scholarly journals Rod nuclear architecture determines contrast transmission of the retina and behavioral sensitivity in mice

2019 ◽  
Author(s):  
Kaushikaram Subramanian ◽  
Martin Weigert ◽  
Oliver Borsch ◽  
Heike Petzold ◽  
Alfonso Garcia ◽  
...  
Keyword(s):  
Contrast Sensitivity ◽  
Nuclear Architecture ◽  
Light Condition ◽  
Optical Quality ◽  
Low Light ◽  
Rod Cells ◽  
Behavioral Sensitivity ◽  
Nocturnal Vision ◽  
Underlying Mechanisms ◽  
Image Detail

AbstractRod photoreceptors of nocturnal mammals display a striking inversion of nuclear architecture, which has been proposed as an evolutionary adaptation to dark environments. However, the nature of visual benefits and underlying mechanisms remains unclear. It is widely assumed that improvements in nocturnal vision would depend on maximization of photon capture, at the expense of image detail. Here we show that retinal optical quality improves 2-fold during terminal development, which, confirmed by a mouse model, happens due to nuclear inversion.We further reveal that improved retinal contrast-transmission, rather than photon-budget or resolution, leads to enhanced contrast sensitivity under low light condition. Our findings therefore add functional significance to a prominent exception of nuclear organization and establish retinal contrast-transmission as a decisive determinant of mammalian visual perception.One Sentence SummaryOur study reveals that chromatin compaction in rod cells augments contrast sensitivity in mice.

scholarly journals Rod nuclear architecture determines contrast transmission of the retina and behavioral sensitivity in mice

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Kaushikaram Subramanian ◽  
Martin Weigert ◽  
Oliver Borsch ◽  
Heike Petzold ◽  
Alfonso Garcia-Ulloa ◽  
...  
Keyword(s):  
Nuclear Organization ◽  
Nuclear Architecture ◽  
Optical Quality ◽  
Rod Photoreceptors ◽  
Behavioral Sensitivity ◽  
Detection Capabilities ◽  
Nocturnal Vision ◽  
Underlying Mechanisms ◽  
Image Detail ◽  
Nocturnal Mammals

Rod photoreceptors of nocturnal mammals display a striking inversion of nuclear architecture, which has been proposed as an evolutionary adaptation to dark environments. However, the nature of visual benefits and the underlying mechanisms remains unclear. It is widely assumed that improvements in nocturnal vision would depend on maximization of photon capture at the expense of image detail. Here, we show that retinal optical quality improves 2-fold during terminal development, and that this enhancement is caused by nuclear inversion. We further demonstrate that improved retinal contrast transmission, rather than photon-budget or resolution, enhances scotopic contrast sensitivity by 18–27%, and improves motion detection capabilities up to 10-fold in dim environments. Our findings therefore add functional significance to a prominent exception of nuclear organization and establish retinal contrast transmission as a decisive determinant of mammalian visual perception.

scholarly journals Effect of Spherical Aberration on the Optical Quality after Implantation of Two Different Aspherical Intraocular Lenses

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Michael Lasta ◽  
Kata Miháltz ◽  
Illés Kovács ◽  
Pia Veronika Vécsei-Marlovits
Keyword(s):  
Contrast Sensitivity ◽  
Pupil Size ◽  
Spherical Aberration ◽  
Optical Quality ◽  
Intraocular Lenses ◽  
Strehl Ratio ◽  
Minimum Diameter ◽  
Link Type ◽  
Medical Optics ◽  
Aspherical Iol

Purpose. To compare the effect of spherical aberration on optical quality in eyes with two different aspherical intraocular lenses. Methods. 120 eyes of 60 patients underwent phacoemulsification. In patients’ eyes, an aberration-free IOL (Aspira-aA; Human Optics) or an aberration-correcting aspherical IOL (Tecnis ZCB00; Abott Medical Optics) was randomly implanted. After surgery, contrast sensitivity and wavefront measurements as well as tilt and decentration measurements were performed. Results. Contrast sensitivity was significantly higher in eyes with Aspira lens under mesopic conditions with 12 cycles per degree (CPD) and under photopic conditions with 18 CPD (p=0.02). Wavefront measurements showed a higher total spherical aberration with a minimal pupil size of 4 mm in the Aspira group (0.05 ± 0.03) than in the Tecnis group (0.03 ± 0.02) (p=0.001). Strehl ratio was higher in eyes with Tecnis (0.28 ± 0.17) with a minimal pupil size larger than 5 mm than that with Aspira (0.16 ± 0.14) (p=0.04). In pupils with a minimum diameter of 4 mm spherical aberration had a significant effect on Strehl ratio, but not in pupils with a diameter less than 4 mm. Conclusions. Optical quality was better in eyes with the aberration-correcting Tecnis IOL when pupils were large. In contrast, this could not be shown in eyes with pupils under 4 mm or larger. This trial is registered with Clinicaltrials.gov NCT03224728.

