Refractive surgery most commonly performed for myopia –
**Core Concept**
Refractive surgery is a type of ophthalmic procedure aimed at correcting vision problems by altering the shape of the cornea. Myopia, or nearsightedness, is a common condition where close objects are seen clearly but distant objects appear blurry due to an elongated eyeball or cornea.
**Why the Correct Answer is Right**
The most commonly performed refractive surgery for myopia is LASIK (Laser-Assisted In Situ Keratomileusis), which involves creating a thin flap in the cornea, lifting it, and reshaping the underlying tissue with an excimer laser. This procedure corrects myopia by flattening the central cornea, reducing its refractive power, and improving vision for distant objects. The excimer laser ablates (removes) microscopic amounts of corneal tissue, allowing the surgeon to precisely control the amount of tissue removal and achieve the desired refractive outcome.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because PRK (Photorefractive Keratectomy) is another type of refractive surgery, but it is more commonly used for treating astigmatism and hyperopia.
* **Option B:** This option is incorrect because LASEK (Laser-Assisted Subepithelial Keratomileusis) is a variation of LASIK, but it is less commonly used and has a higher risk of complications.
* **Option D:** This option is incorrect because Radial Keratotomy is an older type of refractive surgery that was once used to treat myopia but has largely been replaced by LASIK.
**Clinical Pearl / High-Yield Fact**
It's essential to note that LASIK is not suitable for everyone, particularly those with thin corneas, dry eyes, or certain corneal abnormalities. A thorough preoperative evaluation and consultation with an ophthalmologist are crucial to determine the best course of treatment for refractive errors.
**Correct Answer: C. LASIK**