Presbyopia is an age-related condition that causes blurred near vision. It typically starts at around age 40 and affects everyone, even those who have never had vision problems. It may be unavoidable as individuals who have had LASIK or PRK before may still be affected. The gradual loss of vision can interfere with some daily tasks such as reading and operating a smartphone or computer. Aging is truly one part of the biological puzzle that continues to evade even the brightest minds and the most cutting edge technology. The good news is that presbyopia can be easily diagnosed through a refraction assessment and note that there are a good number of treatment options available to help restore near vision.
If presbyopia is the single vision problem present, then glasses may already suffice. Reading glasses bend or refract light before it enters the eye. They can be bought without a prescription and the specific power needed should be determined by a refractive exam.
Yes, some people with other vision problems do prefer wearing contact lenses. Two types help correct presbyopia:
These lenses have several zones that are set at different powers. One is using both near and far vision at the same time resulting to the brain automatically selecting the right focus needed to see properly. Although using such lenses makes the vision less sharp as opposed to monofocal lenses.
One eye is set to close vision and the other to distance vision. Though the two eyes continue to work together as a team, distance vision typically is not as crystal-clear. Also, monovision contact lenses are a good idea to try prior to undergoing Conductive Keratoplasty to make sure that the patient will surely adapt well to the surgery.
PRK does not involve surgical flap complications (unlike LASIK) as it only consists of the mechanical removal of the corneal epithelium (surface cells), that is followed by the use of the excimer laser to remove small amounts of tissue from the front of the cornea. The lights rays are then allowed to focus properly on the back of the eye, the retina. Although the recovery from the PRK eye surgery takes a while longer than that of LASIK, as the outer layer of the cornea needs ample time to heal, it maintains good outcomes, producing improved visual acuity for both near and far in presbyopic patients.
Although LASIK cannot treat the root cause of presbyopia, there are LASIK variations that can help reduce your need for reading glasses or bifocals. With Monovision LASIK, the surgeon fully corrects the distance vision of one eye (usually the dominant eye) and intentionally makes the non-dominant eye mildly nearsighted. The dominant eye takes the lead to provide clear distance vision and the non-dominant eye is responsible for sharpening near vision. While highly efficacious, monovision LASIK involves inducing a degree of anisometropia (two eyes having unequal power). With higher degrees of anisometropia comes a loss of stereopsis (perception of depth) and contrast sensitivity. Also note that distance vision typically is not as crystal-clear after Monovision as it would be if the non-dominant eye was not nearsighted. In some cases when additional distance vision clarity is desired for specific activities (such as driving at night), special eyeglasses or contact lenses can be prescribed to correct the nearsightedness in the non-dominant eye.
PresbyLASIK is a multifocal excimer laser approach that reshapes the cornea for both near and distance vision in each eye. PresbyLASIK creates an increased depth of field as a way to improve visual acuity for both distances. It is achieved by creating a central hyper-positive area of the eye for near vision and leaving the peripheral cornea for distance vision. The treatment has been demonstrated to significantly improve both distance and near vision in presbyopes.
Also referred to as NearVision CK, Conductive Keratoplasty uses radiofrequency energy to apply heat to tiny spots around the cornea. The heat causes the edge of the cornea to shrink slightly, increasing its curve (steepness) and focusing ability. The surgery is most often performed on only one eye, making it a form of Monovision correction.
Refractive Lens Exchange
Refractive lens exchange (RLE) is a procedure that replaces the natural lens of the eye with an artificial lens. RLE treatment for presbyopia is similar to cataract surgery. An artificial intraocular lens (IOL) replacement can improve near vision and reduce a person’s dependence on reading glasses. RLE can be that of a monovision strategy with a distance-correcting lens in one eye and a near-correcting lens in the other or a multifocal strategy where the lenses provide vision correction across a range of distances.
Corneal inlays are tiny implantable lenses that are surgically placed in the cornea to improve vision affected by presbyopia. There are currently two FDA-approved corneal inlays available, each of which works in a slightly different manner. The most widely studied corneal inlay, the KAMRA inlay, was approved by the FDA in April 2015. The KAMRA corneal inlay is implanted in the non-dominant eye where its pinhole design allows it to extend the patient’s range of vision from near to far.
Acu Focus Inc. “KAMRA® Inlay Overview” Online video clip. YouTube. YouTube, Apr 17, 2015. Web. Apr 17, 2015.
The Raindrop Near Vision Inlay is a biocompatible hydrogel that is designed to closely resemble the human cornea. The Raindrop Inlay treats presbyopia in a manner similar to multifocal contact lenses by changing the curvature of the eye. Should the patient not be satisfied with the results of the corneal inlay procedure, the eye surgeon can remove the rings, leaving him free to consider other treatment options.