Tear film stability in patients with symptoms of dry eye after instillation of dual polymer hydroxypropyl guar/sodium hyaluronate vs single polymer sodium hyaluronate.

PURPOSE: This study evaluated the tear film stability in patients with symptoms of dry eye after installation of dual polymer hydroxypropyl guar/sodium hyaluronate (DPHG/SH) vs single polymer SH. METHODS: Patients with recently diagnosed mild to moderate dry eye disease (OSDI score 23-32 points) were included. For each patient, the right eye was randomized to receive DPHG/SH or 0.15% SH. Just after the administration of the drop to the right eye, the fellow eye received the other eye drop. The first non-invasive Keratograph first break-up time (NIKBUT), average NIKBUT and tear meniscus height (TMH) were measured before administration of the eye drops, at 1-min, 15 min, 30 min, 60 min, 90 min, and 120 min after instillation. RESULTS: A total of 29 patients aged 22.8 ± 2.2 years participated in the study (21 women). No differences between the eye receiving DPHG/SH and single polymer SH were observed for the first NIKBUT (p = 0.45) and average NIKBUT (p = 0.24) variables at any time point. Both DPHG/SH and single polymer SH increased the TMH (p of time effect < 0.001), but with no difference between groups (p = 0.95). CONCLUSION: Both DPHG/SH and single polymer SH solutions provide lubrication of the eye surface, however, with no difference in NIKBUT and TMH evaluations for up to two hours following administration.

Corneal Tomography in a Commercially Available Optical Coherence Tomography Device and Comparison With a Rotating Scheimpflug Camera.

OBJECTIVE: To compare the outcomes of corneal tomography obtained with an anterior-to-posterior segment optical coherence tomography device (Revo, Optopol Technologies Sp. z o.o.) and a rotating Scheimpflug camera (Pentacam AXL, Oculus Optikgeräte, Wetzlar, Germany). METHODS: In healthy subjects, agreement in stereometric parameters commonly used in cataract and refractive surgery was assessed. Comparison between the devices was performed using correlation coefficients, the Bland-Altman method, and a paired t test. RESULTS: Results of right eyes of 78 patients (47 women) aged 25.24±5.56 years were analyzed. The flat and steep anterior keratometry values were significantly higher for Revo than Pentacam (43.65±1.58 D vs. 42.99±1.47 D; P = 0.000, and 44.53±1.57 D vs. 43.82±1.49 D; P =0.000, respectively) and showed excellent correlation ( r =0.978 and 0.974, respectively). The results for maximal keratometry manifested a higher difference (45.89±1.69 D vs. 44.27±1.51 D for Revo and Pentacam, P =0.000) but were also strongly correlated ( r =0.871). Revo showed significantly lower corneal thickness values than Pentacam, both for apex pachymetry (535.54±32.45 vs. 550.74±31.55 µm; P =0.000) and for thinnest pachymetry (522.58±32.16 vs. 547.25±31.95 µm; P =0.000). The correlation coefficients for anterior and posterior corneal elevation at the thinnest point showed weak positive correlation ( r =0.179 and 0.185), while the correlation for corneal asphericity was moderate ( r =0.317). CONCLUSIONS: There was a significant difference between keratometric values obtained with Revo and the Pentacam AXL, although the measurements showed excellent correlation. Similar results were found for corneal thickness measurements, but not for corneal surface elevation and corneal asphericity.

The outdoor time in non-myopic children has decreased to that of myopic children during the SARS-CoV-2 pandemic.

Objective: Low levels of outdoor activity are known to be an important risk factor for the development of myopia in schoolchildren. This study aimed to determine outdoor and near work patterns in Polish schoolchildren before and during school closure due to the SARS-CoV-2 pandemic. Methods: All children undergoing a routine pediatric examination in the Elblag branch of the Hygeia Clinic, together with their parents, were asked to fill an anonymous questionnaire. The subject's age, spherical equivalent (SE) refractive error, time spent outdoors, screen time and total near work in hours per day before and during the pandemic, were recorded. As substantial differences in physical activity by time of year were reported, activity patterns for June (summer) and December (winter) were recorded. Multiple logistic regression analysis was used to analyze the association between the presence of myopia and outdoor and total near work time at different timepoints. Results: A total of 61 schoolchildren aged 11.95 ± 2.74 (range 7 to 17) years were included in this study. The mean SE in the right eye was -1.78 ± 2.11 with 46% of the individuals (n=28) classified as myopic. Before the pandemic, higher time outdoors was associated with less myopic SE (OR=0.47, 95% Confidence Interval [CI] 0.24 to 0.93). During the pandemic, time outdoors among non-myopic children was similar to myopic children, both during winter and summer months (2.18 ± 1.81 vs. 1.89 ± 1.50; P=.51, and 3.47 ± 2.66 vs. 3.31 ± 1.65; P=.79 respectively). Time outdoors was not significantly associated with myopia during the pandemic (OR=1.17, 95% CI 0.64 to 2.14). Total near work was not associated with myopia at any time point. Conclusion: The long-term influence of the changing patterns of outdoor and near work on myopia prevalence and progression in our population is still to be established. Nevertheless, it is likely that the decrease of outdoor time may influence the rates of myopia in this region.