Phakic Interocular Lens (IOL) is an eye surgery. The doctor implants contact lenses in the eyes to improve vision for nearsighted people. Read in to learn more about IOL.

Phakic intraocular contact lenses surgically implanted into the eye by an eye surgeon to give the patient clear and better vision. The lenses mainly used to treat myopia.

The word phakic itself means that the doctor inserts the silicon-made lens into the eye with the natural lens intact in a fast and fully reversible procedure.

Refractive Treatments

There are many refractive treatments for shortsightedness, including ICSR or laser treatment. However, the treatment methods cannot treat highly myopic eyes; something Phakic implantation has demonstrated to do effectively.

A 2009 meta-analysis established that phakic ICL lens implantation is secure and efficient and provides stable results as a moderate and critical myopia treatment. It also found the results to be sustainable for at least eight years.

Below is a deeper look into ICL, including an explanation of what it treats, how it works, the procedure itself, the cost and more;

What Phakic IOL Treats?

Phakic lenses fix refractive errors. Refractive errors are eye defects that affect the eye’s focusing ability.

When an object’s light transmission into the eye, an image forms on the retina. Refractive errors in the eye cause the images to appear blurred and out of focus. Myopic or nearsighted people cannot see the object clearly, except when brought closer.

The phakic lens brings more light into the eye and focuses on the retina, thus enabling a clear vision of faraway objects. After implanting Phakic lenses into a myopic patient’s eye, the recipient no longer needs visual aids.

The myopic patient no longer needs visual aids after completing this procedure.

Myopic Patient

 How do Phakic Lenses work?

The phakic lenses bend light from the object and redirect the focused image to the retina. The optic nerve then transmits the focused image to the brain. When the Phakic lens channels the light rays onto the retina, a person with myopia can see objects located far away more sharply.

Benefits

The Phakic lens procedure has several benefits for the patient, including;

• The ability to remove the lens by surgical means
• Lesser likelihood of causing eye dryness
• Patients who don’t qualify for LASIK treatments because of cornea thinness or irregularity.
• Ability to correct severe myopia or shortsightedness when other surgeries fail
• The procedure leaves the natural lens intact, meaning the eye’s near-focusing ability retained in patients below 40 years old.
• Lower risk of halos, glare and soft lighting–outcomes of high laser treatment
• Results in a relatively better vision than using glasses and contact lens

Types of Phakic IOLs

The FDA has approved two kinds of phakic IOLs. An ophthalmologist assesses which one is most suitable. These two types include:

Verisyse:  known as anterior chamber lens. In this procedure, the lens placed above the Iris. The lens made using a medical-grade polymer. Designed in one piece, making it easy to implant.

As per FDA’s recommendations, only patients 45 years and younger can qualify for the procedure. The recommendations stipulate that patients with macular degeneration, glaucoma or cataracts should not use this lens.

Visian ICL

Also referred to as the posterior chamber IOL. In Visian ICL, the lens is inserted behind the Iris, in the colored section of the eye and above the natural lens. The lens is made using Collamer, a biocompatible material that matches the natural eye features and ensures the patient enjoys an effortless experience with the reduced danger of dry eye syndrome. Only patients above 21 are eligible for this procedure.

The Procedure 

The steps used in carrying out the procedure are slightly different because they must correspond with the actual type of phakic implant that the ophthalmologist is inserting.

The eye specialist begins by putting drops into the eye on the day of surgery, just before the procedure.

The patient is then put on anesthesia through IV.

An ophthalmologist may administer an injection to make the eye numb. To keep the eyelid open, the ophthalmologist uses a lid spectrum.

If the implantation is on the anterior chamber, the doctor may administer miotic drops to decrease the size of the pupils.

The surgeon cuts the cornea, the white part of the eye known as the sclera or where the cornea comes into contact with the sclera, a part known as the limbus. The incision is done on the pointy cornea axis to help minimize astigmatism that may be caused by surgery.

A phakic lens is inserted through the incision on the eye into the area above the Iris and at the back of the cornea, also known as the anterior chamber. The lens is placed in the eye’s anterior or posterior chamber based on the phakic lens being implanted.

Ophthalmologist

The ophthalmologist uses small stitches to close the incision. Sometimes, the incision may be left to close naturally. The surgeon puts some ointment or eye drops in the eye and uses a shield or a patch to cover it. The surgery takes about 15- 30 minutes.

