What is it?
The cornea is a transparent structure, almost spherical and regular. Through it penetrate the light rays that are captured by the retina (back of the eye). Any distortion in the cornea causes a reduction in the quality of the image that reaches the retina.
Keratoconus is a non-inflammatory corneal disease in which the low stiffness of the corneal collagen allows the central or paracentral area to assume a conical shape (from the Greek: “kerato” means cornea and “conus” a conical form). The cornea becomes progressively thinner and irregular, resulting in image distortions.
This irregularity, in most cases, causes low visual acuity not recoverable with glasses, that is, even with a good refractive examination the visual acuity is not good. Special rigid or gelatinous contact lenses (CL) often provide good vision as they simulate a new regular corneal surface. The disease’s evolution can lead the patient to be intolerant to CL and require a surgical procedure such as an intracorneal ring (Ferrara Ring). Corneal transplant is performed only in 10% of cases when the progression causes corneal scarring or when vision is not satisfactory with previous treatments.
Keratoconus usually appears in adolescence or in young adults and progresses up to 35-40 years of age. It affects around 1 in every 2000 people.
Progression is usually slow, but there may be periods of time when deterioration is rapid. It is impossible to predict what the progression rate is or whether it will actually occur in any given case. Young people with advanced diseases have a greater chance of progression, whereas after the age of 35 the disease hardly ever worsens.
At its early stages, diagnosis can be difficult, since the biomicroscopic examination (used to evaluate the cornea at a high magnification) is practically normal. Often, the ophthalmologist only diagnoses astigmatism and myopia. Astigmatism arises from the irregularity and myopia from corneal bulging. A minority of patients with keratoconus have hyperopia. In the early stages, the diagnosis is made using an exam called topography and/or corneal tomography (more details in the exams section). These are also the best exams to objectively evaluate the disease’s progression.
In over 90% of cases keratoconus affects both eyes, however, one eye is usually more affected than the other. Men and women are affected in the same proportion.
The specific causes are not yet known, but the most likely origin is genetic. Despite this, only 20% of patients with keratoconus have someone in the family with the disease. When there are no cases in the family the likelihood of children having keratoconus is less than 15%. Patients who are predisposed and have a habit of scratching their eyes will usually have an earlier and more advanced disease. The act of scratching the eyes alters the composition of the enzymes in the cornea, which further reduces their resistance.
The video shows the story of an athlete with keratoconus who was going blind. He almost had to leave the sport, but underwent an innovative treatment and was able to see again. The Santa Catarina Keratoconus Treatment Center would like to clarify some misleading information appearing in this video:
Keratoconus is not a rare disease. It affects about 1 in every 1000 people.
Keratoconus is a corneal degeneration, which, contrary to what is shown in the video, does not lead to blindness. Currently, we have several treatments available for vision improvement, even in the most advanced stages of the disease, it is possible to perform corneal transplant. Corneal transplant is intended to replace the patient’s cornea by a donated disease-free cornea, allowing for the patient’s visual recovery.
Applying Riboflavin vitamin, associated with ultraviolet light, also known as collagen cross-linking, is a treatment that has existed for around 10 years, and aims to halt progression of the disease, that is, prevents worsening of the keratoconus. Contrary to what was stated in the report, this procedure does not diminish light sensitivity (photophobia).
For more information on Cross-linking, visit: https://www.sadalla.com.br/especialidades-oftalmologia/ceratocone/
There is no lens implant on the cornea’s inner surface, as illustrated in the report. Some treatments available to improve vision of the individual with keratoconus include contact lenses (which are adapted on the eye’s outer part), intracorneal rings (known as the Ferrara ring) and, for selected cases, intraocular lens implant, also called phakic lenses. The primary purpose of these lenses is to correct high degrees of myopia, however they do not correct the irregular astigmatism caused by the disease, the leading cause of low vision in keratoconus. The Sadalla Amin Ghanem Eye Hospital has been implanting these lenses for almost 20 years. More information is available on the link in our laser center: http://www.sadallalaser.com.br
For more information about keratoconus and its treatment, visit http://www.cctc.com.br/. Consult your ophthalmologist to indicate the best treatment for your case.
CCTC Team – Santa Catarina Keratoconus Treatment Center
Sadalla Amin Ghanem Eye Hospital