What is Keratoconus

Keratoconus is a progressive bilateral thinning of the cornea. The cornea starts to progress to a cone shape over time from the original spherical shape. Early signs start occurring in adolescence, as thinning occurs then the vision starts to decrease. There is a genetic component associated with the diagnosis but it is not very well understood. Research shows that some patients have a family member with keratoconus and in some cases it is not a direct family member.

There is an association with collagen disorders such as Ehlers-Danlos or Marfans syndrome. This is likely due to the fact that keratoconus occurs with thinning of the collagen bonds in the cornea and these syndromes occur due to collagen disorders. There are cases where keratoconus is associated with allergies and asthma. This association is not as strong as collagen disorders. 

Signs 

Since keratoconus is slowly progressive, it is only noticeable once it’s more severe. At first, vision will be blurry and glasses will be needed to correct vision. With time, glasses will not be enough for good vision at which point contacts will be needed. 

Keratoconus is seen with patients with irregular corneas, high astigmatism and high prescriptions. Patients will present with thin corneas, overtime they can present with vertical lines (Vogt strie), scissoring reflex on retinoscopy and irregular mires in keratometry.  Later signs include hydrops where the thinning leads to edema which results from a tear in a layer of the cornea. 

An eye exam by a healthcare professional is highly recommended for diagnosis. 

Management

There is no cure for keratoconus, but the condition can be managed. There are different treatment options for patients with keratoconus. Mainly contact lenses are recommended as these change the optics of the cornea and optimize vision. There are different types of contact lenses that differ by materials and also how the lens interacts with the eye. Practitioners will asses the cornea and its interaction with the lens. The picture below illustrates a steep cornea with a lens  above it. In this image the cornea and the lens happen to be interacting, ideally    there is a larger space between the lens and the cornea.Scleral lenses 

Scleral lenses

 are one of the best treatment options. Scleral lenses are a type of hard lens that sits on the eye. They are a larger diameter lens that sits on the white part of the eye, these does not touch the cornea which is the most sensitive part of the eye. These lenses allow for a space between the cornea and the lens which is filled with sterile saline. This space allows for optimal vision as the new lens is changing the optics of the eye. These types of lenses are durable and help with comfort and other issues in the eye such as dry eye.

There are different options when it comes to Scleral lenses, different companies  have different materials and make lenses differently. Diameters of the lens vary, as well as how steep or flat the lenses are. Depending on each eye the fit will vary to what is optimal. 

For example, smap3D technology maps the shape of the eye with a topographer that captures all the hills and valleys of the white part of the eye. Meanwhile EyePrint uses impressions to map the shape of the eye. These two options are highly customizable options for patients that have not been successful with other Scleral lenses. 

Rigid Gas Permeable Lenses

These are another form of hard lenses, but unlike Scleral lenses these are smaller in diameter. They sit on the cornea portion of the eye and move with each eye blink. These lenses also change the optics of the eye by smoothing the surface which allows light refracting of the cornea to be regular. Although these lenses are adequate optics, with advanced keratoconus they tend to fall off.

Soft Contact Lenses

Soft contact lenses are helpful for patients with early keratoconus with more regular corneas. Soft lenses are not able to be made as specific to each person as Scleral and RGP lenses which means over time vision will not be as crisp. These types of lenses will also need changes in prescription more often than hard lenses. They also stick to the cornea more which does not give that new optical surface that hard lenses do give.

Corneal Collagen Crosslinking

This is a new form of management that has been shown to slow progression of keratoconus. This is more invasive than contact lenses, it uses UV light to strengthen the collagen cones in the cornea. There has been an overall good prognosis where the patient’s cornea has strengthened.

When managing keratoconus it is always important to know what options there are and what  the best option available is for each patient. 

I underwent LASIK refractive surgery 5 years ago. Shortly afterwards my vision became increasingly worse, much worse than it was before I had the LASIK surgery. In addition, both of my eyes are very dry and feel scratchy every time that I blink. Because of this I have to use different eye drops every waking hour and often wake up during sleep to instill eye drops and a variety of ointments. Also, I am experiencing vision disorders such as halos, starbursts, glare and double vision, especially indoors and at night. My vision at night is so bad that I have not been able to drive at night for the last 5 years. I have visited a number of eye doctors who suggested that I have an enhancement or a retreatment which means another LASIK surgery. I don’t want to do this because I am just afraid that things will get worse. I have been treated with blood serum drops, IPL, Lipiflow eyelid gland treatments, and Alphagan eye drops to make my pupils smaller. My condition is so bad that I cannot work on the computer or do prolonged close work for more than 10 minutes. My family thinks that what I have been complaining about is all in my mind. I am very depressed about this and feel that I have no options left. Can you help me?

Yes, I can help you. In my opinion, most eye doctors and patients don’t have a “handle” on this life altering LASIK induced complication as far as vision loss, eye pain and depression are concerned. All of the treatments that were given to you are temporary. Patient response from these therapies will vary from patient to patient as LASIK induced complications can affect every patient differently. Most of the patients who I have seen exhibiting symptoms such as yours have either very large pupils and/or a small or de-centered treatment zone. LASIK induced dryness is the most common LASIK induced complication. The cause of this is due to the corneal nerves that have been severed during the LASIK surgery. There is no surgical fix for what you have been experiencing.

The most effective treatment to resolve all of your LASIK induced complications is a well designed and fit scleral lens. A scleral lens will eliminate or greatly minimize your dry eye issues. This is because the scleral lens does not rest on the cornea, Instead, this lens vaults over the cornea and rests on the white portion of the eye (the sclera). The space between the back surface of the scleral lens and the front surface of the surgically altered cornea is filled with sterile saline solution. In other words, the front surface of the eye is always in a moist environment. For those patients who cannot sleep through the night due to ocular dryness, we can design the scleral lens with a very highly oxygen permeable material the will provide the cornea with adequate oxygen while the eyes are closed. In addition, the scleral lens is designed to provide the post LASIK patient with greatly improved vision while at the same time promote healing. The vision symptoms that you have been experiencing (glare, halos, double vision and starbursts) are known as higher order aberrations (HOA’s). The scleral lens will eliminate all or almost all of these HOA’s. Occasionally, a few of these vision disorders may remain. In cases like this we have the technology to measure each of these HOA’s and quantify them and have this information embedded into what is known as a “wavefront” designed scleral lens.

We have treated thousands of post-LASIK patients who have suffered significant vision loss with scleral lens technology. All are doing well. If you have any questions or concerns about what I have written and suggested to you please don’t hesitate to contact me. There is definitely hope. Do not get discouraged and do not give up.