Phacoemulsification clinical trials

Comprehensive Study on Dry Eye and Ocular Surface Disease Prior and After Cataract Surgery

Ocular surface disease (OSD), particularly dry eye, is one of the most common conditions seen by ophthalmologists. Dry eye (DE) is a multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance, and tear instability. DE significantly reduces quality of life and affects 5-30% of the population. As the proportion of individuals over age 60 increases because of greater life expectancies, we can anticipate the number of people with dry eye will also increase, which represents a major challenging for aging societies, like the Chilean one. In the last few years clinical research on OSD is being intensely focused on diagnostic criteria, treatment strategies, methods used in diagnosis and better correlations between symptoms and clinical test results. All these lines of interest aim to improve the understanding of alterations and consequences occurring in the ocular surface disorders. Diagnostic testing is greatly valuable both for the detection of early changes due to DE and also to grade the severity of surface disease. The most commonly performed tests include the Schirmer test, tear break up time (TBUT), and ocular surface staining. However, newer point-of-care diagnostics tests such as tear osmolarity and matrix metalloprotease-9 (MMP-9) have been shown to have a high sensitivity and specificity in diagnosing ocular surface dysfunction. Given that ocular surface dysfunction has been shown to have an adverse impact on visual function and can worsen after surgery, it is critical to identify and address any tear film and ocular surface abnormalities before cataract surgery. In the setting of preoperative cataract surgery planning, DE disease and meibomian gland dysfunction can impair critical refractive measures such as keratometry values worsening surgical outcomes. To the best of our knowledge there are no ongoing or published studies that have evaluated DE and OSD as evidenced by either an abnormal tear-film parameter (elevated MMP-9 or abnormal osmolarity), or corneal surface and meibography evaluation findings (using novel non-invasive technology) in patients previous and after cataract surgery.