[Factors influencing the measurement of tear film lipid layer thickness with interferometry]

"Dirty Dry Eye"- A waste volume analysis from topical therapy in keratoconjunctivitis sicca

PURPOSE

The healthcare system is responsible for around 5% of CO2 emissions globally and in Germany. So far, there are no data on the amount of waste from dry eye disease (DED) therapy in ophthalmology. The aim of this project was to evaluate the amount and type of waste from single- and multi-dose units (SDU/MDU) generated by eyedrops used to treat DED in Germany.

METHODS

The net waste weight (outer/inner packaging, instruction leaflet, empty container) from factory-sealed products was determined using a precision scale. Based on prescription data from PharMaAnalyst, a database of medical prescriptions from over 70 million patients in Germany, the total annual waste volume for 2016-2021 and the net weight of a 30-day treatment were calculated.

RESULTS

The total annual waste volume increased significantly (p < 0.0001) from 7.13 tons in 2016 to 20.64 tons in 2021. A 30-day treatment with MDUs (without/with filter) results in a significantly lower mean waste volume (paper: SDU 24.3 ± 18.7 g; MDU 4.8 ± 1.7 g/8.8 g ± 1.7 g; SDU/MDU p = 0.0003, with filter p = 0.0034; plastic: SDU 35.0 ± 4.0, MDU 6.6 ± 0.7 g/ 15.1 g ± 5.8 g, SDU/MDU p < 0.0001, with filter p < 0.0001).

CONCLUSION

Prescription-based treatment of DED in Germany causes an increasing and substantial waste volume. The use of SDUs is considerably more resource-intensive than MDUs. Due to the large and rising number of patients suffering from DED improvements in packaging could considerably reduce the CO2 footprint of DED treatment.

Orthokeratology Lens Wear for 2 Years in Children Did Not Alter Tear Film Lipid Thickness by Non-Invasive Interferometry

Purpose

Previous studies suggest that overnight orthokeratology (OOK) may be detrimental to tear function. We aimed to investigate the effect of OOK on lipid layer thickness (LLT), blink pattern, and meibomian gland and elucidate the relationship of these variables.

Methods

Thirty-seven participants who wore OOK lenses every night for at least 2 years and twenty-four healthy non-contact lens wearers (controls) were enrolled in this retrospective study. LipiView interferometry, blink pattern analysis, the ocular surface status, and morphology and function of the meibomian gland were determined.

Results

The OOK group and healthy controls had similar LLT, blink patterns, ocular surface status, and the function of the meibomian gland. OOK participants demonstrated higher meiboscore in the lower eyelids (p < 0.05) but not in the upper eyelids. Within the OOK group, LLT was significantly impacted by the partial blink rate (p < 0.05) and the total score of the upper meibomian gland (p = 0.10).

Conclusions

Wearing OOK for 2 or more years increased lower eyelid meibomian gland dropout but did not have a reduction of LLT.

Benefits and Safety of Astaxanthin in the Treatment of Mild-To-Moderate Dry Eye Disease

Objectives: To evaluate the effect of astaxanthin in the treatment of mild-to-moderate dry eye disease (DED) in middle-aged and elderly patients.

Methods: 120 eyes of 60 middle-aged and elderly patients with mild-to-moderate DED were enrolled in this prospective, one-group, quasi-experimental study. Six milligram Astaxanthin tablets (Weihong Haematococcus Pluvialis Astaxanthin, Hangzhou Xinwei Low Carbon Technology R&D Co., Ltd., China) were administered orally, twice daily for 30 ± 2 days. History of eye diseases, treatment, systemic disease, and medication before the test were recorded. In addition, the ocular surface disease index (OSDI) questionnaire, non-invasive tear break-up time (NIBUT), fluorescein break-up time (FBUT), corneal fluorescein staining (CFS) score, eyelid margin signs, meibomian gland (MG) expressibility, meibum quality, meibomian gland dropout (MGDR), Schirmer I test (SIt), tear meniscus height (TMH), bulbar conjunctiva congestion degree, blink frequency, incomplete blink rate, and thickness of tear film lipid layer were collected before treatment, 2 weeks after the initiation of treatment, and at the end of treatment. Visual acuity (VA), intraocular pressure (IOP), anterior segment, fundus, discomfort symptoms and other adverse reactions were also monitored throughout the study to assess the safety.

