LASIK, PRK, and contact lens wear are not risk free. However, in terms of infection, LASIK and PRK are slightly safer than wearing contact lenseses on an ongoing basis.

Many patients who are considering undergoing LASIK want to know how the risk of LASIK compares to the risk of wearing contact lenses. The answer may surprise you. Certainly, both LASIK and contact lens wear are not risk free, even if the risks with both options are very small. For both LASIK and contact lens use, one of the most dreaded complications is infection. Fortunately, for both LASIK and contact lenses, the risk of infection is quite low. However, LASIK carries a one-time risk of infection, whereas contact lens wear carries ongoing risk over time, which has a cumulitive effect. Overall, a look at the data comparing having properly performed LASIK to properly wearing soft contact lenses shows that LASIK is actually the safer choice in terms of infection.

One of the most serious complications of either LASIK surgery or of contact lens wear is infection. Infection rates with LASIK vary in the literature widely based on experiences at various LASIK centers. This variability seen in the data is not surprising as LASIK truly is performed differently in different centers: LASIK is not as standardized nor regulated as most people would like to assume. Published studies have shown infection rates in LASIK to be as low as 0 in 2142 cases and 0 in 1747 cases, in two separate large studies — to as high as an infection rate of 1.2% in a small series of 83 cases. In a meta-analysis paper by the American Society of Refractive Surgery (ASCRS) of 56 of its member ophthalmologists, there were a total of 116 cases of infection out of an estimated 338,550 LASIK procedures, representing an infection rate of 0.034%. Another large study of 204,586 eyes undergoing LASIK showed a bacterial infection rate of 0.035% of eyes — a strikingly similar data result. Given the large size of these studies and their nearly identical results, I do think a bacterial infection risk of approximately 0.035% is a reasonable estimate for undergoing properly performed LASIK.

Two large series, one involving 10,452 eyes and the other involving 25,337 eyes, showed a bacterial infection rate of 0.02% with PRK, which is essentially the identical procedure to LASIK, but without the LASIK flap. These data are somewhat surprising as they show an infection rate for PRK actually lower than LASIK, despite the fact that surface (rather than subsurface) healing occurs after PRK, in contrast to LASIK.

Infection, of course, is also one of the most dreaded complications with contact lens use. In contrast to the risk of bacterial infection after LASIK, which generally occurs in the immediate post-operative period but can, in very rare cases, occur up to six months after surgery, the risk of contact lens related infection is an ongoing one with continued contact lens use. The rate of bacterial infection for contact lens use varies depending on the type of contact lens being used. The risk of contact lens infection varies from as low as 0.012% per year for daily wear rigid gas permeable contact lenses to as high as 0.254% per year for overnight extended wear use of silicone hydrogel soft lenses.

The biggest risk factors for contact lens related corneal infection are overnight use of contact lenses, poor storage case hygiene, smoking, internet purchase of contact lenses, new contact lens wearers, and higher socioeconomic class.

Interestingly, the types of infections seen with contact lens wear are, on balance, much more serious than the types of infections seen with LASIK. In one study from Australia, 55% of contact lens infections were caused by Pseudomonas, which is a devastating gram negative bacteria which quickly eats through the corneas. By comparison, the types of bacteria typically seen in LASIK infections tend not to be as aggressive. For this reason, even if the rates of infection were equal between LASIK, PRK, and contact lenses, the types of infections seen with contacts tend to be more dangerous than those seen with LASIK or PRK.

In the end, LASIK, PRK, and contact lenses all carry an element of risk. However, in terms of the feared complication of infection, many patients are surprised to find out that having LASIK or PRK is actually slightly safer than wearing contact lenses on a long term ongoing basis.

See Also

Microbial Keratitis After LASIK
This article looks at bacterial infections after LASIK

Incidence of Contact Lens Associated Microbial Keratitis And Its Related Morbidity
This article from the Lancet looks at contact lens infection rates and problems.

The Clinical Diagnosis of Microbial Keratitis
This article looks at the clinical manifestations of infection of the human cornea.