Vision

13 pages, 1567 KiB

Open AccessArticle

Comparative Evaluation of Pseudomonas aeruginosa Adhesion to a Poly-(2-Methacryloyloxyethyl Phosphorylcholine)-Modified Silicone Hydrogel Contact Lens

by Valerie Harris, Reed Pifer, Paul Shannon and Monica Crary

Vision 2023, 7(1), 27; https://doi.org/10.3390/vision7010027 - 21 Mar 2023

Cited by 2 | Viewed by 2011

Abstract

Pseudomonas aeruginosa is the most common causative agent associated with microbial keratitis. During contact lens wear, pathogens may be introduced into the ocular environment, which might cause adverse events. Lehfilcon A is a recently developed contact lens with a water gradient surface composed [...] Read more.

Pseudomonas aeruginosa is the most common causative agent associated with microbial keratitis. During contact lens wear, pathogens may be introduced into the ocular environment, which might cause adverse events. Lehfilcon A is a recently developed contact lens with a water gradient surface composed of polymeric 2-methacryloyloxyethyl phosphorylcholine (MPC). MPC is re-ported to impart anti-biofouling properties onto modified substrates. Therefore, in this in vitro experimental study, we tested the capability of lehfilcon A to resist adhesion by P. aeruginosa. Quantitative bacterial adhesion assays using five strains of P. aeruginosa were conducted to compare the adherence properties of lehfilcon A to five currently marketed silicone hydrogel (SiHy) contact lenses (comfilcon A, fanfilcon A, senofilcon A, senofilcon C, and samfilcon A). Compared to lehfilcon A, we observed 26.7 ± 8.8 times (p = 0.0028) more P. aeruginosa binding to comfilcon A, 30.0 ± 10.8 times (p = 0.0038) more binding to fanfilcon A, 18.2 ± 6.2 times (p = 0.0034) more binding to senofilcon A, 13.6 ± 3.9 times (p = 0.0019) more binding to senofilcon C, and 29.5 ± 11.8 times (p = 0.0057) more binding to samfilcon A. These results demonstrate that, for various strains of P. aeruginosa, lehfilcon A reduces bacterial adhesion compared to other contact lens materials. Full article

(This article belongs to the Special Issue Development, Progression and Management of Contact Lenses, and Eye Care)

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15 pages, 2657 KiB

Open AccessArticle

Peripheral Flicker Fusion at High Luminance: Beyond the Ferry–Porter Law

by Maydel Fernandez-Alonso, Will Innes and Jenny C. A. Read

Vision 2023, 7(1), 26; https://doi.org/10.3390/vision7010026 - 20 Mar 2023

Viewed by 1706

Abstract

The relationship between luminous intensity and the maximum frequency of flicker that can be detected defines the limits of the temporal-resolving ability of the human visual system, and characterizing it has important theoretical and practical applications; particularly for determining the optimal refresh rate [...] Read more.

The relationship between luminous intensity and the maximum frequency of flicker that can be detected defines the limits of the temporal-resolving ability of the human visual system, and characterizing it has important theoretical and practical applications; particularly for determining the optimal refresh rate for visual displays that would avoid the visibility of flicker and other temporal artifacts. Previous research has shown that this relationship is best described by the Ferry–Porter law, which states that critical flicker fusion (CFF) increases as a linear function of log retinal illuminance. The existing experimental data showed that this law holds for a wide range of stimuli and up to 10,000 Trolands; however, beyond this, it was not clear if the CFF continued to increase linearly or if the function saturated. Our aim was to extend the experimental data available to higher light intensities than previously reported in the literature. For this, we measured the peripheral CFF at a range of illuminances over six orders of magnitude. Our results showed that for up to 10⁴ Trolands, the data conformed to the Ferry–Porter law with a similar slope, as previously established for this eccentricity; however, at higher intensities, the CFF function flattens and saturates at ~90 Hz for a target size of 5.7 degrees, and at ~100 Hz for a target of 10 degrees of angular size. These experimental results could prove valuable for the design of brighter visual displays and illumination sources that are temporally modulated. Full article

(This article belongs to the Section Visual Neuroscience)

