An intraocular lens is placed in the eye after the natural lens has become opaque due to cataract removal, aiming to restore vision to its best state. With technological advancements in cataract surgery, the types of intraocular lenses, known as IOLs, have experienced significant transformation. The initial IOL implanted in a human eye by Sir Harold Ridley in 1949 was constructed from acrylic material known as Perspex.
Intraocular lenses received approval as “safe and effective” in the United States by the Food and Drug Administration (USFDA) in 1981. Since that time, the variety of lenses available for implantation has undergone a remarkable transformation in the treatment of cataracts.
Types of Intraocular Lenses (IOLs)
The two most common types of lenses are:
- Anterior Chamber Lenses (ACIOL):
These lenses are positioned over the iris, which is the brown section of the eye. This placement does not reflect the natural physiological position of the eye’s lens, and this specific type of lens is not the recommended intraocular lens (IOL) following uncomplicated cataract surgery. Anterior chamber intraocular lenses (ACIOLs) are utilized when the posterior capsule of the lens is either deficient or compromised.
- Posterior Chamber Lenses (PCIOL):
These lenses are positioned over the remaining posterior capsule in the natural location of the eye’s lens and are considered the preferred option.
The remainder of this article will explore the primary categories of advanced PCIOLs that can be implanted following contemporary cataract surgery techniques, specifically phacoemulsification, Microincision cataract surgery, or Femtosecond laser cataract surgery. These lenses are collectively referred to as Premium IOLs.
Types of Premium IOLs
Premium IOLs are of three broad categories:
1. Monofocal Lenses
Monofocal lenses, in contrast to the eye’s natural lens, are designed to restore vision at only one distance, either for far or near sight. The strength of monofocal lenses is typically determined to ensure that the patient does not require glasses for distance vision. Following the implantation of a monofocal lens, you will likely need reading glasses or possibly bifocals, which accommodate both distance and near vision, based on your prior refractive error, particularly if you have astigmatism.
Below are the various types of monofocal lenses:
- Aurium (Monofocal): Aurium monofocal lenses are produced by Medennium (USA). These lenses possess photochromatic properties, meaning they acquire a slight tint in daylight or bright conditions, thereby shielding against harmful UV rays. In typical indoor lighting, these lenses appear clear.
- Acrysof IQ (Monofocal):
Acrysof IQ is a monofocal lens imported from Alcon (USA). These lenses offer outstanding distance vision. However, for near vision, individuals may need to use additional reading glasses. This lens incorporates a yellow pigment chromatophore that prevents harmful UV rays and blue light from penetrating the eye and causing damage to the retina.
- Aurovue(Monofocal):
An Indian firm, Aurolab, produces Aurovue lenses. These lenses are regarded as basic options for cataract surgery and are suggested for individuals with limited financial resources.
- Akreos AO(Monofocal):
Akreos AO lenses are comparable to Aurovue lenses. Nevertheless, these lenses are imported and produced by Bausch & Lomb (USA).
- Acrysof SP(Monofocal): .
Acrysof SP is a monofocal lens imported from Alcon (USA). These lenses are particularly favored among diabetic patients. Additionally, it is a suggested choice for individuals selecting a monofocal lens during standard phacoemulsification surgery.
2. Multifocal Lenses
Multifocal IOLs are lenses that provide a satisfactory restoration of vision for both near and far distances. When selecting an IOL, it is crucial to keep in mind that multifocal lenses grant you the convenience of not needing glasses for both near and distant vision, and they can be tailored to suit your active lifestyle.
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Nevertheless, your physician will address the noticeable disadvantages of these lenses, specifically glare and a reduction in contrast sensitivity. If you prefer not to use glasses for either near or distant vision and wish to avoid the additional cost of a multifocal intraocular lens (IOL), your physician will talk to you about the option of monovision.
Following are the best multifocal lenses:
- Tecnis Symphony (Multifocal):
Tecnis Symphony is a multifocal lens produced by Abbott (USA). This lens offers outstanding distance and intermediate vision, particularly for computer use.
- Zeiss Trifocal (Multifocal):
Zeiss trifocal lenses are a type of multifocal lens produced by Zeiss (USA). They are the sole lenses that offer outstanding vision for near, intermediate, and distant viewing.
- iDiff (Multifocal): i
iDiff lenses are multifocal lenses produced by Care Group. These lenses offer clear vision for both near and far distances, allowing individuals to perform everyday tasks with distance vision and also engage in near activities like reading and writing comfortably without the need for additional glasses. However, it is important to note that iDiff lenses do not correct intermediate vision.
- Tridiff (Multifocal):
Tridiff lenses are multifocal lenses produced by Care Group. These lenses offer excellent vision for near, intermediate, and distance viewing, allowing individuals to perform everyday tasks with ease. They facilitate distance vision, enable intermediate tasks like working on a laptop, and support near activities such as reading and writing comfortably, all without the need for additional assistance.
- Alcon Pantopix (Multifocal): This represents the most significant advancement in multi-focal lenses. The lens is designed to deliver outstanding vision for distant, immediate, and near objects.
3. Toric Lenses
It represents the most significant introduction of excellent vision for distance, immediate, and near sight. An eye possesses two types of power: spherical power, which arises from the natural lens within the eye, and cylinder power, which results from the asymmetry in the curvature of the cornea. Monofocal and Multifocal Lenses are designed to correct only the spherical component of the eye, leaving the cylinder power unaddressed, which must subsequently be corrected with additional prescription glasses. Toric Lenses, on the other hand, can rectify both the spherical and cylinder components of the eye. These lenses are particularly recommended for individuals with a high pre-existing cylinder or astigmatism.
Below are the recommended Toric lenses:
- Acrysof IQ (Toric):
These lenses are specifically engineered to address astigmatism during cataract surgery. This particular lens is produced by Alcon (USA).
- Acrysof Toric (Toric):
These lenses possess all the characteristics of Acrysof IQ, in addition to providing cylinder correction.
- Zeiss (Toric): The lens is produced by the German firm Carl Zeiss and is regarded as a standard for exceptional cylinder correction.
Which is the best lens for your eyes?
In the field of medicine, much like in life, there is no definitive best answer. Your physician will engage in a discussion with you regarding the possible advantages of each of these lenses, assisting you in choosing the one that is most appropriate for your lifestyle and visual requirements, in addition to your expectations from the cataract surgery.
Lifestyle and priorities:
If you lead a highly active lifestyle that requires significant focus outdoors, such as in golf, you may find that your near vision is compromised while your distance vision remains unaffected. For frequent travelers, the desire to avoid reliance on glasses altogether may take precedence over achieving precision in both near and distance vision. Conversely, if you have a passion for sewing or embroidery, you will prioritize having excellent near vision.
Pre-existing diseases:
In instances of specific eye conditions such as advanced glaucoma, corneal disorders, or age-related macular degeneration, you might not qualify as an ideal candidate for certain lenses, including the multifocal lens. Your eye care professional will conduct a thorough eye examination and review the findings and their significance with you, assisting you in selecting the most suitable lens for your vision needs.
Costs:
These lenses incur a higher cost compared to conventional intraocular lenses (IOLs), contributing additional expenses to cataract surgery.
Generally, premium lenses are set at a price point that is typically not covered by insurance providers.
Dr. Shashi Kapoor at Kapoor Eye Centre possess extensive knowledge in the application of Premium IOLs after cataract surgery and have successfully implanted thousands of these lenses. Your ophthalmologist will gladly review all available options with you and assist in selecting the most suitable lens for your ocular health and visual requirements.
