Quantitative evaluation of lipid layer thickness and blinking in children with allergic conjunctivitis.

PURPOSE: To quantitatively evaluate the lipid layer thickness (LLT) and blinking in children with or without allergic conjunctivitis (AC), and to compare those between the different types of AC. METHODS: For this case-control study, 81 children with symptomatic AC with an average age of 9.62 ± 2.67 years were enrolled and subdivided according to the subtypes of AC, including seasonal/perennial allergic conjunctivitis group and vernal keratoconjunctivitis (VKC)/atopic keratoconjunctivitis (AKC) group. Another 82 age-matched healthy children were enrolled as control group. All subjects underwent routine eye examination and measurements of LLT, the number of incomplete or total blinking, partial blinking rate by the LipiView interferometer over a 10-s period. Other ocular surface assessment included fluorescein tear breakup time (TBUT), lower tear meniscus height, meibomian gland loss (MGL), meibum expressibility and quality. RESULTS: Pediatric patients with AC had significant thinner LLT, shorter TBUT, decreased total blinking but increased partial blinking rate, especially in those with VKC/AKC (all P < 0.05). A significant deterioration of meibomian gland parameters was observed in AC group when compared with control subjects, demonstrated by severe upper and lower MGL, lid margin abnormalities, decreased meibum expressibility, and abnormal meibum quality, all of which were worse in the severe type of AC (all P < 0.05). Thinner LLT was significantly correlated with decreased TBUT (ß = 3.666, P < 0.001) and severity of upper MGL (ß = - 7.701, P = 0.002). CONCLUSION: Decreased LLT and blinking disorders in pediatric patients with AC may contribute to lipid layer deficiency in the long run, which should be considered and appropriately diagnosed for a more precise treatment.

Prevalence of Ocular Demodex Infestation in Children: An Epidemiological Survey in South China.

OBJECTIVES: To investigate the prevalence of and risk factors for Demodex mite infestation of the eyelashes in Chinese children. METHODS: A total of 1,575 children were surveyed from June 2017 to January 2019 and stratified into two age groups: 3 to 6 and 7 to 14 years. All subjects underwent routine eye examination and lash epilation for Demodex mite identification and counting using microscopy. Demographic data and lifestyle habits were also recorded. RESULTS: Demodex mites were detected in 189 of 1,575 (12.0%) children, including Demodex folliculorum (D. folliculorum) in 180 (11.4%), Demodex brevis (D. brevis) in 11 (0.7%), and both mites in 2 (0.1%). The median number of D. folliculorum mites was 1 (interquartile range [IQR], 1-2) and that of D. brevis was 1 (IQR, 1-1). Children with Demodex infestation did not exhibit more ocular discomfort than those without (21.2% vs. 23.1%; P=0.56). However, lash abnormalities, including trichiasis, cylindrical dandruff, or scaly discharge at the lash root, were more prevalent in children with Demodex infestation (24.9% vs. 12.8%; P<0.001) and in the 7 to 14-year subgroup (33.7% vs. 12.8%; P<0.001). Multiple logistic regression revealed that autumn-winter was associated with a higher detection rate of Demodex infestation (all P<0.05). In the 3-6-year subgroup, children residing in rural regions exhibited a higher prevalence of Demodex infestation (P=0.03). CONCLUSIONS: Ocular Demodex infestation, with a low Demodex mite count, was found in healthy Chinese children aged 3 to 14 years.

High Prevalence of Demodex Infestation is Associated With Poor Blood Glucose Control in Type 2 Diabetes Mellitus: A Cross-Sectional Study in the Guangzhou Diabetic Eye Study.

PURPOSE: The aim of this study was to investigate the association between type 2 diabetes mellitus (T2DM) and ocular Demodex mite infection. METHOD: About 381 patients with T2DM from nearby communities were enrolled, and 163 age-matched and sex-matched nondiabetic patients from the cataract clinic were included as the control group. All subjects underwent personal history and demographic data collection, ocular examination, and lash sampling, followed by microscopic identification and counting of Demodex mites. Binocular fundus photography was performed for diabetic patients. Statistical correlation between ocular Demodex infestation and T2DM and blood glucose control status was performed. RESULTS: The Demodex mite infestation rate (62.5% vs. 44.8%, P < 0.001) and count [3 (0-12) vs. 2 (0-9.6), P = 0.01], especially of Demodex brevis (18.9% vs. 4.9%, P < 0.001) [0 (0-1) vs. 0 (0-0), P < 0.001], were significantly higher in the T2DM patient group than that in the control group. The ratio of Demodex brevis to Demodex folliculorum in the T2DM patient group was significantly higher than that in the control group (1:3 vs. 1:9, P < 0.001). Diabetic patients presented with more cylindrical dandruff (55.1% vs. 39.3%, P = 0.001). Ocular Demodex infestation was strongly associated with poor blood glucose control (HbA 1 c > 7%) (odds ratio = 1.82; 95% confidence interval, 1.12-2.94; P = 0.2) and female sex (odds ratio = 1.69, 95% confidence interval, 1.08-2.65, P = 0.02). No association was found between Demodex infestation and the severity of diabetic retinopathy. CONCLUSIONS: Patients with T2DM, especially those with poor blood glucose control, tend to have a higher prevalence of ocular Demodex infestation, suggesting that high blood glucose is a risk factor for demodicosis .