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13 pages, 1449 KiB

Open AccessArticle

Using Speed and Accuracy and the Simon Effect to Explore the Output Form of Inhibition of Return

by Ralph S. Redden, Matthew D. Hilchey, Sinan Aslam, Jason Ivanoff and Raymond M. Klein

Vision 2023, 7(1), 25; https://doi.org/10.3390/vision7010025 - 20 Mar 2023

Cited by 1 | Viewed by 1187

Abstract

Inhibition of return (IOR) refers to slower responses to targets presented at previously cued locations. Contrasting target discrimination performance over various eye movement conditions has shown the level of activation of the reflexive oculomotor system determines the nature of the effect. Notably, an [...] Read more.

Inhibition of return (IOR) refers to slower responses to targets presented at previously cued locations. Contrasting target discrimination performance over various eye movement conditions has shown the level of activation of the reflexive oculomotor system determines the nature of the effect. Notably, an inhibitory effect of a cue nearer to the input end of the processing continuum is observed when the reflexive oculomotor system is actively suppressed, and an inhibitory effect nearer the output end of the processing continuum is observed when the reflexive oculomotor system is actively engaged. Furthermore, these two forms of IOR interact differently with the Simon effect. Drift diffusion modeling has suggested that two parameters can theoretically account for the speed-accuracy tradeoff rendered by the output-based form of IOR: increased threshold and decreased trial noise. In Experiment 1, we demonstrate that the threshold parameter best accounts for the output-based form of IOR by measuring it with intermixed discrimination and localization targets. Experiment 2 employed the response-signal methodology and showed that the output-based form has no effect on the accrual of information about the target’s identity. These results converge with the response bias account for the output form of IOR. Full article

(This article belongs to the Special Issue Combined Approaches to Study Visuomotor Interactions)

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12 pages, 1682 KiB

Open AccessArticle

Path Configuration Complexity Affects Spatial Memory Span on the eCorsi Task but Does Not Influence Performance of a Concurrent Auditory Discrimination Task

by Anthony Tapper and Ewa Niechwiej-Szwedo

Vision 2023, 7(1), 24; https://doi.org/10.3390/vision7010024 - 18 Mar 2023

Viewed by 1180

Abstract

Visuospatial working memory is often assessed using the Corsi block-tapping task where set size is used to estimate capacity. It is well established that characteristics of the Corsi task path configuration such as length, crossings, and angles influence recall accuracy suggesting that more [...] Read more.

Visuospatial working memory is often assessed using the Corsi block-tapping task where set size is used to estimate capacity. It is well established that characteristics of the Corsi task path configuration such as length, crossings, and angles influence recall accuracy suggesting that more complex path configurations increase the load on working memory. However, the interaction between set size and path configuration is not well understood. Here we used a secondary auditory task to probe if set size and path configuration impose a similar type of load on the system. Nineteen participants (age = 25.3 ± 3.9 years) performed a computerized version of the Corsi test either alone (single) or simultaneously with an auditory tone discrimination task (dual). The eCorsi task involved a set of simple (no crosses, shorter lengths, larger angles) or complex (>2 crosses, longer lengths, smaller angles) paths at set sizes of five to eight blocks. Results showed significantly lower recall accuracy for the complex compared to the simple paths (63.32% vs. 86.38%, p < 0.001) at all set sizes, regardless of task condition (single, dual). Auditory performance (accuracy and response time) was significantly lower in the dual compared to single task (85.34% vs. 99.67%, p < 0.001), but performance was not affected by the complexity of the eCorsi path configuration. These findings suggest that set size and path complexity impose a different type of load on the working memory system and may rely on different resources. Full article

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10 pages, 653 KiB

Open AccessArticle

The Mental Health State of Canadian Ophthalmologists during the COVID-19 Pandemic: A Survey-Based Study and Review

by Mélanie Hébert, Soumaya Bouhout, Ellen E. Freeman and Marie-Josée Aubin

Vision 2023, 7(1), 23; https://doi.org/10.3390/vision7010023 - 17 Mar 2023

Cited by 1 | Viewed by 1474

Abstract

The coronavirus disease 2019 (COVID-19) pandemic disrupted the practice of medicine, causing stress and uncertainty among ophthalmologists. This cross-sectional, survey-based study of Canadian Ophthalmological Society members (n = 1152) aims to report on Canadian ophthalmologists’ mental health during the COVID-19 pandemic. Four [...] Read more.

