Presbyopia is the loss of ability to see near without bifocals or reading glasses. Presbyopia typically becomes evident in our 40’s. Presbyopia can be managed with reading glasses after cataract surgery. However, you can also consider two other methods. These are:
1. Monovision (monovision, mini-monovision, and micro-monovision).
2. Specialty lenses: Extended Depth of Focus Lens, Multifocal Lens, and Accomodative Lens
Monovision strategies, including micro monovision, mini monovision, and full monovision, are highly customizable. Read up on monovision strategies so that you understand that you have alternatives to the presbyopia correcting lenses.
Multifocal and Extended Depth of Focus lenses (MF/EDOF)
The Multifocal (MF) lens treats presbyopia by focusing some light at near and some at distance. The Extended Depth of Focus (EDOF) lens provides an increased depth of field. These lenses are discussed together because they appeal to similar patients and have similar side effect profiles. The term MF/EDOF will be used as a shorthand when discussing these lenses.
The MF/EDOF lenses have a more complex refractive structure than standard intraocular lenses. For the multifocals, this will typically provide two different focal distances. For the EDOF lenses, there is a single focal distance, but the range of clear vision (depth of field) is greater than for single focus lenses. The most common MF/EDOF lenses on the US market are the Johnson and Johnson Symfony extended depth of focus lens, the Alcon ReSTOR multifocal lens, and the the Johnson and Johnson Tecnis multifocal lens. These are not the only high quality presbyopia correcting lenses on the market in the United States, they are simply the most widely used. There are more options available outside the United States. Presbyopia correcting lenses have undergone rapid development in the last decade.
The accommodative lens uses forward and backward movement of the lens inside the eye to shift focus. The Crystalens by Bausch and Lomb is FDA approved in the United States.
Presbyopia correcting lenses achieve important goals- but they are not perfect. Side effects can occur with presbyopia correcting lenses. The most important are reduced contrast, glare, and halos. These side effects occur to some degree in all patients who get MF/EDOF lenses, but can be more pronounced in some patients than others.
Are You a Good Candidate for Presbyopia Correcting Lenses? The 4 P's
Some patients are very happy with presbyopia correcting lenses. But not everybody is a good candidate. Your happiness with presbyopia correcting lenses can be affected by your Personality, Physique, Pathology, and Predispositions. Let’s look at each of these in detail:
Good: relaxed, flexible, outgoing, positive, easy-going.
Bad: high strung, picky, particular, rigid, inflexible, easily upset.
The longer your arms are, the better. It is not essential to have longer arms, but it is an advantage. The lenses with the least side effects have a "near add" (near focus) that is a little further away than typical reading distance.
The best candidates for presbyopia correcting lenses have healthy eyes and no history of previous corneal disease, injury, or corneal refractive surgery (LASIK, PRK, RK). They have no problems with the retina (such as macular degeneration and diabetic retinopathy), and do not anticipate developing these issues. They also have no problems with the optic nerve other than early and controlled glaucoma without visual field defects. They have no significant dry eye.
How you like to spend your time is important. Patients who are most likely to be happy with presbyopia correcting lenses prioritize things like sports, hiking, and seeing objects at a distance. Presbyopia correcting lenses are less ideal for patients who spend all day on the computer or reading. If your calling in life is making jewelry, drawing, or carving, then the presbyopia correcting lenses may not be for you.
Consider how important it is for you to be free of glasses for most tasks. If it is important, a few side effects may be a reasonable tradeoff for you. On the other hand, if wearing bifocals is fine with you, you may be happier sticking with glasses.
If the 4P’s line up for you, then your chances of being happy with presbyopia correction during cataract surgery are relatively high. If they don’t, and you still want presbyopia correction, be sure to discuss your options with your surgeon and openly address potential topics of concern prior to making a final decision.