Various surgical solutions for presbyopia
Presbyopia is an unavoidable vision problem that bothers people above 40. Some eye doctors think that presbyopia is caused by the stiffening of the lens, while others suspect lens’ continued growth or related muscle atrophy.
Treatments of presbyopia are most associated with eyeglasses or contact lenses such as bifocal and trifocal eyeglasses, reading glasses as well as various multifocal contact lenses. In modern times, certain surgeries are also available for some presbyopic patients. FDA has yet approved the application of monovision LASIK and CK for presbyopia surgical treatment, while some other devices and procedures are still under trials.
Normal binocular vision means both of people’s two eyes perform equally during vision activities. But in fact, most people have a dominant eye that burdens more responsibility in seeing. Based on this fact, special monovision LASIK corrects the dominant eye for distance vision and the non-dominant eye for near vision. The distance eye will do most distance work and the near eye will manage most near tasks. Not everyone can adjust to monovision effect created by monovision LASIK, so that a prior test using monovision contact lenses is necessary. Good candidates for monovision LASIK can receive satisfying vision recovery.
The FDA approved conductive keratoplasty (CK) as a surgery for temporary hyperopia reduction in 2002. CK steepens central cornea by shrinking peripheral corneal fibers using low-level radio-frequency energy. A CK procedure makes only a minimal incision and may bring temporary tearing, foreign-body sensation and vision fluctuation. What’s important is that CK is actually another monovision technology. During the surgery, one eye is made nearsighted and the other eye remains untouched. Monovision CK also requires a prior adaption test.
Artificial lenses or refractive lens exchange is available off label for qualified presbyopic candidates. The procedure removes the eye’s natural lens and inserts an artificial lens. These artificial lenses include multifocal and accommodative lenses. Another investigational procedure for presbyopia correction is multifocal or PresbyLASIK, which creates zones of different vision on the eye’s cornea. Corneal inlays and onlays are devices that can be inserted below the eye’s cornea to provide vision correction. The ACI 7000, InVue intracorneal microlens and the PresbyLens are some of the devices that are still under studies.
Possible presbyopia surgical solutions also include various combinations of these above surgeries. For instance, cataract surgery and refractive lens exchange can be accompanied by single vision intraocular lens (IOL) implantation in one eye and multifocal IOL in the other eye. In this way, versions of modified monovision can be applied. PresbyLASIK may also be coupled with one modified monovision that creates distance correction in the dominant eye and multifocal correction in the other eye.