MicroRNA-23b-3p promotes the proliferation,migration, and epithelial–mesenchymal transition of lens epithelial cells by targeting Sprouty2

Cataract, opacification of the lens, is one of the most important reasons of visual impairment and blindness. Though microRNAs (miRNAs) have been demonstrated to play important roles in cataractogenesis, the underlying molecular mechanisms in this progress remain obscure. In the present study, microRNA-23b-3p (miR-23b) overexpression promoted the proliferation, migration and epithelial-mesenchymal transition (EMT), whereas miR-23b knockdown markedly inhibited the proliferation, migration and TGF-β-induced EMT of lens epithelial cells (LECs). In TGF-β-induced LECs, the expression of miR-23b was markedly upregulated and the expression of Sprouty2 (SPRY2) was markedly downregulated, furthermore the mRNA and protein levels of SPRY2 were markedly decreased in miR-23b inhibitor-transfected LECs. We then performed a Dual-luciferase reporter assay to confirm that miR-23b directly targeted SPRY2. The promoted migration and EMT of LECs by enforced expression of miR-23b were suppressed by SPRY2 overexpression. The findings present the first evidence indicating that miR-23b can promote the proliferation, migration, and EMT of LECs by targeting SPRY2 and the inhibition of miR-23b may possess the therapeutic potential for cataract.     

Visual masking and the contrast-flash effect

We have compared the effect of disk-shaped masking flashes, 2° or 8° dia, to the effect of an annular contrast-flash, 2–8° dia, on the threshold for a 2° test flash. At all stimulus onset asynchronies and stimulus intensities studied, the threshold curves for the annulus are similar to those for the masking disks. We have evaluated the possibility that the annulus acts like a masking disk due to light scattered from the annulus to its center, and find that when stimulus onsets are synchronous, scattered light can account for the annulus data. When the test onset precedes the annulus onset by 100 msec, scattered light cannot account for the results.     

温州医学院眼视光学临床实习出科考核体系设计与分析

为提高医学教育质量,培养高素质医学人才,结合视光学人才培养目标和临床发展现状,制定一套较为科学合理且行之有效的眼视光学专业临床实习出科考核体系,填补国内眼视光学专业临床实习评估体系的空白,对完善医学教育教学评估体系起到积极的作用。     

Newham Waterworth 1867–1949

ABSTRACT A biographical account of Newham Waterworth is presented, documenting in particular his contribution to the profession of optometry and its struggle to achieve legislative recognition in the State of Tasmania.     

Alteration in directional sensitivity of the retina by monocular occlusion

Monocular occlusion (dark patching) of adults for a period of days produces marked reduction in the directional sensitivity of the eye (Stiles-Crawford effect). The effect reaches a maximum 3–5 days after the onset of patching. Recovery occurs in a comparable period. The second eye is not affected, and a simple light diffuser fails to produce the same effect. Coupled with alteration in directional sensitivity are an overall increase in sensitivity, and modest resolution and perceived color changes. These findings, coupled with other research, suggest that directional sensitivity is at least partially mediated by light and that orientation of photoreceptors is an active process.     

A preliminary report of acuity and contour interactions across the amblyope's visual field

Acuity and contour interactions were assessed across the visual field of representative strabismic amblyopes. Acuity profiles display large variations between amblyopes who exhibit the same degree of eccentric fixation; however, in no case was foveal acuity significantly better than that found eccentrically. The acuity abnormality for most amblyopes is visual field locus dependent. Contour interactions are abnormal in both form and magnitude for some amblyopes. This abnormality does not depend upon the acuity deficit, is field locus dependent and cannot be easily accounted for by optical, oculomotor or eccentric fixation factors.     

Visual and ocular changes in VDU operators

This report details and analyses visual and occular characteristics of a population of VDUoperators and the changes found after an interval of approximately 20 months. The first examination was carried out close to commencement of work on VDUs. This was a study without a control group because the examinations were originally part of a contractual arrangement. Most factors showed no statistically significant change. Where a significant change was shown it was either an improvement or clinically insignificant or both. Observed ocular changes could not be analyzed statistically in the absence of a control group.     

Psychophysical relationships among mechanisms sensitive to pattern,motion and flicker

Sensitivity to drifting gratings was measured both before and after adaptation to a uniform flickering field. In the first experiment, it was found that viewing uniform flicker with one eye impaired sensitivity for drifting gratings presented to the same or contralateral eye. Likewise, adaptation to drifting gratings increased flicker detection thresholds. In the second experiment, temporal tuning of the adaptation effect was determined by adapting observers to several different flicker frequencies and testing with gratings of different drift rate. The data suggested the existence of broadly tuned temporal channels which respond to both flicker and motion. In a third experiment, spatial tuning of uniform flicker adaptation was evaluated by employing test gratings of different spatial frequency. The threshold elevation curves were low-pass in shape and exhibited an upper cut-off at 3–4 c/deg. Moreover, the 3–4 c/deg limit was found even when observers explicitly set thresholds for detecting temporal change. The results of the three experiments are consistent with the view that the human visual system contains separate sustained and transient mechanisms. Contrary to previous suggestions that the two systems play specialized roles in perception, however, our data indicate that both transient and sustained mechanisms can signal motion.