Keratoconus

Keratoconus is an idiopathic disease that affects the cornea causing it to lose its natural spherical shape and take a conical shape, which distorts the refraction of light rays coming into the eye onto the retina causing numerous visual  problems.

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What is keratoconus?

The cornea of the eye is the transparent outer surface of the eye, it is smooth and spherical with a certain degree of curvature. Sometimes the degree of corneal curvature increases more than normal, it  transforms from its natural shape that resembles a dome, to a more pointed conical, cup or funnel – shaped structure, and continues to bulge out at the apex of this cone.  its thickness decreases relatively with increased convexity. This condition occurs gradually, i.e. the cornea of the eye does not change its shape all at  once from the dome to the cone, but this transformation occurs very slowly over years. Did you know that this condition, keratoconus, is most likely to be hereditary.

 

What effect does that have on vision?

Due to this change that affects the surface of the cornea, the functions of the cornea are negatively affected.  The smooth curvature of the cornea which is essential for the proper refraction of light rays and their collection onto the retina is no longer present therefore not carried out with the same efficiency, hence  the clarity of vision and images seen is markedly affected.  The conical shape affects corneal measurements, creating irregularities on the corneal surface leading to a condition known as irregular astigmatism, which essentially means that light rays entering the eye are not focused on one retinal point but at numerous points , leading to progressive blurring of vision, frequent change of glasses up to failure of glasses to correct the blurring.

What is the cause of keratoconus?

There are many causes due to the occurrence of keratoconus, the most important of which is the hereditary or genetic cause as previously   mentioned.  The cone shaped protrusion occurs as a result of the progressively increasing weakness in the cohesion of the corneal collagen fibers, resulting in decreased thickness of the cornea and tendency to bulge out in a conical shape.

When does the keratoconus begin?

Most cases start developing  around the age of puberty. But this  varies from case to case, and routine follow up and  monitoring are crucial once  symptoms begin to appear.

 

Is keratoconus a genetic disease?

It is not possible to predict the existence of a specific cause of the occurrence of keratoconus, and therefore it cannot be said that keratoconus is a genetic disease, but it can be said that there are some factors that raise the risk of developing keratoconus, and the genetic factor is one of the most important of these factors of course, but it is not the  direct or single cause. Keratoconus can also occur as a symptom for other systemic diseases, such as spring catarrhal, where constant eye itching and rubbing affects the strength of the corneal tissue leading to keratoconus.  

 

How is keratoconus  diagnosed?

To be clinically seen the case must be advanced , but this is rarely seen nowadays due to advances in diagnostic imaging and advanced examination dedicated to detect this condition at an early stage. Corneal topography, Schiemflug camera imaging, as well as the appearance of some visual symptoms in the patient may help to diagnose and detect the disease.

 

What are treatment options available for keratoconus?

Keratoconus occurs gradually as previously mentioned, and therefore has multiple stages. each stage has a treatment method that best suits it. Initially,  in the early stages glasses can be tried and sometimes  hard contact lenses. More moderate and severe cases are treated by methods to delay the corneal  thinning or to support or correct the corneal bulge
the treatment of keratoconus with intracorneal  rings, in more advanced cases the  treatment option is with penetrating (full thickness) or lamellar (partial thickness) keratoplasty or corneal transplant .

Many treatment methods for keratoconus include:

Glasses

In the early stages of the keratoconus, eyeglasses may avoid other processes or procedures in correcting some visual problems such as myopia, but glasses do not stop conical deviation and do not prevent it from increasing, and are therefore a temporary solution. In addition, when the irregular astigmatism increases, glasses will fail to correct it

 

Hard eye lenses

hard contact lenses are placed on the corneal surface  similar to normal contact lenses.  regular lenses are flexible and soft, while lenses used in the treatment of keratoconus are solid, to strengthen the surface of the cornea and tighten it and return it to the natural curvature.

 

Cross Linking corneal installation

The process of stabilizing the cornea is the first way to treat the disease and stop the progressive thinning of the cornea, and this process is done by instilling vitamin  
B2 eye drops on the cornea for 30 mins. This is followed by a strong dose of UV radiation on it, resulting in the triple interaction between the corneal collagen and vitamin and UV increasing the stability of the cornea and prevent further conical deviation.

Intacs Ring 

Another method used in the treatment of keratoconus is the implantation of PMMA rings or ring segments, where they act as stents, and  are installed to adjust and stabilize the degree of corneal curvature.

Cornea Transplant

In late cases that cannot be treated with hard lenses or through stabilization processes or rings , corneal transplantation is used in Egypt, and
corneal transplantation in Egypt is one of the most successful recent operations. The chances of success are high, but in any case corneal transplantation is only a last resort in cases that cannot be treated in other ways, and with the possibility of early detection and speed of treatment, the risk of deterioration of the condition and the need for treatment with corneal transplantation is reduced in part or in whole.

Is it possible to correct the vision in a keratoconus patient?

Errors pf refraction resulting from keratoconus can be corrected either by using hard lenses, through lens implantation or otherwise, but more important than always correcting sight is to stop deterioration and prevent increased conical deviation by strengthening the cornea and increasing stability either through uv stabilization or through loop implantation.

Is lasik possible in the keratoconus?

Excess corneal curvature is usually accompanied by a decreased thickness, this thinning does not allow lasik operations on the cornea in the vast majority of keratoconus cases, and lens implantation is used to correct visual distortionin these cases as a lasik alternative.

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Best Doctor for Keronic Keratoconus Treatment

Dr. Ashraf Hassan Soliman, is a consultant of corneal, cataract and glaucoma surgery and laser and refractive  vision correction. He  is  also professor of ophthalmology at The Faculty of Medicine of Ain Shams University, comes at the head of the best ophthalmologists in Egypt and the Arab world to perform keratoconus implants in his field of specialization.