Lasik is an excellent procedure for lower degrees of nearsightedness where the cornea is thick enough, there is no dry eye, and the corneal topography or shape is completely normal.

Phakic lenses are an excellent procedure for higher degrees of nearsightedness especially when the cornea is not thick enough, there is dry eye or there is subtle abnormality of the corneal shape.

But what about the patient who is somewhere in between? Someone who is not extremely nearsighted, maybe has a little bit of dry eye or just a little bit of irregularity of shape? What would be the argument to do a phakic lens over Lasik?

The answer lies in the differences between Lasik and Phakic lenses.  For example, phakic lenses provide phenomenal visual acuity. It is fair to say that the visual acuity is superior to Lasik - which is also excellent.  Furthermore, phakic lenses are reversible.   They can be removed. It is not possible to reverse a Lasik procedure. Finally, sometimes we cannot predict who will have a dry eye. We know that if we do a phakic lens there cannot be a dry eye wheras Lasik can slightly worsen a dry eye situation.

The Lasik expert may say that phakic lenses are too new. They might argue that going inside the eye should be a procedure of last resort. They might argue that there is the risk of infection.  They will argue that astigmatism management is easier with Lasik and millions of Lasik cases have been done.  Good arguments.

The phakic lens surgeon would push back and say that phakic lenses are not old. They have been in development now since the 1980s. The FDA has approved two lenses and the worst case scenario could be a cataract but, cataracts are easily treated whereas a worst-case scenario in a Lasik patient could be irregular astigmatism which is not easily treated.

As for infection, it is extremely rare in both conditions. Phakic lens surgery is "super simplified" cataract surgery and we all know that cataract surgery is extremely safe.

Sometimes the final determination as to what procedure to go with comes from the patient. Some might argue, I want perfect vision. Some don't want irreversibility as with Lasik. Some will say that Lasik is what they want because their friends have had it and they want to be like their friends and millions of others.  Over time the marketing and the salespeople of companies that make phakic lenses will be promoting these lenses more and more. In these words above I have provided you the underlying arguments that I am sure will be talked about more and more in the future.

One interesting tie breaker between Lasik and Phakics may be in the area of presbyopia management.  In my experience, having done Phakic lenses since 1996, I have noticed that older patients who are left a little nearsighted can still see well at a distance -- and read.  I am fascinated by this observation because it is unexpected.    I suspect this observation is more true the more nearsighted the eye.   I have seen this effect in the highly nearsighted (8 diopters and above).  Time will tell if it has value in the lower levels of nearsightedness, say down to a glasses prescription of 5 diopters, or less.

April 13, 2008