Laser-Assisted in Situ Keratomileusis, or LASIK, is a widely performed surgical procedure that offers a permanent solution for correcting common refractive errors. While it is highly successful for many, not every person seeking vision correction is an ideal candidate for the procedure. One of the most significant limiting factors for eligibility is the presence of pre-existing dry eye disease, which requires careful evaluation to ensure a safe and successful outcome.
Understanding the Connection Between Dry Eyes and LASIK
The primary concern regarding LASIK and dry eyes stems from how the surgery affects the corneal nerves. The procedure involves creating a thin flap on the cornea’s surface, which temporarily severs many small nerve endings. These nerves are responsible for sensing the eye’s surface and triggering the reflex that stimulates tear production.
When these nerves are compromised, the signal to the lacrimal glands to produce tears is significantly reduced. This temporary decrease in corneal sensitivity and tear production destabilizes the tear film, causing dryness symptoms. Though the corneal nerves typically regenerate over several months, the resulting instability can cause prolonged discomfort and affect vision clarity during healing.
Criteria for Determining LASIK Eligibility
Eligibility for LASIK depends on the severity and cause of the dry eye condition. A thorough pre-operative assessment differentiates between mild, manageable dry eye and a chronic, severe condition that may disqualify a patient. This evaluation measures the quantity and quality of tear production.
The Schirmer’s test measures tear fluid produced over five minutes; less than 10 millimeters often signals inadequate production. Clinicians also perform a Tear Break-Up Time (TBUT) test, which measures how quickly the tear film evaporates, and use corneal staining dyes to identify surface damage. Patients with mild to moderate dry eye may proceed after treatment, but those with severe, chronic dry eye are typically unsuitable candidates due to the risk of long-term complications.
Pre- and Post-Operative Dry Eye Management
Pre-operative Management
For individuals approved for LASIK, managing dry eye involves protocols before the procedure to optimize the ocular surface. Pre-operative optimization ensures the corneal surface is healthy prior to surgery. This may involve the prescribed use of anti-inflammatory drops, such as cyclosporine or mild corticosteroids, to reduce surface inflammation. Other pre-surgery treatments may include punctal plugs, which are tiny devices inserted into the tear ducts to block drainage and conserve natural tears. A doctor may also recommend dietary supplements containing omega-3 fatty acids, which can improve the quality of the tear film’s oily layer.
Post-operative Management
Following the procedure, patients must adhere to an aggressive schedule of lubricating eye drops, often preservative-free artificial tears, for several months. Anti-inflammatory drops are typically continued to support nerve regeneration and healing. Patients are encouraged to use a humidifier, especially while sleeping, and to practice conscious blinking exercises. These comprehensive management strategies are a necessary part of the recovery process to facilitate healing and restore ocular comfort.
Alternative Vision Correction Procedures
If a patient is ineligible for LASIK due to severe or resistant dry eye, several alternative vision correction procedures are available. Photorefractive Keratectomy (PRK) is a surface ablation technique that avoids creating a corneal flap, which may result in less severe post-operative dry eye than LASIK. Though PRK has a longer initial recovery period, it is a safer option for those with thinner corneas or pre-existing dry eye concerns.
Small Incision Lenticule Extraction (SMILE) is another laser procedure that involves a smaller incision than LASIK. This minimal approach is designed to disrupt fewer corneal nerves, making it a viable option for patients concerned about dry eye symptoms. For individuals with very high prescriptions, thin corneas, or chronic dry eye, an Implantable Collamer Lens (ICL) may be recommended. The ICL is surgically placed inside the eye and does not alter the corneal tissue, completely bypassing the risk of laser-induced dry eye.