The coronavirus disease 2019 (COVID-19) pandemic disrupted the practice of medicine, causing stress and uncertainty among ophthalmologists. This cross-sectional, survey-based study of Canadian Ophthalmological Society members (n = 1152) aims to report on Canadian ophthalmologists’ mental health during the COVID-19 pandemic. Four questionnaires were administered between December 2020 and May 2021: the Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), the 7-item Insomnia Severity Index (ISI), and the Impact of Event Scale—Revised (IES-R). From all of the responses, 60/85 answers were deemed complete and were included. The median age was 50–59 years and 53% were women. On PHQ-9, most respondents had no or minimal depressive symptoms (n = 38, 63%), while 12% (n = 7) had moderately severe depressive symptoms and 12% (n = 7) reported impaired daily functioning and/or thoughts of suicide or self-harm. On the GAD-7 scale, 65% (n = 39) had no significant anxiety, while 13% (n = 8) had moderate to severe anxiety. Most respondents did not have clinically significant insomnia (n = 41, 68%). Finally, 16 respondents (27%) had an IES-R score ≥24 suggesting possible post-traumatic stress disorder. No significant differences were found based on demographics. During the COVID-19 pandemic, up to 40% of respondents experienced varying degrees of depression, anxiety, insomnia, and distress from the event. In 12%, there were concerns for impaired daily functioning and/or suicidal thoughts. Full article

(This article belongs to the Special Issue Vision Research in Québec: Selected Papers from the 25th Annual Meeting of the Vision Health Research Network)

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26 pages, 392 KiB

Open AccessReview

Management of Stromal Corneal Dystrophies; Review of the Literature with a Focus on Phototherapeutic Keratectomy and Keratoplasty

by Zahra Ashena, Magdalena Niestrata and Shokufeh Tavassoli

Vision 2023, 7(1), 22; https://doi.org/10.3390/vision7010022 - 13 Mar 2023

Cited by 2 | Viewed by 2060

Abstract

Corneal dystrophies are a group of non-inflammatory inherited disorders of the cornea. This review considers treatment options for epithelial-stromal and stromal corneal dystrophies: namely Reis–Bücklers, Thiel–Behnke, lattice, Avellino, granular, macular and Schnyder corneal dystrophies. Where there is visual reduction, treatment options may include [...] Read more.

Corneal dystrophies are a group of non-inflammatory inherited disorders of the cornea. This review considers treatment options for epithelial-stromal and stromal corneal dystrophies: namely Reis–Bücklers, Thiel–Behnke, lattice, Avellino, granular, macular and Schnyder corneal dystrophies. Where there is visual reduction, treatment options may include either phototherapeutic keratectomy (PTK) or corneal transplantation. Due to the anterior location of the deposits in Reis-Bücklers and Thiel–Behnke dystrophies, PTK is considered the treatment of choice. For lattice, Avellino, granular and macular corneal dystrophies, PTK provides temporary visual improvement; however, with recurrences, repeat PTK or a corneal transplant would be needed. For Schnyder dystrophy, should treatment be required, PTK may be the preferred option due to the potential for recurrence of the disease in corneal transplantation. This review discusses the literature and evidence base for the treatment of corneal dystrophies in terms of visual outcomes and recurrence rate. Full article

18 pages, 21684 KiB

Open AccessArticle

Simulation of the Human Myopic Eye Cornea Compensation Based on the Analysis of Aberrometric Data

by Pavel A. Khorin and Svetlana N. Khonina

Vision 2023, 7(1), 21; https://doi.org/10.3390/vision7010021 - 12 Mar 2023

Cited by 1 | Viewed by 1498

Abstract

Various diffractive, refractive and holographic optical elements, such as diffraction gratings; microlens raster; phase plates; multi-order diffractive optical elements; adaptive mirrors; diffractive and refractive axicons; holographic multiplexes and many others are used to analyze wavefront aberrations. We shortly discuss the features (advantages and [...] Read more.

