What are phakic intraocular lenses and who are they suitable for?

Phakic intraocular lenses are another treatment option for severe myopia that can be an alternative to LASIK and PRK surgeries. Results have shown that in some cases, these lenses provide better vision compared to laser procedures.

Phakic intraocular lenses are clear and implantable. They are surgically placed between the lens and the iris, or behind the iris without removing the lens. In fact, phakic intraocular lenses focus light rays precisely on the retina, eliminating the need for glasses.

These lenses work in a similar way to contact lenses. The only difference is where they are placed; phakic lenses correct myopia problems from inside the eye, while contact lenses are placed on the surface of the eye. These lenses work in a similar way to contact lenses. The only difference is where they are placed; phakic lenses correct myopia problems from inside the eye, while contact lenses are placed on the surface of the eye.

These lenses are best used in situations where the patient has high myopia and LASIK surgery is not suitable for them.

Procedure time: about 15 minutes for each eye

Results: Vision 40/20 or better without glasses or contact lenses

Recovery time: a few days to a few weeks

Cost: $4,000 per eye

Interestingly, phakic intraocular lenses are a permanent treatment for myopia unless the lens is removed for some reason.

Phakic intraocular lenses have advantages over contact lenses, including:

The person cannot feel the lens inside the eye.
These lenses are maintenance-free.

The US Food and Drug Administration (FDA) has approved two types of phakic intraocular lenses, which are selected based on the opinion of the treating surgeon and recommended to the patient.

Vision ICL: This type is commercialized by Star Surgical. It is located between the iris and the lens of the eye. It is used to correct myopia of -3 to -20 diopters. Because this lens is implanted intraocularly, it can only be seen with a microscope. It is made of a biocompatible collagen copolymer. Since this lens is soft and highly flexible, it can be folded during surgery. Therefore, it leaves very little scarring.
Varicose: It is located in front of the iris of the eye. It is used to correct myopia of -5 to -20 diopters. It is made of rigid, inflexible plastic polymethyl methacrylate (PMMA). Another brand name is Artisan, which is common in Europe. Usually, this lens is also not visible after being placed in the eye; however, it may be visible in front of a mirror at a very close distance.

Vision ICL

The Vision ICL and Verisure intraocular lenses are both FDA-approved and are undergoing extensive studies for their use in treating farsightedness. The Vision toric model is being studied for the treatment of astigmatism and nearsightedness.

Alcon lenses are also receiving FDA approval and are made of soft acrylic. They are placed in front of the iris. Many clinical studies have been conducted on these lenses in Canada, the United States, and Europe. Of course, their use has started in Europe since 2008, and no complaints have been reported in the last few years. The results have shown that these lenses are able to correct refractive errors from -10 diopters to -0.25 diopters.

Phakic intraocular lenses compared to LASIK surgery

LASIK uses computer-controlled laser radiation to treat refractive errors of the eye, including nearsightedness, farsightedness, and astigmatism. However, LASIK surgery is not suitable for all patients. Contraindications to LASIK include: very high myopia (usually greater than -8 diopters); thin cornea; irregular corneal shape; keratoconus; chronic dry eye.

People with moderate to severe myopia problems are better off using phakic intraocular lenses.

Studies in 2010 showed that both treatments were able to improve myopia (from -6 diopters to -20 diopters) and provide 20/20 vision for patients.

The improvement in vision was sustained with both procedures, and no recurrence was observed. However, patients who underwent phakic intraocular lens surgery had greater contrast in vision.

The cost of LASIK surgery is much lower than phakic intraocular lenses. The choice of either method depends solely on the opinion of the treating physician, which is done after an eye examination and evaluation of other factors.

Considerations

Are you able to use phakic intraocular lenses?

To make sure you meet the medical requirements to wear these types of lenses, consider the following questions:

Is your myopia less than -20 diopters?
Is your eye capable of accommodating this lens? In this case, the depth of the anterior chamber of the eye and the health of the corneal epithelium should be determined during the examination.
Are you between the ages of 21 and 40? These lenses are not suitable for treating blurred vision caused by presbyopia. This condition usually develops in the early 40s. Monovision intraocular lenses are recommended for this condition.
Have your vision problems worsened despite wearing glasses or contact lenses? For all surgeries, the patient must have a fixed eye number for one year.
Is it possible that you have other eye diseases such as cataracts, glaucoma, or eye infections?
Is it possible that you also have other autoimmune or degenerative diseases, such as Sjögren's syndrome, rheumatoid arthritis, type 1 diabetes, HIV, and AIDS?
Does your insurance cover medical expenses from the pre-operative examination stage to the follow-up after the procedure?

Considerations Needed About Phakic Intraocular Lenses

Before the operation

People who wear contact lenses should remove them for a period of time before an eye exam because the lenses affect the natural shape of the cornea.
A week or two before the procedure, your doctor will use a laser iridotomy to create a small opening in your iris to allow the aqueous humor to flow more easily into the angle of your eye. This laser procedure helps prevent pressure from building up inside your eye after the lens is inserted.
Laser iridotomy is very quick and only takes a few minutes, so it can be performed on the same day as surgery for phakic intraocular lens implantation.

During the operation

Special eye drops or some oral medications are used for anesthesia. A speculum is used to hold the eyelids open. A small, thin incision is made on the cornea to place the lens in the appropriate position. The length of this incision is 6 mm for Versys lenses and 2.3 mm for Vision ICL lenses.
The Versys lens is placed in the anterior chamber of the eye behind the cornea, where it is attached to the front of the lens of the eye. Non-absorbable sutures are used to close the wounds. Finally, a dressing is placed on the eye.
The surgery takes about 10-30 minutes and is performed on an outpatient basis. You will be asked to rest for a short time before you can return home (of course, you will need someone to drive you there). Your doctor will usually prescribe antibiotics and anti-inflammatory medications to reduce any discomfort and speed up the healing process.

After the operation

Many patients experience significant improvement in their vision. However, vision may be slightly blurry and light-sensitive at first after surgery. It takes two to four weeks for clear, stable vision to return.
If you use the Vision ICL lens, this time is reduced to at least one to seven days, which is a much faster recovery process compared to the Versys lens.
Usually after this surgery, the patient feels a little discomfort in the form of itching in the eye, as if there is a foreign object in the eye.
Based on your doctor's prescription, these symptoms can be minimized by using medication.
The person's presence is required the day after surgery, as well as other follow-up sessions.
Avoid rubbing or squeezing your eyes too hard.
Avoid strenuous activities, such as lifting heavy objects, until you are fully recovered.
One to three weeks after surgery, most people will be able to drive or return to work.

Risks and side effects

Like all surgical procedures, the use of phakic intraocular lenses carries certain risks. Although these are rare, the short-term and long-term complications of this surgery include:

Retinal detachment: This condition is very serious and poses a serious threat to the patient's vision.
Loss of cells in the thin inner layer of the cornea (epithelium); this condition causes corneal edema and progressive blurring of vision. Therefore, the doctor will measure the number of endothelial cells at each visit.
Eye inflammation or infection
Visual distortions such as halos and glare, especially when driving, and blurred vision
Cataracts; if ignored, can lead to complete blindness.
Pupil deviation, which increases the likelihood of glare and blurred vision.

Therapeutic results of using phakic intraocular lenses

In a three-year study of Versys lenses, the FDA found that about 84 percent of patients achieved vision of 40/20 or better, which is good enough for driving without glasses in most states. Of those, 31 percent achieved vision of 20/20.