Keratectomy - Know It All

Introduction:

Keratectomy is the surgical procedure done to remove a section or layer of the cornea. The cornea is the transparent part of the eye that focuses the light and covers the iris, pupil, and anterior chamber. The cornea must be clear. Otherwise, the light gets scattered and gives a blurry vision. Keratectomy procedures are typically performed to correct refractive errors, treat corneal diseases, or improve vision. It is important to note that any surgical procedure on the eyes should be discussed thoroughly with an eye care professional who can provide personalized advice based on individual circumstances.

What Are the Types of Keratectomy?

Three primary forms of keratectomy are present:

• Excimer Laser Keratectomy - This includes treatments like Laser in situ Keratomileusis (LASIK) and Photorefractive Keratectomy (PRK), which reshape the cornea using excimer lasers to correct vision.

• Wedge-Shaped Keratectomy(Wedge Resection) - This reduces astigmatism following penetrating keratoplasty or cataract surgery.

• Lamellar Keratectomy - This procedure removes only a portion of the cornea.

Other variations include:

• Phototherapeutic Keratectomy (PTK) - PTK removes or reshapes corneal tissue using laser technology. It is frequently used to treat specific irregularities or disorders of the cornea.

• Anterior Lamellar Keratoplasty (ALK) - This kind of keratectomy involves removing and replacing the cornea's front layer while maintaining the integrity of the endothelium or inner layer.

• Deep Anterior Lamellar Keratoplasty (DALK) - Removes nearly the whole thickness of the cornea while sparing the endothelium.

How Is the Procedure Done?

The patient is prepared by being placed in a comfortable position on a surgical bed or examination chair. The eye is made numb by applying anesthetic eye drops.

• Debridement: To reveal the underlying corneal tissue, the surgeon slices away the cornea's epithelium.

• Application of Laser: The corneal tissue is precisely removed or reshaped using an excimer laser. The areas affected by corneal irregularities, scars, or dystrophies are targeted by the laser, which is programmed by the surgeon based on the particular requirements of the procedure.

• Monitoring: To guarantee precise and controlled tissue removal, the surgeon uses cutting-edge imaging technology to keep an eye on the procedure throughout.

• Postoperative Care: A bandage contact lens is typically used to protect the eye following laser treatment, and prescription eye drops containing antibiotics or anti-inflammatory agents may be given to help with healing.

When Is the Procedure Indicated?

Keratectomy is indicated for:

• Corneal Dystrophies: PTK may be useful in the management of granular or lattice dystrophies, among other corneal dystrophies.

• Corneal Scarring: Injuries, infections, or prior surgeries can leave corneal scars, which PTK can help to smooth out or eliminate.

• Superficial Corneal Irregularities: PTK can be used to treat corneal surface irregularities that are superficial.

Keratomileusis in Situ Using a Laser (LASIK):

• Refractive Errors: Myopia, hyperopia, and astigmatism are among the refractive errors that LASIK is primarily indicated to correct.

• Stable Prescription: Patients with stable refractive errors whose prescriptions have stayed mostly unchanged for a predetermined amount of time should consider LASIK.

• Good General Eye Health: Candidates for LASIK should typically have no serious ocular diseases and good general eye health.

When Is the Procedure Contraindicated?

Keratectomy is contraindicated for:

• Corneal Thinning: In cases of severe corneal thinning, PTK may not be appropriate because the removal of extra tissue could damage the structure.

• Active Corneal Infections: Because of the possibility of an aggravation, PTK is typically avoided when corneal infections are active.

Laser in situ Keratomileusis is contraindicated for:

• Pregnancy and Breastfeeding: Because hormone fluctuations may impact vision, LASIK is frequently postponed during these times.

• Autoimmune Disorders: Those who have autoimmune disorders may not be good candidates for LASIK surgery and may be more susceptible to complications.

• Thin Corneas: In situations where there is not enough corneal thickness, laser reshaping may not be possible due to insufficient tissue for the safe creation of the corneal flap.

• Severe Dry Eye: Conditions resulting in severe dry eyes may heighten the risk of postoperative complications.

What Could Be the Risks and Complications?

Although keratectomy techniques, such as Phototherapeutic Keratectomy (PTK) and Laser in situ Keratomileusis (LASIK), are generally regarded as safe and efficacious, there are certain risks and possible complications associated with them.

General Risks:

• Infection: Surgical procedures are naturally risky in terms of infection. Preoperative and postoperative antibiotic medications are often prescribed to minimize this risk.

• Inflammatory Response: They are transient inflammatory reactions in the eye that can happen during the healing process.

• Dry Eyes: Dry eyes can be temporary or, in some cases, chronic due to decreased tear production or changes in the composition of the tear film.

• LASIK Flap Complications: Making a corneal flap is a part of LASIK. Flap creation or repositioning complications can include free caps, buttonholes, or uneven flaps.

Risks Specific to a Procedure:

• Corneal Haze following Phototherapeutic Keratectomy (PTK): PTK may cause the cornea to become cloudy, a condition known as corneal haze that can impair vision but is typically transient.

• Overcorrection or Undercorrection: There is a risk of overcorrection or undercorrection of refractive errors, particularly if the laser ablation is not precisely controlled.

General Considerations:

• Basis Conditions: Complication risk may be increased by systemic health issues or preexisting eye conditions. Before the procedure, these should be carefully evaluated.

• Patient Satisfaction: Although many patients experience notable improvements in their vision, individual outcomes can differ, and not all patients attain perfect vision.

• Effects Over Time: It is unclear what the long-term consequences of keratectomy procedures will be, particularly after several decades.

Conclusion

In summary, keratectomy refers to a range of surgical techniques that involve the removal or reshaping of corneal tissue, each intended to treat a particular ocular condition. Phototherapeutic keratectomy (PTK) and laser in situ keratomileusis (LASIK) are the two most common types. For the treatment of corneal dystrophies, scars, and refractive errors, these procedures are generally regarded as safe and effective. But keratectomy has risks and potential complications just like any other surgical procedure. Adherence to postoperative care instructions and routine follow-up visits contribute to successful outcomes and enhanced visual function for many individuals who undergo keratectomy procedures.