Various diffractive, refractive and holographic optical elements, such as diffraction gratings; microlens raster; phase plates; multi-order diffractive optical elements; adaptive mirrors; diffractive and refractive axicons; holographic multiplexes and many others are used to analyze wavefront aberrations. We shortly discuss the features (advantages and disadvantages) of various wavefront aberration sensors in the Introduction. The main part of the paper is devoted to the analysis of the weight coefficients of Zernike polynomials obtained during medical examinations of the cornea in the human eye. Using data obtained by aberrometers, the average values of the Zernike polynomial coefficients for the anterior and posterior surfaces of the healthy eye cornea and a myopic one were calculated. The original wavefront for the anterior and posterior surfaces of the cornea was restored separately, as well as the total wave aberration. For an objective assessment of the quality of vision, the corresponding point spread functions (PSFs) were calculated. We propose to compensate for the aberrations of the myopic eye, taking into account the physical features of the corneal surface. The results of numerical simulation showed that in order to improve the quality of the patient’s vision, it is necessary to take into account high-order aberrations of the anterior surface of the cornea in the form of a coma of the third order and aberrations of the fourth order. Full article

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17 pages, 7020 KiB

Open AccessArticle

Coenzyme Q10 and Fish Oil Supplementation for Reducing Retinal Oxidative Stress in a Rat Model

by Faisal Siddiqui, Charles Cai, Jacob V. Aranda and Kay D. Beharry

Vision 2023, 7(1), 20; https://doi.org/10.3390/vision7010020 - 11 Mar 2023

Cited by 1 | Viewed by 1366

Abstract

Extremely low gestational-age neonates requiring supplemental oxygen experience intermittent hypoxia (IH) episodes, which predispose them to oxidative stress and retinopathy of prematurity. We tested the hypothesis that early supplementation with fish oil or CoQ10 confers benefits reducing the severity of IH-induced retinopathy. At [...] Read more.

Extremely low gestational-age neonates requiring supplemental oxygen experience intermittent hypoxia (IH) episodes, which predispose them to oxidative stress and retinopathy of prematurity. We tested the hypothesis that early supplementation with fish oil or CoQ10 confers benefits reducing the severity of IH-induced retinopathy. At birth, rat pups were exposed to two clinically relevant neonatal IH paradigms with recovery in either hyperoxia (50% O₂) or room air (RA) between episodes for 14 days, during which they received daily oral fish oil, coenzyme Q10 (CoQ10) in olive oil (OO), or OO only (vehicle). At postnatal day 14 (P14), pups were allowed to recover in RA with no further treatment until P21. Retinas were examined at P14 and at P21. Both IH paradigms resulted in severe ocular oxidative stress and retinopathy regardless of recovery in hyperoxia or RA in the vehicle groups. Although early supplementation with fish oil was beneficial, CoQ10 provided superior benefits for reducing IH-induced oxidative stress and retinopathy. These effects were associated with lower retinal antioxidants and biomarkers of angiogenesis. The therapeutic benefits of CoQ10 suggest a potential treatment for IH-induced retinopathies. Further studies are needed to establish appropriate, safe, and effective doses for use in preterm infants. Full article

(This article belongs to the Section Retinal Function and Disease)

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14 pages, 1488 KiB

Open AccessReview

Central and Peripheral Ocular High-Order Aberrations and Their Relationship with Accommodation and Refractive Error: A Review

by Jessica Gomes, Kishor Sapkota and Sandra Franco

Vision 2023, 7(1), 19; https://doi.org/10.3390/vision7010019 - 07 Mar 2023

Cited by 3 | Viewed by 2004

Abstract

High-order aberrations (HOAs) are optical defects that degrade the image quality. They change with factors such as pupil diameter, age, and accommodation. The changes in optical aberrations during accommodation are mainly due to lens shape and position changes. Primary spherical aberration (Z(4.0)) is [...] Read more.

