Optometric Management Can Affect Post LASIK, PRK Outcomes

Patients frequently depend on optometric management for a variety of ophthalmic conditions, even when surgical procedures to treat the condition were performed by an ophthalmologist. Corneal refractive surgeries, which include laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK), are among the procedures optometrists are expected to manage postoperatively, and the clinician’s management strategy may affect patient outcomes. While not much has changed with respect to these 2 decades-old treatments, clinicians can benefit from some practical anecdotal tips, accumulated from personal experience working with a variety of patients over the years. 

Setting Realistic Expectations

Patients demonstrate a wide spectrum of personalities, and some require more postoperative reassurance than others. One thing they share in common, however, is that they have often spent thousands of dollars for these procedures and likely have the expectation that their refractive error will resolve, or at a minimum, improve. 

Setting realistic visual expectations before the surgery and reviewing the expected transitory side effects after the surgery will help to avoid any postoperative shock. It is important to explain that vision may fluctuate for about a month after the surgery, likely due to dryness. This can prompt a discussion about the need to use good quality artificial tears for a period of 3 to 6 months following the procedure. The patient can also expect to see starbursts or halos around lights at night, particularly within the first few weeks. Near vision may be especially challenging within the first month, particularly for patients with myopia and presbyopia. 

Considering Patients With Hyperopia 

Patients with hyperopia may have limited options for treating their refractive error. LASIK and PRK are sometimes potential treatments, but healing is unpredictable, particularly in patients with higher hyperopia. Although the US Food and Drug Administration (FDA) has approved LASIK and PRK for hyperopia between 0.50 and 6.00 diopters (D), surgeons will have their own treatment parameters.¹ Since individuals with hyperopia may be more likely to experience postoperative halos or need future retreatment, it is crucial for optometrists to communicate reasonable postoperative expectations.²

Postoperative visual recovery can be a difficult experience for individuals with hyperopia following the LASIK and PRK procedures, and patient management may involve a bit of extra reassurance. Decades of treatment outcome tracking has shown that hyperopic treatments are more likely to regress than myopic treatments. Corneal biomechanics are complex, and research has failed to identify a particular culprit.³

For the first 4 to 6 weeks, the patient may observe significantly improved near vision, but express disappointment with their mildly blurred distance vision. As the patient, who is now mildly myopic, regresses towards emmetropia during the first year after treatment, these visual outcomes may reverse — distance vision will improve, while near vision worsens.³ Some individuals may find these vision changes to be particularly menacing, particularly individuals with presbyopia. 

Managing With Artificial Tears

All patients should use artificial tears for several months following these procedures to optimize healing and visual outcomes. Corneal nerves have been severed or disrupted and can take several months to repair, which leads to reduced corneal sensitivity and tear production.^4,5 For the first month after surgery, patients should instill preservative-free tears every 1 to 2 hours while awake. This can be reduced to a minimum of 4 times daily at the 1-month mark. If patients are comfortable with 4-times daily instillation, and no punctate epithelial keratitis is observed, they may be switched to bottled tears. Since bottled tears, particularly generic formulations, frequently contain thimerosal or benzalkonium chloride (BAK) — agents that can cause increased dryness when used too frequently — branded artificial tears may be a better option.⁶ Consulting with the surgeon and becoming familiar with their postoperative regimen is highly recommended.

Environmental factors can exacerbate these dry eye symptoms and create a risk for recurrent corneal erosions, especially after PRK.⁷ Instilling artificial tears with higher viscosity may help to form a protective coating that appears to last longer than less viscous artificial tears. Recommending a sleeping mask at night can help to block fan or vent drafts, while simultaneously keeping eyelids shut if lagophthalmos is suspected. 

Progression to an ointment may be a logical next step if higher viscosity tears fail to relieve PRK- or LASIK-associated dry eye. However, this treatment option may not be optimal for individuals who frequently awaken during the night. A sodium chloride hypertonicity ophthalmic solution may be the best option for these individuals or for patients with reduced visual acuity without signs of corneal involvement (punctate epithelial erosions, delayed PRK healing patterns) a few weeks after the surgery.

Accepting That Flap Debris Often Resolves on its Own

When an optometrist observes a corneal opacity, the natural instinct may be to try to make it go away, perhaps by treating it with steroids and hoping for the best. LASIK surgery is mechanically stressful to the cornea and surrounding tissue and it is not uncommon to observe debris — oil droplets from meibomian glands, small fibers or bits of dust, corneal striae, or even corneal epithelial cells — at the flap interface.

The surgeon likely noted this upon finishing the treatment in the operating room. If the debris was in a location that could potentially impact vision, the surgeon may have lifted the flap or its edge and rinsed out as much as possible. This would likely be noted in the procedure report. Most of the time, these debris are peripheral and do not impact visual outcome. Watching them carefully during the first few weeks is important to ensure epithelial ingrowth or diffuse lamellar keratitis (DLK) do not develop. To err on the side of caution, patients should return for weekly follow-up visits.

While oil droplets will usually resolve within a month, fibers are likely permanent. When fibers are present, it is important to watch carefully for signs of epithelial cell migration toward the fiber. If a fiber is protruding from the flap incision, it is good practice to discuss this with the surgeon, as they may prefer to remove this potential source of bacterial accumulation and infection.

Carefully measuring the affected area and noting the shapes or patterns are imperative for progression monitoring. Anterior segment photography is particularly useful to track changes with time and can quickly provide surgeons with updates. Excessive epithelial cells that conglomerate and increase in size with time warrant communication with the surgeon. 

Steroid Tapering and Vision

Patients who undergo PRK are frequently put on a steroid taper to help regulate corneal healing and control the refractive outcome. The length of the taper varies between surgeons, and can range from 1 month to several months postoperatively. Some patients may experience a subjective vision plateau between 4 to 6 weeks after surgery — visual acuity may measure 20/25 or 20/20 with little refractive error, but the vision just doesn’t seem as sharp as they were expecting.

Once the patient finishes the steroid taper, they may report visual improvement and satisfaction with the outcome. If the patient has not attained satisfactory vision and still has several weeks left in the steroid taper, adding the sodium chloride hypertonicity ophthalmic solution may enable a faster subjective recovery.

Showcasing Optometry’s Abilities

Optometric management of patients who undergo refractive surgery can be extremely rewarding. As the gatekeeper to a patient’s freedom from glasses and contacts, the optometrist plays a critical role in postoperatively managing these patients. As optometry continues to evolve and clinicians incorporate more duties into their scope of practice, effective postoperative LASIK and PRK management gives optometrists an opportunity to showcase their abilities and prove their expertise to patients and ophthalmologists alike.