Search

Background There are few clinical data on retinal involvement after acute exposure to high concentrations mercury and the available reports are based on a small number of patients suffering chronic exposure. The purpose of this paper is to report findings in workers acutely exposed to very high concentrations of mercury vapor with the aim of providing data on a possible direct retinal involvement. Methods Twenty-nine patients and 16 controls were evaluated in a comparative case series. Mercury levels in blood and urine samples, visual acuity (VA), contrast sensitivity (CS), visual field (VF), color discrimination and optical coherence tomography (OCT) were recorded. The pattern reversal visual-evoked potentials (PRVEP), full-field and multifocal electroretinography (ffERG/mfERG), pattern electroretinography (PERG), systemic symptoms, presence of erethism, and electromyography (EMG) were also gathered. A descriptive analysis was performed. The correlations between variables also were studied. In addition, electrophysiological data from those patients with deeper VF defects (group 1) were compared with a normal control group. Results Twenty-six workers exhibited symptoms of erethism. The EMG showed sensorimotor polyneuropathy and multiple mononeuropathy. The VA was slightly affected in 48.27% (n = 14) of subjects. Loss of CS in at least one of four spatial frequencies and color vision alterations occurred in 96.5% (n = 28) and 44.8% (n = 13), respectively. VF alterations were identified in 72.4% (n = 21) patients. No morphologic changes were seen in the OCT scans. Latencies over 100 milliseconds and reduced amplitudes of P100 were found in the PRVEP (p Conclusions In this case series, showed that acute exposure to mercury vapor had a hazardous effect on the visual system. Although neurologic and visual pathway involvement was clearly demonstrated, the differences found compared to control support the existence of a direct functional retinal damage and participation in impaired vision in mercury poisoning.

Angela Morejon,1 Agustin Mayo-Iscar,1,2 Raul Martin,1,3,4 Fernando Ussa1,5 1IOBA-Eye Institute, Universidad de Valladolid, Valladolid, Spain; 2Department of Statistics and Operational Research and IMUVA, Universidad de Valladolid, Valladolid, Spain; 3Department of Theoretical Physics, Atomic Physics and Optics, Universidad de Valladolid, Valladolid, Spain; 4Faculty of Health and Human Sciences, Plymouth University, Plymouth, England, UK; 5Ophthalmology Department, The James Cook University Hospital, Middlesbrough, UK Purpose: The purpose of this study was to develop an objective algorithm to discriminate the earliest stages of glaucoma using frequency doubling technology (FDT) Matrix perimetry and spectral domain-optical coherence tomography (OCT) technology to improve primary care detection. Materials and methods: Three hundred six eyes (mean age 58.67±15.12) from 161 patients were included and classified in the following three groups: 101 nonglaucoma (GI-NG), 100 glaucoma suspect (GII-SG), and 105 open-angle glaucoma (GIII-OAG). All participants underwent a visual field exploration using the Humphrey Matrix visual field instrument and retinal nerve fiber layer evaluation using the Topcon 3D OCT-2000. Pattern deviation plot was divided into 19 areas and five aggrupation or quadrants and ranked with a value between 0 and 4 according to its likelihood of normality, and differences among three groups were analyzed. Principal component analysis (PCA) was also used to extract the most notable features of FDT and OCT, and a logistic regression analysis was applied to obtain the classification rules. Results: Only area numbers 7 and 12 and the central zone of FDT Matrix showed statistical differences (P

BACKGROUND: There are almost no available data on retinal involvement after acute exposure to high concentrations mercury and the available reports are on a small number of patients that suffered chronic expposure. The purpose of this paper is to report visual findings in 29 workers exposed to very high concentrations of mercury vapor in a factory in northern Spain in 2012.METHODS: Twenty-nine patients and 16 controls were evaluated in a comparative case series. Fifteen of the 29 workers underwent belated chelation for heavy metal intoxication, only 3 in a prompt way. The mercury levels in blood and urine samples, visual acuity (VA), contrast sensitivity (CS), visual field (VF), color discrimination and optical coherence tomography (OCT) data were recorded. The pattern reversal visual-evoked potentials (PRVEP), full-field and multifocal electroretinography (ffERG/mfERG), pattern electroretinography (PERG), systemic symptoms, presence of erethism, and electromyography (EMG) were also gathered. A descriptive analysis was performed. The evolution of patients who did not undergo chelation (group 1), those who underwent late chelation (group 2), and those with deep VF defects (group 3) were compared with a control group. The correlations between variables also were studied.RESULTS: The VA was affected slightly. The loss of CS in at least one of four spatial frequencies and color vision alterations occurred in 96.5% (n=28) and 44.8% (n=13), respectively, in the entire group. VF alterations were identified in 72.4% (n=21). No morphologic changes were seen in the OCT scans. Latencies over 100 milliseconds and reduced amplitudes of P100 were found in the PRVEP. The ffERG and PERG results suggested that both the outer and inner retinal processes were involved. The mfERG indicated reduced parafoveal retinal function. Twenty-six workers exhibited symptoms of erethism. The EMG showed sensorimotor polyneuropathy and multiple mononeuropathy alterations. Significant negative correlations among blood mercury levels, VA, and ffERG were observed.CONCLUSION: Advanced visual functions were impaired significantly independent of the mercury levels. Delayed chelation was not beneficial. Although neurologic and visual pathway involvement was clearly demonstrated, this study also showed clear functional retinal participation in impaired vision.

To evaluate the intra-test variability of ARK-30 handheld autorefractor and the agreement with subjective refraction and retinoscopy after uneventful cataract surgery.Prospective and non-randomized study that included 6 visits by patients undergoing uneventful cataract surgery at IOBA (Instituto de Oftalmobiología Aplicada) Eye Institute (University of Valladolid).The mean age of the 79 patients was 66.5years (range 23-90years). For the 124 eyes, the mean spherical equivalent of the sample at baseline visit was -3.59±6.28D (range -21.00D to +4.44D).Automated refraction was performed on follow-up visits 1day and weekly for 4weeks. Retinoscopy and subjective refraction were conducted at the Week 4 follow up.Automated refraction.Sphere, cylinder and mean spherical equivalent, J(0) and J(45) coefficient variabilities were low in all visits. Standard deviations and the limits of agreement were smallest for the last visit. Subjective refraction sphere and cylinder values were more positive than autorefraction by 0.12±0.53D (P=0.031) and 0.23±0.42D (P0.001), respectively. Comparison between autorefraction and retinoscopy showed a similar trend with the sphere and cylinder differences, 0.32±0.77D and 0.38±0.43D (P0.05), respectively.The ARK-30 is sufficiently accurate and repeatable for automated refraction after uneventful cataract surgery. This instrument may be useful for monitoring refractive outcome in these patients.