High-order aberrations (HOAs) are optical defects that degrade the image quality. They change with factors such as pupil diameter, age, and accommodation. The changes in optical aberrations during accommodation are mainly due to lens shape and position changes. Primary spherical aberration (Z(4.0)) is closely related to accommodation and some studies suggested that it plays an important role in the control of accommodation. Furthermore, central and peripheral HOAs vary with refractive error and seem to influence eye growth and the onset and progression of myopia. The variations of central and peripheral HOAs during accommodation also appear to be different depending on the refractive error. Central and peripheral high-order aberrations are closely related to accommodation and influence the accuracy of the accommodative response and the progression of refractive errors, especially myopia. Full article

(This article belongs to the Special Issue Exclusive Papers Collection of Editorial Board Members and Invited Scholars in Vision)

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12 pages, 5518 KiB

Open AccessArticle

Intraretinal Microvascular Abnormalities and Venous Beading Have Different Genetic Profiles in Caucasian Patients with Non-Proliferative Diabetic Retinopathy

by Elizabeth Pearce, Sobha Sivaprasad, Suzanne Broadgate, Christine Kiire, Susan M. Downes, Stephanie Halford and Victor Chong

Vision 2023, 7(1), 18; https://doi.org/10.3390/vision7010018 - 02 Mar 2023

Viewed by 1368

Abstract

Diabetic Retinopathy (DR) is a leading cause of preventable visual impairment in the working age population. Despite the increasing prevalence of DR, there remain gaps in our understanding of its pathophysiology. This is a prospective case-control study comparing the genetic profiles of patients [...] Read more.

Diabetic Retinopathy (DR) is a leading cause of preventable visual impairment in the working age population. Despite the increasing prevalence of DR, there remain gaps in our understanding of its pathophysiology. This is a prospective case-control study comparing the genetic profiles of patients with no DR vs. non-proliferative DR (NPDR) focusing on intraretinal microvascular abnormalities (IRMA) and venous beading (VB) in Caucasians. A total of 596 participants were recruited to the study; 199 with moderate/severe NPDR and 397 with diabetes for at least 5 years without DR. Sixty-four patients were excluded due to technical issues. In total, 532 were analysed; 181 and 351 were in the NPDR group and no DR group, respectively. Those with severe IRMA and VB had distinctly different genetic profiles from each other and from the no DR group, which further supports the theory that these two features of DR might have different etiologies. This also suggests that IRMA and VB are independent risk factors for the development of PDR and may have different pathophysiologies. If these findings are confirmed in larger studies, this could pave the way for personalised treatment options for those more at risk of developing different features of NPDR. Full article

(This article belongs to the Section Retinal Function and Disease)

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15 pages, 2201 KiB

Open AccessReview

The Use of Visualizations to Improve Bayesian Reasoning: A Literature Review

by Lucy Cui, Stephanie Lo and Zili Liu

Vision 2023, 7(1), 17; https://doi.org/10.3390/vision7010017 - 02 Mar 2023

Cited by 1 | Viewed by 1608

Abstract

Decisions are often made under uncertainty. The most that one can do is use prior knowledge (e.g., base rates, prior probabilities, etc.) and make the most probable choice given the information we have. Unfortunately, most people struggle with Bayesian reasoning. Poor performance within [...] Read more.

Decisions are often made under uncertainty. The most that one can do is use prior knowledge (e.g., base rates, prior probabilities, etc.) and make the most probable choice given the information we have. Unfortunately, most people struggle with Bayesian reasoning. Poor performance within Bayesian reasoning problems has led researchers to investigate ways to improve Bayesian reasoning. Many have found success in using natural frequencies instead of probabilities to frame problems. Beyond the quantitative format, there is growing literature on the use of visualizations or visual representations to improve Bayesian reasoning, which will be the focus of this review. In this review, we discuss studies that have found visualizations to be effective for improving Bayesian reasoning in a lab or classroom setting and discuss the considerations for using visualizations, paying special attention to individual differences. In addition, we will review the factors that influence Bayesian reasoning, such as natural frequencies vs. probabilities, problem format, individual differences, and interactivity. We also provide general and specific suggestions for future research. Full article

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11 pages, 4261 KiB

Open AccessArticle

A 10-Year Single-Center Study of the Clinical Characteristics of Optic Neuritis-Related NMOSD, MS, and Double Seronegative Optic Neuritis, Together with Factors Predicting Visual Outcomes

by Parinee Kemchoknatee, Chotika Singhakul, Niracha Arjkongharn, Methaphon Chainakul, Duanghathai Tangon and Thansit Srisombut

