Astigmatism is a refractive defect that causes images to focus on the retina in a distorted way, affecting near and far vision. Astigmatism can occur by itself or in association with myopia or hyperopia, and is usually stable throughout life.
Contact lenses are an option for an increasing number of people looking for an alternative to glasses, whether for day-to-day, sports, aesthetics, or a special day. There is a wide variety of contact lenses available on the market, including disposable lenses and long-wearing lenses. Oftalconde works with the best laboratories. Our experts will identify the type and shape of the contact lens that best suits your vision and lifestyle, and teach you its correct use and hygiene behaviors.
Hyperopia, or farsightedness, is a refractive defect or error in visual focusing. Images are focused behind the retina so vision becomes blurred, especially up close.
Myopia, or nearsightedness, is a refractive defect or error in visual focusing. Images are focused in front of the retina and not on it, making long distance vision difficult. Myopia usually appears in childhood and develops approximately until the age of 20, when it tends to stabilise. If the refractive error is greater than eight dioptres, it is referred to as high myopia, which can involve serious specific visual risks and complications.
Presbyopia, also known as "old eyes", is the diminished ability to focus the eye, causing a loss of sharpness in near vision. It usually occurs from the age of 40-45.
They are completely transparent lenses with a 2 mm Diameter, which are placed in a centred position on the cornea so that its asphericity is changed. In this way a change in depth of focus can be achieved that combats the difficulty to focus in near vision, a typical symptom of presbyopia. This option is easily reversible by removing the lens and, if it is decided to be suitable, it is replaced for another lens.
Intrastromal Corneal Rings:
These rings can be used for the treatment of corneal deformation caused by keratoconus. The procedure involves inserting rings between the layers of the corneal stroma to raise the cone that these patients have developed.
Refractive Surgery with Intraocular Lenses:
Refractive surgery with intraocular lenses involves implanting phakic or pseudophakic lenses to correct refractive errors (myopia, hyperopia and astigmatism). It's indicated for those who wish to do without an optical correction.
Phakic lenses are implanted between the cornea and the crystalline lens, without removing it; thus, they tend to be indicated for young patients (40/45). One of its great advantages is that it is a reversible technique. Depending on the space that is available within the eye, they can correct some 20-21 dioptres in myopia and up to 10-12 dioptres in hyperopia. They can be placed in front of the iris (iris support lenses) or between the iris and the crystalline lens (ICL lenses).
Unlike phakic lenses, pseudophakic lenses do replace the crystalline lens, either because it has lost its accommodating function or because the crystalline lens is cloudy (cataract). All gradations (myopia or hyperopia) can be corrected with pseudophakic lenses, including astigmatism (toric lenses) or close-up view and computer (multifocal lenses).
Laser refractive surgery (LASIK E PRK):
Laser-based refractive surgery techniques (LASIK, PRK) offer the possibility of altering the thickness and/or curvature of the cornea (and, therefore, its dioptric value) to correct refractive defects: myopia, hyperopia and astigmatism. This surgery is indicated only after age 20 and when there's a stabilization of the "refractive error". Lasik surgery takes an average of 7 minutes per eye.
There are two types of refractive surgery:
LASIK: Is a laser surgery that corrects refractive errors. This correction is done through a laser that frames the anterior surface of the cornea.
Correction of Myopia: the laser removes tissue from the central area of the cornea, leveling it in this region.
Correction of Hyperopia: the laser removes tissue from the peripheral zone of the cornea increasing its curvature.
Correction of Astigmatism: the laser will reshape the irregular areas of the cornea, making it flatter and elliptical.
Insertion of phakic intraocular lenses.
Both can reduce or eliminate glasses or contact lenses dependence. For perfect vision, the lens and cornea of the eye need to refract the light rays correctly. The Lasik uses a special Laser to permanently correct the shape of the cornea, allowing a better focus. It is performed primarily in people with low myopia or Hyperopia.
It is the most precise laser that currently exists in eye surgery and represents one of the latest great technological advances in ophthalmology, thanks to its speed and safety. This laser works at a millionth of a second and reproduces the micro-incisions the surgeon has previously designed by computer, with micrometric precision, to which it is connected. It therefore does not depend so much on the ophthalmologist’s manual skills and the results are more predictable.
Another distinguishing feature of the Femtosecond Laser is its reversibility, as it splits the tissue by placing minimum doses of energy to produce a disruption between the cells. Hence, it uses infrared light to avoid cutting with burns or heat transfer to the cornea. Despite all of these advantages, it is not recommended or is not the best option for certain patients.
It is an option available to patients with low myopia and presbyopia who want to avoid having to wear glasses. It is either performed by phacoemulsification, the technique used in Cataract Surgery, or by LASIK Eye Surgery, which is also used for the treatment of refractive errors.