Eye surgery encompasses a variety of procedures performed to treat conditions ranging from common refractive errors to serious sight-threatening diseases. These interventions are primarily aimed at restoring or improving vision, preventing blindness, and managing chronic eye health issues. The field of ophthalmology has advanced significantly, making many once-complex procedures routine, safe, and highly effective. Success rates for many procedures are very high, transforming the quality of life for millions of people annually.
Procedures for Correcting Refractive Errors
Refractive surgeries focus on reshaping the cornea, the clear front surface of the eye, to reduce or eliminate a person’s dependence on glasses or contact lenses. These procedures are elective and address common vision problems like myopia (nearsightedness), hyperopia (farsightedness), and astigmatism (uneven curvature). The goal is to alter the eye’s focusing power so light rays land precisely on the retina.
LASIK
Laser-Assisted In Situ Keratomileusis, or LASIK, is the most frequently performed type of refractive surgery. This procedure involves creating a thin, hinged flap on the cornea using a specialized blade or a femtosecond laser. The surgeon lifts this flap to expose the underlying corneal tissue. An excimer laser is then used to remove microscopic amounts of tissue, precisely reshaping the corneal curvature. After the laser sculpts the cornea, the flap is repositioned, where it adheres. This flap creation allows for rapid visual recovery, with many patients experiencing significant improvement within 24 hours.
PRK
Photorefractive Keratectomy, or PRK, is an alternative procedure preferred for patients with thin corneas or those whose occupations involve contact sports. Instead of creating a flap, the surgeon removes the outer layer of corneal cells, called the epithelium, entirely. The excimer laser then reshapes the exposed corneal surface, similar to LASIK. The epithelium grows back naturally over several days, meaning the recovery process is longer and involves more initial discomfort than LASIK. PRK results in a structurally stronger cornea because no permanent flap is created.
Cataract Removal and Lens Replacement
Cataract surgery is the most common major surgical procedure performed globally. A cataract is the clouding of the eye’s natural lens, which sits behind the iris, causing blurred or dim vision. The surgery involves removing this cloudy lens and replacing it with an artificial Intraocular Lens (IOL).
Phacoemulsification
The standard technique is phacoemulsification, often called phaco, which is a minimally invasive approach. A micro-incision, usually less than 3 millimeters, is created in the cornea, and a small probe is inserted into the lens capsule. This probe emits high-frequency ultrasound energy to break the dense cataract into tiny fragments. These emulsified fragments are then suctioned out, leaving the lens capsule intact. Once the natural lens material is removed, a foldable IOL is inserted through the small incision and positioned within the preserved lens capsule. The small incision is often self-sealing and rarely requires sutures.
Intraocular Lens (IOL) Options
Modern IOLs offer various options to enhance vision beyond simply clearing the cataract.
- Monofocal IOLs provide clear focus at a single distance, meaning glasses may still be needed for reading or close work.
- Toric IOLs correct existing astigmatism.
- Multifocal or extended depth of focus IOLs provide a wider range of vision, potentially reducing the need for glasses at multiple distances.
Surgical Treatments for Glaucoma
Glaucoma is a group of diseases that damage the optic nerve, often due to abnormally high pressure inside the eye, which can lead to permanent vision loss. The pressure increase results from a buildup of aqueous humor, the fluid that normally flows in and out of the front of the eye. Surgical interventions aim to improve the drainage of this fluid to lower the intraocular pressure (IOP).
Laser Procedures
Laser surgery is frequently the first surgical step used to manage open-angle glaucoma. Selective Laser Trabeculoplasty (SLT) uses a low-energy laser to target specific pigmented cells in the trabecular meshwork, the eye’s natural drainage system. The laser application stimulates a biological response that improves the outflow of aqueous humor, thus lowering the pressure over several weeks.
Incisional Procedures
When medication and laser procedures are insufficient to control IOP, traditional incisional surgeries are performed. A trabeculectomy creates a new, controlled drainage channel, or filtration bleb, in the white of the eye, allowing aqueous humor to bypass the blocked meshwork and filter into a space beneath the conjunctiva. This procedure effectively reduces pressure. Another incisional option is the placement of a glaucoma drainage device, often called a tube shunt. These devices consist of a small tube inserted into the anterior chamber and connected to a plate secured on the eye’s exterior wall. The shunt acts as a permanent bypass to drain excess fluid and maintain a lower pressure level.
Interventions for Retinal and Vitreous Conditions
Procedures involving the retina and vitreous humor are performed at the back of the eye to address complex conditions that threaten vision. These surgeries are reserved for acute problems like retinal detachment, severe complications of diabetic retinopathy, or the repair of macular holes. They require specialized microsurgical instruments and techniques due to the delicate nature of the posterior eye structures.
Vitrectomy
A vitrectomy is the primary procedure for many posterior segment issues, involving the removal of the vitreous humor, the clear, gel-like substance that fills the eye’s center. The surgeon uses tiny instruments inserted through small openings in the sclera to remove the vitreous, which may be cloudy due to blood, scar tissue, or inflammation. The vitreous is replaced with a saline solution, gas, or silicone oil to help hold the retina in its proper position while it heals.
Scleral Buckle
Retinal detachment, where the light-sensitive tissue pulls away from its underlying support layers, is often treated with a vitrectomy or a scleral buckle. The scleral buckle procedure involves sewing a silicone band or sponge to the outside wall of the eye. This gently pushes the sclera inward, creating an indent that physically supports the detached retina and moves it closer to the underlying tissue to allow it to reattach. These interventions are performed to preserve vision following a sudden event or progressive disease process.