Vision 2023, 7(1), 16; https://doi.org/10.3390/vision7010016 - 28 Feb 2023

Cited by 1 | Viewed by 2847

Abstract

The clinical characteristics of three types of optic neuritis (double seronegative optic neuritis; DN-ON, Neuromyelitis optica spectrum disorder-related optic neuritis; NMOSD-ON, and multiple sclerosis-related optic neuritis; MS-ON) were examined in order to identify factors that may affect good visual recovery in Thai patients. [...] Read more.

The clinical characteristics of three types of optic neuritis (double seronegative optic neuritis; DN-ON, Neuromyelitis optica spectrum disorder-related optic neuritis; NMOSD-ON, and multiple sclerosis-related optic neuritis; MS-ON) were examined in order to identify factors that may affect good visual recovery in Thai patients. The study included patients diagnosed with three types of optic neuritis at Rajavithi Hospital between 2011 and 2020. Visual acuity at the end of 12 months was used as the treatment outcome. Multiple logistic regression analysis was used to evaluate potential predictors of good visual recovery. Of the 76 patients, 61 had optic neuritis, with DN-ON as the most common subtype (52.6%). MS-ON patients were significantly younger (28.3 ± 6.6 years, p = 0.002) and there was a female predominance in all subgroups (p = 0.076). NMOSD-ON patients had a significantly higher proportion of poor baseline VA (p < 0.001). None of the NMOSD-ON patients achieved 0.3 logMAR visual recovery in the 12-month period (p = 0.022). A delay in treatment with intravenous methylprednisolone (IVMP) for more than 7 days increased the risk of failure to gain 0.3 logMAR visual recovery by five times (OR 5.29, 95% CI 1.359–20.616, p = 0.016), with NMOSD-ON as the strongest predictor (OR 10.47, 95% CI; 1.095–99.993, p = 0.041). Early treatment with intravenous methylprednisolone may be important for achieving at least 0.3 logMAR visual recovery in Thai patients with optic neuritis. Full article

(This article belongs to the Section Retinal Function and Disease)

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15 pages, 1400 KiB

Open AccessSystematic Review

Flash Electroretinography as a Measure of Retinal Function in Myopia and Hyperopia: A Systematic Review

by Sania Zahra, Melanie J. Murphy, Sheila G. Crewther and Nina Riddell

Vision 2023, 7(1), 15; https://doi.org/10.3390/vision7010015 - 27 Feb 2023

Cited by 3 | Viewed by 2068

Abstract

Refractive errors (myopia and hyperopia) are the most common visual disorders and are severe risk factors for secondary ocular pathologies. The development of refractive errors has been shown to be associated with changes in ocular axial length, suggested to be induced by outer [...] Read more.

Refractive errors (myopia and hyperopia) are the most common visual disorders and are severe risk factors for secondary ocular pathologies. The development of refractive errors has been shown to be associated with changes in ocular axial length, suggested to be induced by outer retinal elements. Thus, the present study systematically reviewed the literature examining retinal function as assessed using global flash electroretinograms (gfERGs) in human clinical refractive error populations. Electronic database searching via Medline, PubMed, Web of Science, Embase, Psych INFO, and CINAHL retrieved 981 unique records (last searched on the 29 May 2022). Single case studies, samples with ocular comorbidities, drug trials, and reviews were excluded. Demographic characteristics, refractive state, gfERG protocol details, and waveform characteristics were extracted for the eight studies that met the inclusion criteria for the review and were judged to have acceptable risk of bias using the OHAT tool (total N = 552 participants; age 7 to 50). Study synthesis suggests that myopia in humans involves attenuation of gfERG photoreceptor (a-wave) and bipolar cell (b-wave) function, consistent with the animal literature. Meaningful interpretation of the overall findings for hyperopia was limited by inconsistent reporting, highlighting the need for future studies to report key aspects of gfERG research design and outcomes more consistently for myopic and hyperopic refractive errors. Full article

