LASIK (Laser-Assisted In Situ Keratomileusis) is a widely recognized surgical procedure designed to correct common vision problems. It works by precisely reshaping the cornea, the clear front surface of the eye, to improve how light focuses on the retina. While LASIK offers a promising path to clearer vision and reduced reliance on glasses or contact lenses, it is not universally suitable. Determining candidacy involves a thorough evaluation of an individual’s eye health and overall medical profile.
Vision Conditions LASIK Addresses
LASIK primarily targets refractive errors, which occur when the eye does not bend light properly, leading to blurry vision. Myopia, or nearsightedness, is one such condition where distant objects appear blurred because light focuses in front of the retina. LASIK corrects myopia by flattening the cornea, allowing light to focus directly on the retina.
Conversely, hyperopia, or farsightedness, causes close objects to appear blurry as light focuses behind the retina. For hyperopia, LASIK reshapes the cornea to make it steeper, which helps light converge correctly on the retina. Astigmatism, another refractive error, results from an irregularly shaped cornea or lens, leading to distorted vision at all distances. LASIK addresses astigmatism by smoothing out these irregularities.
Key Candidacy Criteria
To be considered a suitable candidate for LASIK, individuals must meet specific medical and physiological requirements. Age is a factor, with most surgeons recommending the procedure for individuals aged 18 or older, as eye development and vision stabilize by this age. A stable vision prescription is also important, meaning no significant changes (less than 0.5 diopters) for at least 12 to 24 months prior to surgery. An unstable prescription can lead to unsatisfactory long-term results.
Adequate corneal thickness and health are also necessary for LASIK. The cornea must be thick enough to allow for the creation of a flap and subsequent reshaping, while leaving a sufficient residual stromal bed to maintain stability. Normal corneal thickness ranges from 500 to 600 micrometers. Overall eye health is assessed to ensure the absence of conditions like advanced glaucoma, cataracts, or severe dry eye syndrome. Certain systemic health conditions, such as uncontrolled diabetes or active autoimmune diseases, can also affect healing and increase complication risks, requiring careful evaluation.
Factors Influencing Recommendation
Beyond the objective medical criteria, several individual factors influence a LASIK recommendation. A person’s lifestyle, including participation in active sports or hobbies, is a consideration. For instance, individuals involved in contact sports might benefit from reduced reliance on corrective eyewear. Occupational requirements, such as those for pilots or first responders, often necessitate clear uncorrected vision, making LASIK an appealing option.
The desire to reduce or eliminate dependence on glasses or contact lenses is a common motivation for seeking LASIK. A comprehensive pre-operative evaluation is important, as it determines if a patient’s eyes can safely undergo the procedure and helps manage realistic expectations. This evaluation involves detailed corneal measurements and assessment of ocular health.
When LASIK is Not Recommended
LASIK is not advised in certain circumstances due to potential risks or suboptimal outcomes. Unstable or fluctuating prescriptions are a contraindication because the eye’s refractive error may continue to change after surgery, diminishing the long-term effectiveness. Corneas that are very thin or abnormally shaped, particularly in conditions like keratoconus, increase the risk of complications such as corneal ectasia, where the cornea bulges outward.
Severe dry eye syndrome can worsen after LASIK, leading to prolonged discomfort and impaired healing. Advanced eye diseases like glaucoma or the presence of cataracts preclude LASIK, as these conditions are addressed by different surgical procedures. Systemic conditions such as uncontrolled autoimmune diseases (e.g., lupus, rheumatoid arthritis) or poorly controlled diabetes can compromise wound healing and increase infection risk. Pregnancy or nursing are also temporary contraindications due to hormone-related vision fluctuations. Unrealistic patient expectations about the degree of vision correction or the elimination of all visual aids can also lead to a recommendation against the procedure.