Phakic intraocular lenses are permanent, artificial lenses that are designed to be placed in front of an individual's natural lenses. By doing so, they can help to resolve common visual conditions including myopia, reducing the need for more invasive surgery, removable contact lenses, or eyeglasses.
Phakic intraocular lenses are designed to be placed inside the eye (hence the word "intraocular"). The word "phakic" refers to the nature of the implantation process, which does not require the removal of the natural lens. Lenses are implanted either behind or in front of the iris, and implantation is intended to be permanent. Phakic lenses are a modern innovation and tend to be made from advanced plastic polymers. They are an effective treatment for myopia (short-sightedness) but are not suitable for farsightedness (presbyopia).
Phakic intraocular lenses must be implanted inside the eye, so a degree of invasive surgery is necessary. However, the procedure is very quick and results in few complications. Here is a brief outline of how it typically unfolds:
1. Consultation The first step is to meet with your ophthalmologist to discuss the various options. Remember, phakic lenses are just one possibility. Laser surgery, disposable lenses, or glasses may be preferable in some cases. Your specialist will also want to establish that your eye is healthy enough to undergo implantation. This consultation may be preceded by a request to stop wearing your existing disposable lenses, as this allows the eye to focus naturally when you are assessed.After that, you will elect a suitable form of phakic lens, and preparation for surgery will begin.
2. Laser iridotomy
In some cases, preparation for implantation will include an extra procedure called a laser iridotomy. This procedure involves using a laser to make tiny holes in the iris, which ensures that your eye pressure will remain within safe limits following phakic lens implantation. It's not required in all cases.
3. Admission and surgery
Before surgery, you may need to self-administer antibiotic and cleansing eye drops, and it will generally be advisable to refrain from eating and drinking 12 hours before surgery. Surgery itself can be carried out without the need for an overnight hospital stay. Instead, it can usually be carried out at eye clinics, and you will be free to return home immediately. The first step in surgery is to administer anaesthetic eye drops. You may also require an injection to "freeze" the eye, and stop twitching or allowing eye movement during the implantation procedure. Your surgeon will then thoroughly clean the eye and use a speculum to hold the eye completely open, making it easily accessible.
Whatever type of lens you choose, the next step will be to make an incision in your cornea (the outer part of the eye). This will be combined with a form of lubricant, which helps to avoid damaging the cornea while the lens is introduced.
Next, your surgeon will carefully attach your phakic lenses inside the eye. This may be in the anterior or posterior chamber of the eye, depending on the form of lens deemed appropriate for your visual needs. When this is done, the corneal lubricant is removed, and the incision will be sutured with very small stitches. Eye drops may then be administered, and you may also be issued with a patch to protect the eye following surgery.
Before discharge, you will probably be prescribed certain antibiotics and eye drops that are intended to minimise inflammation. You will also be able to request advice about eye care following the procedure. After that, you're free to return home and begin the recovery process.
Yes, there are two major types of phakic intraocular lenses:
Posterior chamber - Posterior chamber lenses are placed behind the coloured part of the eye (the iris) but in front of the lens. Approved in the USA to correct nearsightedness between -3.00 and -20.00 D, these phakic lenses are totally invisible to the naked eye because they are concealed by the iris. Most versions are made with very soft, highly flexible plastics. This means they can be folded precisely and slipped through tiny incisions in the iris, making implantation as non-invasive as possible.
Anterior chamber - Conversely, patients could choose anterior chamber phakic lenses. As the name suggests, these versions are designed to be placed in front of the iris, making the implantation procedure even less invasive. They tend to be much more rigid because they are exposed to the elements more. But they are almost as difficult to spot from the outside. In the USA, they are approved to handle myopia from -5.00 to -20.00 D.
If you suffer from myopia and your eye specialist recommends you for phakic intraocular lens implantation, you can expect significantly improved close vision following surgery. Results tend to be seen around 1 month after the procedure is carried out, at which point you should notice that activities like reading are becoming much easier. During the process, expect a few appointments to discuss the procedure, carry out preparatory measures and implant the lenses. The duration of the actual treatment is not very long. There won't be a need for overnight hospital stays, and treatment shouldn't interfere too much with your regular lifestyle. However, there will be a recovery period during which careful eye care is absolutely essential. Caring for your eyes post-surgery is vital to avoiding side effects and complications further down the line. But this period won't last long, and within a month or two, you may not even notice the presence of your phakic lenses.