ASSESSMENT OF PREVALENCE OF DIGITAL EYE STRAIN AMONG DIGITAL SCREEN USERS IN SETTING OF COVID-19 PANDEMIC.

AIMS AND OBJECTIVES: To assess the impact of the increased digital device usage and its ocular surface health implications along with circadian rhythm abnormalities related to digital eye strain during COVID-19 pandemic. METHODS: A validated questionnaire was provided to all the participants and various symptoms people experienced were analyzed. Dry eye tests were performed in all the study subjects. RESULTS: A total of 256 participants were included of which 88.3% of subjects reported an increase in their screen time since the onset of pandemic. The average increase in digital device usage was calculated at about 4.4 ± 1.9 h per day. The total usage per day was found to be7.85 ± 3.63 hours. Sleep disturbances have been reported by 59.8% of participants. Typically, 93% of respondents had experienced at least one symptom related to digital device usage, and 66.4% said that the frequency and intensity of these symptoms increased since the pandemic started. Dry eye diagnosed clinically by Schirmer's test was present in 18.8 % of participants. CONCLUSION: The study highlights the increase in usage of digital devices after the onset of the COVID-19 pandemic leading to increase in digital eye strain across all age groups.

Serum vitamin D in Indian children with vernal keratoconjunctivitis

AIM: To determine the vitamin D levels in vernal keratoconjunctivitis (VKC) patients in Indian population. METHODS: A total of 30 non-atopic healthy children and 30 children having VKC were included in the study. The serum vitamin D levels and the time spent outside was compared between the two groups (P<0.05). RESULTS: The mean serum vitamin D level in the VKC group was significantly lower (mean 19.17±10.76 ng/mL) compared to the control group (mean 31.19±9.09 ng/mL) (P=0.0003). The vitamin D levels were found to be deficient (10-20 ng/mL) in 43.33%, whereas severe deficiency (<10 ng/mL) was found in 20% of the VKC patients. The deficiency of vitamin D correlated with the level of severity of VKC (P<0.02). The time spent outside in the VKC group was 1.07±0.76h, whereas in the healthy subjects it was 2.08±0.72h (P<0.0001), and it showed a significant correlation with the serum 25 (OH) D3 levels (r=0.478, P<0.001). CONCLUSION: The study shows that children with VKC had a significantly lower serum vitamin D levels as compared to the healthy children which correlated with time spent outside. The severity of VKC also correlated with the severity of vitamin D deficiency which suggests that vitamin D plays an important role in maintaining ocular surface health.

Strain heterogeneity, cooccurrence network, taxonomic composition and functional profile of the healthy ocular surface microbiome

Background There is growing evidence indicating that the microbial communities that dwell on the human ocular surface are crucially important for ocular surface health and disease. Little is known about interspecies interactions, functional profiles, and strain heterogeneity across individuals in healthy ocular surface microbiomes. Methods To comprehensively characterize the strain heterogeneity, cooccurrence network, taxonomic composition and functional profile of the healthy ocular surface microbiome, we performed shotgun metagenomics sequencing on ocular surface mucosal membrane swabs of 17 healthy volunteers. Results The healthy ocular surface microbiome was classified into 12 phyla, 70 genera, and 140 species. The number of species in each healthy ocular surface microbiome ranged from 6 to 47, indicating differences in microbial diversity among individuals. The species with high relative abundances and high positivity rates were Streptococcus pyogenes, Staphylococcus epidermidis, Propionibacterium acnes, Corynebacterium accolens, and Enhydrobacter aerosaccus. A correlation network analysis revealed a competitive interaction of Staphylococcus epidermidis with Streptococcus pyogenes in ocular surface microbial ecosystems. Staphylococcus epidermidis and Streptococcus pyogenes revealed phylogenetic diversity among different individuals. At the functional level, the pathways related to transcription were the most abundant. We also found that there were abundant lipid and amino acid metabolism pathways in the healthy ocular surface microbiome. Conclusion This study explored the strain heterogeneity, cooccurrence network, taxonomic composition, and functional profile of the healthy ocular surface microbiome. These findings have important significance for the future development of probiotic-based eye therapeutic drugs.

