Information about Phakic Intraocular Lenses (PIOLs)

Phakic Intraocular Lenses (PIOLs)

Introduction

Not every person who desires LASIK corrective eye surgery is a candidate. Patients who have severe myopia or a thin corneal surface are usually unfit for corrective laser surgery. Phakic Intra-Ocular Lenses (PIOLs) can be a suitable alternative in some instances. PIOLs are plastic lenses that can be surgically implanted (either in front of or behind the iris) to work with the eye’s natural crystalline lens to correct refractive errors. The following article will help you understand the basics about PIOLs.

What is a PIOL?

A phakic IOL is essentially an implantable contact lens designed to work in conjunction with the patient’s own image-forming elements, i.e., the cornea and natural crystalline lens.

What is the procedure?

Phakic lenses have been designed for placement in both the anterior chamber (between the cornea and the iris) and the posterior chamber (between the iris and the natural crystalline lens). However, it is now generally accepted that the safest location for a phakic lens is in the anterior chamber because posterior-chamber phakic IOLs have a greater probability of inducing a cataract. During the surgery, the lens is generally inserted into the anterior chamber (behind the cornea and in front of the iris) through an incision made in your cornea, sclera, or limbus. Your doctor will place some eye drops or ointment in your eye and cover your eye with a patch and/or a shield. The surgery will probably take around 30 minutes.

What types of problems does it best correct?

  • Typically, a PIOL can be designed to correct any form of:
  • Ametropia
  • Astigmatism or presbyopia, as well as
  • Higher-order wave aberrations;

Who should be advised against having Phakic Intraocular Lenses?

  • You are probably NOT a good candidate for phakic lenses if:
  • You have large pupils, a shallow anterior chamber, an abnormal iris, had uveitis, had problems with the posterior part of your eye.
  • You are not an adult. There are no phakic lenses approved by the FDA for persons under the age of 21.
  • You have a disease or are on medications that may affect wound healing.
  • You have a low endothelial cell count or abnormal endothelial cells.
  • You actively participate in sports with a high risk of eye trauma.
  • You only have one eye with potentially good vision

What advantages does it have over other methods of vision correction surgery, including LASIK?

Phakic IOLs are advantageous because

  • They can be removed in case of complications;
  • They can be less than 600 µm thick;
  • Their optic diameter can be more than 6 mm, which reduces the risk of halos and other optical distortions In addition, the high optical quality and accurate, stable correction of refractive errors associated with phakic IOLs will attract cataract surgeons to the technology, particularly since the surgical implantation techniques are already familiar to them and the cost of the instruments is only a few thousand dollars, as opposed to the large capital expenditures associated with LASIK and PRK.
  • Finally, PIOLs can be inserted during a relatively simple and inexpensive outpatient procedure that takes only a few minutes for the surgeon to perform.
  • What are the disadvantages and potential long-term risks of this procedure?

    Cataract risk: Long-term rate of cataract formation secondary to implantation, removal and/or replacement is widely unknown.

    Lens opacities risk: The occurrence of lens opacities in the future is unknown but is still a possibility after the implantation of PIOLs.

    Corneal complications risk: The long-term effects on the corneal endothelium have not been established. Patients should be advised about potential risk of corneal edema (swelling), possibly requiring corneal transplantation.

    Other possible unknown risks: The potential of the lens to alter intraocular pressure and long-term risk of glaucoma, peripheral anterior synechiae and pigment dispersion are unknown.

    Possible long term risks

    Blindness: Although a rare possibility, you may lose vision. You may also develop a retinal detachment.

    Visual symptoms: You may develop debilitating visual symptoms. Other symptoms include inflammation (pain, redness, and decreased vision).

    More surgeries required: You may need additional eye surgery to reposition, replace or remove the phakic lens implant.

    Treatment risks: You may be under treated or over treated.

    High IOL: You may develop increased intraocular pressure.

    You may experience infection, bleeding, or severe ulceration.

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