Aphakic

Definition

An Aphakic lens is an artificial lens that has been implanted into the eye to correct nearsightedness (Myopia) without the presence of a natural lens, such as the ones present in human eyes. Unlike Contact Lenses or intraocular lenses (IOLs), which are designed for vision correction after Cataract surgery or eye injuries, Aphakic lenses are inserted into the eye permanently.

History

The concept of using artificial lenses to correct Myopia dates back to the early 20th century. In 1917, Dr. Charles Magonell developed a lens that could be used in place of an eye’s natural lens to correct nearsightedness. However, this was not widely adopted due to the high cost and limited availability of such lenses. The first commercially available Aphakic lenses were introduced in the 1960s.

Anatomy

Aphakic lenses are designed to replace the natural eye’s lens, which is typically shaped like a dome or an ellipsoid. In the case of aphakia, the natural lens has been removed or replaced with an artificial one. The remaining cornea and pupil provide some refractive power for nearsighted individuals.

Types

There are two main types of Aphakic lenses:

  • Toric lenses: These lenses have a different curvature in the periphery compared to the center, which allows for more precise correction of Astigmatism (a type of irregular refraction) and Myopia.
  • Multifocal lenses: These lenses have different powers in each section to allow for clear vision at various distances.

Applications

Aphakic lenses are used to correct nearsightedness (Myopia), farsightedness (hyperopia), and Astigmatism. They can also be used to correct Presbyopia, a age-related loss of accommodation that affects the eye’s ability to focus on close objects.

Contact Lenses

Contact Lenses with built-in Aphakic lenses are available for nearsighted individuals who want to correct their vision without surgery or other invasive procedures. These lenses come in different powers and are designed to fit comfortably on the wearer’s eye.

Surgical Procedures

Aphakic surgery is performed under local anesthesia and typically involves the following steps:

  1. Removal of the natural lens: The surgeon will remove the removed or replaced natural lens.
  2. Implantation of an Aphakic lens: A new artificial lens is implanted in its place, providing corrected vision.

Complications

While Aphakic surgery is generally safe and effective, some potential complications can arise:

  • Dry eye syndrome: Aphakic lenses can cause dry eyes due to the presence of a foreign body in the eye.
  • Infection: As with any surgical procedure, there is a risk of infection with Aphakic surgery.

Conclusion

Aphakic lenses offer an alternative solution for individuals who want to correct their vision without undergoing Cataract surgery or other invasive procedures. While they may have some limitations and potential complications, Aphakic lenses can provide excellent vision correction for nearsighted individuals.

References

  • National Eye Institute (NEI). (2020). Aphakia.
  • American Academy of Ophthalmology. (2020). Cataract Surgery.
  • Dry Eye Foundation. (n.d.). Aphakic Contact Lenses.