Premium Intraocular Lens
What is a cataract and how is it treated?
A cataract is a condition that causes clouding of the natural lens of the eye, resulting in blurring or glaring of vision. Surgery is the only treatment for cataracts and is recommended based on the severity of the disease and the impact on the daily activities of the patient. During the surgery the cloudy lens is removed and replaced with a clear plastic lens in the same lens capsule as the natural lens.
What are premium intraocular lens implants?
Earlier, monofocal lenses were used in cataract surgery where patient was able to see the far distance objects with the new artificial lens implanted during surgery and they required additional glasses or lens to enable them see the near distance objects or for reading. A premium intraocular lens (IOL) is a new type of IOL used in cataract patients that enables the patients to view both far distance and near distance objects without using glasses.
What are the types of premium IOLs?
The most common types of premium IOLs are:
Multifocal lenses: A multifocal lens provides excellent vision after cataract surgery at various distances. Multifocal lenses work much like bifocal eyeglasses that have multiple focal zones, enabling the patient to see distance as well as near vision. In certain cases, these lenses are different in each eye to enable better vision at intermediate distances.
Toric lens: Toric intraocular lenses are a type of premium lens that can be used to treat astigmatism (blurred vision).
Why are multifocal and toric lens recommended?
Multifocal IOL lens are recommended after a thorough preoperative diagnostic evaluation. You will be questioned on your visual expectations and lifestyle - both work and leisure activities – and the importance given to both and amount of time spent on each. Key considerations for patient selection for multifocal IOLs include:
- Keen on being spectacle-independent
- Willing to accept a small sacrifice in distance acuity
- Near tasks primarily involve reading
- Not heavily dependent on working on the computer
- Moderate to high hyperopia or moderate to high myopia
- Has realistic expectations
Multifocal IOL may be contraindicated in the following:
- Insists on the clearest, sharpest vision (monofocals are recommended)
- Dependent on night vision and intermediate vision
- Low myopes
- Drivers of public service vehicles, commercial pilots and truck drivers
Toric IOL will be recommended in the following cases:
- Keen on being spectacle-independent with improved distance vision
- Astigmatism greater than or equal to 0.75 D
- No pre-existing ocular problems
- Not undergone any previous refractive surgery
- Intact capsular bag
What are the disadvantages of multifocal and toric lens?
As with any surgical procedure, certain complications may occur. These are generally rare and may include damage to the retina, blurred vision, halo or glare, and the development of cataract or glaucoma.
You should be aware that your vision can fluctuate for some time soon after the insertion of the multifocal IOL and the lens do not allow perfect vision in all distances under all illuminations of light. You may also experience loss of contrast and night glare.
Vision degradation may occur with multifocal lens in cases of residual refractive error, basement membrane dystrophy, decentration, blepharitis, posterior capsular opacification, IOL tilt, corneal scarring and oedema, macular oedema, surface dryness or astigmatism greater than 0.5 D.