A New Modified Experimental Meibomian Gland Injury Model: Partial Loss of Gland Due to Orifice Cauterization and the Alleviating Potential of 22-Oxacalcitriol

1α,-25-dihydroxy-22-oxacalcitriol (maxacalcitol) is a non-calcemic vitamin D3 analog clinically approved to treat psoriasis, and its role has been increasingly recognized in suppressing keratinocyte proliferation, mediating inflammation, and regulating the immune response. A large number of studies have suggested that vitamin D plays an important role in maintaining ocular surface health. However, its topical effects on the Meibomian gland (MG) has been insufficiently investigated. Here, we introduce an experimental MG orifice injury model, where the partial glandular loss occurred after electrical cauterization on a limited number of MG orifices, and investigate the efficacy and safety of maxacalcitol ointment in treating this MG orifice injury model. We confirm the alleviation of MG atrophy and ductal dilation by maxacalcitol ointment application. The recovery of injured MG visualizing as the residual MG area is significantly better in the maxacalcitol group (p = 0.020) compared with the Vaseline® group, especially during the first two weeks. The cornea and other ocular tissues were not affected by maxacalcitol ointment application during our two-month observation period. Altogether, this work indicates that maxacalcitol has therapeutic potential in the amelioration of initial injury of MG orifices caused by electrocautery.

Comparative analysis of spontaneous blinking and the corneal reflex

Ocular surface health, the cognitive status, psychological health or human neurological disorders, among others, can be assessed by studying eye blinking, which can be differentiated in spontaneous, reflex and voluntary. Its diagnostic potential has provided a great number of works that evaluate their characteristics and variations depending on the subject's condition (sex, tiredness, health, …). The objective of this study was to analyse the differences in blinking kinematics of spontaneous and reflex blinks, distinguishing between direct and consensual reflexes, using a self-developed, non-invasive and image processing-based method. A video-oculography system is proposed using an air jet driven by a syringe to induce reflex and a high-speed camera to record the blinking of both eyes. The light intensity diffused by the eye changes during blinking and peaks when the eyelid closes. Sixty-second sequences were recorded of 25 subjects blinking. Intensity curves were off-line fitted to an exponentially modified Gaussian (EMG) function, whose σ , μ and τ parameters were analysed. A two-way analysis of variance (ANOVA) of these parameters was conducted to test the influence of the subject, the eye and blink type. In the closing phase, direct and consensual corneal reflexes are faster than spontaneous blinking, but there was no significant difference between them, nor between right and left eyes. In the opening phase, the direct corneal reflex was the slowest and significant differences appeared between right and left eyes.

Tear Proteomics in Young Malays with Dry Eyes

Introduction: Changes in tear protein concentrations may reflect ocular surface health. This study analyzes changes in tear protein concentrations of young Malays with dry eye (DE) and determines its association with the clinical findings. Methods: Subjects were screened using McMonnies questionnaire (MDEQ) and flourescein tear break up time (TBUT). Total tear protein concentration (TTPC) was determined using Bradford's technique and specific tear protein (sIgA, lysozyme, lactoferrin and human serum albumin (HSA)) concentrations were determined using SDS-PAGE. Parametric and nonparametric tests were used to compare means between groups. Spearman correlation was used to determine the association between variables measured. Results: A total of 42 subjects (21 DE and 21 NDE) were included. Mean MDEQ score for DE was 16.00±1.48 and NDE was 8.47±3.47. Mean TBUT for DE was 3.47±0.47s and NDE was 4.98±0.43s. Mean TTPC for DE and NDE was 9.84±2.40mg/ml and 8.96±1.84mg/ml respectively. Mean sIgA, lysozyme, lactoferrin and HSA for DE was 0.54±0.10mg/ml, 1.68±0.17mg/ml, 1.47±0.25mg/ml, 0.06±0.03mg/ml and for NDE was 0.57±0.09mg/ ml, 2.04±0.19mg/ml, 1.75±0.23mg/ml, 0.06±0.03mg/ml accordingly. Significant differences were noted in MDEQ score (p=0.01), TBUT (p=0.01), lactoferrin (p=0.01) and lysozyme (p=0.01) but not in TTPC (p=0.19), HSA (p=0.74) and sIgA (p=0.24) between groups. Significant correlations were noted between TBUT with lactoferrin (r=0.02, p=0.02) and lysozyme (r=0.63, p=0.01) and between MDEQ score with lactoferrin (r=-0.34, p=0.02) and lysozyme (r=-0.64, p=0.01). Conclusions: There are changes in specific tear protein in dry eye patients, which correlate well with clinical results. Tear protein analysis may play an important role in the diagnosis of the dry eye.