Intraocular Lenses (IOLs)
Northeastern Eye Institute Serves Clients in Scranton, Wilkes-Barre, Hazelton, and Surrounding Areas in Lackawanna, Luzerne and Other Counties
An intraocular lens is used to replace the eye's natural lens. As we age, the lens becomes gradually less able to provide clear close-up vision - a condition called presbyopia. The causes of presbyopia are not fully clear and new treatments are being tested by the FDA, but an IOL is one way of correcting it.
IOLs are also used to treat cataracts, another age-related problem with the natural lens. After we reach mid-life, the lens may start to develop little opacities that block light from entering the eye. Cataracts are progressive and will lead to blindness if nothing is done. Since there is no way these can be removed from the lens, the lens is replaced with an IOL to restore full vision.
The Eye's Ability to Accommodate
When you look from a far object to one close by, the eyes automatically accommodate to that distance change so that all objects will be in focus. The lens is the structure that accomplishes this – it changes its curvature continually, between a steeper curvature for near vision and a flatter one for far vision. There are two tiny muscles, called ciliary muscles, which tighten and relax to change the lens’ curvature.
When the natural lens becomes clouded with cataracts and is removed, the eyes lose that accommodative ability. Modern IOLs are designed to replace it. At Northeastern Eye Institute, we offer four IOLs that use four different technologies.
Crystalens® IOL
The Crystalens is the only accommodating IOL. In other words, when it is placed in the eye, it is connected to the same little muscles that previously controlled the natural lens’ shape. The Crystalens does not change its shape but the muscles push it forward a little to simulate the natural lens becoming steeper in its curvature for near vision. For far vision, the muscles pull it back a little, simulating a flatter lens curvature for distance vision.
Just as we don’t feel that happening to the natural lens, so a person does not feel the Crystalens moving forward or back. Crystalens is a good IOL choice if you have strong ciliary muscles that can attach well to the Crystalens’ hinges and move it appropriately.
ReSTOR® IOL
The ReSTOR IOL is not moved by the ciliary muscles. Instead, it has inbuilt concentric steps, creating circular areas that react to light differently. The center step is highest and contributes most to near vision; and as the steps move towards the periphery they become lower and provide distance vision. The ReSTOR IOL is made of a proprietary material called AcrySof.
Tecnis™ IOL
The Tecnis lens also has concentric areas that interact with light differently. However, its design is based on Wavefront data – the same type of data that our eye doctors gather from each patient in the diagnostic process before Custom Vision Correction (Custom LASIK).
Wavefront diagnosis is more detailed than the diagnosis done for glasses or contact lenses, or for LASIK in the early days (Traditional LASIK). It includes information, not included in traditional LASIK diagnosis, about microscopic irregularities on the corneal surface. The vision defects caused by those irregularities are called Higher Order Aberrations (HOAs), as opposed to the three Lower Order Aberrations of myopia, hyperopia, and astigmatism.
There are dozens of HOAs such as halos and starburst shapes around lights, and ghosting – faint duplicate images in dim light. HOAs mostly relate to dim light vision. The Tecnis Wavefront design provides better night vision than some other IOLs and Tecnis is a good IOL choice if you do a lot of night driving.
Toric IOLs
If you have a significant degree of astigmatism, a toric IOL would be a good choice. Astigmatism (blurriness at all distances) occurs when the cornea has an oval shape instead of a spherical shape. An oval has two curvatures: a steeper one on the shorter side and a flatter one on the longer side. If you picture a football or the back of a spoon, you will get the idea.
Toric IOLs are designed to compensate for this oval shape at the same time as they restore near and far distance vision.
These IOLs are known as “Premium Lenses” because of this double correction.
If you would like to know more about Premium Lens implants and which one might be best for you, a consultation with one of our eye surgeons would be the next step. Please call or email Northeastern Eye Institute today and we will be happy to schedule your consultation. Our phone no. is 1-800-334-2233.
