Examining Tear Film Dynamics Using the Novel Tear Film Imager.

PURPOSE: The purpose of this study was to examine Tear Film Imager (TFI, AdOM, Israel) generated parameters across controls and dry eye (DE) subgroups and examine the changes in TFI parameters with contact lens (CL) placement. METHODS: The retrospective study (n = 48) was conducted at the Miami Veterans Hospital. Symptoms were assessed through validated questionnaires and signs of tear function by tear break-up time and Schirmer scores. Participants were grouped as 1) healthy, 2) evaporative, 3) aqueous deficient, and 4) mixed DE based on tear function. Seventeen individuals had a baseline scan and a repeat scan following CL placement. Descriptives were compared across groups and over time. RESULTS: The median age was 27 years, 74% self-identified as White, 45% as male, and 51% as Hispanic. Subjects in the aqueous deficiency category had lower muco-aqueous layer thickness (MALT) (2672 vs. 3084 nm) but higher lipid layer thickness (47.5 vs. 38.3 nm), lipid break-up time (4.4 vs. 2 seconds), and interblink interval (13.9 vs. 5.4 seconds) compared with the evaporative group. Subjects in the evaporative group had the highest MALT values (3084 vs. 2988, 2672, 3053 nm) compared with healthy, aqueous-deficient, and mixed groups. Symptoms were not significantly correlated with TFI parameters. CL placement significantly decreased MALT values (2869 → 2175 nm, P = 0.001). CONCLUSIONS: The TFI provides unique information regarding the dynamic function of the tear film not captured by clinical examination. TFI generated metrics demonstrate a thinner aqueous layer in individuals with aqueous deficiency but highlight a thicker aqueous layer in those with evaporative DE.

Positive Bacterial Cultures on Spinal Wound Closure Do Not Predict Postoperative Outcomes.

BACKGROUND: Complex surgical back wounds represent significant morbidity in patients who have undergone spinal procedures requiring closure or revision by plastic surgeons. This study aimed to assess the utility of bacterial wound culture data for predicting surgical outcomes of wound management. METHODS: This study is a single-institution retrospective review of consecutive patients who required plastic surgery intervention for wound infection following spinal procedures between the years 2010 and 2021 (n = 70). Statistical analysis was performed for demographics, comorbidities, perioperative laboratory studies, and treatment methods. The primary outcomes of interest were rate of postoperative complications after soft tissue reconstruction and reconstructive failure. The secondary outcome of interest was time to healing in number of days. RESULTS: The overall complication rate after wound closure was 31.4%, with wound infection in 12.9%, seroma in 10%, dehiscence in 12.9%, and hematoma in 1.4%. Increasing number of debridements before wound closure increased the likelihood of a surgical complication of any kind (odds ratio [OR], 1.772; 95% confidence interval [CI], 1.045-3.002). Positive wound cultures before reconstruction were associated with development of seroma only (OR, 0.265; 95% CI, 0.078-0.893). Use of incisional vacuum-assisted closure devices significantly decreased the odds of postoperative wound dehiscence (OR, 0.179; 95% CI, 0.034-0.904) and increased odds of healing (hazard ratio, 3.638; 95% CI, 1.547-8.613). CONCLUSIONS: Positive wound cultures were not significantly associated with negative outcomes after complex closure or reconstruction of infected spinal surgical wounds. This finding emphasizes the importance of clinical judgment with a multidisciplinary approach to complex surgical back wounds over culture data for wound closure timing.

Functional Near-Infrared Spectrometry as a Useful Diagnostic Tool for Understanding the Visual System: A Review.

This comprehensive review explores the role of Functional Near-Infrared Spectroscopy (fNIRS) in advancing our understanding of the visual system. Beginning with an introduction to fNIRS, we delve into its historical development, highlighting how this technology has evolved over time. The core of the review critically examines the advantages and disadvantages of fNIRS, offering a balanced view of its capabilities and limitations in research and clinical settings. We extend our discussion to the diverse applications of fNIRS beyond its traditional use, emphasizing its versatility across various fields. In the context of the visual system, this review provides an in-depth analysis of how fNIRS contributes to our understanding of eye function, including eye diseases. We discuss the intricacies of the visual cortex, how it responds to visual stimuli and the implications of these findings in both health and disease. A unique aspect of this review is the exploration of the intersection between fNIRS, virtual reality (VR), augmented reality (AR) and artificial intelligence (AI). We discuss how these cutting-edge technologies are synergizing with fNIRS to open new frontiers in visual system research. The review concludes with a forward-looking perspective, envisioning the future of fNIRS in a rapidly evolving technological landscape and its potential to revolutionize our approach to studying and understanding the visual system.

Impact of Tumor Necrosis Factor Receptor 1 (TNFR1) Polymorphism on Dry Eye Disease.

