Ocular Surface Disease
Dry eye after LASIK is the most common and anticipated complication of refractive surgery, although symptoms are typically self-limited. During creation of the flap, corneal nerves are severed, which may result in corneal anesthesia lasting 3–6 months and may less frequently persist for years. As a result, many patients develop keratopathy, decreased tear production, and related symptoms as a result of the neurotrophic state of their cornea. Patients who had dry eyes prior to surgery, or whose eyes were marginally compensated before surgery, may experience more severe symptoms postoperatively. These individuals demonstrate tear-film and ocular surface disruption and often report fluctuating vision between blinks throughout the day. In a review of 109 patients who had undergone LASIK surgery, Levinson and colleagues found that dry eye symptoms and blepharitis were the most common diagnoses among patients dissatisfied with the procedure, even for patients with relatively good postoperative vision outcomes. Fortunately, in the great majority of these patients, symptoms resolve 3–6 months after surgery but those whose symptoms persist are among the least satisfied in this series.
Ophthalmologists may take several steps to reduce the incidence and severity of dry eye symptoms after refractive surgery. One of the most important is to screen patients carefully for dry eye and tear-film abnormalities and to treat them aggressively before surgery. Many patients seeking refractive surgery are actually dry eye patients who are intolerant of contact lens wear because of their preexisting dry eye disease. Any history of contact lens intolerance should suggest the possibility of underlying dry eye.
Any refractive surgery candidate with signs or symptoms of dry eye should be thoroughly evaluated. Patient history should include questions about collagen vascular diseases and conjunctival cicatrizing disorders; these conditions are relative contraindications to refractive procedures and should be addressed prior to any surgical consideration (see Chapter 2).
External examination should include evaluation of eyelid anatomy and function for conditions such as incomplete blink, lagophthalmos, entropion, ectropion, and eyelid notching. On slit-lamp examination, the ophthalmologist should note anterior and posterior blepharitis, tear-film quantity and quality, and the presence of conjunctivochalasis, subconjunctival fibrosis, or symblepharon. Screening questionnaires to highlight or elicit dry eye–related symptoms could help start the discussion and lead to further workup. Ancillary testing for dry eyes (eg, Schirmer testing, tear breakup time, fluorescein corneal staining, lissamine green or rose bengal conjunctival staining) should be performed on all patients considering refractive surgery. Corneal topography should be reviewed for evidence of irregularity or patchy, poor image quality often seen in the presence of an unstable tear film. A screening evaluation in patients considering refractive surgery may also include other testing. An immunoassay for matrix metalloproteinase 9 levels, as an inflammatory biomarker in the tear film, and tear osmolarity measurement, as an indicator of tear deficiency, could be helpful in screening for ocular surface disease. Imaging the quality of the tear lipid layer and the health of the meibomian gland structure and function are other tools for screening at-risk patients. Once the at-risk patient is identified, aggressive preoperative treatment often leads to better outcomes, fewer complications, and patients more satisfied with the results of surgery.
Treatment of ocular surface disease with aqueous deficiency may include topical tear replacement, punctal occlusion, and use of topical anti-inflammatory drugs, such as corticosteroids, cyclosporine, or lifitegrast (see BCSC Section 8, External Disease and Cornea). These drops can improve dry eye and refractive outcomes in patients with dry eye who are undergoing LASIK and surface ablation. Patients with meibomian gland dysfunction should be instructed in the use of hygienic eyelid scrubs and dietary supplements, such as flaxseed or omega-3 fish oils, to improve the tear film. Meibomian gland expression, oral or topical medications (eg, doxycycline or azithromycin), and a short course of topical corticosteroids may help improve the quality of the tear film and optimize the ocular surface prior to surgery. A delay in surgery may be necessary to allow time for treatment response. In addition, patients must be cautioned that their dry eye condition may worsen postoperatively. Such an occurrence may result in additional discomfort or decreased vision and may be permanent.
American Academy of Ophthalmology Cornea/External Disease Panel. Preferred Practice Pattern Guidelines. Blepharitis. San Francisco: American Academy of Ophthalmology; 2013. For the latest guidelines, go to www.aao.org/ppp.
American Academy of Ophthalmology Cornea/External Disease Panel. Preferred Practice Pattern Guidelines. Dry Eye Syndrome. San Francisco: American Academy of Ophthalmology; 2013. For the latest guidelines, go to www.aao.org/ppp.
Bower KS, Sia RK, Ryan DS, Mines MJ, Dartt DA. Chronic dry eye in photorefractive keratectomy and laser in situ keratomileusis: Manifestations, incidence, and predictive factors. J Cataract Refract Surg. 2015;41(12):2624–2634.
Levinson BA, Rapuano CJ, Cohen EJ, Hammersmith KM, Ayres BD, Laibson PR. Referrals to the Wills Eye Institute Cornea Service after laser in situ keratomileusis: reasons for patient dissatisfaction. J Cataract Refract Surg. 2008;34(1)32–39.
Salib GM, McDonald MB, Smolek M. Safety and efficacy of cyclosporine 0.05% drops versus unpreserved artificial tears in dry-eye patients having laser in situ keratomileusis. J Cataract Refract Surg. 2006;32(5):772–778.
Excerpted from BCSC 2020-2021 series: Section 13 - Refractive Surgery. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.