Results: OSDI score, NIBUT, BUT, CFS score, eyelid margin signs, MG expressibility, meibum quality, and blink frequency improved significantly to varying degrees after treatment compared with those before the treatment (P < 0.05), while TMH, SIt, conjunctival congestion, the thickness of tear film lipid layer, MGDR, incomplete blink rate, VA and IOP did not differ (P > 0.05).

Conclusions: Oral administration of astaxanthin improves the symptoms and signs of middle-aged and elderly patients with mild-to-moderate DED.

Assessment of tear film lipid layer thickness in patients with Meibomian gland dysfunction at different ages

BACKGROUND

To evaluate the correlations between lipid layer thickness (LLT) and morphology and function of the meibomian glands in patients who were diagnosed as meibomian gland dysfunction (MGD) in different age groups.

METHODS

Patients who have diagnosed as obstructive MGD were included in this prospective, cross-sectional study. Patients were divided into three groups: young (ages 20-39 years), middle-aged (ages 40-59 years), and older (aged ≥60 years). All patients completed an Ocular Surface Disease Index (OSDI) questionnaire and were evaluated for LLT, tear meniscus height (TMH), noninvasive tear film break-up time (NI-BUT) measurement, invasive TBUT (ITBUT), corneal fluoresceinstaining (CFS) score, eyelid margin abnormalities, Schirmer I test, and MG function and morphology, by using the Keratograph 5 and LipiView interferometer.

RESULTS

Two hundred and nine patients (209 eyes) were included. The median LLT of all patient was 57 nm (IQR, 36.5 nm), and the LLT values were significantly different among the young group (median, 51 nm; IQR, 23.5 nm), middle-aged group (median, 59.5 nm; IQR 46.5 nm) and older group (median, 62 nm; IQR, 42.5 nm) (P = 0.033, Kruskal-Wallis test). In regression analyses controlling for confounder factors sex and MG loss, the LLT was positively correlated with age (β = 5.539, P = 0.001). There was a negative correlation between LLT and MG dropout in the all (r = - 0.527, P < 0.001), young (r = - 0.536, P < 0.001), middle-aged (r = - 0.576, P < 0.001), and older (r = - 0.501, P < 0.001) groups. LLT was positively correlated with the MG expressibility in the all (r = 0.202, P = 0.003), middle-aged (r = 0.280, P = 0.044) and older (r = 0.452, p < 0.001) groups, but it was no statistical significance in the young group (r = 0.007, P = 0.949).

CONCLUSIONS

The thickness of LLT was increased with age and significantly correlated with both MG secretion and morphology in middle-aged and older patients with obstructive MGD. LLT measurement is a useful screening tool for detecting obstructive MGD and age as an influential factor should be accounted for when interpreting the meaning of the LLT value.

TRIAL REGISTRATION

NCT02481167 ; Registered 25 June, 2015.

Meibomian Gland Dysfunction in Type 2 Diabetic Patients

Purpose

To investigate meibomian gland and tear film function in patients with type 2 diabetes.

Methods

This prospective study compared changes in meibomian gland and tear film function in type 2 diabetic patients with nondiabetic patients. Meibomian gland function was evaluated by measuring lipid layer thickness (LLT), grading of meibomian gland loss, lid margin abnormalities, and expression of meibum. Tear film function was assessed by measuring tear breakup time (TBUT), the Schirmer I test, noninvasive breakup time (NIBUT), tear meniscus height (TMH), and corneal fluorescein staining.

Results

Meibography scores were significantly higher in the diabetic group compared with the nondiabetic group (p = 0.004). The number of expressible glands was significantly lower in the diabetic group in temporal, central, and nasal third of the lower eyelid (nasal: p = 0.002; central: p = 0.040; and temporal: p = 0.039). The lid margin abnormality score was significantly higher in the diabetic group than in the nondiabetic group (p = 0.04). There was no statistically significant difference in the tear film function parameters between the two groups.

Conclusions

Meibomian gland dysfunction (MGD) in type 2 diabetic patients is more severe compared with nondiabetic patients. Overall, most of the diabetic patients manifest as having asymptomatic MGD.