Recovery

After the procedure, a patient is likely to feel itchiness, commonly experienced when an object enters the eye. The patient is also likely to feel pain when the eyes are exposed to light. Taking a painkiller for the initial few days following the surgery may help relieve the pain. Additionally, the doctor may prescribe a painkiller.

It’s advisable to consult a doctor when excruciating pain is experienced. See a doctor a day after the surgery is also advisable for examination.

The patient is advised to use eye drops a few weeks after the surgery to ensure the eyes do not get infected. The eye drops also assist in reducing swelling.

The eye may be blurry for a few days during the recovery, but the vision improves after a while. In four weeks, the vision becomes stable.  

The patient may also experience starbursts, halos around lights, glare, and light sensitivity. Eyes’ whites may also become bloodshot red. But the symptoms reduce as the eye heals.

In the initial week after the surgery, the patient must refrain from physically demanding tasks like bending over and carrying heavy items. However, after the first week, they may return to routine tasks. However, caution is advised when swimming and carrying weighty loads. 

Risks

The phakic intraocular lens renders patients vulnerable to certain risks, including;

• Reduction of Endothelial cell count, which ensures the cornea is clear. Endothelial cells don’t regenerate, and aging results in the loss of approximately 0.4% of the cells each year. Phakic implants increase the rate of losing endothelial cells to 7.5% in five years. But after two years, the rate of cell loss stabilizes.
• The risk of retina detachment is a condition that may result in irreversible vision loss. The retina cells pull away from blood cells, curtailing the oxygen supply.
• Experiencing halos near light or faintly blurred visions that get worse when driving at night

Indications

• Sometimes, eye pressure may increase, a condition that results in glaucoma. When it occurs, the patient will be required to apply eye drops to the eye. The eye specialist may have to remove the lens from time to time.
• A LASIK retouch or a pair of glasses may be required to correct minor stigmatism.
• Cataracts may also develop. A cataract operation gives the patient a lens implant that lets him see distance properly.
• The patient may also suffer from iritis, where the eye becomes inflamed due to irritation caused by eye rubbing.
• The rear window of the eye may swell or experience clouding. The condition can, however, be treated with eye drops. Sometimes, the eye may recover naturally. But in severe cases, a cornea transplant may be needed.
• A patient may experience subtle discomfort following the procedure in the initial 24 hours.
• A rare condition called cystoid macular edema that results in retina swelling is also possible. It affects the middle part of the retina. While there is a treatment for the same, some patients may suffer permanent residual visual problems.
• Endophthalmitis may also occur. It is an intraocular infection that can result in blindness. It happens rarely, a one in a few thousand patient scenarios. The danger can be greatly minimized when the condition is detected early. And when not detected early enough, the patient can lose sight irreversibly.
• The laser iridotomy procedure has risks, including retina burns and cornea injury. The procedure is undertaken in preparation for phakic lens surgery.
• Pupil distortion is also a probability when the IOL procedure is undertaken. It results in intractable glare and may make someone lose sight.

Can They Be Removed?

ICLs can be surgically removed when the need arises. While they’re designed to remain in the eye permanently, situations may arise where removal is necessary. There is no guarantee that vision is restored to its previous state after lens removal.

Phakic vs. IOL after cataract surgery?

Phakic intraocular lenses are inserted into the eye while the natural lens is still in place. Intraocular lenses are implanted into the eye after removing the natural lenses.

Costs

Compared to LASIK, Phakic is relatively more expensive. The cost ranges from $3,000 to $5,000 per eye, while the cost of LASIK ranges between $1,500 and $3,000 per eye.

References

What are Phakic Lenses? U.S Food & Drug Administration

Before, During & After Surgery. U.S Food & Drug Administration

Phakic Intraocular Lens Myopia. (Feb 2022) NCBI

Phakic Intraocular Lenses (IOLs) or Implantable Contact Lenses (ICLS). Kellogg Eye Center University of Michigan Health

A Guide to Phakic Intraocular Lenses (IOLS) for Myopia Correction. (Jul 2017) Tear Film

Phakic Intraocular Lenses. (Sep 2021) Eye Wiki

Retinal detachment. Mayo Clinic

Visian Phakic Intraocular Lens Implant. UR Medicine