Characterizing the Robustness of Distinct Clinical Assessments in Identifying Dry Eye Condition of Animal Models.

PURPOSE: The study aims to characterize the robustness of distinct clinical assessments in identifying the underlying conditions of dry eye disease (DED), with a specific emphasis on the involvement of conjunctival goblet cells. METHODS: Seven rabbits receiving surgical removal of the lacrimal and Harderian glands were divided into two groups, one with ablation of conjunctival goblet cells by topical soaking of trichloroacetic acid (TCA) to the bulbar conjunctiva (n = 3) and one without (n = 4), and the conditions of DED were assessed weekly using Schirmer test, tear breakup time (TBUT), tear osmolarity, and National Eye Institute (NEI) fluorescein staining grading. After 8 weeks, the rabbits were sacrificed, and the eyes were enucleated for histopathological examination. RESULTS: Histopathological analysis revealed corneal epithelial thinning in both groups. While TCA soaking significantly decreased the density of conjunctival goblet cells, DED rabbits without TCA also showed a partial reduction in goblet cell density, potentially attributable to dacryoadenectomy. Both groups showed significant decreases in Schirmer test and TBUT, as well as an increase in tear osmolarity. In DED rabbits with TCA soaking, tear osmolarity increased markedly, suggesting that tear osmolarity is highly sensitive to loss and/or dysfunction of conjunctival goblet cells. Fluorescein staining was gradually and similarly increased in both groups, suggesting that fluorescein staining may not reveal an early disruption of the tear film until the prolonged progression of DED. CONCLUSION: The Schirmer test, TBUT, tear osmolarity, and NEI fluorescein grading are distinct, yet complementary, clinical assessments for the evaluation of DED. By performing these assessments in definitive DED rabbit models, both with and without ablation of conjunctival goblet cells, the role of these cells in the homeostasis of tear osmolarity is highlighted. Characterizing the robustness of these assessments in identifying the underlying conditions of DED will guide a more appropriate management for patients with DED.

Peripheral ulcerative keratitis secondary to chronic Citrobacter koseri canaliculitis.

Citrobacter koseri is a rarely reported ocular pathogen. It may induce severe peripheral corneal inflammation and subsequent perforation by canaliculitis. Timely detection of the reservoir of this pathogen would halt its progression. The purpose of this study was to report a rare presentation of C. koseri chronic canaliculitis complicated with perforating peripheral ulcerative keratitis (PUK). A 71-year-old female who had several episodes of C. koseri conjunctivitis in the past 6 months was admitted to our infection ward under the impression of fever that was suspected to be related to urinary tract infection. She had concurrent copious mucopurulent discharge and blurred vision. Ocular examination disclosed hyperemic conjunctiva and an oval-shaped corneal infiltrate at 5-6 o'c periphery, which later rapidly progressed to PUK and corneal perforation. Despite aggressive treatment, the cornea continued to thin, and a second perforation occurred. After meticulous examination of the ocular adnexa, irrigation of inferior canaliculi revealed pustular discharge with profuse concretions indicating chronic canaliculitis. A cutaneous-lacrimal fistula was also found. Frequent antibiotic irrigation of the canaliculus finally halted the corneal melting and the cornea healed. Although rare, C. koseri may not only cause chronic canaliculitis but also induce peripheral corneal inflammation mimicking autoimmune-related PUK. Identification of C. koseri from conjunctival swab cultures should prompt the physicians to check chronic persistent canaliculus infections, which may help prevent rapidly progressive corneal inflammation and thus perforation. Management of C. koseri canaliculitis-induced PUK must also include antibiotic irrigation to eradicate canaliculitis infection at the reservoir and not just topical antibiotics.

Acute effects of noise exposure on 24-h ambulatory blood pressure in hypertensive adults.