scholarly journals Contrast sensitivity and visual acuity under low light conditions in macular telangiectasia type 2

2018 ◽  
Vol 103 (3) ◽  
pp. 398-403 ◽  
Author(s):  
Simone Müller ◽  
Tjebo F C Heeren ◽  
Roberto Bonelli ◽  
Marcus Fruttiger ◽  
Peter Charbel Issa ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Neutral Density Filter ◽  
Light Conditions ◽  
Low Light ◽  
Cross Sectional ◽  
Macular Telangiectasia ◽  
Low Luminance ◽  
Macular Telangiectasia Type 2

Background/AimMacular pigment optical density (MPOD) is centrally depleted early on in macular telangiectasia type 2 (MacTel). Contrast sensitivity (CS) might be related to MPOD, and thus impaired in early MacTel. The effect of low luminance was assessed on both CS and best corrected visual acuity (BCVA).MethodsThis is a cross-sectional study. Pelli-Robson charts were used for CS testing at 1 m in photopic (110 lux) and mesopic (1 lux) conditions. BCVA was tested with ETDRS charts and low luminance visual acuity (LLVA) with a 2.0 log unit neutral density filter. MPOD was obtained with dual-wavelength autofluorescence.ResultsOne hundred and three eyes of 52 patients with MacTel (mean±SD age 62.9±10.2, range 35–77) were compared with 34 healthy eyes of 17 controls (mean±SD age 65.2±7.4, range 53–78). CS was significantly lower in the eyes with MacTel. This impairment was higher in low light conditions (low light contrast sensitivity (LL-CS)). Eyes at the early stages of MacTel had significantly lower LL-CS than controls, but normal (photopic) CS. The results were similar but less pronounced for BCVA/LLVA. Decrease in CS was correlated with loss of MPOD.ConclusionsLow light conditions have a detrimental effect on visual performance in MacTel. Impaired CS might correlate with MPOD depletion as a pathognomonic finding in MacTel. Functional impairment might precede structural disintegration, indicating dysfunction at the cellular level. The applied tests might be useful as additional functional assessments in clinical routine and as outcome measures in future interventional clinical trials.

scholarly journals Clinical outcomes with a diffractive trifocal intraocular lens

2018 ◽  
Vol 28 (4) ◽  
pp. 419-424 ◽  
Author(s):  
Jorge L Alió ◽  
Ana B Plaza-Puche ◽  
Jorge L Alió del Barrio ◽  
Pedro Amat-Peral ◽  
Vicente Ortuño ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Intraocular Lens ◽  
Case Series ◽  
Optical Quality ◽  
Near Vision ◽  
Case Series Study ◽  
Defocus Curve ◽  
Near Visual Acuity

Purpose: To evaluate clinical and visual outcomes, quality of near vision, and intraocular optical quality of patients bilaterally implanted with a trifocal PanOptix intraocular lens. Methods: In this prospective consecutive case-series study, 52 eyes of 26 bilateral patients (mean age, 60.2 ± 7.4 years) were implanted with the AcrySof IQ Panoptix intraocular lens. Visual acuity, defocus curve, contrast sensitivity (Pelli-Robson test), near activity visual questionnaire, and internal aberrations with Osiris were evaluated. A prototype light-distortion analyzer was used to quantify the postoperative light-distortion indices. The follow-up was 6 months after surgery. Results: Uncorrected, corrected distance, and uncorrected near visual acuities improved with the surgery (p ≤ 0.02). Distance corrected near visual acuity was 0.13 ± 0.10, 0.13 ± 0.13, and 0.13 ± 0.08 at 1, 3, and 6 months after surgery, respectively (p = 0.82). Distance corrected intermediate visual acuities were 0.09 ± 0.13, 0.13 ± 0.15, and 0.12 ± 0.12 at 1, 3, and 6 months, postoperatively. Binocular contrast sensitivity was 1.86 ± 0.15 Log Units. Defocus curve provided a visual acuity equal or better to 0.30 LogMAR between defocus levels of +0.50 to −3.00 D. The near activity visual questionnaire scores improved significantly with the surgery (p < 0.01). Conclusion: The AcrySof IQ Panoptix intraocular lens is able to restore visual function with an acceptable intermediate and near vision after cataract surgery with good contrast sensitivity and an improvement in the near activity visual questionnaire.

