Question

Describe different refractive surgeries. And how will you investigate a patient undergoing refractive surgery.

Hint:

A thorough preoperative evaluation is crucial in selecting the appropriate refractive surgery for each patient and ensuring the best possible outcomes.

Answer 1

Refractive surgeries are procedures aimed at correcting refractive errors such as myopia, hyperopia, and astigmatism, in order to reduce or eliminate the need for corrective lenses like glasses or contact lenses.

Step 1: Different Types of Refractive Surgeries:
1. LASIK (Laser-Assisted in Situ Keratomileusis):
$\,$ - LASIK is the most commonly performed refractive surgery. It involves the use of a laser to reshape the cornea, improving the focus of light onto the retina. A thin flap is created in the cornea, and the underlying tissue is reshaped using an excimer laser.
$\,$ - Indicated for myopia, hyperopia, and astigmatism.
2. PRK (Photorefractive Keratectomy):
$\,$ - In PRK, the surface layer of the cornea (epithelium) is removed, and an excimer laser is used to reshape the corneal tissue underneath. Unlike LASIK, no flap is created.
$\,$ - PRK is generally recommended for patients with thin corneas or those with higher refractive errors.
3. SMILE (Small Incision Lenticule Extraction):
$\,$ - SMILE is a minimally invasive procedure that involves creating a small incision in the cornea through which a lenticule (a small disc of corneal tissue) is removed. This reshapes the cornea and corrects refractive errors.
$\,$ - SMILE is primarily used to treat myopia and mild astigmatism.
4. LASEK (Laser Epithelial Keratomileusis):
$\,$ - LASEK is similar to PRK, but in this procedure, the epithelium is preserved by loosening it with an alcohol solution and then repositioning it after the corneal reshaping.
$\,$ - LASEK may be preferred for patients with thinner corneas or those who are at higher risk for complications with LASIK.
5. ICL (Implantable Collamer Lens): $\,$ - ICL involves surgically implanting a synthetic lens into the eye to correct refractive errors, typically in cases where LASIK is not suitable due to very high prescriptions or thin corneas.
$\,$ - It is an option for both myopia and hyperopia and can be removed if necessary.

Step 2: Investigation of a Patient Undergoing Refractive Surgery:
1. Preoperative Assessment:
$\,$ - A comprehensive eye exam, including refraction testing, measurement of the corneal thickness (pachymetry), and corneal topography, to assess the shape and health of the cornea.
2. Assessment of Visual Acuity:
$\,$ - Detailed measurement of the patient's visual acuity, both with and without corrective lenses, to understand their baseline vision and goals for surgery.
3. Dry Eye Evaluation:
$\,$ - Evaluation of the patient's tear production and corneal surface health. Dry eyes can affect the outcome of refractive surgeries, and preoperative management may be required.
4. Slit Lamp Examination:
$\,$ - A slit-lamp exam is used to assess the health of the eye's structures, particularly the cornea, lens, and retina, ensuring no underlying pathology before surgery.
5. Intraocular Pressure (IOP) Measurement:
$\,$ - Measuring IOP helps to detect any potential risk for glaucoma, which may complicate refractive surgery outcomes.
6. Patient History and Expectations:
$\,$ - A detailed patient history to assess for any contraindications such as autoimmune diseases, pregnancy, or previous ocular conditions. It's also important to set realistic expectations regarding the outcome of surgery.