advertisement
For this study, Leung et al. (1216) asked sequential patients with glaucoma or ocular hypertension to complete the Ocular Surface Disease Index, a validated tool for studying OSD symptoms that is commonly used in studies of treatment of dry eye. Symptoms were graded as normal, mild to moderate or severe based on prior criteria. Signs of OSD were measured using Schirmer test without anesthesia, lissamine green staining, and tear break up time. All signs were classified as normal, mild to moderate or severe. This is the first cross sectional study of glaucoma and ocular hypertension patients providing subjective and objective indicators that OSD has a relatively high prevalence in these patients but also illustrates the difficulties involved in studying OSD ‐ symptoms do not correlate well with signs and the signs do not agree well among themselves; the greatest overlap was between abnormal Schirmer test and tear break-up time. Subjects with symptoms of OSD often had normal clinical signs. This problem is well appreciated within the dry eye research community and has plagued study design for dry eye treatments. This study also explored the relationship between BAK-containing drops and symptoms and signs. Patients using more BAK-containing drops had increased odds of lissamine green staining but this study does not provide any direct evidence of causality between BAK and symptomatic OSD. The authors caution that this study was performed in a single tertiary care center and cannot be generalized. They note that future studies should investigate the prevalence of OSD in an unselected population of glaucoma patients.