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10 pages, 665 KiB

Open AccessArticle

Internal Tube Occlusion with An Easily Removable Non-Absorbable Double Suture: A Novel Surgical Technique Adjunct for Non-Valved Glaucoma Drainage Devices

by Alfonso Savastano, Gloria Gambini, Maria Cristina Savastano, Matteo Mario Carlà, Clara Rizzo, Tomaso Caporossi, Emanuele Crincoli and Stanislao Rizzo

Vision 2023, 7(1), 14; https://doi.org/10.3390/vision7010014 - 24 Feb 2023

Viewed by 1466

Abstract

To describe a surgical variant for non-valved glaucoma drainage device implants using an easily removable non-absorbable double suture into the lumen of the tube. A retrospective, non-comparative case series of 10 patients who underwent a non-valved glaucoma drainage device implant with an endoluminal [...] Read more.

To describe a surgical variant for non-valved glaucoma drainage device implants using an easily removable non-absorbable double suture into the lumen of the tube. A retrospective, non-comparative case series of 10 patients who underwent a non-valved glaucoma drainage device implant with an endoluminal double-suture for refractory glaucoma. The sutures were easily removed postoperatively without the need for an operating room. Intraocular pressure, number of medications, and early and late complications were evaluated with a follow-up of 12 months. None of the eyes that underwent an operation developed early or late complications. The first endoluminal suture was removed in all eyes with a mean time of removal of 30 ± 7 days. The second suture was removed in all eyes with a mean time of removal of 90 ± 7 days. No complications were noted, either, after or during suture removal. The mean preoperative IOP was 27.3 ± 4.0 and the postoperative IOP, at the end of the follow-up, was 12.7 ± 1.4. At the end of the follow-up, six patients (60%) achieved complete success and four patients (40%) achieved qualified success. In conclusion, in our case series, the surgical variant allowed for a safe and gradual regulation of the flow during postoperative management. Considering the efficacy of non-valved glaucoma drainage devices, an improvement in the safety profile allows surgeons to broaden the surgical indications. Full article

(This article belongs to the Special Issue Recent Advances in Glaucoma: Diagnosis and Treatment)

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11 pages, 819 KiB

Open AccessArticle

Retinal Nerve Fiber Layer Changes after Intraocular Silicone Oil Tamponade in Rhegmatogenous Retinal Detachment

by Fitri Annur Chikmah, Andi Muhammad Ichsan, Itzar Chaidir Islam, Joko Hendarto, Habibah Setyawati Muhiddin and Budu

Vision 2023, 7(1), 13; https://doi.org/10.3390/vision7010013 - 21 Feb 2023

Cited by 1 | Viewed by 1593

Abstract

Rhegmatogenous retinal detachment (RRD) is a serious and emergency condition that may cause visual disturbance. Treatment includes pars plana vitrectomy with a tamponade such as intraocular gas or silicone oil (SO). In many countries, silicone oil is still favorable compared to intraocular gases [...] Read more.

Rhegmatogenous retinal detachment (RRD) is a serious and emergency condition that may cause visual disturbance. Treatment includes pars plana vitrectomy with a tamponade such as intraocular gas or silicone oil (SO). In many countries, silicone oil is still favorable compared to intraocular gases as tamponade for reattachment of retinal detachment surgery. The application provides a higher anatomical success rate, especially in cases of proliferative vitreoretinopathy (PVR) that were previously considered untreatable. Objective assessment of the retinal nerve fiber layer (RNFL) using optical coherence tomography (OCT) in the eye with silicone oil tamponade is a challenge because of the limitations and difficulties in taking images. This study aims to assess the RNFL thickness changes in rhegmatogenous retinal detachment patients using SO tamponade and its subsequent removal conducted on a total of 35 post-operative RRD patients. Central macular and RNFL thickness, as well as best-corrected visual acuity (BCVA), were recorded at the time of tamponade and after the removal of the SO at 1, 4, and 8 weeks, respectively. The results showed that the changes in RNFL thickness significantly decreased in the group of ≤6 months, especially in the superior and temporal quadrants, and BCVA increased after SO removal (p < 0.05). Central macular thickness was significant (p < 0.001) at the end of the visit. Improved visual acuity is associated with decreased RNFL and central macular thickness after SO removal. Full article

