Multifocal electroretinogram and Optical Coherence tomography spectral-domain in arc welding macular injury: a case report

<p>Abstract</p> <p>Background</p> <p>the purpose of this study was to report a binocular photic retinal injury induced by plasma arc welding and the follow-up after treatment with vitamin supplements for a month. In our study, we used different diagnostic tools such as fluorescein angiography (FA), optical coherence tomography (OCT) and multifocal electroretinogram (mfERG).</p> <p>Case presentation</p> <p>in the first visit after five days from arc welding injury in the left eye (LE) the visual acuity was 0.9 and 1.0 in the right eye (RE). FA was normal in both eyes. OCT in the left eye showed normal profile and normal reflectivity and one month later, a hyperreflectivity appeared in the external limiting membrane (ELM). The mfERG signal in the LE was 102.30 nV/deg2 five days after the injury and 112.62 nV/deg2 after one month and in the RE respectively 142.70 nV/deg2 and 159.46 nV/deg2.</p> <p>Conclusions</p> <p>in cases of retinal photo injury it is important for the ophthalmologist to evaluate tests such as OCT and the mfERG in the diagnosis and follow-up of the patient because the recovery of visual acuity cannot exclude the persistence of phototoxic damage charged to the complex inner-outer segment of photoreceptors.</p

Understanding disability glare: light scatter and retinal illuminance as predictors of sensitivity to contrast

The presence of a bright light in the visual field has two main effects on the retinal image: reduced contrast and increased retinal illuminance due to scattered light; the latter can, under some conditions, lead to an improvement in retinal sensitivity. The combined effect remains poorly understood, particularly at low light levels. A psychophysical flicker-cancellation test was used to measure the amount and angular distribution of scattered light in the eye for 40 observers. Contrast thresholds were measured using a functional contrast sensitivity test. Pupil-plane glare-source illuminances (i.e. 0, 1.35, 19.21 lm/m2), eccentricities (5°, 10°, 15°), and background luminances (1, 2.6, 26 cd/m2) were investigated. Visual performance was better than predicted, based on loss of retinal image contrast caused by scattered light, particularly in the mesopic range. Prediction accuracy improved significantly when the expected increase in retinal sensitivity in the presence of scattered light was also incorporated in the model

Detection of heat shock protein 70 in choroidal neovascular membranes secondary to age related macular degeneration

<p>Abstract</p> <p>Background</p> <p>Heat shock proteins are acute phase proteins that are upregulated in inflammation or following thermal stress. We analyzed the presence of the heat shock protein 70 (Hsp 70) in choroidal neovascular (CNV) membranes secondary to AMD after treatment with verteporphin photodynamic therapy (PDT) or transpupillary thermo therapy (TTT) to determine whether treatment correlated with the presence of Hsp70.</p> <p>Results</p> <p>CNV membranes were removed by pars plana vitrectomy (ppV) and subretinal extraction. The membranes were analysed by light microscopy and the presence of Hsp 70 was examined using histochemistry. HeLa Cells served as controls.</p> <p>Of the 14 membranes analysed 11 were Hsp70 positive and 3 negative. In the no pre-treatment group of 8 membranes 6 were Hsp70 positive and 2 negative; in the PTD group all 4 membranes were positive and in the TTT group 1 membrane was positive and 1 membrane was negative for Hsp70.</p> <p>Conclusion</p> <p>Hsp70 is present in the most CNV membranes secondary to AMD. Pre-treatment of the membrane with PTD or TTT does not appear to influence the expression of Hsp70.</p

The effect of blue-light blocking spectacle lenses on visual performance, macular health and the sleep-wake cycle: asystematic review of the literature

Purpose: Blue-blocking (BB) spectacle lenses, which attenuate short-wavelength light, are being marketed to alleviate eyestrain and discomfort when using digital devices, improve sleep quality and potentially confer protection from retinal phototoxicity. The aim of this review was to investigate the relative benefits and potential harms of these lenses. Methods: We included randomised controlled trials (RCTs), recruiting adults from the general population, which investigated the effect of BB spectacle lenses on visual performance, symptoms of eyestrain or eye fatigue, changes to macular integrity and subjective sleep quality. We searched MEDLINE, EMBASE, the Cochrane Library and clinical trial registers, until 30 April 2017. Risk of bias was assessed using the Cochrane tool. Results: Three studies (with 136 participants) met our inclusion criteria; these had limitations in study design and/or implementation. One study compared the effect of BB lenses with clear lenses on contrast sensitivity (CS) and colour vision (CV) using a pseudo-RCT crossover design; there was no observed difference between lens types (log CS; Mean Difference (MD) = −0.01 [−0.03, 0.01], CV total error score on 100-hue; MD = 1.30 [−7.84, 10.44]). Another study measured critical fusion frequency (CFF), as a proxy for eye fatigue, on wearers of low and high BB lenses, pre- and post- a two-hour computer task. There was no observed difference between low BB and standard lens groups, but there was a less negative change in CFF between the high and low BB groups (MD = 1.81 [0.57, 3.05]). Both studies compared eyestrain symptoms with Likert scales. There was no evidence of inter-group differences for either low BB (MD = 0.00 [−0.22, 0.22]) or high BB lenses (MD = −0.05 [−0.31, 0.21]), nor evidence of a difference in the proportion of participants showing an improvement in symptoms of eyestrain or eye fatigue. One study reported a small improvement in sleep quality in people with self-reported insomnia after wearing high compared to low-BB lenses (MD = 0.80 [0.17, 1.43]) using a 10-point Likert scale. A study involving normal participants found no observed difference in sleep quality. We found no studies investigating effects on macular structure or function. Conclusions: We find a lack of high quality evidence to support using BB spectacle lenses for the general population to improve visual performance or sleep quality, alleviate eye fatigue or conserve macular health