OBJECTIVE: Noise exposure is associated with elevated blood pressure, but the effects on susceptible workers have not been reported. This repeated-measure study investigated the effects of noise exposure on 24-h ambulatory blood pressure among hypertensive, pre-hypertensive, and normotensive adults. METHODS: We enrolled 113 volunteers in an occupational cohort in 2009. Individual noise exposure and personal blood pressure were measured simultaneously over 24 h on working and non-working days. Linear mixed-effects regressions were used to estimate the effects on SBP and DBP by controlling for potential confounders. RESULTS: Each A-weighted decibel (dBA) increase in a 30-min time-lagged exposure was associated with transient elevations of work-time SBP [0.30 (95% confidence interval: 0.06, 0.54) mmHg] on working days as well as sleep-time SBP [0.39 (0.12, 0.66) mmHg] and DBP [0.33 (0.14, 0.51) mmHg] on non-working days among 19 hypertensive adults. In contrast, 46 normotensive workers had transient increases in work-time SBP [0.16 (0.03, 0.29) mmHg] and DBP [0.25 (0.15, 0.34) mmHg] on working days as well as sleep-time SBP [0.17 (0.06, 0.29) mmHg] and DBP [0.21 (0.14, 0.29) mmHg] on non-working days caused by a 1-dBA increase in the current exposure. All groups had sustained increases in 24-h average ambulatory SBP and DBP induced by noise exposure on 2 days, but the hypertensive workers had the most pronounced increase in SBP. CONCLUSION: Hypertensive adults are more susceptible to noise exposure with a greater effect on ambulatory SBP. These results suggest a need for more protection for this subpopulation.

Effects of environmental noise exposure on 24-h ambulatory vascular properties in adults.

Exposure to environmental noise has been associated with hypertension, but the related mechanism of vascular structural changes is unclear. This repeated-measure study investigated the effects of noise exposure on the 24-h ambulatory vascular structural properties in 66 adults aged 18-32 years. Individual noise exposure and personal vascular parameters were measured simultaneously in all subjects. Linear mixed-effects regressions were used to estimate the effects. A 1-A-weighted decibel (dBA) increase was significantly associated with the transient effects of 1.39 (95% confidence interval: 1.07, 1.79) %mL/mmHg in arterial compliance at nighttime but -1.70 (-2.05, -1.10) kdynes·s/cm(5) in arterial resistance during the daytime and -2.38 (-3.44, -1.64) kdynes·s/cm(5) in arterial resistance at nighttime among all subjects. Such effects were observed in arterial distensibility only during the daytime after the 30-min (-1.84 [-2.61, -1.29] %/mmHg) and 60-min (-2.06 [-2.95, -1.44] %/mmHg) time-lagged noise exposures. For 24-h environmental noise, a 1-dBA increment was significantly associated with a sustained increase of 1.25 (1.10, 1.42) %mL/mmHg in arterial compliance but a decrease of 2.12 (-2.51, -1.80) kdynes·s/cm(5) in arterial resistance. Environmental noise exposure may have transient and sustained effects on adult vascular properties.

Effects of environmental noise exposure on ambulatory blood pressure in young adults.

Epidemiological studies have demonstrated that environmental noise exposure is associated with hypertension in middle-aged and older populations, but the relationship in the young subpopulation and between the genders is still unclear. This panel study investigated effects of environmental noise exposure on 24-h ambulatory blood pressure in 60 adults aged 18-32 years. Individual noise exposure and personal blood pressure were measured simultaneously for 30 males and 30 females. Linear mixed-effects regression models were applied to estimate effects. Total subjects (56.6+/-16.5A-weighted decibels (dBA)) had transient elevations of 1.15 (95% CI=0.86-1.43)mmHg SBP and 1.16 (0.93-1.38)mmHg DBP at daytime, as well as 0.74 (0.21-1.26)mmHg SBP and 0.77 (0.34-1.20)mmHg DBP at nighttime, significantly associated with a 5-dBA increase in noise exposure. Such effects on SBP and DBP still persisted at the 30- and 60-min time-lagged noise exposure. Per 5-dBA increase in 24-h average noise exposure was significantly associated with sustained increments of 1.15 (0.76-1.54)mmHg SBP and 1.27 (0.96-1.58)mmHg DBP in males (57.4+/-16.0dBA), as well as the higher levels of 1.65 (1.36-1.94)mmHg SBP and 1.51 (1.27-1.75)mmHg DBP in females (55.9+/-17.0dBA). We found that environmental noise exposure may have elevated effects on adults' blood pressure. Young females are more susceptible to noise exposure than males.