Comparison between Tear Film Osmolar Cocentration and Other Tear Film Function Parameters in Patients with Diabetes Mellitus

The role of endothelial growth factor and tear levels in diabetic retinopathy in type 2 diabetes

PURPOSE

To evaluate the tear level of VEGF and the quantity of tear film in type 2 diabetic patients.

METHODS

Thirty patients with diabetic retinopathy (DR group) and 30 patients with no DR (NDR group), and 30 healthy subjects with age and gender matching were enrolled in this prospective comparative study. The tear samples were collected using the Schirmer strips, and the amount of moisture absorbed by the strips was used to determine the quantitative level of the tear film. The concentration of VEGF in the tear samples was measured using the enzyme-linked immunosorbent assay method. The variables were compared with an independent t-test and covariance analysis.

RESULTS

Mean tear level of VEGF was significantly higher in DR group (235.42 pg/ml) compared to NDR (75.11 pg/ml) and control (58.77 pg/ml) groups (P ≤ 0.001). There was no significant difference in the mean of VEGF between NDR and control patients (P = 1.00). Mean quantitative tear film levels were 7.15%, 9.72%, and 15.11% in DR, NDR, and healthy subjects, respectively (P < 0.05). The pairwise analysis showed significant differences in the level of VEGF between DR and both NDR (P = 0.001) and normal (P = 0.017) groups. However, there was no significant difference observed between NDR and normal eyes (P = 0.743).

CONCLUSION

The VEGF level in tear was higher in diabetic patients with DR, independent of tear volume. The tear VEGF measurement can be used as a valuable predictor to prevent DR in diabetic patients.

Dry eye disease in patients with type II diabetes mellitus: A retrospective, population-based cohort study in Taiwan

Purpose

To investigate the risk and protective factors of dry eye disease (DED) in patients with type II diabetes mellitus (DM).

Design

A retrospective cohort study using Chang- Gung research database collecting data from 2005 to 2020.

Methods

Patients with type II DM were included, and those with previous ocular diseases were excluded. Ten thousand twenty nine developed DED (DED group), and 142,491 didn't (non-DED group). The possible risk and protective factors were compared and analyzed using the logistic regression model.

Results

A majority of the DED group were female with significantly higher initial and average glycated hemoglobin levels, and higher incidence of diabetic neuropathy and retinopathy. In conditional logistic regression model, advanced age was a risk factor. After adjusting for sex, age, and DM duration; average glycated hemoglobin level, diabetic neuropathy, retinopathy, and nephropathy with eGFR 30 ~ 59 and intravitreal injection, vitrectomy, pan-retinal photocoagulation, and cataract surgery were contributing factors of DED. Considering antihyperglycemic agents, DPP4 inhibitor, SGLT2 inhibitor, GLP-1 agonist, and insulin monotherapy and dual medications combining any two of the aforementioned agents were protective factors against DED compared with metformin alone. In the monotherapy group, SLGT2 inhibitor had the lowest odds ratio, followed by GLP1 agonist, DPP4 inhibitor, and insulin.

Conclusions

DED in patients with DM is associated with female sex, advanced age, poor diabetic control, microvascular complications and receiving ocular procedures. GLP-1 agonist, SGLT-2 inhibitor, DPP4 inhibitor, and insulin are superior to metformin alone in preventing DM-related DED. A prospective randomized control trial is warranted to clarify our results.

Evaluation of Tear Evaporation Rate in Patients with Diabetes Using a Hand-Held Evaporimeter

Diabetes is a very common disease and is considered a risk factor for many diseases such as dry eye. The aim of the current work was to evaluate the tear evaporation rate (TER) in patients with diabetes using a hand-held evaporimeter. This observational, case–control and non-randomized study included 30 male patients with diabetes (17 controlled and 13 uncontrolled) with a mean ± standard deviation (SD) of 33.1 ± 7.9 years. An age-matched (18–43 years; 32.2 ± 6.5 years) control group consisting of 30 male subjects was also enrolled for comparison. Subjects with thyroid gland disorder, a high body mass index, high blood cholesterol, or thalassemia, contact lens wearers, and smokers were excluded. The TER was measured after the completion of the ocular surface disease index (OSDI) by each participant. The OSDI and TER median scores were significantly (Wilcoxon test, p < 0.05) higher in patients with diabetes (median (interquartile range; IQR) = 12.0 (8.3) and 46.4 (36.7) g/m2h, respectively) compared to the subjects within the control group (5.6 (7.0) and 15.1 (11.9) g/m2h, respectively). The median scores for the OSDI and TER measurements were significantly (Wilcoxon test, p < 0.05) higher among uncontrolled diabetes patients (13.0 (11.5) and 53.4 (14.2) g/m2h, respectively) compared to those obtained for patients with controlled diabetes (11.0 (8.0) and 27.3 (32.6) g/m2h, respectively). The tear evaporation rate in patients with diabetes was significantly higher compared to those obtained in subjects without diabetes. Uncontrolled diabetes patients have a higher tear evaporation rate compared to controlled diabetes patients. Therefore, diabetes can lead to eye dryness, since these patients possibly suffer excessive tear evaporation.

