ICL known as implantable contact lenses; actual name is Implantable Collamer lenses. It is also called phakic intraocular lenses (pIOLs) that placed surgically inside of the eye. It functions like external a contact lens to correct nearsightedness but placed at inside not the external surface of the eye (Over Cornea and Conjunctiva). The contact lens is positioned behind the iris and in front of the natural crystalline lens. This surgery can be done for a patient who is not suitable for LASIK surgery due to various reasons.
Currently 2 two types FDA approved pIOLs available in market – Visian ICL and Verisyse phakic IOL.
Visian ICL is known as posterior chamber pIOLs, marketed STAAR surgical. The procedure was first developed by Dr. Fydorovin in 1986 where the ICL is inserted behind the iris and in front of the natural lens by a small surgical procedure. The lens is made by “collamer” material which is a copolymer of hydroxyethyl methacrylate and porcine collagen. It is biocompatible (Safe to stay inside of eye for a long time without any harmful or toxin effects) polymer material. It can correct a wide range of shortsightedness -3.00D to -20.00D. Not only myopia it can correct hypermetropia (Plus power) up to +8.00D along with -6.00D astigmatism (Currently under clinical trial).
Verisyse is an anterior chamber pIOLs from AMO (Abbott medical optics) where the lens placed in front of iris. This pIOLs got FDA approval for correcting myopia (-5.00D to -20.00D) in 2004 and currently under trial for correcting hypermetropia. The lens is made by PMMA (Polymethylmethacrylate) material. The first pIOLs surgery was done in 1953 by Dr. Strampeli but not widely used to complications like glaucoma, pupil distortion, endothelial decompensation. Later iris fixated “iris-claw” lens was introduced by Jan Worst in 1977 with a biconcave design which reduces all above complications and got FDA approved as Verisyse pIOL. Lens will not be visible until you observe closely with mirror and it is normally not visible to others.
Who are the suitable candidates for permanently implantable contact lenses?
- Age must be more than 18 years
- Refractive error should be stable for 1-year minimum
- High refractive error and not suitable for Lasik surgery
- Unsatisfactory vision with spectacles
- Contact lens intolerance
- Thin cornea and not suitable for Lasik surgery
- Deep anterior chamber > 2.80 mm
- Absence of serious ocular and retinal pathology
- Endothelial cell count >2000 cells/mm2
- No history of Herpes or Zoster eye infections
- No history of severe eye trauma or retinal detachment
Who are not suitable for implantable contact lenses surgery?
- Age less than 18 years and more than 45 years of age
- Unstable refractive error means glass power
- Family history of glaucoma or high IOP (Intraocular pressure) >20 mm of Hg
- Presence of serious retinal pathology
- Family history of RD (Retinal detachment)
- Shallow anterior chamber < 2.80mm
- Presence of anterior or posterior synechiae
- Corneal endothelial cell count < 2000 cells/mm2
- Presence of cataract or nuclear sclerosis of lens
- History of recurrent Uveitis
- Corneal dystrophy
- Iris neovascularization
- PXF (Pseudoexfoliation)
- Small pupil size is not good for surgery
- Pigment dispersion syndrome
Advantages of implantable contact lenses surgery:-
Many cases ICL is much better than Lasik surgeries like –
- Dry eye patient can get ICL surgery instead of Lasik or Contact lens use
- No tissue will be removed like Lasik surgery, as lens will be placed inside of the eye
- Natural lens does not remove from the eye, so accommodation will be affected
- Anytime lens can be removed if required
- Contrast sensitivity will not affect
- Retains asphericity of cornea
- Risk of retinal detachment (RD) lower than clear lens extraction procedure
- Still, you can wear glasses, sunglasses and contact lenses after the surgery
- The surgery can be done for thinner cornea patients like Keratoconus patients also
- Post RK (Radial Keratectomy) and post-PK (Penetrating Keratoplasty)
- Very high refractive error along with astigmatism can be corrected (+8.00D to -20.00D with -6.00D Astigmatism)
- If your refractive error is high or cornea is thin (<480 microns), then you can go for ICL surgery
- Also if you are a sportsman and maintaining contact lenses are difficult for your eyes then you can think for ICL (If you are unsuitable candidates for Lasik surgeries)
What are the advantages of implantable contact lenses over external contact lenses?
- No need to wear and remove daily
- No headache for cleaning of lenses
- You will not feel presence of lens at the inside of eye
- Those who are suffering from dry eye, they can do this surgery
- No contact lens-related complications
Advantages of posterior chamber implantable contact lenses (Visian ICL) than anterior chamber implantable contact lenses (Verisyse phakic IOL):
- Less damage to endothelial cells of cornea
- Less damage of iridocorneal angle of the eye
- Less chance of developing glaucoma after the surgery
- Less damage of pupil
Complications & Disadvantages of implantable contact lenses surgery:-
Though ICL is a very safe surgery but complications have seen very cases which may occur during the surgery or develop at postoperative period. Complications may be minor to serious vision loss which can lead vision loss.
- Damages of the intraocular tissues such as natural lens, iris, during the surgery
- Potential complications are cataract, iritis, glaucoma and irreversible endothelial cells loss
- Rare retinal complications are CME (Cystoid macular edema) and RD (Retinal detachment)
- Increase IOP after the surgery
- Glare and haloes (Very rare evidence reported)
- Decentration of ICL
- Damage of Optic zone or haptic of lens while implanting inside of the eye
Contact your local hospital to know the more details about the surgery and cost of the surgery. Surgical cost varies hospital to hospital.
Author Bio: – Krishnendu Mandal is an Optometrist by profession. He works many eye hospitals in India. He writes about health topics in his blog.
Image Sources :
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