Thursday, February 23, 2017

ICL in 14 Days: Complications Research

It's now 14 days, or two weeks, until my ICL surgery. I mentioned in a previous post that I have been more nervous about the ICL surgery in my left eye than I was about the PRK surgery in my right eye. I've been spending a lot of time reading blogs, reviews, and research about the ICL procedure and complications. Even though my left eye (-11 diopters) is almost twice as bad as my right eye (-6.5 diopters), my left eye has always been my dominant eye because (a) my left eye doesn't have a cataract which limits the amount of light that can enter my right eye, and (b) my left eye can be corrected to 20/15 while my right eye can only be corrected to 20//25. My left eye (when corrected) sees more contrast and has much better depth perception.

Therefore, having surgery in my left eye is somewhat scary because if something where to happen I would be stuck with worse vision in general.

I thought it might be useful to make a post about some of the potential complications of ICL surgery. Note that this post should not be used as medical advice and you should always do your own research and consult your own surgeon about potential complications.

Iridotomy/Iridectomy Side Effects

Although the Visian ICL V4c model is available in many countries and not require an iridotomy because it has a tiny hole in the middle of the lens, in the United States only the V4 model is available and does require an iridotomy. The purpose of the iridotomy is to allow fluid to move freely from the front to back of your eye. If this fluid cannot flow freely, eye pressure can increase causing glaucoma, which can in turn damage the optic nerve and lead to irreversible vision loss. 

While an iridotomy is a relatively common procedure, it has its own potential complications and side effects. Sometimes people see white lines of light or other light aberrations due to the iridotomy acting like a second pupil that lets light into the inside of the eye. 

Cataracts

Cataracts, or lens opacification, are probably the most common complication from the ICL implantation. According to the FDA study, which only followed patients for three years after implantation, cataracts formed in 14 eyes (2.7%) after three years, with only 2 (less than 1%) requiring surgery to remove the cataracts (the other 12 were not clinically significant). A more recent study found that 40.9% of eyes developed cataracts at year 5 and 54.8% at 10 years. However, only 4.9% required cataract surgery at 5 years and 18.3% at 10 years. This study might also overestimate the incidence of cataracts because they lost some patients (about 5% every year) who did not return to their clinic, and it may be that those who did not return had fewer complications.

Cataracts can be caused by different variables. According to this research study:
There are several theories in the literature to explain the development of anterior subcapsular cataracts that do not incidentally occur in the myopic population; these include perioperative trauma from the Nd:YAG laser during creation of peripheral iridotomies or accidental contact with the anterior capsule during pIOL implantation. Other proposed factors include intermittent microtrauma from accommodation, increased overall size of the natural crystalline lens throughout life, constant trauma from pIOL–anterior capsule contact, and subclinical inflammation from continuous disruption of the blood–aqueous barrier, causing metabolic and nutritional changes within the crystalline lens.
So in other words, cataracts can be caused by the ICL touching the natural lens during the implantation surgery, inadequate vaulting between the natural lens and ICL lens, the laser iridotomy procedure itself, and other factors.

Retinal Detachment

Retinal detachment and tears are scary. The retina is basically a layer in your eyeball that is essential to being able to see. When retinal detachment occurs, it can usually be repaired, but that eye might never have the same best corrected visual acuity again. In other words, if you had 20/20 vision before the detachment with glasses or contacts, glasses or contacts might only be able to correct you to 20/80 after the detachment. 

That said, being a high myope increases the chance of retinal detachment across a person's lifetime, but ICL surgery does not. However, an ICL may cause cataracts, which may require explantation of the ICL and extraction of the clouded natural lens, which is then replaced with an artificial intraocular lens (IOL) that can correct nearsightedness. This procedure can cause retinal detachment. 

So if, say in 10 years, I get cataracts in my left eye that obscure my vision enough to require surgery to remove the clouded natural lens, I will then have a higher chance of retinal detachment indirectly because of the ICL. 


There are other potential complications of the ICL, including infection, endothelial cell loss, pigment dispersion, and halos at night. So while complications are uncommon, they can happen and it's kind of terrifying!

I am now certain I'm going to go through with the surgery in two weeks. I will update again afterwards! 

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