Tear function in patients with diabetes mellitus: A systematic review and meta-analysis

PURPOSE

To examine tear function in patients with diabetes mellitus (DM).

DESIGN

Systematic review and meta-analysis.

METHOD

We searched Embase and PubMed from database inception to March 16, 2022. We included observational studies that compared tear function between patients with and without DM. Tear function was measured using invasive tear breakup time (ITBUT) and Schirmer's 1 test. Pooled results are presented as standard mean difference (SMD) with 95% confidence interval (CI) based on random-effects models.

RESULTS

We included 59 studies (7,234 eyes) comparing the tear function between patients with and without DM. This meta-analysis indicated that patients with DM had worse tear function than those without DM (ITBUT: SMD: -0.98, 95% CI: -1.27 to -0.69; Schirmer's 1 test: SMD: -0.45, 95% CI: -0.64 to -0.26), and the results remained consistent in patients with different types of DM (e.g., type 1 DM and type 2 DM) and from different ethnic backgrounds (e.g., Asian vs. non-Asian). Patients with DM under poor glycemic control had worse tear function than those of the non-DM group (ITBUT: SMD: -1.26, 95% CI: -1.86 to -0.66; Schirmer's 1 test: SMD: -0.25, 95% CI: -0.48 to -0.02), whereas there were no significant differences in tear function between patients with DM under optimal glycemic control and non-DM groups.

CONCLUSIONS

We found that patients with type 1 or type 2 DM had significantly reduced tear function. The level of tear function could be determined by glycemic control, and therefore, our findings suggest that glycemic control in patients with DM is critical for maintaining tear function.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero, identifier CRD42021250498.

Incidence and Risk Factors of Dry Eye in Children and Adolescents With Diabetes Mellitus: A 3-Year Follow-Up Study

Purpose: To investigate the incidence and risk factors of dry eye in children with diabetes mellitus (DM) over a period of 3 years. Methods: Children and adolescents with DM (age: 3-14 years) from the Shanghai Children and Adolescent Diabetes Eye (SCADE) study cohort who did not have dry eye in January 2018 were followed-up for 3 years and re-examined in January 2021, and the incidence rate and risk factors for dry eye were calculated. Results: Forty children and adolescents with DM came for follow-up in 2021. Nine of them were diagnosed with dry eye, resulting in a 3-year incidence rate of 22.5% and an annual mean incidence rate of 7.5% for dry eye. Univariate regression analysis confirmed that decreased corneal sensation (OR [Odds Ratio] = 25.60; 95%CI [Confidence Interval] = 1.31~501.69; P = 0.03) was the risk factor for dry eye incidence. Long course of DM (OR = 1.80; 95%CI = 0.96~3.38; P = 0.07), eye pain (OR = 12.27; 95%CI = 0.65~231.48; P = 0.09), and dry eye in parents (OR = 15.99; 95%CI = 0.76~337.75; P = 0.08) may interfere with the incidence of dry eye in them. Conclusions: The incidence of dry eye in children and adolescents with DM is high.

Effect of microincisional cataract surgery on inflammatory indicators in tears and corneal endothelial cells in cataract patients

OBJECTIVE

To analyze the effect of microincisional cataract surgery on inflammation in tears and corneal endothelial cells in cataract patients.

METHODS

A total of 103 patients with cataracts in our hospital were enrolled and randomly divided into group A (n=52) and group B (n=51) by a random double-blind lottery. Group A received 1.8 mm coaxial microincision cataract surgery (C-MICS) while group B received 3.0 mm C-MICS, and the efficacy was compared between the two groups.

