LASER EYE SURGERY – PATIENT SELECTION
This page is for patients with pre-existing dry eye who are considering laser eye surgery and want to understand what the risks are, how they are assessed, and whether laser is the right choice for them.
Pre-Existing Dry Eye Determines Outcome More Than the Laser Itself
Approximately 5% of laser candidates at Blue Fin Vision® are redirected to ICL annually on dry eye grounds. LASIK does not create dry eye in a previously healthy eye, it creates a transient reduction in corneal nerve density that temporarily reduces tear production and blink reflex function.¹ ² In an eye with a healthy, abundant tear film, this transient reduction produces mild symptoms that resolve over three to six months. In an eye with pre-existing dry eye, where tear production is already marginal or the ocular surface is already compromised, the same nerve disruption produces disproportionately worse symptoms, sometimes persisting beyond twelve months.³
The question is not whether LASIK causes dry eye. The question is whether this patient’s ocular surface can tolerate the transient nerve disruption without producing a chronic symptomatic state. That assessment is the purpose of pre-operative tear film evaluation.
The Pre-Operative Screening Tests
- Schirmer’s test: identifies baseline aqueous tear production. A low result indicates LASIK caution or contraindication.
- Tear meniscus height (OCT): measures tear reservoir volume. A low result indicates dry eye investigation before surgery.
- NIBUT (non-invasive break-up time): measures tear film stability. A short result indicates meibomian gland assessment.
- Meibomian gland imaging: identifies gland dropout and obstruction. Significant dropout requires treatment before surgery.
- Corneal staining: indicates epithelial surface integrity. Staining requires surface optimisation.
Who Should Avoid LASIK
Moderate to severe pre-existing dry eye: patients with Schirmer’s under 5mm at five minutes, significant meibomian gland dropout, or symptomatic dry eye not controlled by topical treatment are not suitable for LASIK.⁴ For this group, ICL, which leaves the corneal surface and its nerve supply entirely undisturbed, is the appropriate alternative. Trans-Epi PRK, which disrupts the corneal surface more than LASIK in the short term, is also not ideal for this group.
Contact lens intolerance due to dryness: a patient who cannot tolerate contact lenses because of dryness will almost certainly have worsened dry eye after LASIK. ICL eliminates spectacle and contact lens dependency without touching the corneal surface. This is the strongest indication for ICL over laser in the dry eye population.
Optimising the Ocular Surface Before Surgery
Where dry eye is mild and potentially reversible, surgery is not automatically declined. A structured pre-operative ocular surface optimisation programme, lipid-based drops, omega-3 supplementation, warm compress, and meibomian gland expression if indicated, can bring a borderline ocular surface to a state where LASIK or Trans-Epi PRK is safely possible. In our 2024-2025 series, approximately 12% of presenting patients required a period of pre-operative surface optimisation before their laser assessment was completed.
Clinical Perspective
At Blue Fin Vision®, Mr Mfazo Hove assesses every laser candidate’s tear film using Schirmer’s testing and tear meniscus height as standard, not as an optional add-on. Approximately 5% of laser candidates at Blue Fin Vision® are redirected to ICL on dry eye grounds annually. This is a figure that is rarely disclosed by volume laser providers, who have a commercial incentive to treat rather than redirect. Chronic post-LASIK dry eye occurs in under 5% of appropriately selected patients;² in patients with pre-existing dry eye who were not adequately screened, the rate is substantially higher.
Clinical Takeaway
Pre-existing dry eye is the strongest predictor of post-LASIK dry eye severity. Patients with moderate-to-severe dry eye or contact lens intolerance should be assessed for ICL rather than LASIK. At Blue Fin Vision®, Mr Mfazo Hove performs full tear film assessment at every laser consultation. Approximately 5% of laser candidates are redirected to ICL on dry eye grounds, a number that reflects honest screening, not restrictive practice. If you have dry eyes and are considering refractive surgery, book a full ocular surface assessment at Blue Fin Vision® before committing to any procedure.
References
- Ang RT, Dartt DA, Tsubota K. Dry eye after refractive surgery. Curr Opin Ophthalmol. 2001;12(4):318-22.
- Shtein RM. Post-LASIK dry eye. Expert Rev Ophthalmol. 2011;6(5):575-82.
- Nettune GR, Pflugfelder SC. Post-LASIK tear dysfunction and dysesthesia. Ocul Surf. 2010;8(3):135-45.
- Toda I, Asano-Kato N, Komai-Hori Y, Tsubota K. Dry eye after laser in situ keratomileusis. Am J Ophthalmol. 2001;132(1):1-7.
- Liu Z, Pflugfelder SC. Corneal surface regularity and the effect of artificial tears in aqueous tear deficiency. Ophthalmology. 1999;106(5):939-43.
