Intraocular Lens Options
What are IOLs?
After cataract surgery, a replacement is needed for the natural lens in order to see clearly. Measurements are done at a clinic visit beforehand to help us figure out the exact prescription for the intraocular lens (IOL). There are many IOLs that are available and they are different in their own way. Let’s take a look at a few.
Monofocal IOLs are the standard type of IOL. They help focus images onto one point of the retina. This provides a clear image at either distance, intermediate, or near. Most patients choose to have good distance vision, as seen in the simulation on the above right. Notice that distance objects like the trees and clouds look crisp, but the hand and compass at near are blurry. This is generally fixed by reading glasses and had been the norm until relatively recently. A way around this is to set the dominant eye for distance and the non-dominant eye for near. This is called monovision and is tolerated by most people, but not all. It can disrupt depth perception and may not be the best choice for a golfer, for instance.
Not all eyes are perfect. Most eyes have some irregularity so their eye is shaped less like a ball and more like an egg. When this happens, objects tend to have a shadowy image, or ghosting, to them without glasses.
This can affect the uncorrected vision after surgery, if the astigmatism is not addressed. In patients with suspected postoperative astigmatism, having the astigmatism treated at the same time as the cataract just makes sense! There are two ways to accomplish this.
a) In mild cases, ReLACS (Refractive Laser-Assisted Cataract Surgery) can make incisions in the eye to help eliminate these small refractive errors.
b) In moderate to severe cases, a Toric IOL can be placed. This kind of IOL is weighted and must be rotated in the correct direction. There is NO compromise in visual quality and most patients see better than they have ever seen after surgery. Dr. Raja prefers the Alcon Toric IOL for this purpose, though it must be noted that like a monofocal IOL, it is only set at one distance. If a patient does not have appreciable astigmatism, they do not need a Toric IOL. A monofocal IOL would be sufficient.
Different patients have different expectations for their vision after surgery. Some do not mind wearing glasses, while others would like to take advantage of the opportunity to be more spectacle-independent. This can seem unbelievable, especially after a lifetime of wearing glasses. For people who are good candidates, these lifestyle IOLs can be a revelation. It is important to note that these are not for everyone, however. After examining the patient’s pre-operative questionnaire and lens measurements, Dr. Raja will make an IOL recommendation based on the patient’s expectations. The three major classes of Lifestyle IOLs are accomodating, multifocal, and extended-depth-of-focus.
a) Accomodating IOLs
The Crystalens HD and Trulign Toric IOLs both work in a similar fashion and use the body’s natural muscles to help focus images. In general, the quality of the vision is perfect and the distance and intermediate is excellent. Reading glasses may need to be worn for the smallest print and in low-light conditions, unless a variation of monovision is done. Of note, the Trulign Toric corrects moderate to severe astigmatism and provides accomodation. It works better in younger patients.
b) Multifocal IOLS
Multifocal IOLs function in a different way. These concentric circles help focus at either distance or near. While they have better near vision than the accomodating IOLs, there may some sacrifice in the quality of the vision for the price of that convenience, especially in the early months. Patients can have some problems with glare at night that tends to improve as the brain neuroadapts to these new lenses. There may also be some trouble seeing up close in dim light. Patients tend to do their best once the IOLs have been placed in both eyes. If there are any other signs of eye diseases, patients will not be a good candidate for these IOLs. Patients who pass the screening process, however, can see quite well at distance, intermediate and near.
AcrySof® IQ ReSTOR® +2.5 D IOL with ACTIVEFOCUSTM looks similar in appearance to the multifocal IOLs but operate differently. The ACTIVEFOCUSTM optical design is engineered to take patients’ distance vision a step further while providing the balanced near and intermediate performance. It does not compromise the quality of the vision for the convenience factor, which is why it is Dr. Raja’s Lifestyle IOL of choice. There may be some mild self-resolving problems with glare, but these are usually minimal compared to previous multifocal IOLs. As Dr. Raja likes to say, this is his “20/Happy” lens. Adaptation is much easier as compared to the other Lifestyle IOLs.
The Surgeon’s Role
Besides doing the surgery itself, Dr. Raja’s role is also playing the role of patient advocate. He makes IOL recommendations based on what he feel would be safe for the patient and would make them have a happy post-operative result. Sometimes, even though the patient may want a multifocal IOL, it may not be the best for them based the findings of the eye exam. Additionally, these Toric and Lifestyle IOLs have an out-of-pocket expense that is not covered by insurance and can be admittedly costly. However, when considered an investment in one’s vision–our most important sense–this can be well worth it. To help offset the cost, we do offer financing.