A study published in the July 2009 issue of the journal Eye & Contact Lens: Science and Clinical Practice highlights the frequency of risks faced by contact lens users. The study, which analyzed a cross-section of contact lens users in a university practice setting (UCLA), showed that as many as half of all contact lens users experienced a contact lens-related complication. Some of these complications were vision-threatening, although most were benign. Complications were seen by users of all types of contact lenses, although users of rigid gas permeable lenses had a statistically significant reduction of risk compared to users of soft contact lenses.
The most common complications seen were papillae and giant papillary conjunctivitis. These can typically be treated and do not generally threaten vision. They typically cause infection, mucoid discharge, irritation, and blurred vision. Papillae and giant papillary conjunctivitis can lead to lens intolerance, forcing a return to glasses for best lens corrected vision.
Comparing Risks of LASIK and Contact Lenses
Although about half of contact lens users experience complications, contact lenses still compare favorably with LASIK and other forms of refractive surgery in terms of preserving your vision. Studies show that less than 1% of people receiving LASIK surgery experience a loss in best corrected vision. However, the likelihood of a loss of vision related to contact lens use is still significantly less.
At one time, contact lens use was associated with a potential for vision loss as high as 0.9%, but improvement in contact lens technology and wearing habits has reduced that risk significantly. Post-market studies required of all 30-day contact lenses approved by the FDA show that the approximate annual risk of vision-threatening microbial keratitis associated with contact lens use is 4 per 10,000 wearers, or 0.04%. If we assume a 14-year life for refractive surgeries, that amounts to a cumulative risk of about 0.6%. However, rates of infection are increased 4 times for people who wear contacts overnight, and up to 15 times for people who wear their contacts for more than two weeks.
LASIK complication rates resulting in vision loss used to be as high as 5%, but recently they have been reduced to about 1%, which is close to the rates for contact lenses. For most people, the comparable safety rate of LASIK seems better when compared to the vigilance necessary to keep contacts clean with daily, weekly, or biweekly removal and cleaning.
Safety Trends
However, in the near future, LASIK may be safer than contact lenses. LASIK has improved significantly in safety since its introduction. Advanced technology and experienced surgeons are largely responsible for the decrease in complications. As surgeons continue to gain experience and technology continues to advance, we can expect rates to continue dropping. Contact lenses, on the other hand, may be more risky in the future.
Microbial keratitis used to be caused by a relatively small number of microorganisms that were controllable with specific formulae of antibiotics. However, in recent years there have been more outbreaks associated with Acanthamoeba and fungal species. Some of this has been associated with specific contact lens solutions. Other times, it has been associated with the reduction of water quality standards by the EPA under the Bush administration. In the latter outbreak in Chicago during June to November of 2005, 40 people contracted Acanthamoeba keratitis, nearly seven times the historical rate of this type of infection.
In the future we may see more of what are described as "atypical" cases of microbial keratitis that may increase the risk of wearing contact lenses.
The most common complications seen were papillae and giant papillary conjunctivitis. These can typically be treated and do not generally threaten vision. They typically cause infection, mucoid discharge, irritation, and blurred vision. Papillae and giant papillary conjunctivitis can lead to lens intolerance, forcing a return to glasses for best lens corrected vision.
Comparing Risks of LASIK and Contact Lenses
Although about half of contact lens users experience complications, contact lenses still compare favorably with LASIK and other forms of refractive surgery in terms of preserving your vision. Studies show that less than 1% of people receiving LASIK surgery experience a loss in best corrected vision. However, the likelihood of a loss of vision related to contact lens use is still significantly less.
At one time, contact lens use was associated with a potential for vision loss as high as 0.9%, but improvement in contact lens technology and wearing habits has reduced that risk significantly. Post-market studies required of all 30-day contact lenses approved by the FDA show that the approximate annual risk of vision-threatening microbial keratitis associated with contact lens use is 4 per 10,000 wearers, or 0.04%. If we assume a 14-year life for refractive surgeries, that amounts to a cumulative risk of about 0.6%. However, rates of infection are increased 4 times for people who wear contacts overnight, and up to 15 times for people who wear their contacts for more than two weeks.
LASIK complication rates resulting in vision loss used to be as high as 5%, but recently they have been reduced to about 1%, which is close to the rates for contact lenses. For most people, the comparable safety rate of LASIK seems better when compared to the vigilance necessary to keep contacts clean with daily, weekly, or biweekly removal and cleaning.
Safety Trends
However, in the near future, LASIK may be safer than contact lenses. LASIK has improved significantly in safety since its introduction. Advanced technology and experienced surgeons are largely responsible for the decrease in complications. As surgeons continue to gain experience and technology continues to advance, we can expect rates to continue dropping. Contact lenses, on the other hand, may be more risky in the future.
Microbial keratitis used to be caused by a relatively small number of microorganisms that were controllable with specific formulae of antibiotics. However, in recent years there have been more outbreaks associated with Acanthamoeba and fungal species. Some of this has been associated with specific contact lens solutions. Other times, it has been associated with the reduction of water quality standards by the EPA under the Bush administration. In the latter outbreak in Chicago during June to November of 2005, 40 people contracted Acanthamoeba keratitis, nearly seven times the historical rate of this type of infection.
In the future we may see more of what are described as "atypical" cases of microbial keratitis that may increase the risk of wearing contact lenses.
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