RESULTS

Average ultrasound energy (AVG), accumulative phaco time (APT), and effective phaco time (EPT) did not differ between groups (P > 0.05). Group A exhibited higher interleukin-2 (IL-2) levels at 5 days postoperatively and lower interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and tumor necrosis factor-β1 (TNF-β1) levels than group B (P < 0.05). The density of corneal endothelial cells, coefficient of variation, and percentage of hexagonal cells showed no significant difference in both groups at 5 days postoperatively (P > 0.05). Group A had higher visual acuity and lower visual acuity loss, visual fatigue, foreign body sensation, tingling, and photophobia scores than group B at 7, 14, and 28 days postoperatively (P < 0.05). The tear film break-up time (TBUT) in group A was longer than that in group B at 7, 14, and 28 days postoperatively, and the tear secretion length (in mm) on the strip in group A was longer than that in group B at 14 and 28 days postoperatively (P < 0.05).

CONCLUSION

Compared with other types of similar surgery, C-MICS can significantly control inflammation levels, with less effect on corneal endothelial cells, improve postoperative visual acuity, delay tear film break-up, increase tear secretion, and improve dry eye syndrome.

Correlation of Non-invasive Tear Break-Up Time with Tear Osmolarity and Other Invasive Tear Function Tests

Aim: To compare the outcomes of non-invasive break-up time (NI-BUT) test and the other conventional dry eye tests.Methods: The right eyes of 170 subjects were included in the study. In order to evaluate the tear quality of the patients, NI-BUT levels were measured by the Scheimplug-Placido disk system (Sirius topography). Tear osmolarity test was performed with TearLab Osmolarity System. Topical anesthesia-assisted type I Schirmer test and topical anesthesia-assisted BUT were lastly applied to all patients in order not to affect other measurements.Results: The mean NI-BUT value was 9.59 ± 4.37 sec, tear osmolarity was 292.93 ± 9.30 mOsm/L, Schirmer test was 15.32 ± 6.05 mm/5 min, and biomicroscopic BUT value was 8.98 ± 3.79 sec. The Schirmer test results were statistically significantly correlated with biomicroscopic BUT and NI-BUT values (p = .019, r = 0.180 and p = .030, r = 0.166; respectively). It was also found that tear osmolarity was strongly and inversely correlated with biomicroscopic BUT and topographic NI-BUT values (p < .001, r = -0.554 and p < .001, r = -0.528; respectively). There was no significant correlation between Schirmer test and tear osmolarity.Conclusion: It is important to use a sensitive, reproducible and non-invasive method in the evaluation of tear functions. We think that the objective and noninvasive topographic NI-BUT measurements and the minimally invasive osmolarity measurements should be used more frequently in practice because they are correlated with the measurements obtained by invasive methods and should be widespread in clinics.

Evaluation of Tear Film Osmolarity Among Diabetic Patients Using a TearLab Osmometer

PURPOSE

The purpose of the present study is to determine the effects of type 2 diabetes mellitus on tear osmolarity using a TearLab Osmolarity system. Moreover, the relationship between tear film osmolarity and ocular surface discomfort in controlled and uncontrolled diabetic patients was assessed.

MATERIALS AND METHODS

This study included 20 male type 2 diabetic patients aged 20 to 70 years (mean ± SD 49±12). A control group (18-43 years; 32.2 ± 6.5 years) consisting of 40 male subjects was also enrolled for comparison. The tear osmolarity was measured using the TearLab Osmolarity System. The ocular surface disease index questionnaire (OSDI) was used to assess ocular discomfort symptoms.

RESULTS

The mean tear osmolarity was 297 ± 8.00 and 296 ± 11 mOsm/L for controlled and uncontrolled diabetic subjects, respectively, while the average osmolarity in the control group was 299 ± 8.00 mOsm/L. No significant differences were detected in tear osmolarity between the control and diabetes groups. The ocular surface disease index questionnaire (OSDI) score was significantly higher in the diabetic patient group. No significant correlation was found between tear osmolarity and OSDI scores.

CONCLUSION

The ocular discomfort symptoms score in diabetic patients was significantly higher compared to normal eye subjects. Tear osmolarity was not significantly different in diabetic patients. This finding may be explained by a lack of relationship between tear film parameters and diabetic severity; tear film parameters may correlate more with diabetic duration rather than severity. Therefore, studies focused on diabetes duration and tear film parameters are recommended.