What is Cataract?
Cataracts, the clouding of the eye's natural lens, can significantly impact one's vision. The lens, located behind the pupil, plays a vital role in focusing light on the retina to enable clear vision. When cataracts form and the lens becomes opaque, it impairs this function. In this article, we will explore the symptoms, causes, and treatments for cataracts, with a particular focus on the revolutionary advancements in cataract surgery using femtosecond lasers and intraocular lenses.
Symptoms of Cataract
Cataracts can manifest through various symptoms, including:
● Blurred vision
● Double vision
● Difficulty seeing at night
● Photophobia (light sensitivity)
● Perception of dull or yellowish colors
● Need for increased light while reading
● Halos in night-time vision
● Improved near vision without apparent cause
● Frequent changes in prescription glasses or contact lenses
Causes of Cataract
Cataracts are most commonly associated with aging and typically appear after the age of 60. Other contributing factors include:
● Genetic predisposition
● Ocular or systemic diseases, such as diabetes
● Eye trauma
● Prolonged exposure to UV radiation without UV-protective eyewear
● Use of certain medications, such as steroids
● Congenital conditions, where cataracts are present from birth
Treatment for Cataract
While cataracts may be initially managed with prescription glasses or contact lenses, the definitive treatment for cataracts is surgical. Cataract surgery involves removing the opaque lens and replacing it with an artificial intraocular lens (IOL) of the latest technology. Different types of IOLs offer varying focal capabilities for distance, intermediate, and near vision.
Intraocular Lenses
Traditional IOLs can introduce minor optical imperfections known as higher-order aberrations, which may affect vision quality, especially in low-light conditions. Aspheric intraocular lenses closely mimic the natural eye lens's shape and optical quality, potentially providing sharper vision. They come in various types:
● Aspheric monofocal lenses: for correction of cataracts, myopia, and hyperopia, offering a single focal point for distance vision. Patients may require glasses for intermediate and near vision post-surgery.
● Toric aspheric lenses: for correction of cataracts, astigmatism, myopia and hyperopia. They provide good distance vision but patients may require glasses for intermediate and near vision.
● Aspheric trifocal intraocular lenses: for correction of cataracts and presbyopia, enabling patients to see clearly at varying distances without or with minimal dependence on glasses post-surgery.
● Extended Depth of Focus (EDOF) aspheric intraocular lenses: offering good distance and intermediate vision, and functional near vision for moderate-sized objects, with the potential need for glasses for small objects and reading small text.
Before cataract surgery, patients undergo several diagnostic tests to determine the appropriate IOL power and type of lens based on their unique eye characteristics. Not all patients are candidates for every type of IOL.
Femtosecond Laser Technology
The most advanced technique used in cataract surgery is the femtosecond laser (a femtosecond is one billionth of a second [10-15]), which allows the procedure to be personalized to each patient's eye. Even though all human eyes share the same anatomical structure, each eye varies in its size, distribution of spaces between its internal structures, curvature of the cornea and other key characteristics, so each eye must be carefully measured and mapped. The use of laser produces less inflammation in the intraocular tissues, so visual recovery is faster. In addition, it achieves greater visual quality with advanced technology lenses because it allows the intraocular lens to be implanted and located within the eye in a more centered and stable way.
The femtosecond laser allows for a higher level of predictability and precision that usually cannot be achieved with traditional phacoemulsification surgery. Its application is painless and extremely fast.
Nowadays after cataract surgery many people will have no need for contacts or glasses, depending on the IOL they choose. However, in some patients there may be ocular reasons that make the use glasses necessary for very specific activities and, in very few cases, to wear them all the time after surgery.
Although they cannot be prevented, cataracts can be detected during a routine eye exam. This is why it is advisable to visit your ophthalmologist periodically.
