Christopher Starr

The utility of a normal tear osmolarity test in patients presenting with dry eye disease like symptoms: A prospective analysis

OBJECTIVE To explore the diagnostic utility of normal tear osmolarity in patients with symptoms suggestive of dry eye disease (DED). METHODS Prospective observational cohort study of 100 patients that underwent tear osmolarity testing (TearLab™) if they endorsed one or more symptoms of potential DED. Patients were included for the study if they had a normal tear osmolarity test (value <308 mOsm/L in each eye, and an inter-eye difference <8 mOsm/L). The main outcome measure was the presence of any alternate diagnosis to explain the patients symptoms. Results were recorded and descriptive and univariate statistics were employed. RESULTS Mean tear osmolarity was 293.40 mOsms/L (±6.82), with a mean absolute difference of 2.85 mOsms/L (±1.98) between the eyes. A possible alternate diagnosis was established in 89% of patients with normal tear osmolarity testing. The most frequent diagnoses included anterior blepharitis (26%) and allergic conjunctivitis (21%). CONCLUSIONS Common symptoms of DED overlap significantly with a wide variety of other ocular surface diseases, and a normal tear osmolarity test should increase clinical suspicion for alternate causes of those symptoms. Anterior blepharitis and allergic conjunctivitis were the most common diagnoses made in symptomatic patients with normal tear osmolarity who may have otherwise been misdiagnosed and treated for DED.

Dynamic Roles of the Corneal Epithelium in Refractive Surgery

PurposeThe purpose of this study was to review the role of the corneal epithelium in refractive surgery, with a focus on corneal epithelial thickness changes and corneal wound healing.Recent FindingsCorneal epithelial thickness changes according to the type of ablation performed, with most studies reporting increased paracentral thickening after myopic corrections and central thinning and paracentral thickening after hyperopic corrections. In addition, there are complex interactions between the corneal epithelium and the stroma that occur as part of the wound healing response after refractive surgery. Both the corneal epithelial thickness and the corneal response to injury can greatly influence the post-operative course.SummaryThe corneal epithelium is a dynamic entity in refractive surgery that contributes to refractive outcomes and complications. Further investigation of corneal epithelial cell biology, particularly with respect to determinants of epithelial thickness and mechanisms of wound healing, may allow surgeons to better control the corneal response to refractive surgery with improved outcomes and fewer complications.