The ocular surface is the first optical surface. Before light reaches the cornea, the iris, the lens, or the macula, it must first cross the tear film. If that surface is irregular, through dry eye, meibomian gland dysfunction (MGD, inflammation of the oil-producing glands of the eyelid), or blepharitis (inflammation of the eyelid margin), every measurement taken from it is unreliable, and every implant chosen on the basis of those measurements is implanted under false pretences.
This matters in every cataract patient. It matters disproportionately in patients receiving premium intraocular lenses (IOLs, the artificial lenses used to replace the natural lens during cataract surgery). Diffractive trifocal optics split incoming light across three focal points and depend on a smooth, stable tear film to deliver the contrast and image quality the patient was promised¹. A premium implant cannot rescue a poor ocular surface. If the surface is treated only after surgery, the patient experiences the dysfunction as a lens problem; if the surface is treated before surgery, the implant performs as designed.
Why Pre-operative Biometry Is at Risk
Pre-operative biometry compounds the issue. Keratometry (a measurement of the curvature of the cornea, used to calculate IOL power) readings taken across a disrupted tear film carry a measurement error sufficient to shift the recommended lens power by half a dioptre or more, producing a refractive surprise that is misattributed to surgical inaccuracy². The fix is not technological. It is sequence: identify ocular surface disease at the consultation, treat it, re-measure on a stable surface, and only then quote a lens.
At Blue Fin Vision®, ocular surface assessment, including meibography (an imaging test that maps the oil-producing glands in the eyelids) where indicated, precedes every premium IOL discussion. Patients who are not yet ready for accurate biometry are told so. This is one of the quietest determinants of premium IOL satisfaction, and one of the most reliably ignored.
References
- Trattler WB, Majmudar PA, Donnenfeld ED, McDonald MB, Stonecipher KG, Goldberg DF. The Prospective Health Assessment of Cataract Patients’ Ocular Surface (PHACO) study: the effect of dry eye. Clin Ophthalmol. 2017;11:1423-1430.
- Epitropoulos AT, Matossian C, Berdy GJ, Malhotra RP, Potvin R. Effect of tear osmolarity on repeatability of keratometry for cataract surgery planning. J Cataract Refract Surg. 2015;41(8):1672-1677.
Related Topics
- Why Trifocal Lenses Are the Lens of Choice for the Glaucoma Patient Wanting Spectacle Independence
- Why Ocular Surface Disease Matters Before Premium Lens Surgery
- What Is a Goal-Lens Mismatch in Cataract Surgery?
- Can Glaucoma Patients Have Trifocal Lenses?
- Is Mild Glaucoma a Contraindication to Trifocal IOLs?
- What Level of Glaucoma Is Suitable for Premium IOLs?
- Do Trifocal IOLs Reduce Contrast Sensitivity?
- Do EDOF Lenses Give True Spectacle Independence?
- Is an EDOF Lens the Right Choice for a Glaucoma Patient?
- Can You Monitor Glaucoma After a Trifocal IOL?
- When Is a Monofocal IOL the Right Lens for a Glaucoma Patient?
