Stephen Wexler, MD, explains LASIK prescription limits and when other vision correction options may be a better fit for patients with high myopia.
Many patients with strong glasses or contact lens prescriptions wonder whether laser vision correction is an option for them. In a recent video, Stephen Wexler, MD, refractive surgeon with the WashU Medicine John F. Hardesty, MD Department of Ophthalmology & Visual Sciences, explains how surgeons evaluate high levels of nearsightedness (also called myopia) when considering LASIK or PRK.
While today’s excimer lasers are FDA-approved to treat nearsightedness up to –14 diopters, Dr. Wexler notes that most surgeons take a more conservative approach in real-world practice to prioritize long-term eye health and safety.
Watch: LASIK Prescription Limits Explained by Stephen Wexler, MD
Why Do Surgeons Set Lower Limits Than the Laser Approval?
Although the technology can technically treat very high prescriptions, laser vision correction works by reshaping the cornea. Higher prescriptions require removing more corneal tissue, which may weaken the cornea if too much tissue is removed.
“For LASIK and PRK, we usually don’t feel comfortable treating much above about –9 diopters,” Wexler explains. “Sometimes a little higher if the cornea is thick and everything looks perfect, but patient safety always comes first.”
This is why corneal thickness, corneal shape, and overall eye health are just as important as the prescription itself when determining candidacy.
What Are the Options for Very High Myopia?
For patients with prescriptions stronger than what is safe for LASIK or PRK, other refractive surgery options may provide excellent vision outcomes, including:
- Implantable lenses (phakic IOLs) — sometimes described as a permanent contact lens placed inside the eye
- Refractive lens exchange (RLE) — similar to cataract surgery, where the eye’s natural lens is replaced with an artificial lens
Wexler recalls treating a patient with a prescription of about –16 diopters who did very well after cataract surgery with lens replacement, even though laser surgery would not have been appropriate.
It’s also important to note that patients with high myopia may be at increased risk for certain retinal conditions, making careful evaluation and long-term monitoring especially important.
Why a Comprehensive Evaluation Matters
There is no single prescription cutoff that determines whether someone is a candidate for LASIK. Surgeons consider multiple factors, including:
- Corneal thickness and structure
- Prescription stability
- Eye health and retinal risk factors
- Lifestyle and visual goals
That’s why a full refractive surgery consultation is essential before deciding which vision correction approach is best.
Exploring the Best Vision Correction Option for You
Patients with high prescriptions should not assume they have no surgical options. With advances in refractive surgery and lens-based procedures, many people who are not good LASIK candidates can still achieve excellent vision outcomes through alternative treatments.
A personalized evaluation with an experienced refractive surgeon is the best way to determine the safest and most effective path forward.
About WashU Medicine
WashU Medicine is a global leader in academic medicine, including biomedical research, patient care and educational programs with 2,900 faculty. Its National Institutes of Health (NIH) research funding portfolio is the second largest among U.S. medical schools and has grown 56% in the last seven years. Together with institutional investment, WashU Medicine commits well over $1 billion annually to basic and clinical research innovation and training. Its faculty practice is consistently within the top five in the country, with more than 1,900 faculty physicians practicing at 130 locations and who are also the medical staffs of Barnes-Jewish and St. Louis Children’s hospitals of BJC HealthCare. WashU Medicine has a storied history in MD/PhD training, recently dedicated $100 million to scholarships and curriculum renewal for its medical students, and is home to top-notch training programs in every medical subspecialty as well as physical therapy, occupational therapy, and audiology and communications sciences.