PRK Surgery Eye

PRK Surgery

Photorefractive keratectomy (PRK) is a form of refractive eye surgery which aims to reduce the need for correction with glasses or contacts.  PRK uses a specific type of laser (called an excimer laser) to reshape the cornea and correct near sightedness, far sightedness and/or astigmatism. During PRK the outer layer of the cornea, called the epithelium, is removed and a laser called an excimer laser is used to remove a portion of the cornea. The epithelium is then allowed to heal and regrow which usually takes 3-7 days. The vision will initially be blurry and gradually improve as the epithelium regrows.  Often, a bandage contact lens is placed on the eye to aid in healing and to help reduce discomfort after the procedure. The amount and location of the cornea removed is determined by preoperative measurements. Removal of this section of the cornea changes the corneal curvature and the overall refractive power of the eye with an overall goal of reducing the patient's need for glasses. PRK is typically performed in an outpatient surgery center or medical office with a special room for performing refractive surgery. After surgery you will need to use eye drops to help prevent infection and reduce inflammation.  It is also typical to need lubricant eye drops or artificial tears.  During the postoperative period there will be restrictions on certain activities including but not limited to touching/rubbing the eyes, wearing makeup, and/or swimming.  Specific instructions will be given to by the surgeon at the time of surgery and these should be followed to ensure proper healing. Only an ophthalmologist is trained to know if you are a good candidate for PRK, so you will need to  schedule an evaluation with a refractive surgery specialist.  Refraining from contact lens use for a specific period of time prior to the evaluation will be required to ensure accurate measurements, this period is usually two weeks.  A complete eye exam including refraction, corneal topography, dilated exam and corneal thickness measurement will determine if a patient is eligible for PRK. Criteria which make a patient a good candidate for PRK include myopia in range of -1 diopter to -10 diopters, hyperopia in the range of +1 diopter to +6 diopters and/or astigmatism in the range of 1 diopter tp 5 diopters, generally healthy eyes, age 22 or older with a stable refraction. There are certain medical conditions or eye characteristics which will make a patient a poor candidate for PRK.  These include thin corneas, visually significant cataracts, advanced glaucoma, uncontrolled diabetes, excessive scarring or keloid formation, or women who are pregnant or nursing.Unlike LASIK, PRK does not involve creating a flap prior to lasering the corneal bed.  This allows PRK to be an option for some patients that are not good candidates for LASIK due to thin corneas. However, there are still criteria which must be met regarding refractive error and corneal thickness to ensure PRK can be done safely.  There is also evidence that PRK can result in fewer damage to corneal nerves resulting in fewer dry eye symptoms.  Due to there being no fap creation, PRK does not pose a risk for a dislodged flap from eye trauma after surgery.  PRK is an elective procedure to reduce the need for glasses and contacts. For this reason, it is typically not covered by vision or medical insurance. The cost of PRK varies but is often in the range of $1,000-$3,000 per eye. Sources:Somani SN, Moshirfar M, Patel BC. Photorefractive Keratectomy. 2021 Nov 2. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan–. PMID: 31751077.Li SM, Kang MT, Wang NL, Abariga SA. Wavefront excimer laser refractive surgery for adults with refractive errors. Cochrane Database Syst Rev. 2020 Dec 18;12(12):CD012687. doi: 10.1002/14651858.CD012687.pub2. PMID: 33336797; PMCID: PMC8094180.
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SMILE eye surgery

SMILE Eye Surgery : What Is It? What Does It Cost?

Small incision lenticule extraction (SMILE) is a form of refractive eye surgery. Refractive eye surgery is a type of eye surgery that reduces the need for glasses or contacts.  SMILE eye surgery has the ability to correct myopia (near sightedness) and/or astigmatism. There may be options for correcting hyperopia (far sightedness) with SMILE, however, this has been less studied.  The cost of SMILE varies depending on location, however, typical costs are $2500-$3500 per eye which is overall comparable to LASIK.  SMILE is an elective procedure and it is typically not covered by medical or vision insurance.  SMILE is performed by separating a small section of the cornea using a laser.  This cornea is then removed from the cornea through a small incision, also created by the laser.  The size and shape of the cornea removed is determined by pre-operative measurements.  These will measure the amount of prescription that needs to be corrected and calculate how much cornea to remove.  When the cornea section is removed it changes the curvature of the cornea which in turn changes how the cornea bends light.  This change in cornea shape is what changes the patient’s need for glasses or contacts.  Only a trained ophthalmologist can know if someone is a good candidate for SMILE.   A thorough evaluation with an ophthalmologist will include checking a glasses prescription (refraction), measuring the thickness of the cornea, and measuring the curvature of the cornea (topography) along with performing a complete eye exam.  Contact lens use prior to being evaluated for SMILE will affect the measurement and most ophthalmologists will prohibit using contacts for at least 2 weeks prior to an evaluation.  Criteria which make a patient a good candidate for SMILE include near sightedness (myopia) in the range of -1.00 diopter to -10.00 diopters and/or astigmatism in the range of 1.00 diopter to 3.00 diopters, generally healthy eyes, age 22 or older with a stable glasses prescription. Certain medical conditions or eye characteristics can make a patient a poor candidate for SMILE.  These include thin corneas, visually significant cataracts, advanced glaucoma, uncontrolled diabetes, excessive scarring or keloid formation, or women who are pregnant or nursing.If someone is found to be a good candidate for SMILE they will be scheduled for the procedure.  SMILE is typically performed at an outpatient surgery center or a medical office with a specialized procedure room.  During the procedure a specialized laser (called a femtosecond laser) is used to create a 2-3mm incision and separate the cornea to be removed from the rest of the cornea.  Once the laser has finished, the patient is moved to a microscope where the cornea is removed through the incision.  The incision will typically self-seal and no sutures are needed during the procedure.  After surgery, it will be necessary to use eye drops to help prevent infection and reduce inflammation.  It is also typical to need lubricant eye drops or artificial tears.  During the postoperative period there will be restrictions on certain activities including but not limited to touching/rubbing the eyes, wearing makeup, and/or swimming.  Specific instructions will be given to by the surgeon at the time of surgery and these should be followed to ensure proper healing.  Vision outcomes from SMILE are comparable to outcomes from LASIK.  There is also evidence that SMILE may result in a lower side effect profile, including improved corneal sensation and a better tear film compared to LASIK.  This could result in fewer symptoms from dry eye after the procedure.  SourcesReinstein DZ, Archer TJ, Gobbe M. Small incision lenticule extraction (SMILE) history, fundamentals of a new refractive surgery technique and clinical outcomes. Eye Vis (Lond). 2014 Oct 16;1:3. doi: 10.1186/s40662-014-0003-1. PMID: 26605350; PMCID: PMC4604118.https://pubmed.ncbi.nlm.nih.gov/26605350/Zhang Y, Shen Q, Jia Y, Zhou D, Zhou J. Clinical Outcomes of SMILE and FS-LASIK Used to Treat Myopia: A Meta-analysis. J Refract Surg. 2016 Apr;32(4):256-65. doi: 10.3928/1081597X-20151111-06. PMID: 27070233.https://pubmed.ncbi.nlm.nih.gov/27070233/Denoyer A, Landman E, Trinh L, Faure JF, Auclin F, Baudouin C. Dry eye disease after refractive surgery: comparative outcomes of small incision lenticule extraction versus LASIK. Ophthalmology. 2015 Apr;122(4):669-76. doi: 10.1016/j.ophtha.2014.10.004. Epub 2014 Nov 22. PMID: 25458707.https://pubmed.ncbi.nlm.nih.gov/25458707/
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