Intraocular Lens Implant
Once upon a time, those with cataracts had their cloudy lenses removed only to be replaced with very thick and heavy glasses or contact lenses that not everyone could wear. Nowadays, people get new lenses, called intraocular lenses (IOLs), to replace their old ones. The lenses we’re born with, although literally ‘intra-ocular’ (within the eye), are called the ‘crystalline lenses’ because they are full of proteins called crystalins. ‘Intraocular’ refers to the replacement lenses not being in a heavy frame sitting atop one’s nose.
Synthetic replacement lenses were developed in the 1960’s and won approval from the Food and Drug Administration (FDA) in 1981. They are sterile and stable, never deteriorating in the course of a person’s lifespan. The main drawback of basic IOLs is their fixed shape, preset to focus near, far or in-between, depending on what a person needs most. The other distance(s) needed are still accommodated by a pair of glasses or contact lenses, but at least of normal thickness and appearance, not “Coke bottles.” These were the original type of IOLs and are still used today.
These mono-focal lenses are also made to correct for any simple vision problems a person had in addition to their cataracts, such as being near- or far-sighted. For people who want both near and far vision capabilities, an IOL of each type is put into each eye, and the patient learns how to see in mono-vision. That is, the ever-amazing brain learns to use one eye over the other, switching back and forth as needed.
Recently, newer version IOLs have been developed. Called ‘premium IOLs’, these are more adaptable and may allow some patients to not even need glasses – even if they did before. Newer optical materials can be made in such a way that different portions of the individual lenses focus at different distances. Since this isn’t the way our natural lenses work, the brain still goes through a learning phase as we “getting used to” them. There are now even IOLs correcting for astigmatism, something not possible until relatively recently.
As one might expect, these premium IOLs will almost always cost more. Though offering obvious advantages to users, most insurance companies do not consider premium IOLs “essential.” They typically cover only the cost of the cataract removal and implantation of standard IOLs, with the patient making up the difference. Those with insurance options and early stage cataracts, or at risk of developing them (e.g., by having diabetes), should find out what is covered in various medical and vision insurance plans.
Whether basic or premium, IOLs have certain things in common including basic shape. It can surprise a person to see that this isn’t just a little curved circle, like a contact lens, but has two little arms, called haptics, curving out from the lens. A contact lens is only curved in one direction, making a concave shape; it thus sits stably over the eye, a convex and complimentary shape. An IOL is not concave, but will vary depending on a person’s sight, so it needs a bit of stabilization.
Also, modern IOLs of either type are so thin and flexible they can be folded over by the eye surgeon to be inserted through a small opening cut in the side of an eye. Lastly, whether receiving standard or premium intraocular lenses, today’s patients are benefitting from the latest technologies and doctors’ decades of experience in cataract removal and IOL implants.