyesight, your optometrist or ophthalmologist often suspects that you have keratoconus, especially in young people.At the initial stage of the disease, the corneal distorts very little, but begins to change its shape. At this stage, diagnosis can only occur with special equipment designed to thoroughly examine the cornea. By taking a special landscape image of the cornea, you can detect the irregularity in it, that is formed when it changes it´s shape. Based on these pictures, the ophthalmologist can usually see if there is a healthy regular cornea or if a cone is present.Imaging (TOPOGRAPHY) of cornea is essential for baseline exam and monitoring of keratoconus. This testing should be done as a basline and if keratoconus is suspected, as soon as possible; it will be done routinely if you are diagnosed with keratoconus.
Why does an individual get a Keratoconus?Keratoconus is a rather rare disease. Males get the disease more often than women. Causes of keratoconus are unknown, but in some cases the disease appears to be hereditary. Keratoconus is not contagious. The disease may coexist with allergies, for example asthma, eczema and pollen allergies. Many of those who have a keratoconus have a tendency to rub their eyes a lot, but it is quite unlikely that it is an actual cause. The reason for the rubbing can be attributed to allergies and dry eye.
VisionAt the onset of the disease, most patients complain of worsening vision, as well as eye fatigue and an increased sensitivity to light and glare.With further development of the disease, most people experience their vision deteriorating and increasingly blurred, an may even see multiples of images or text.As the disease progresses, most patients will experience worsening blurred vision, however for some this happens rapidly, and if scarring occurs in the cornea, a cornea transplant may be required. The operation gives the best vision, although most people still will have to use either contact lenses or glasses.
How does Keratoconus develop?Most people are diagnosed with the disease in adolescence, but it may occur in older people. A scar can develop on the cornea when swollen, which may appear as a white spot or a streak on the corneal surface. The scar can affect the vision, depending on the location. In about 2% of cases, corneal edema develops rapidly. The edema usually resolves over time, but leaves behind scar tissue that can significantly affect the vision. Often you can significantly reduce the damage if an operation is performed on the eye at the start of edema, then you must visit the Eye Department at the National Hospital.
What is the prognosis?Although it is difficult to predict how fast or how much the disease will develop per individual, the disease does not lead to total blindness. In the worst cases, the sight may be very bad. With today's therapies, most people to maintain a normal life. Most of the time, vision and daily life is only disrupted while people are changing or getting used to lenses, or waiting for the vision to stabilize after corneal transplantation.
TreatmentKeratoconus can not be cured or treated with drugs, it is not possible to turn the cornea back to its former healthy form. However, there are many treatment options that significantly improve eyesight so that most people maintain sufficiently good visibility to perform their daily lives.
GlassesAt the onset of the disease you can get glasses that correct your vision, but it usually only works for a short period of time.
Contact lensesContact lenses are the most common treatment for keratoconus. There is no single-lens lens that works best, they have all their advantages and disadvantages. Today, the so-called hybrid lenses and semisclera lenses that work best. Regarding contact lenses, hard contact lenses will give best focus.It can take a long time to get used to lenses and fit them just right, but most people achieve very good vision. Continuous lens wear improves the irregular shaped cornea and it can also reduce photophobia and visual defects.If you do not carefully think about your lenses and hygiene around them, there is a risk of infection. It is important not to use the contact lenses with any type of infection in the eyes. It's good to have glasses that are adjusted your prescription at all times.
Crosslinking (Crosslinking (CXL))This is a relatively new treatment that strengthens the cornea and is the only treatment that stops the development of keratoconus. The majority of the treatments can prevent disease progression, but the vision does not improve. In 2% cases, corneal distortion may be worsened, and vision more blurred and worse than before treatment. For the procedure itself, the patient is awake but drowsy and treatment takes about 2 hours. First, corneal surface cells are removed and then B12 vitamin is distributed to the cornea for 30 minutes. After that, the cornea is exposed to ultraviolet light for half an hour. This causes chemical change that corrodes the cornea. The treatment is performed as an outpatient procedure. The vision gradually worsens after treatment and the first 24 hours patients may experience pain in the eye. Usually, patients have to wait at least a month before using contact lenses after this treatment.CROSS-LINKING PROCEDURE USUALLY IS PERFORMED ON PATIENTS AT TIME OF EARLY DIAGNOSIS (<20 YEARS) AND IN THE CASE OF RAPID DETERIORATION OF VISION IN OLDER PATIENTS. HOWEVER, THERE IS STILL GREAT NEED TO MONITOR THE CORNEA AS YOU RECOVER. TIME BETWEEN EXAMS WILL BE MUCH SHORTER FOR PATIENTS UNDER THAN 20 YEARS OLD.
