Ocular Straylight and Artificial Lenses

Disability glare has often been related to visual symptoms that appear under different light conditions. Disability glare originates from light scattering (straylight) that takes place in the eye, and is a consequence of the projection of the scattered (unwanted) light onto the retina. The unwanted light is superimposed over the retinal image and results in a loss of contrast. This is typically described by patients as looking through a fog or hazy vision, but other symptoms have also been reported, such as blinding by approaching car's headlights, decreased color discrimination and changes in light adaptation. Mostly these difficulties increase with aging of the natural eye lens and cataract formation, in which case the natural lens can be replaced by a lens implant. However, artificial lenses (implant lenses, but also contact lenses) have shown potential for increasing straylight, but it is not yet clear where the scattered light originates from (e.g. optical design, material properties). Therefore, the goal of this thesis was to study straylight (both in vivo and in vitro) to determine sources of light scattering in the artificial lenses

Semi‐Automated Quantification of Retinal and Choroidal Biomarkers in Retinal Vascular Diseases: Agreement of Spectral‐Domain Optical Coherence Tomography with and without Enhanced Depth Imaging Mode

Background: We compared with and without enhanced depth imaging mode (EDI) in semi-automated quantification of retinal and choroidal biomarkers in optical coherence tomography (OCT) in patients with diabetic retinopathy (DR) or retinal vein occlusion (RVO) complicated by macular edema. We chose to study three OCT biomarkers: the numbers of hyperreflective foci (HF), the ellipsoid zone reflectivity ratio (EZR) and the choroidal vascularity index (CVI), all known to be correlated with visual acuity changes or treatment outcomes. Methods: In a single examination, one eye of each patient (n = 60; diabetic retinopathy: n = 27, retinal vein occlusion: n = 33) underwent macular 870 nm spectral domain-OCT (SD-OCT) B-scans without and with EDI mode. Semi-automated quantification of HF, EZR and CVI was applied according to preexisting published protocols. Paired Student’s t-test or Wilcoxon rank-sum test was used to test for differences in subgroups. Intraclass correlation coefficient (ICC) and Bland–Altman plots were applied to describe the agreement between quantification in EDI and conventional OCT mode. The effect of macular edema on semi-automated quantification was evaluated. Results: For the entire cohort, quantification of all three biomarkers was not significantly different in SD-OCT scans with and without EDI mode (p > 0.05). ICC was 0.78, 0.90 and 0.80 for HF, EZR and CVI. The presence of macular edema led to significant differences in the quantification of hyperreflective foci (without EDI: 80.00 ± 33.70, with EDI: 92.08 ± 38.11; mean difference: 12.09, p = 0.03), but not in the quantification of EZR and CVI (p > 0.05). Conclusion: Quantification of EZR and CVI was comparable whether or not EDI mode was used. In conclusion, both retinal and choroidal biomarkers can be quantified from one single 870 nm SD-OCT EDI image

Surface modification of nanocrystalline TiO2TiO_2 materials with sulfonated porphyrins for visible light antimicrobial therapy

Highly-active, surface-modified anatase TiO2 nanoparticles were successfully synthesized and characterized. The morphological and optical properties of the obtained (metallo)porphyrin@qTiO2 materials were evaluated using absorption and fluorescence spectroscopy, scanning electron microscopy (SEM) imaging, and dynamic light scattering (DLS). These hybrid nanoparticles efficiently generated reactive oxygen species (ROS) under blue-light irradiation (420 ± 20 nm) and possessed a unimodal size distribution of 20–70 nm in diameter. The antimicrobial performance of the synthetized agents was examined against Gram-negative and Gram-positive bacteria. After a short-term incubation of microorganisms with nanomaterials (at 1 g/L) and irradiation with blue-light at a dose of 10 J/cm2, 2–3 logs of Escherichia coli, and 3–4 logs of Staphylococcus aureus were inactivated. A further decrease in bacteria viability was observed after potentiation photodynamic inactivation (PDI), either by H2O2 or KI, resulting in complete microorganism eradication even when using low material concentration (from 0.1 g/L). SEM analysis of bacteria morphology after each mode of PDI suggested different mechanisms of cellular disruption depending on the type of generated oxygen and/or iodide species. These data suggest that TiO2-based materials modified with sulfonated porphyrins are efficient photocatalysts that could be successfully used in biomedical strategies, most notably, photodynamic inactivation of microorganisms

