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A nice benefit of having ICL surgery over laser eye surgeries such as lasik is the significantly lower issue of dry eye. Because ICL doesn’t involve any corneal flap or removal of any corneal tissue, the corneal nerves responsible for triggering tear production remain largely intact. But this does not mean that ICL is “dry eye free”. There will still be some post-operative dry eye with ICL.

Dilating drops and antiseptic used prior to the surgery irritate the surface of the eye. On top of this, during surgery, the eye is held open while the surgeon places the ICL lens. This causes the eye to dry out a little more. So immediately after ICL, the cornea is more irritated and dry just from going through a procedure.

Additionally, ICL involves a small incision in the cornea. This incision does disrupt a small localized amount of nerves within the cornea. These nerves within the cornea are important to signal tear production when the eye is drying out. So until these nerves regenerate, the cornea is a little less sensitive and less capable to responding to dry eye.

But the biggest contributing factor to dry eye after ICL is the post-op eye drops. After ICL, many of the prescribed antibiotic and steroid eye drops contain preservatives to prevent the eye drop from going bad. Preservatives are known to irritate the cornea. And so the use of these drops after the surgery will cause some additional corneal irritation and dry eye. (But not enough to outweigh the benefit of the medication in the drop. Still continue to follow your doctor’s instructions).

Fortunately this post-operative dry eye after ICL surgery is usually very transient and once the post-operative eye drops are finished, the cornea heals up and the dry eye improves. In the meantime, however, using preservative-free artificial tears can help with the recovery to minimize this post-operative dry eye as much as possible and allow for the quickest healing.

ICL offers a unique advantage for individuals with Keratoconus. Other procedures such as Lasik remove corneal tissue to reshape the eye. For corneas that are already structurally compromised, this can potentially accelerate the Keratoconus and make it worse. However, ICL does not involve any removal of corneal tissue, it preserves the existing corneal architecture. This makes it much safer option with Keratoconus. But there are some things to consider.

ICL doesn’t “cure” Keratoconus. It can only correct the prescription. And so one of the most important requirements for ICL is having a stable prescription. Because Keratoconus is a progressive condition, placing an ICL into an eye that is still changing is a sure way to lead to the development of residual prescription in the future. So it’s critically important to make sure the Keratoconus is done progressing. If you are at risk for progression you may need corneal cross-linking (CXL) prior to ICL surgery to stop the progression of the Keratoconus to ensure that the prescription doesn’t change after ICL.

Additionally, it’s also important to understand limitations regarding irregular astigmatism. Toric ICL lenses correct what’s known as “regular” astigmatism. This is the type of astigmatism that glasses can correct. Irregular astigmatism comes from an asymmetric shape to the cornea - such as the “cone-shaped” cornea in Keratoconus. ICL can’t correct that irregular shape. (However, of note there are other surgeries that are designed to reduce that irregular shape in Keratoconus to reduce this irregular astigmatism; ICL isn’t one of them though).

If you need hard contact lenses or scleral contact lenses to get good vision, you probably have a lot of irregular astigmatism and ICL won’t be able to match those lenses (but it can still reduce the amount of prescription that you have). But if you see well with glasses or soft contact lenses, you likely don’t have much of this irregular astigmatism and ICL can work well for you.

Nothing is 100% accurate and even though ICL does a pretty nice job, there are still times when one may have some residual prescription or astigmatism after ICL surgery. Usually somewhere around 1-2% of cases. This residual prescription can blur vision and be bothersome; but there are ways to correct it.

The most common method by far is doing a laser vision correction procedure such as Lasik or PRK. You may be thinking “But I wasn’t a candidate for those procedures”. If you had a high prescription prior to ICL, this would be because the high treatment would need to remove a significant amount of cornea tissue. And removing too much corneal tissue can lead to problems such as a weakening of the cornea called ectasia.

But after ICL, if you have a residual prescription, it will be a much smaller prescription and require very little corneal tissue to treat. This makes lasik and PRK a very easy and highly accurate way to get rid of that remaining prescription.

But not everyone is suited for a laser enhancement procedure. The cornea may show suspicious signs of weakness or have bad dry eye. And the ICL is removable. So an alternative way to correct things is to exchange out the ICL lens for one with a different power to correct the prescription. But if lasik or PRK can be performed, it will usually be able to more accurately get rid of the small residual prescription, so ICL exchange for residual prescription is less commonly done.

Regardless of the approach, it is pretty common for the surgeon to give some time to allow the prescription to stabilize in order to ensure the treatment is the most accurate.