The lid wiper is defined as that portion of the marginal conjunctiva of the upper eyelid that wipes the ocular surface during blinking. The purpose of this study was to investigate whether lid wiper epitheliopathy occurred with patients who reported dry eye symptoms, yet had normal fluorescein breakup time (FBUT) and Schirmer test values and an absence of fluorescein corneal staining. One hundred patients were divided into two groups based on the presence or absence of dry eye symptoms, as determined with the Standard Patient Evaluation of Eye Dryness questionnaire. Other criteria for admission to both groups were FBUT of 10 seconds or more, Schirmer test value of 10 mm or more, and absence of fluorescein corneal staining. After instillation of fluorescein and rose bengal dyes, the lid wipers of 50 asymptomatic and 50 symptomatic patients were graded for staining from grade 0 (absent) to grade 3 (severe). Of the symptomatic patients, 76% had staining of the lid wiper: 44%, grade 1; 22%, grade 2; and 10%, grade 3. Of the asymptomatic patients, 12% had staining; 8%, grade 1; 4%, grade 2; and 0%, grade 3. The difference in prevalence of lid wiper staining between the symptomatic and asymptomatic groups was significant (P<0.0001). Lid wiper epitheliopathy, diagnosed by staining with fluorescein and rose bengal dyes, is a frequent finding when symptoms of dry eye are experienced in the absence of routine clinical dry eye findings.

To evaluate the safety and effectiveness of the LipiFlow System compared to the iHeat Warm Compress (WC) for adults with meibomian gland dysfunction (MGD). This was a non-significant risk, prospective, open-label, randomized, crossover multicenter clinical trial. One hundred thirty-nine subjects were randomized between LipiFlow (n=69) and WC control (n=70). Subjects in the LipiFlow group received a 12-minute LipiFlow treatment and were reexamined at 1 day, 2 weeks and 4 weeks. Control subjects received a 5-minute iHeat treatment with instructions to perform the same treatment daily for 2 weeks. At 2 weeks, they crossed over (LipiFlow Crossover) and received the LipiFlow treatment. Effectiveness parameters: meibomian gland (MG) assessment, tear break-up time (TBUT) and dry eye symptoms. Safety parameters: adverse events, ocular health exam, ocular surface staining, intraocular pressure, visual acuity and discomfort. LipiFlow resulted in significant improvement (P < 0.05) in MG secretion at 2 and 4 weeks (mean ± standard deviation at baseline = 6.3 ± 3.5; 2 weeks = 14.3 ± 8.7; 4 weeks = 16.7 ± 8.7); and TBUT at 2 and 4 weeks: (at baseline = 5.5 ± 2.9; 2 weeks = 6.9 ± 5.0; 4 weeks = 7.4 ± 5.5). There was no significant change in MG secretion or TBUT in the control group. LipiFlow resulted in a greater significant reduction in dry eye symptoms than the iHeat WC. The crossover group demonstrated similar significant improvement 2 weeks post-treatment with the LipiFlow. There was no significant difference between groups in the incidence of non-serious, device-related adverse events. The LipiFlow System was significantly more effective than iHeat WC. These results support its safety and effectiveness in the treatment of MGD and dry eye symptoms.

Alterations in the tear film lipid layer as a function of blinking were investigated using a custom-designed specular reflection monitoring system. The tear film lipid layer of 104 subjects under conditions of normal ("baseline") blinking and "forceful" blinking was quantitated on the basis of specific interference colors. Deliberate, forceful blinking was found to significantly increase the lipid layer thickness (LLT) of the tear film. The magnitude of increase was found to be correlated with the baseline LLT values; individuals with baseline LLT values of 75-150 nm demonstrated a mean increase in LLT of 33 nm following forceful blinking, whereas subjects with baseline LLT values < or = 60 nm experienced a mean increase of 19 nm. The difference in the magnitude of increase between the groups was highly significant (p = 0.0001). The data suggest that, in addition to playing a role in the spreading of lipid across the tear film, the blinking mechanism may be important in the maintenance of the lipid layer by augmenting the expression of lipids from the meibomian glands.

Purpose: (1) To investigate the relationship between dry eye symptoms and lipid layer thickness (LLT) in patients presenting for routine eye examination and (2) to consider the practicality of interferometry in a clinical practice. Methods: Patients presenting consecutively for routine eye examinations were recruited (n = 137, age range = 18-60 years, mean = 41.7 ± 15.5 years, 102 females and 35 males). Patients were required to complete the Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire after which their LLT was evaluated using a new interferometer (Ocular Surface Interferometer). Patients were assigned to 1 of 3 symptom categories: no symptoms (SPEED = 0), mild to moderate symptoms (SPEED = 1-9), and severe symptoms (SPEED ≥ 10). Categorical analysis (contingency table) and linear regression were performed on the data. Results: For patients with severe dry eye symptoms, 74% had an LLT ≤60 nm. Conversely, 72% of patients with no dry eye symptoms had an LLT of ≥75 nm (contingency table, χ² = 12.63, df = 2, p = 0.0018). Furthermore, a linear regression of LLT and SPEED score reveal a significant linear relationship (as LLT increases, SPEED score decreases; p = 0.0014). Conclusions: (1) The data indicate that approximately 3 of 4 patients reporting severe symptoms have relatively thin lipid layers of 60 nm or less, whereas approximately 3 of 4 patients without symptoms have relatively thick lipid layers of 75 nm or more. Thus, the presence of dry eye symptoms significantly increases the likelihood of a relatively thin lipid layer. LLT seems to correlate better to symptoms, especially severe symptoms, than other reported correlations with objective clinical tests for dry eye disease. (2) Interferometry has the potential to be a practical and useful addition to clinical practice.