Prevention of age-related macular degeneration

Age-related macular degeneration (AMD) is one of the leading causes of blindness in the developed world. Although effective treatment modalities such as anti-VEGF treatment have been developed for neovascular AMD, there is still no effective treatment for geographical atrophy, and therefore the most cost-effective management of AMD is to start with prevention. This review looks at current evidence on preventive measures targeted at AMD. Modalities reviewed include (1) nutritional supplements such as the Age-Related Eye Disease Study (AREDS) formula, lutein and zeaxanthin, omega-3 fatty acid, and berry extracts, (2) lifestyle modifications, including smoking and body-mass-index, and (3) filtering sunlight, i.e. sunglasses and blue-blocking intraocular lenses. In summary, the only proven effective preventive measures are stopping smoking and the AREDS formula

Comparison of Blue Light-Filtering IOLs and UV Light-Filtering IOLs for Cataract Surgery: A Meta-Analysis

Background: A number of published randomized controlled trials have been conducted to evaluate visual performance of blue light-filtering intraocular lenses (IOL) and UV light-filtering intraocular lenses (IOL) after cataract phacoemulsification surgery. However, results have not always been consistent. Therefore, we carried out a meta-analysis to compare the effectiveness of blue light-filtering IOLs versus UV light-filtering IOLs in cataract surgery. Methods and Findings: Comprehensive searches of PubMed, Embase, Cochrane Library and the Chinese BioMedical literature databases were performed using web-based search engines. Fifteen trials (1690 eyes) were included for systematic review, and 11 of 15 studies were included in this meta-analysis. The results showed that there were no significant differences in postoperative mean best corrected visual acuity, contrast sensitivity, overall color vision, or in the blue light spectrum under photopic light conditions between blue light-filtering IOLs and UV light-filtering IOLs [WMD = 20.01, 95%CI (20.03, 0.01), P = 0.46; WMD = 0.07, 95%CI (20.04, 0.19), P = 0.20; SMD = 0.14, 95%CI (20.33, 0.60), P = 0.566; SMD = 0.20, 95%CI (20.04, 0.43), P = 0.099]. However, color vision with blue light-filtering IOLs was significantly reduced in the blue light spectrum under mesopic light conditions [SMD = 0.74, 95%CI (0.29, 1.18), P = 0.001]. Conclusion: This meta-analysis demonstrates that postoperative visual performance with blue light-filtering IOLs is approximately equal to that of UV light-filtering IOLs after cataract surgery, but color vision with blue light-filtering IOL

Nature, extent and ecological implications of night-time light from road vehicles

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record1.The erosion of night‐time by the introduction of artificial lighting constitutes a profound pressure on the natural environment. It has altered what had for millennia been reliable signals from natural light cycles used for regulating a host of biological processes, with impacts ranging from changes in gene expression to ecosystem processes. 2.Studies of these impacts have focused almost exclusively on those resulting from stationary sources of light emissions, and particularly streetlights. However, mobile sources, especially road vehicle headlights, contribute substantial additional emissions. 3.The ecological impacts of light emissions from vehicle headlights are likely to be especially high because these are (i) focused so as to light roadsides at higher intensities than commonly experienced from other sources, and well above activation thresholds for many biological processes; (ii) projected largely in a horizontal plane and thus can carry over long distances; (iii) introduced into much larger areas of the landscape than experience street lighting; (iv) typically broad ‘white’ spectrum, which substantially overlaps the action spectra of many biological processes; and (v) often experienced at roadsides as series of pulses of light (produced by passage of vehicles), a dynamic known to have major biological impacts. 4.The ecological impacts of road vehicle headlights will markedly increase with projected global growth in numbers of vehicles and the road network, increasing the local severity of emissions (because vehicle numbers are increasing faster than growth in the road network) and introducing emissions into areas from which they were previously absent. The effects will be further exacerbated by technological developments that are increasing the intensity of headlight emissions and the amounts of blue light in emission spectra. 5.Synthesis and applications. Emissions from vehicle headlights need to be considered as a major, and growing, source of ecological impacts of artificial night‐time lighting. It will be a significant challenge to minimize these impacts whilst balancing drivers’ needs at night and avoiding risk and discomfort for other road users. Nonetheless, there is potential to identify solutions to these conflicts, both through the design of headlights and that of roads.The research leading to this article has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no. 268504 and Natural Environment Research Council grants NE/N001672/1 and NE/P01156X/1