Excimer laser operationIn rare cases, you can do what is called excimer laser surgery. In the operation, the cornea is cut into regular form, reducing the need for a continuous lens. This intervention causes distorted parts of the corneal to reshape, and CXL treatment must be done before surgery.
ICRSICRS (Intra corneal ring segments) is an procedure suitable for many. There are small arcuate plastic rings inserted into the cornea which then receives regular shapes. The purpose of this is to reduce the need for a continuous lens and improve vision. This procedure is performed at the Eye Department of the National Hospital.
Cataract surgeryOlder patients with continuous keratoconus, who need to have an cataract surgery due to clouding of the natural lens, may receive a special lens that corrects a visual disturbance that has developed in the cornea. There is no need for a continuous lens.
Corneal transplantAbout 10-20% of those with keratoconus, will undergo corneal transplant and less than half of them receive transplants on both eyes. Corneal transplant is not painful but it requires a lot of patience to wait for the vision to recover. It takes a long time to heal the cornea, and it may take up to one and a half years for the vision to return to normal. Because there are no veins in the cornea itself, it is not associated with the vascular system, and it is rather uncommon for the body to reject the corneal membrane. However, there is always a risk of rejection, and therefore those with a transplanted cornea should seek an eye doctor immediately if the eye becomes red and light-sensitive.Most people need to wear glasses or contact lenses after corneal transplantation. Sometimes there is a greater visual disturbance in the new cornea, but you can correct it with, for example excimer laser procedure.Corneal transplant can be done on the cornea that has been cross-linked.CORNEA TRANSPLANT IS DONE IF CONTACT LENS, ICRS OR EXCIMERLASER TREATMENT FAILS TO RESULT IN VISION NECESSARY TO COMPLETE DAILY TASK.
Dry eye and allergiesIt is important to treat dry eye and allergies so that contact lenses are tolerable, so that the symptoms decrease/ dissipate.
Good adviceIn Iceland there is an organization that cares for all those with illness or disability in the eye called the “Þjónustu og þekkingarmiðstöð fyrir blinda sjónskerta og daufblinda einstaklinga” (Service and Knowledge Center for the blind, visually impaired and deafblind persons). There you can get all the services that the state offers. Audio books and financial support for lens purchasing, is an example of what is available.If a person with a keratoconus is good, take care of things that make life easier and reduce fatigue in the eyes. Every little bit counts.When reading, it is important to have good light. In dim light, the pupil becomes smaller and then the aperature you see through can be greatly affected by the irregular cornea.It is good to try out different lighting. Some feel better with warm lights and others with cool. You can also get colored lights and different types of LED lights that work well.Computer work becomes easier with larger screen, 24 inches or larger and with great backlighting. It's also a good idea to have more screens in order to have more applications open at once. It is also good to try out a font, what is best for a person may be different for another.It may be a good idea to use colored glasses or filter glasses to get better use of the screen protector as well as enhance sharpness.Sometimes it is good to use glasses, both to rest on the lenses and to protect themselves from overuse. Use good sun glasses in high sun, as sunlight may be uncomfortable.It is good to try to limit the rapid change between light and darkness. In Iceland there will be a very dark winter, and darkness often difficult for those who have a keratoconus. Often turning a light on the dark can be very uncomfortable and weary to the eyes. It's good to leave lights on in the rooms you use or wait to go to the room until light is on. There are many websites about keratoconus. Some are misleading, but here are some practical pages:• https://www.aao.org/eye-health/diseases/what-is-Keratoconus • www.nkcf.org• www.midstod.isThere is also a facebook site called “Keiluglæra á Íslandi“ where people with a keratoconus can chat and share experiences.