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Keratoconus

Keratoconus (KC) is a bilateral, non-inflammatory corneal thinning occurring in only about 1 in 2000 people. Keratoconus (from Greek: kerato- horn, cornea; and konos cone) is a degenerative non-inflammatory disorder of the eye in which structural changes within the cornea cause it to thin and change to a more conical shape than its normal gradual curve. KC can cause substantial distortion of vision, with multiple images, streaking and/or sensitivity to light all often reported by the patient.

The usual symptom of KC is the perception of multiple 'ghost' images, which is known as monocular polyopia. This effect is most clearly seen with a high contrast field, such as a point of light on a dark background. Instead of seeing just one point, a person with KC sees many images of the point, spread out in a chaotic pattern. This pattern does not typically change from day to day, but over time it often takes on new forms. Patients also commonly notice streaking and “flaring” distortion around light sources. Some even notice the images moving relative to one another in time with their heartbeat. KC is the most common dystrophy of the cornea, affecting around 1 person in a 1,000. Some ethnic groups may experience a greater prevalence than others. It is typically diagnosed in the patient's adolescent years and becomes most severe in a person’s twenties and thirties.

According to a study, 13.5% of KC patients had a family history. There is a 15 to 67 times greater incidence in first-degree relatives than in the general population. There may be at least 10 different chromosomes that are associated with KC and, more likely, there are multiple genes involved that are related to final common pathway. In susceptible individuals, the mitochondrial DNA is damaged, energy production is reduced and a biochemical series of events occurs that result in an increase in free radicals, which is then toxic to cells. These corneas can’t eliminate the free radicals as efficiently as they should, therefore, it is important to minimize exposure of the cornea to environmental stressors such as UV light, eye rubbing, mechanical pressure from an improperly fit contact lens and atopy. Forceful eye rubbing appears to be a factor in the etiology and progress of KC. It’s important to control allergies with medications to minimize inflammation and resultant eye rubbing. In addition, the use of UV protection in glasses is highly recommended.

At the Eye Center, we utilize the Orbscan for detection of KC. This is a highly sophisticated state-of-the-art piece of equipment. Read about the Orbscan under our technology heading.

KC is treated most successfully utilizing rigid contact lenses. Dr Rebecca Ng has over 35 years of experience and is considered an expert in the field of fitting rigid contact lenses. Please call our office to make an appointment for your evaluation