The goal of the study was to examine whether a genetic polymorphism in tumor necrosis factor receptor 1 (TNFR1) gene impacted the dry eye disease (DED) phenotype and response to anti-inflammatory therapy. The prospective study included 328 individuals with various dry eye (DE) symptoms and signs recruited from the Miami Veterans Hospital eye clinic between October 2013 and October 2017. The population underwent genetic profiling for a polymorphism within the TNFR1 gene (rs1800693 [TT, TC, CC]). The study examined the genotype distribution and relationships between the genotype, phenotype, and response to anti-inflammatory therapy. The mean age of the population was 61.7 ± 9.8 years. Here, 92% self-identified as male, 44% as White, and 21% as Hispanic; 13% (n = 42) of individuals had a CC genotype. DED symptoms and signs were similar across the three genotype groups. Thirty individuals (four with CC) were subsequently treated with an anti-inflammatory agent. There was a non-significant trend for individuals with CC genotype to have a partial or complete symptomatic response to treatment compared with the other two groups (100% for CC vs. 40% for TT and 36.4% for TC, p = 0.22). In conclusion, the presence of homozygosity of minor allele C (CC genotype) in a single nucleotide polymorphism (SNP) within TNFR1 was noted in a minority of individuals with various aspects of DED, but did not impact the DED phenotype. Our findings suggest that the current phenotyping strategies for DED are insufficient to identify underlying disease contributors, including potential genetic contributors.

Long-Term Trigeminal Nerve Stimulation as a Treatment for Ocular Pain.

OBJECTIVES: Ocular pain symptoms (e.g., hypersensitivity to light and wind, "burning" sensations) can be debilitating and difficult to treat. Neuromodulatory therapies targeting sensory trigeminal and central pain pathways may help treat chronic ocular pain refractory to traditional therapies. The current study evaluates the long-term effects of a trigeminal neurostimulator (TNS) on ocular pain. MATERIALS AND METHODS: Retrospective review of 18 individuals at the Miami Veterans Affairs Eye Clinic with chronic, severe ocular pain who were prescribed and used TNS at home for ≥3 months. The primary outcome measures were 1) ocular symptom intensity over a 24-hour recall period (dryness, pain, light sensitivity, wind sensitivity, burning; rated on 0-10 scales) captured pre-TNS and at monthly follow-up intervals and 2) side effects. The frequency and duration of TNS was a secondary outcome measure. RESULTS: The mean age of the population (n = 18) was 57.5 years (range, 34-85 years) with a male majority (67%). Two individuals discontinued use due to lack of efficacy and one due to confounding health issues. Initial mean weekly frequency of TNS use was 3.7 ± 1.9 sessions of 25.8 min at month 1 and 2.7 ± 2.3 sessions of 28.0 min at month 6. At six months, pain intensity (↓ 31.4%), light sensitivity (↓ 36.3%), wind sensitivity (↓ 32.6%), and burning sensation (↓ 53.9%) were all decreased compared to baseline (p < 0.01 for all); greater decreases in ocular pain were noted in individuals with migraine (n = 10) than those without migraine (n = 8). No significant change was noted in mean dryness scores. Fifteen subjects experienced sedation with TNS use, persisting throughout the follow-up visits. No other adverse effects were communicated by any subjects. CONCLUSION: Our study suggests TNS is a safe, adjunctive treatment option in individuals with severe, chronic ocular pain. Individuals demonstrated gradual, continual improvement in pain symptoms over time within a multimodal approach.

Neurite orientation dispersion and density imaging reveals white matter and hippocampal microstructure changes produced by Interleukin-6 in the TgCRND8 mouse model of amyloidosis.

Extracellular ß-amyloid (Aß) plaque deposits and inflammatory immune activation are thought to alter various aspects of tissue microstructure, such as extracellular free water, fractional anisotropy and diffusivity, as well as the density and geometric arrangement of axonal processes. Quantifying these microstructural changes in Alzheimer's disease and related neurodegenerative dementias could serve to monitor or predict disease course. In the present study we used high-field diffusion magnetic resonance imaging (dMRI) to investigate the effects of Aß and inflammatory interleukin-6 (IL6), alone or in combination, on in vivo tissue microstructure in the TgCRND8 mouse model of Alzheimer's-type Aß deposition. TgCRND8 and non-transgenic (nTg) mice expressing brain-targeted IL6 or enhanced glial fibrillary protein (EGFP controls) were scanned at 8 months of age using a 2-shell, 54-gradient direction dMRI sequence at 11.1 T. Images were processed using the diffusion tensor imaging (DTI) model or the neurite orientation dispersion and density imaging (NODDI) model. DTI and NODDI processing in TgCRND8 mice revealed a microstructure pattern in white matter (WM) and hippocampus consistent with radial and longitudinal diffusivity deficits along with an increase in density and geometric complexity of axonal and dendritic processes. This included reduced FA, mean, axial and radial diffusivity, and increased orientation dispersion (ODI) and intracellular volume fraction (ICVF) measured in WM and hippocampus. IL6 produced a 'protective-like' effect on WM FA in TgCRND8 mice, observed as an increased FA that counteracted a reduction in FA observed with endogenous Aß production and accumulation. In addition, we found that ICVF and ODI had an inverse relationship with the functional connectome clustering coefficient. The relationship between NODDI and graph theory metrics suggests that currently unknown microstructure alterations in WM and hippocampus are associated with diminished functional network organization in the brain.