Inflammation Increases Neuronal Sensitivity to General Anesthetics

2016 ◽  
Vol 124 (2) ◽  
pp. 417-427 ◽  
Author(s):  
Sinziana Avramescu ◽  
Dian-Shi Wang ◽  
Irene Lecker ◽  
William T. H. To ◽  
Antonello Penna ◽  
...  
Keyword(s):  
Gabaa Receptor ◽  
Cortical Neurons ◽  
Receptor Activity ◽  
Aminobutyric Acid ◽  
General Anesthetics ◽  
Enhanced Sensitivity ◽  
Behavioral Sensitivity ◽  
Underlying Mechanisms

Abstract Background Critically ill patients with severe inflammation often exhibit heightened sensitivity to general anesthetics; however, the underlying mechanisms remain poorly understood. Inflammation increases the number of γ-aminobutyric acid type A (GABAA) receptors expressed on the surface of neurons, which supports the hypothesis that inflammation increases up-regulation of GABAA receptor activity by anesthetics, thereby enhancing the behavioral sensitivity to these drugs. Methods To mimic inflammation in vitro, cultured hippocampal and cortical neurons were pretreated with interleukin (IL)-1β. Whole cell patch clamp methods were used to record currents evoked by γ-aminobutyric acid (GABA) (0.5 μM) in the absence and presence of etomidate or isoflurane. To mimic inflammation in vivo, mice were treated with lipopolysaccharide, and several anesthetic-related behavioral endpoints were examined. Results IL-1β increased the amplitude of current evoked by GABA in combination with clinically relevant concentrations of either etomidate (3 μM) or isoflurane (250 μM) (n = 5 to 17, P &lt; 0.05). Concentration–response plots for etomidate and isoflurane showed that IL-1β increased the maximal current 3.3-fold (n = 5 to 9) and 1.5-fold (n = 8 to 11), respectively (P &lt; 0.05 for both), whereas the half-maximal effective concentrations were unchanged. Lipopolysaccharide enhanced the hypnotic properties of both etomidate and isoflurane. The immobilizing properties of etomidate, but not isoflurane, were also increased by lipopolysaccharide. Both lipopolysaccharide and etomidate impaired contextual fear memory. Conclusions These results provide proof-of-concept evidence that inflammation increases the sensitivity of neurons to general anesthetics. This increase in anesthetic up-regulation of GABAA receptor activity in vitro correlates with enhanced sensitivity for GABAA receptor–dependent behavioral endpoints in vivo.

Contrast Sensitivity and Optical Quality of the Eye after Instillation of Timolol Maleate Gel-Forming Solution and Brinzolamide Ophthalmic Suspension

Ophthalmology ◽  
2010 ◽  
Vol 117 (11) ◽  
pp. 2080-2087 ◽  
Author(s):  
Takahiro Hiraoka ◽  
Masakazu Daito ◽  
Fumiki Okamoto ◽  
Takahiro Kiuchi ◽  
Tetsuro Oshika
Keyword(s):  
Contrast Sensitivity ◽  
Optical Quality ◽  
Timolol Maleate ◽  
Ophthalmic Suspension

Effectiveness of dye sensitised solar cell under low light condition using wide band dye

2015 ◽  
Author(s):  
Ahmad Zahrin Sahmer ◽  
Norani Muti Mohamed ◽  
Siti Nur Azella Zaine
Keyword(s):  
Solar Cell ◽  
Light Condition ◽  
Wide Band ◽  
Low Light
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