[Relationship between gender and posterior pole choroidal thickness in normal eyes].

OBJECTIVE: To investigate and compare the choroidal thickness between healthy male and female subjects. METHOD: Six-hundred and twenty eyes of 310 healthy volunteers with no ophthalmic disease history were recruited, including 152 males and 158 females. All volunteers were subgrouped into Group A to F according to their ages. Enhanced depth imaging choroidal scans were obtained in all eyes by using spectral-domain optical coherence tomography. Subfoveal choroidal thickness (SFCT) and choroidal thickness at 1 mm/3 mm superior, inferior, nasal and temporal to the fovea were measured. Choroidal thickness was compared between male and female in the subgroups with different age. RESULTS: Mean SFCT was higher in 152 males (298.02 ± 101.47) µm than that in 158 females (256.28 ± 90.87) µm with statistically significant difference (t' = 4.853, P < 0.05). Choroid at 1 mm and 3 mm from the fovea were also thicker in the male (t' = 5.050, t = 4.597, t = 5.225, t = 5.363, t = 5.608, t' = 4.239, t = 4.108, t' = 5.589; P < 0.05). In any subgroup from A to E, SFCT in male was significantly thicker than female, after adjusted for refractive error (t = 2.343, t' = 2.163, t = 3.239, t = 2.181, t' = 2.982; P < 0.05). In Group F, mean SFCT in male was thicker than female, but without statistical significance (t' = 0.681, P > 0.05). CONCLUSIONS: Gender was one of the factors that affect the choroid thickness in healthy populations. In subjects under 70, male have thicker choroid than female. This result at least partially explained the gender predilection of macular diseases, such as central serous chorioretinopathy and idiopathic macular hole.

Macular Vascular Density Analysis Using Adobe Photoshop Software In Diabetic Eyes: Optical Coherence Tomography Angiography Study.

BACKGROUND: Optical Coherence Tomography Angiography (OCTA) is dye less microvascular visualizing technique. In study we binaries OCTA images of macular vessels in healthy and diabetic subjects without macular oedema using Adobe Photoshop CS3 extended version. METHODS: Prospective, single centered, observational study total of 58 eyes of 108 Diabetic Retinopathy (DR) subjects and 20 eyes of 40 normal subjects with mean age of 58.3±10.5 range (40-82) were included in our study. Ten eyes with Non-Diabetic Retinopathy (NDR), twenty-nine eyes with Non-Proliferative Diabetic Retinopathy (NPDR) (mild-10, moderate-7 and severe-12) and nineteen eyes with Proliferative Diabetic Retinopathy (PDR)are studied with images obtained using OCTA between September 2016 to June 2017. Scan area of 6×6 mm was selected to find morphological changes in the superficial retinal layers and deep retinal layers. Captured OCTA images were binarized using automated thresholding algorithm. Macular Vessel Density (MVD) (%) and Foveal Avascular Zone area (mm2) measured for superficial and deep retinal vessel arcade. For comparison, analysis of variance and Kruskal-Wallis test are applied. RESULTS: Diabetic eyes were grouped according to their severity level. MVD and FAZ are compared in all groups. Results are significantly lower in all groups except in controls and NDR. Significant decrease is observed in vascular density of most layers with progress in retinopathy. CONCLUSIONS: Adobe Photoshop CS3 extended version is an excellent tool for image binarization. Calculating FAZ area and MVD using OCTA images agreed closely with clinical grading system. Application of this method can be helpful in monitoring disease progression.

[Intervention of nicotinamide on skin melanin genesis after UVA exposed].

OBJECTIVE: To investigate the interference effect of nicotinamide on UVA-induced melanin genesis and melanin transport in human skin melanocyte. METHODS: The optimum UVA dose expected to cause cell proliferation: 0.2 J/cm(2), nicotinamide was added immediately after the 0.2 J/cm(2) UVA exposure and the melanin content, cell cycles, cell apoptosis and mRNA express level were measured respectively. RESULTS: Melanin content in melanocytes was increased significantly after exposed to 0.2 J/cm(2) UVA. Melanin content in melanocytes was decreased after treatment with 10.0 mmol/ml nicotinamide following UVA exposure, but the cell cycles and the cell apoptosis rate were not significantly altered. mRNA express levels of TYR, TRP-1 were modulated by nicotinamide. CONCLUSION: Nicotinamide has more effect on decreasing melanin genesis after UVA exposure, nicotinamide also plays a role in modulating the mRNA express of TYR, TRP-1 gene. It is possible to consider nicotinamide as an efficient and safe sun screen to provide a certain level of protection for UVA exposed skin.

[The intervention of nicotinamide on skin melanocyte's cell proliferation after UVA (365 nm) exposed.].

OBJECTIVE: To investigate the interference effect of nicotinamide on UVA-induced cell proliferation in human skin melanocyte. METHODS: To apply the optimum UVA dose expected to cause cell proliferation: 0.2 cm2, nicotinamide was added after the 0.2 cm2 UVA exposure immediately or 48 h later, then the rate of cell proliferation, calcium concentration and the activities of Na+-K+, Ca2+-ATP enzymes of melanocytes were measured respectively. RESULTS: After treatment with 1.000 mg/ml nicotinamide following UVA exposure, the rate of cell proliferation was decreased significantly 24 hours later. Treatment with 0.125 mg/ml nicotinamide 48 hours after UVA exposure also significantly inhibited the cell proliferation; 1.25 mg/ml nicotinamide increased calcium concentration in cells; 0.250 mg/ml nicotinamide increased the activities of Na+-K+, Ca2+-ATP enzymes in melanocytes (P < 0.05). CONCLUSION: Nicotinamide has more obvious effect on inhibiting melanocyte's proliferation if added immediately following UVA exposure. Our discovery indicated that nicotinamide may affect the melanocyte through modulating the calcium concentration. It is possible to consider nicotinamide as an efficient and safe sun screen to provide a certain level of protection for UVA exposed skin.