Two-Photon Vision in Age-Related Macular Degeneration: A Translational Study

The recently introduced term “two-photon vision” relates to the visual perception resulting from a simultaneous absorption of two photons by photoreceptors. In this study, we determined two-photon retinal sensitivity in age-related macular degeneration (AMD) and compared it that in normal aging. Microperimetry was performed with visible (white) light and infrared (IR) light, which was perceived as green in the two-photon stimulation. In total, 45 subjects were included with one (better) eye studied. Furthermore, best-corrected visual acuity (VA) and ocular straylight were assessed. AMD resulted in decreased median (interquartile range) logMAR VA, i.e., 0.15 (0.05; 0.24), which in normal eyes was −0.02 (−0.06; 0.02). The two groups showed comparable straylight levels. Sensitivity to IR light was significantly lower in the AMD group (p < 0.001): 8.3 (7.4, 9.3) dB than in controls 10.7 (9.7, 11.2) dB. AMD also significantly affected visible light sensitivity (p < 0.001): 14.0 (11.0; 15.5) dB vs. 18.0 (16.3; 18.9) dB. Notably, the two-photon approach yielded a lower data spread. In conclusion, AMD considerably impairs retinal sensitivity measured in the single- and two-photon realm. However, two-photon-vision microperimetry may improve the testing accuracy and offer an additional diagnostic parameter (beyond VA measurements) for retinal function assessment

Utopy and antiutopy in Strugacki's works

Utopia to gatunek literacki, który narodził się razem z literaturą. Jest to marzenie o idealnym społeczeństwie stworzonym przez człowieka. XX wiek, czas wojen i totalitaryzmów, stworzył przeciwny gatunek - antyutopię. Antyutopia wyrosła na glebie walki z utopią, która proponowała raj na ziemi za cenę wolności i możliwości wyboru. Głównym punktem pracy jest analiza i interpretacja najbardziej charakterystycznych i ważnych dla twórczości braci Strugackich dzieł: Południe, XXII wiek, Stażyści, Pora deszczów, Drapieżne rzeczy wieku, Ślimak na zboczu, Przenicowany świat.Utopia is a literary genre that was born along with literature. This is the dream of the perfect society created by man. The 20th century, the time of wars and totalitarian, created the opposite genre-antyutopię. Ray Bradbury has grown on the soil of Utopia, which proposed paradise on Earth for the price of freedom and choice. The main point of work is the analysis and interpretation of the most characteristic and important works of Strugatsky brothers works: Noon: 22nd Century, Space Apprentice, The Final Circle of Paradise, The Ugly Swans, Snail on the Slope, The Inhabited Islan

Spectral Effects and Range of Focus in a Multizonal-Refractive Intraocular Lens Compared with a Standard Trifocal Diffractive Design

Abstract Introduction This study was performed to compare the optical performance of a multizonal presbyopia-correcting intraocular lens (IOL) and a conventional trifocal model. Methods The optical quality and simulated visual acuity (VA) of 570 Precizon Presbyopic NVA (OPHTEC BV) and AcrySof IQ PanOptix (Alcon) were compared. The Precizon features a refractive design consisting of alternating optical zones that converge the incident light into two principal foci and a transitional zone for intermediate vision. By contrast, the PanOptix applies a diffractive (non-apodized) profile to achieve trifocality. Simulated VA was derived from the modulation transfer function. Chromatic aberration effects were also studied. Results The diffractive and multizonal-refractive lenses yielded comparable simulated VAs at far focus (0.00 logMAR). All curves showed a reduction in expected VA with an increase in negative defocus. At − 1.0 D, the multizonal-refractive IOL's VA dropped by 0.05 logMAR, but for the diffractive model, it was one line (0.11 logMAR). The multizonal-refractive lens's VA prediction at the secondary peak was 0.03 logMAR—minimally better than the 0.06 logMAR of the diffractive lens at − 2.5 D. The refractive lens exhibited a 24% decrease in polychromatic optical quality due to material dispersion. The performance of PanOptix was more substantially affected, showing a 44% loss at 50 lp/mm at far, with minimal effects at other distances. Conclusion The multizonal-refractive lens does not fall short of the established trifocal IOL, and it can be used to extend the visual range of pseudophakic patients. Although the multizonal-refractive lens has lower material dispersion, the diffractive model corrects chromatism beyond far focus

Comparison of ocular straylight after implantation of multifocal intraocular lenses

UNLABELLED: A comprehensive review of the effect of multifocal intraocular lens (IOL) designs on postoperative ocular straylight was performed. Studies reporting straylight values obtained with the natural pupil using the C-Quant device after uneventful multifocal IOL implantation were included. The IOLs were categorized based on their material characteristics; that is, hydrophobicity and presence of colored chromophores. Age adjustment was achieved using the straylight age-dependency norm for pseudophakic eyes. This norm also served as a reference for comparing mean straylight levels of the various IOLs. The literature review identified 10 studies reporting 9 multifocal IOL designs. The hydrophilic IOLs showed less straylight than the hydrophobic IOLs by 0.08 log(s) (P = .001). Blue violet light-filtering IOLs showed less straylight than standard IOLs by 0.04 log(s), which was not statistically significant (P = .32). Hydrophobicity was a factor that significantly affected straylight in multifocal IOLs. FINANCIAL DISCLOSURES: The Netherlands Academy of Arts and Sciences owns a patent on straylight measurement, with Dr. van den Berg as the inventor, and licenses it to Oculus Optikgeräte GmbH for the C-Quant instrument. No other author has a financial or proprietary interest in any material or method mentioned