Trifocal (Smart), EDOF and Toric (Astigmatism Correcting) Intraocular Lenses
" The most up-to-date method to get rid of far, near and astigmatism glasses "
Trifocal and Toric Intraocular Lenses
Today, after cataract surgery, these type of intraocular lenses (IOLs), which provide far and near vision without glasses, have started to be used more frequently.
In order for us to see the world around us clearly, light must pass through the cornea, pupil, and lens of the eye and fall flawlessly on the retina. If we think of the eye as a camera, the lens and the cornea together form the lens of the camera, and the retina does the work of the film inside the camera. 70% of the focusing power generated by the lens and cornea consists of the cornea and 30% of the lens. Any problems or shape changes that may occur in the lens or cornea prevent the image from focusing on the retina and allow us to see blurred.
For correction of refractive errors (Myopia, Hypermetropia, Astigmatism and presbyopia), corrective treatments on the cornea or lens to get rid of glasses or contact lenses show their effect. In the procedures performed on the cornea (for example, LASIK), the cornea permanently changes its shape and allows the rays to fall on the retina. It is possible to achieve the same goal by replacing the natural lens with the appropriate intraocular lens (IOL).
Who are these lenses applied to?
Trifocal lenses are special intraocular lenses produced with advanced technology that can provide our far, middle and close distance vision without glasses. These lenses are implanted to patient’s eye for two main reasons:
In the first group of patients, there is no significant cataract, but there is especially high hyperopia. He has to be dependent on glasses in far and near vision. In order to eliminate the distant and close problem of such patients, refractive surgical interventions on the cornea such as LASIK are often insufficient, and the LASIK procedure cannot adequately solve the problem of close vision (presbyopia). In such patients, even if there is no cataract, trifocal intraocular lenses are placed in place of the patient’s own transparent lens and the patient is given the opportunity to see far, intermediate and close independent of glasses.
In the other group of patients, they need to undergo surgery due to cataracts. If the eyes of those patients are suitable, trifocal intraocular lenses can give very successful results.
In addition, if the patient has astigmatism before surgery, it is possible to correct this with the Toric (astigmatism corrector) intraocular lens.
In recent years there are another category ofintraocular lenses in the market which is called EDOF (Extended Depth of Focus) lenses. These type of lenses have their own advantages and disadvantages in comparison to trifocsl lenses which is explained in another topic in this website under Vivity.
How are Trifocal Intraocular Lenses applied?
Whether it is a cataract surgery or a transparent (clear) lens replacement surgery, the implantation of these lenses in the eye is performed by phaco method. After giving detailed information to the patient before surgery, the lens number is determined as a result of very sensitive measurements made on the eye. The surgical procedure, which is usually anesthetized with eye drops for surgery, takes about 10 minutes. After the transparent lens or cataract is removed by entering to the patient’s eye through a small incision, the appropriate trifocal intraocular lens is placed inside the lens capsule. One hour after the procedure, the patient is sent home and the next day after the surgery, the patient can return to normal life by opening his eye.
Attention to detail must be paid for the successful outcome!
In terms of patient satisfaction, bringing the appropriate patient together with the appropriate lens is the main factor of success. It is necessary to evaluate patient expectations thoroughly before surgery and to act accordingly.Trifocal, EDOF or Toric intraocular lens may not be suitable for every patient. The surgeon can decide this by evaluating the patient’s eye with sharp measuring devices before surgery. The implantation of trifocal intraocular lenses to the inappropriate patient group may lead to unevitable difficult surgical interventions for replacing the trifocal lens with a monfocal lens.
In order to place these high-tech lenses in the eye, the surgery should be performed in the most perfect way and care should be taken to ensure that there is no residual astigmatism higher than 0.5 diopters after the operation. Both Multifocal and Toric intraocular lenses offer highly effective options for correcting these high astigmatisms. For this reason, the quality of the lens material used together with the experience and knowledge of the surgeon is extremely important for successful results.
After the trifocal lens is implanted, it takes a few days or weeks for patients to get used to this new multifocal vision. Especially pilots, drivers who drive at night, those who spend most of their time in front of the computer are not suitable for multifocal lenses. In addition, people who are extremely sensitive to light may have problems with this type of lens.
Trifocal Intraocular Lenses should not be implanted to which patients!
- Yellow spot disease (macular degeneration)
- Those with retinal problems due to diabetes
- Glaucoma (especially in advanced cases)
- Those with uveitis
- Those with retinal and macular disease
What can be the side effects of trifocal lenses?
- Correcting the eye more or less than number zero (risk of myopia or hyperopia after surgery)
- Increased risk of retinal detachment
- Loss of focus as a result of shifting of the lens and reduced vision
- Difficulty distinguishing colors in low-light environments
- Opacification in the capsule behind the intraocular lens
- Requiring additional surgery to reset the glasses number
- Seeing halos, round rings, and scattering of lights around the lights
- Vision loss
The Final Word
As a final word, it is not the right approach to apply this type of high-tech intraocular lenses to every patient. With setting appropriate patient expectations before thesurgery, it is extremely important toimplant these type of lenses to the eyes that can anatomically and functionally accept such lenses in order to obtain successful and permanent results.