Introduction
PRK eye surgery, also known as photorefractive keratectomy, is a type of refractive surgery that aims to correct vision problems like nearsightedness, farsightedness, and astigmatism. Unlike eyeglasses or contact lenses which compensate for refractive errors, PRK eye surgery permanently reshapes the cornea to improve focus of light entering the eye and allow clearer vision.
PRK and the similar LASIK procedure are the most common elective surgeries in the United States. While LASIK involves creating a corneal flap, PRK simply uses an excimer laser to ablate (remove) corneal tissue in order to change the eye’s refractive power. This laser corneal reshaping removes tiny amounts of the cornea’s surface until the desired vision correction is achieved.
While PRK eye surgery offers freedom from glasses and contact lenses, it’s important to understand both the procedure and the recovery process. We’ll explore how PRK works, the step-by-step surgery, what to expect post-op, risks and side effects, typical results, and if you are a good candidate for PRK eye surgery. This comprehensive guide will provide key information to help you determine if PRK for vision correction is right for you.
How PRK Surgery Works
PRK improves vision by reshaping the cornea – the clear, dome-shaped surface that covers the front of the eye. The cornea acts as a lens, bending and focusing light that enters the eye. But with nearsightedness, farsightedness or astigmatism, the cornea’s shape causes blurred vision at certain distances.
PRK utilizes an excimer laser to precisely sculpt and reshape the cornea so that light can focus properly on the retina at the back of the eye. The excimer laser emits a cool ultraviolet light beam, which removes ultra-thin layers of corneal tissue in a highly controlled manner. Unlike a surgical blade, the laser vaporizes tissue without cutting or burning.
During PRK, the surgeon first applies alcohol to the cornea to remove the thin outer layer of cells called the epithelium. This exposes the underlying corneal stroma, which the laser then gently reshapes. The excimer laser makes calculated ablation patterns on the stroma to flatten or steepen specific areas of the cornea depending on the individual’s needed vision correction.
Once the cornea’s shape has been finely tuned by the laser, the epithelium will grow back over several days. The newly shaped cornea then focuses light rays correctly onto the retina, resulting in clearer vision.
The PRK Procedure
The PRK procedure is done on an outpatient basis and takes about 15 to 30 minutes per eye. The steps include:
Pre-operative Evaluation
Before the procedure, the ophthalmologist will conduct tests to determine your corneal thickness, refractive error, and pupil size. These measurements allow the laser to be calibrated precisely for reshaping your unique cornea.
Numbing and Smoothing the Cornea
On surgery day, anesthetic eye drops are applied to numb the eye. The surgeon then uses a gentle brush or blunt instrument to remove the thin epithelial layer from the cornea’s surface. This is the only uncomfortable part of the procedure.
Laser Corneal Reshaping
With the corneal surface exposed, you will lie under the laser. An instrument will hold your eyelids open while the laser emits rapid bursts of ultraviolet light to remove microscopic layers of corneal tissue. The doctor may apply more smoothing of the cornea between laser passes. This ablation and smoothing continues until the desired corneal shape is achieved.
Bandage Contact Lens
After the laser treatment, a soft bandage contact lens is placed over the cornea to protect its surface as the epithelium regenerates. Antibiotic drops are applied to prevent infection. The contact lens is typically removed after 3 to 5 days once the surface has partially healed.
Recovery After PRK
PRK recovery typically spans several days to weeks before vision stabilizes and side effects resolve. Here’s what to expect:
• Week 1 – Severe eye pain, blurred vision, and light sensitivity are common. Eyes may water, tear and feel gritty. Pain medication will be prescribed. Activity is restricted.
• Weeks 2-4 – Vision starts improving but may fluctuate. Discomfort subsides though eyes remainsensitive. Epithelium continues regenerating. Contact lens is removed once corneal surface heals.
• 1-3 Months – Vision is clearer but can still fluctuate. Mild irritation or dryness may persist. Doctor checks vision stabilization and prescribes glasses or contacts if needed.
• 3-6 Months – Vision is significantly improved but still healing. Some experience dramatic visual changes during this time. Twinges of pain or discomfort may come and go.
• 6-12 Months – Vision is stabilized, although enhancement surgery may be recommended if vision is still unsatisfactory. Full recovery takes up to one year.
