The effects of actomyosin disruptors on the mechanical integrity of the avian crystalline lens

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited, used for non-commercial purposes, and is not altered or transformed. Original Publication: Won, G.-J., Fudge, D. S., & Choh, V. (2015, January 27). The effects of actomyosin disruptors on the mechanical integrity of the avian crystalline lens. Molecular Vision, 21, 98-XX. http://www.molvis.org/molvis/v21/98/Actin and myosin within the crystalline lens maintain the structural integrity of lens fiber cells and form a hexagonal lattice cradling the posterior surface of the lens. The actomyosin network was pharmacologically disrupted to examine the effects on lenticular biomechanics and optical quality.This project was generously funded by the Natural Sciences and Engineering Research Council of Canada (V.C. and D.S.F.) and the Canadian Optometric Education Trust Fund (G.W.)

Correlation of visually evoked intrinsic optical signals and electroretinograms recorded from chicken retina with a combined functional optical coherence tomography and electroretinography system

Akhlagh Moayed, A., Hariri, S., Choh, V., & Bizheva, K. (2012). Correlation of visually evoked intrinsic optical signals and electroretinograms recorded from chicken retina with a combined functional optical coherence tomography and electroretinography system. Journal of Biomedical Optics, 17(1), 0160111–0160115. Copyright 2012 Society of Photo Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. http://dx.doi.org/10.1117/1.JBO.17.1.016011Visually evoked fast intrinsic optical signals (IOSs) were recorded for the first time in vivo from all layers of healthy chicken retina by using a combined functional optical coherence tomography (fOCT) and electroretinography (ERG) system. The fast IOSs were observed to develop within ∼5  ms from the on-set of the visual stimulus, whereas slow IOSs were measured up to 1 s later. The visually evoked IOSs and ERG traces were recorded simultaneously, and a clear correlation was observed between them. The ability to measure visually evoked fast IOSs non-invasively and in vivo from individual retinal layers could significantly improve the understanding of the complex communication between different retinal cell types in healthy and diseased retinas.This work was supported by a research grant from the Natural Sciences and Engineering Research Council of Canada and in-kind contributions from Diagnosys LLC

Inhibition of Defocus-Induced Myopia in Chickens

Woods, J., Guthrie, S. E., Keir, N., Dillehay, S., Tyson, M., Griffin, R., … Irving, E. (2013). Inhibition of Defocus-Induced Myopia in Chickens. Investigative Opthalmology & Visual Science, 54(4), 2662. https://doi.org/10.1167/iovs.12-10742Purpose.: To determine the effect of wearing a lens with a unique peripheral optical design on the development and progression of defocus-induced myopia in newly hatched chickens.Methods.: Eighty-five newly hatched chickens underwent bilateral retinoscopy and A-scan ultrasound to determine their refractive error and axial length. They were randomly divided into Control and two Test groups, in which each chicken was fitted with a goggle-lens over the right eye, with the left eye remaining untreated. The Control group wore a lens of power −10.00 diopters (D) of standard spherical optical design. The two Test lenses both had a central optical power −10.00 D, but used different peripheral myopia progression control (MPC) designs. For all groups, retinoscopy was repeated on days 3, 7, 10, and 14; ultrasound was repeated on day 14. Results.: On day 0 there was no statistical difference in refractive error (mean +6.92 D) or axial length (mean 8.06 mm) between Test and Control groups or treated and untreated eyes (all P > 0.05). At day 14, 37 (43.5%) of 85 chickens had not experienced goggle detachment and were included in the final analyses. In this cohort there was a significant refractive difference between the treated eyes of the Control group (n = 17) and those of Test 1 (n = 14) and Test 2 (n = 6) groups (both P < 0.01): Control −4.65 ± 2.11 D, Test 1 +4.57 ± 3.11 D, Test 2 +1.08 ± 1.24 D (mean ± SEM). There was also a significant axial length difference (both P < 0.01): Control 10.55 ± 0.36 mm, Test 1 9.99 ± 0.14 mm, Test 2 10.17 ± 0.18 mm. Conclusions.: Use of these unique MPC lens designs over 14 days caused a significant reduction in the development of defocus-induced myopia in chickens; the degree of reduction appeared to be design specific

Short-Term Moderately Elevated Intraocular Pressure Is Associated With Elevated Scotopic Electroretinogram ResponsesShort-Term Elevated IOP and Scotopic ERG Responses

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited, used for non-commercial purposes, and is not altered or transformed. Original publication: Choh, V., Gurdita, A., Tan, B., Prasad, R. C., Bizheva, K., & Joos, K. M. (2016). Short-Term Moderately Elevated Intraocular Pressure Is Associated With Elevated Scotopic Electroretinogram ResponsesShort-Term Elevated IOP and Scotopic ERG Responses. Investigative Ophthalmology & Visual Science, 57(4), 2140–2151. https://doi.org/10.1167/iovs.15-18770Moderately elevated intraocular pressure (IOP) is a risk factor for open-angle glaucoma. Some patients suffer glaucoma despite clinically measured normal IOPs. Fluctuations in IOP may have a significant role since IOPs are higher during sleep and inversion activities. Controlled transient elevations of IOPs in rats over time lead to optic nerve structural changes that are similar to the early changes observed in constant chronic models of glaucoma. Because early intervention decreases glaucoma progression, this study was done to determine if early physiological changes to the retina could be detected with noninvasive electrophysiological and optical imaging tests during moderately elevated IOP.Supported by the Natural Sciences and Engineering Research Council (NSERC) of Canada Discovery Grants (VC, KB), the Ontario Research Fund (KB), the Canadian Foundation for Innovation (VC), the University of Waterloo Propel Centre Grant (VC, KB, KMJ), University of Waterloo Research Incentive Fund (KB, VC, KMJ), Joseph Ellis Family and William Black Research Funds (KMJ), VUMC Cell Imaging Shared Resource supported by Vanderbilt Vision Research Center-NIH 5P30EY008126-27 (KMJ), and Unrestricted Vanderbilt Eye Institute Departmental Grant from Research to Prevent Blindness, Inc., N.Y. (KMJ)