Keratoconus can cause substantial distortion of vision, with multiple images, streaking and sensitivity to light all often reported by the patient. It is typically diagnosed in the patient's adolescent years. If afflicting both eyes, the deterioration in vision can affect the patient's ability to drive a car or read normal print.
In most cases, corrective lenses fitted by a specialist are effective enough to allow the patient to continue to drive legally and likewise function normally. Further progression of the disease may require surgery, for which several options are available, including intrastromal corneal ring segments, corneal collagen cross-linking, mini asymmetric radial keratotomy and, in 25% of cases, corneal transplantation.
Estimates of the prevalence for keratoconus range from 1 in 500 to 1 in 2000 people, but difficulties with differential diagnosis cause uncertainty as to its prevalence. It seems to occur in populations throughout the world, although it is observed more frequently in certain ethnic groups, such as South Asians. Environmental and genetic factors are considered possible causes, but the exact cause is uncertain. It has been associated with detrimental enzyme activity within the cornea.
MyoRing
MyoRing (Dioptex) is a complete continous ring for implantation into a corneal pocket for the treatment of low, moderate and high myopia and all grades of Keratoconus. MyoRing is an internationally patented device. It is approved for treatment as a medical device in the European Union since 2006 and many other countries outside EU. MyoRing insertion into the cornea (CISIS) can replace keratoplasty in most cases of keratoconus. CISIS stands for Corneal Improvement and Safe Imaging Solution. It cannot be used anymore if the corneal thickness is less than 350 microns. MyoRing treatment can be combined with corneal cross linking
Keraflex (Microwave Thermoplasty)
Keraflex (Avedro, Inc.) is a new microwave thermokeratoplasty procedure used for the treatment of keratoconus. Keraflex transforms and flatten the corneal shape by the means of microwave energy transmitted by a circular electrode, which automatically delivers the treatment to the desired specification. Microwaves cause collagen fibers to shrink, hence producing a corneal flattening. After the actual corneal flattening with microwave energy, riboflavin drops are administered over the treatment area and ultraviolet light is administered to crosslink the corneal collagen to lock-in the corneal flattening.
Radial keratotomy
Radial keratotomy is a refractive surgery procedure developed by Russian ophtalmologist Svyatoslav Fyodorov in 1974, where the surgeon makes a spoke-like pattern of incisions into the cornea to modify its shape. This early surgical option for myopia has been largely superseded by LASIK and other similar procedures. LASIK is absolutely contraindicated in keratoconus and other corneal thinning conditions as removal of corneal stromal tissue will further damage an already thin and weak cornea