Proper post-op care is vital during recovery. This includes using prescribed antibiotic and anti-inflammatory eye drops, wearing protective sunglasses outdoors, avoiding eye rubbing, and keeping follow-up appointments with your ophthalmologist.
Risks and Potential Side Effects
While serious complications are rare, there are some risks and potential side effects to consider with PRK eye surgery:
• Corneal Haze – Some patients develop corneal haze, which is cloudiness in the cornea caused by the healing process. Mild haze often resolves on its own, but severe haze may impair vision and require a second surgery.
• Infection – As with any surgery, infection is possible but very unlikely with proper sterile technique. Signs include severe pain, light sensitivity, discharge, and vision changes. This requires prompt treatment with antibiotic eye drops or other interventions.
• Dry Eyes – PRK can damage nerves in the cornea, causing temporary or permanent dry eye which can be uncomfortable. Lubricating eye drops, gels or ointments can ease symptoms.
• Under/Over Correction – In rare cases, vision may be under-corrected or over-corrected, requiring a second enhancement surgery for ideal results.
Other rare risks include remodeling of the cornea over time, glare or halo effects around lights at night, and thinning of the cornea. Your ophthalmologist will discuss all potential complications and your individual risks in greater detail.
Results After PRK Surgery
Most patients see significant improvement in vision within 1-3 months after PRK surgery. As the cornea heals and side effects resolve, vision will continue to improve over 6-12 months. Results include:
• Clear vision at all distances without eyeglasses or contact lenses. Over 90% achieve 20/40 vision or better.
• Freedom from the hassle and costs of prescription eyewear. Waking up to clear vision is life-changing for many PRK patients.
• Improved night vision and contrast sensitivity. The crisp, sharp vision can make colors seem more vibrant.
• The ability to safely participate in sports and activities without eyewear getting in the way.
For a small percentage of patients, vision may regress slightly over the first year, requiring a secondary enhancement surgery or prescription glasses. Overcorrecting initially often compensates for this regression. Your ophthalmologist will examine your eyes thoroughly before determining if you are likely to need “touch up” surgery.
In general, PRK provides excellent, long-lasting vision correction results for nearsightedness, farsightedness, and astigmatism. Over 95% of patients report satisfaction with the improved clarity and convenience of life after PRK eye surgery.
Is PRK Right for You?
Although many people with nearsightedness, farsightedness, and astigmatism can benefit from PRK eye surgery, the best candidates include:
• Adults with stable vision prescriptions. PRK only treats existing vision issues and cannot prevent future prescription changes.
• Those with corneal thickness of 500 microns or more. Thinner corneas may not be suitable for laser reshaping.
• Patients wanting to be less dependent on glasses or contacts. PRK provides freedom and convenience.
• People with active lifestyles frustrated by glasses moving out of place. PRK enables sports, recreation and work without vision wear.
• Those ineligible for LASIK due to thin corneas or other factors. PRK can be done when LASIK is not an option.
• Minimal pre-existing conditions like dry eye syndrome or corneal scarring. Severe cases will make recovery more challenging.
PRK may not be recommended for people with autoimmune diseases, uncontrolled diabetes, severe dry eyes, or corneal dystrophy. Every candidate must receive a customized evaluation examining their eyes and overall health to determine if PRK is appropriate.
Conclusion
PRK eye surgery is an effective procedure to correct nearsightedness, farsightedness, and astigmatism without eyeglasses or contacts. The excimer laser gently reshapes the cornea to improve focus and provide clearer vision.
While the recovery period can involve significant discomfort and visual fluctuations, most patients experience excellent results within 1-3 months after PRK surgery. Over 90% achieve 20/20 vision or better, and over 95% report satisfaction with their vision correction.
Although PRK does not guarantee perfect vision, most patients find the surgery life-changing – allowing them to wake up every day and see the world clearly without eyewear. The freedom and convenience after healing makes the temporary recovery period worthwhile for millions of people.
If you are tired of dealing with glasses and contacts, PRK eye surgery may be the solution. Consult with a qualified ophthalmologist to determine if you are a good candidate and weigh the benefits versus the risks. With advanced excimer laser technology and skilled surgeons, PRK can safely and effectively correct common vision problems.
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