Correlation between Macular Pigment Optical Density and Neural Thickness and Volume of the Retina.

Macular pigment (MP), which is composed of lutein/zeaxanthin/mezo-zeaxanthin, is concentrated in the central part of the retina, the macula. It protects the macula by absorbing short-wavelength light and suppressing oxidative stress. To evaluate whether MP levels are related to retinal neural protection and resulting health, we analyzed the association between the MP optical density (MPOD), and the macular thickness and volumes. Forty-three eyes of 43 healthy adult volunteers (21 men and 22 women; age: 22-48 (average 31.4 ± 1.1) years) were analyzed. Highly myopic eyes (<-6 diopters) were excluded. MPOD was measured using MPS2®, and the neural retinal thickness and volume were measured using optical coherence tomography. The mean MPOD was 0.589 ± 0.024, and it positively correlated with the central retinal thickness (P = 0.017, R = 0.360) and retinal volume of the fovea (1-mm diameter around the fovea; P = 0.029, R = 0.332), parafovea (1-3-mm diameter; P = 0.002, R = 0.458), and macula (6-mm diameter; P = 0.003, R = 0.447). In the macular area (diameter: 6 mm), MPOD was correlated with the retinal neural volume of the ganglion cell layer (P = 0.037, R = 0.320), inner plexiform layer (P = 0.029, R = 0.333), and outer nuclear layer (P = 0.020, R = 0.353). Thus, MPOD may help in estimating neural health. Further studies should determine the impact of MP levels on neuroprotection.

Reduced Expression of VAMP8 in Lacrimal Gland Affected by Chronic Graft-versus-Host Disease.

PURPOSE: To investigate whether the SNARE protein vesicle-associated membrane protein 8 (VAMP8) was implicated in the development of chronic ocular graft-versus-host disease (GVHD). METHODS: Firstly, the chronic GVHD (cGVHD) and Sjögren's syndrome (SS)-impaired lacrimal gland (LG) tissue sections from humans for diagnostic purpose were evaluated for VAMP8 expression by histopathology and immunohistochemistry. Next, serial changes of tear secretion and VAMP8 expression at both protein and mRNA level of LG in an animal cGVHD model compared with the syngeneic control. RESULTS: Decreased VAMP 8 expression in the cGVHD-affected human LG was detected in comparison with SS-affected LG. Tear secretion in the murine cGVHD model was significantly reduced compared with that in the syngeneic controls 8 weeks after BMT. Protein expression of VAMP8 in the cGVHD-affected LG in murine cGVHD was decreased in comparison with that in the controls. Gene expression of VAMP8 in the cGVHD-affected murine LG was significantly less than that in the syngeneic control 3 weeks after BMT. CONCLUSIONS: Our results suggested that expression of VAMP8 in the cGVHD-affected LG was decreased and accordingly tear secretion in cGVHD was reduced. Collectively, the reduction of VAMP8 expression in the cGVHD-affected LG can be involved in the pathogenic processes of cGVHD-induced dry eye disease.

Elevated Aqueous Cytokine Levels in Eyes With Ocular Surface Diseases.

PURPOSE: To evaluate cytokine and protein levels in the aqueous humor (AqH) of eyes with ocular surface diseases. DESIGN: Prospective consecutive case series. METHODS: This study includes 14 patients (aged 62.4 ± 13.7 years) with chronic-phase ocular surface diseases (4 with ocular cicatricial pemphigoid, 5 with chemical burns, 2 with a thermal burn, 2 with Stevens-Johnson syndrome, and 1 with exposure keratitis), 14 matched patients without ocular surface disease (controls with corneal scar), and 30 patients who underwent cataract surgery (healthy controls). AqH samples were collected at the beginning of surgery. AqH levels of cytokines (interleukin [IL]-1α, IL-1ß, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, IL-17A, monocyte chemotactic protein [MCP]-1, interferon [IFN]-α, IFN-γ, macrophage inflammatory protein [MIP]-1α, MIP-1ß, P-selectin, E-selectin, soluble-intercellular adhesion molecule [s-ICAM]-1, tumor necrosis factor [TNF]-α, granulocyte-macrophage colony-stimulating factor [GM-CSF], IFN-γ-induced protein [IP]-10) were measured using multiplex beads immunoassays. RESULTS: The levels of IL-6, IL-10, IL-17A, GM-CSF, E-selectin, P-selectin, and s-ICAM in AqH were significantly elevated in eyes with ocular surface diseases (in pg/mL: 1696 ± 804, 4.0 ± 1.0, 24.3 ± 9.8, 26.0 ± 18.3, 5150 ± 1232, 13122 ± 7219, and 7914 ± 2813, respectively), compared to healthy controls (IL-6: 6.36 ± 0.94, P = .001; IL-10: 1.68 ± 0.04, P = .0006; IL-17A: 3.7 ± 0.2, P = .008; GM-CSF: 2.7 ± 0.3, P = .007; E-selectin: 2093 ± 37, P = .0001; P-selectin: 3658 ± 137, P = .0001; sICAM-1: 1397 ± 119, P = .008). The levels of IL-6, IL-17A, E-selectin, and P-selectin in AqH were significantly higher in eyes with ocular surface diseases compared to those with corneal scar (IL-6: 44.1 ± 15.0, P = .0077; IL-17A: 4.1 ± 0.7, P = .034; E-selectin: 2439 ± 302, P = .039; and P-selectin: 5673 ± 1553, P = .017). CONCLUSIONS: Multiple AqH cytokine levels were elevated in chronic ocular surface diseases.