When I wrote about my learning curve regarding cataract surgery a few months back, I mentioned the need to deal with any ocular surface matters before cataract evaluation. A compromised ocular surface can negatively affect IOL calculations, and dry eye induced by cataract surgery can affect visual outcomes.1 Post-operative manifest refractions may not be what was predicted preoperatively, resulting in less-than-optimum best-corrected visual acuities (BCVAs) and subsequently, unhappy patients.
Dr. BowlingYet, my ocular surface concerns ought to go far beyond cataract surgery. Elevated lactoferrin levels-a key marker for dry eye-have been shown to play a role in post-operative LASIK best-corrected vision, with one initial study showing that elevated pre-operative lactoferrin levels resulted in a postoperative refractive error that was more hyperopic than expected. This study concluded that pre-LASIK lactoferrin levels are a statistically significant predictor of post-LASIK spherical refractions.2 The interaction between the ocular surface and contact lenses (CLs) is a major factor in CL patient comfort and, likewise, CL dropouts. The main reason for CL-associated dry eye is not the lack of tears, but the lack of tear film stability due to meibomian gland dysfunction (MGD), which reduces the lipid film of tears.3 Eighty-six percent of all patients with dry eye demonstrate signs of MGD.4
We have all had the routine patient who, despite our best efforts, just can’t quite get to 20/20 when, on slit lamp exam, we discover-lo and behold-his ocular surface is compromised. A week of heavy lubrication therapy usually clears up the compromised ocular surface and subsequently restores BCVA to optimal levels.
Everyone knows all this, Ernie. Why are you talking about it?
Because we optometrists ought to own ocular surface disease (OSD):
Just throwing artificial tears at OSD won’t solve the problem. We have to own OSD from initial diagnosis to management. We have to use all the diagnostic tools at our disposal, and there are some really great new objective tests to aid in the diagnosis of dry eye, such as the TearLab Osmolarity System, the RPS InflammaDry Detector, and Advanced Tear Diagnostics’ MicroAssay unit (see "MicroAssay system tests for two tear film biomarkers," Page 25).
These are exciting times for dry eye diagnosis and management. It is time for us to step up our game and make use of the diagnostic and therapeutic tools at our disposal and give OSD the respect it deserves. Our patients, many of whom suffer silently with the disease, will appreciate our efforts.ODT
1. Stephenson M. The relationship between dry eye and cataract surgery. Rev Ophthalmol November 2007. Available at http://www.revophth.com/content/d/features/i/1287/c/24811/. Accessed 5-22-2013.
2. Bethke W. An objective look at dry eye syndrome. Rev Ophthalmol December 2012. Available at: http://www.revophth.com/content/d/technology_update/c/38025/. Accessed 7-10-2013.
3. Khaireddin R. Contact lens associated dry eye: Current study results and practical implementation. Ophthalmologe 2013; 110(6): 511-514.
4. Lemp MA, Crews LA, Bron A J, et al. Distribution of aqueous-deficient and evaporative dry eye in a clinic-based patient cohort: a retrospective study. Cornea 2012; 31(5): 472-478.