By: Alina Stanciu, MD Board Certified Eye Physician & Surgeon –
Ever since November 29, 1949, when Sir Harold Ridley, M.D., F.R.S., first successfully implanted an intraocular lens in a patient during a cataract surgery in a London hospital, surgeons have researched, debated, and sometimes obsessed over the best surgical lens to use. Nearly 63 years later and after many advances in cataract surgery and the lenses themselves, the discussion continues- this time over multifocal versus monofocal IOL implants for presbyopia correction.
VISION CHANGES WITH AGE
The aging process affects the clarity and quality of vision, which may impact the ability to read or drive at night. Two primary causes of vision loss with age are presbyopia and cataracts. If you are 40 or older and have noticed it’s been getting harder and harder to read small print and you have become more dependent on bifocal or progressive eyeglasses you may have a common condition called presbyopia. Presbyopia is a condition in which the lens of the eye loses its ability to focus, making it difficult to see objects up close.
WHY DOES MY VISION SEEM CLOUDY?
The natural crystalline lens of the eye is made mostly of water and protein. As you age some of the protein will clump together, causing the eye’s natural lens to become discolored and clouded. This clouding of the natural lens is called a cataract.
The only treatment for a cataract is removal of the affected natural lens of the eye and implantation of an artificial lens, or intraocular lens (IOL). Historically, we used to delay cataract surgery due to the invasive nature and associated risks of the procedure which resulted in significant lifestyle restrictions. Today, the procedure is safer, faster and more comfortable then ever before.
Correcting Distance Vision with a Monofocal IOL
Artificial lenses (IOLs) are implanted in the eye to replace the natural lenses that have been damaged by cloudy cataracts and or presbyopia. Monofocal IOLs are still considered the standard, especially in distance vision but require reading glasses for near vision activities like reading or playing cards.
Correcting a Full Range of Vision Accommodating IOLs
There are two different premium IOL technologies approved in the United States for presbyopic correction: accommodative and multifocal. An accommodative IOL moves and changes shape using the eye’s natural focusing mechanism, instead of remaining fixed and stationary within the eye. This movement, or accommodation, allows the eye to focus on objects across a vide. Accommodating lenses are also less likely to provide glare, halos and general visual distortion. However, accommodating lenses also have several disadvantages. Although intermediate vision typically is good traditional reading distance often is not as clear as that generated by multifocal IOLs.
Multifocal IOLs
Multifocal IOL’s are designed to provide someone who has a strong desire for greater independence from glasses or contact lenses with multifunctional vision. They work on the same principle as progressive eyeglass lenses and multifocal contact lenses providing different lens powers to improve vision at all distances. Multifocal IOLs produce superior vision at traditional reading distances. This makes them the ideal choice for patients who read novels or do a lot of near detailed work. A typical patient will report surprisingly good near and distance vision at the one day postoperative follow-up.
A drawback to multifocal lenses is that they are more likely to cause minor glare and distortion. Such visual artifacts are rarely debilitating. Because multifocal IOLs have two primary focal points-far and near-a patient may experience inadequate visual quality at intermediate distances. You should know that someone with mutifocal IOLs in both eyes may need reading glasses at computer distance. Additionally, because these lenses split light between multiple focal points they are highly susceptible to visual degradation from a poor ocular surface and mild posterior capsule opacification.
Multifocal IOLs and Individual Consideration
No single presbyopic IOL technology is superior to another. Sometimes, a patient’s anatomy dictates the choice of IOL. Patient’s with a history of radial keratotomy or LASIK have less predictable outcomes as the unnatural curvature makes it more difficult to calculate the proper IOL power. Accommodating IOLs, however, work relatively well in these patients, with the understanding that results are more variable than those experienced by an unadulterated cornea.
SEE the difference Since not everyone is a candidate for a multifocal lens a thorough evaluation is required to assess if this is the right choice for you. Advanced Eye Care & Laser Center offers the newest technology available in advanced cataract surgery. Dr. Alina Stanciu board certified Ophthalmologist will discuss with you which lens will be best suited for you at an individual consultation.
To enjoy better vision in 2012 call 239.949.2020 today for a FREE Cataract Consultation