(This article belongs to the Section Retinal Function and Disease)

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19 pages, 3408 KiB

Open AccessReview

The Action Cycle Theory of Perception and Mental Imagery

by David F. Marks

Vision 2023, 7(1), 12; https://doi.org/10.3390/vision7010012 - 14 Feb 2023

Cited by 3 | Viewed by 4450

Abstract

The Action Cycle Theory (ACT) is an enactive theory of the perception and a mental imagery system that is comprised of six modules: Schemata, Objects, Actions, Affect, Goals and Others’ Behavior. The evidence supporting these six connected modules is reviewed in light of [...] Read more.

The Action Cycle Theory (ACT) is an enactive theory of the perception and a mental imagery system that is comprised of six modules: Schemata, Objects, Actions, Affect, Goals and Others’ Behavior. The evidence supporting these six connected modules is reviewed in light of research on mental imagery vividness. The six modules and their interconnections receive empirical support from a wide range of studies. All six modules of perception and mental imagery are influenced by individual differences in vividness. Real-world applications of ACT show interesting potential to improve human wellbeing in both healthy people and patients. Mental imagery can be applied in creative ways to make new collective goals and actions for change that are necessary to maximize the future prospects of the planet. Full article

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12 pages, 2997 KiB

Open AccessArticle

The Differential Contribution of Macular Pigments and Foveal Anatomy to the Perception of Maxwell’s Spot and Haidinger’s Brushes

by Gary P. Misson, Rebekka Heitmar, Richard Armstrong and Stephen J. Anderson

Vision 2023, 7(1), 11; https://doi.org/10.3390/vision7010011 - 06 Feb 2023

Viewed by 1209

Abstract

The relationship of macular pigments and foveal anatomy to the perception of Maxwell’s spot (MS) and Haidinger’s brushes (HB) entoptic phenomena were investigated. Dual-wavelength-autofluorescence and OCT were used to define macular pigment density and foveal anatomy in 52 eyes. MS was generated by [...] Read more.

The relationship of macular pigments and foveal anatomy to the perception of Maxwell’s spot (MS) and Haidinger’s brushes (HB) entoptic phenomena were investigated. Dual-wavelength-autofluorescence and OCT were used to define macular pigment density and foveal anatomy in 52 eyes. MS was generated by alternating unpolarized red/blue and red/green uniform field illumination. HB was generated by alternating the linear polarization axis of a uniform blue field. In Experiment 1, horizontal widths of MS and HB were measured using a micrometer system and compared with macular pigment densities and OCT-defined morphometry. MS radius (mean 1.4°) was significantly less than HB radius (mean 1.6°), with the spatial extent of both phenomena falling between the boundaries of the foveola and foveal pit. Multiple regression showed MS and HB radii to be significantly associated with the macular pigment spatial profile radius. HB radius, but not MS radius, was also significantly associated with foveolar morphometry. Experiment 2 compared perceptual profiles of MS with macular pigment distribution patterns and demonstrated close agreement. The size and appearance of MS is a direct indicator of macular pigment density and distribution. Measures of HB radii are less specific, with dependence on both macular pigment density and foveal structure. Full article

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9 pages, 2426 KiB

Open AccessCommunication

Full-Thickness Compressive Corneal Sutures with Removal of Anterior Chamber Air Bubble in the Management of Acute Corneal Hydrops

by Zahra Ashena, Ritika Mukhija and Mayank A. Nanavaty

Vision 2023, 7(1), 10; https://doi.org/10.3390/vision7010010 - 28 Jan 2023

Cited by 3 | Viewed by 2414

Abstract

Acute hydrops is a rare complication of corneal ectatic disease, which occurs secondary to Descemet membrane break. Spontaneous resolution of this condition is associated with longstanding ocular discomfort and corneal scar. Intracameral gas/air injection with or without corneal suturing, anterior segment ocular coherence [...] Read more.

Acute hydrops is a rare complication of corneal ectatic disease, which occurs secondary to Descemet membrane break. Spontaneous resolution of this condition is associated with longstanding ocular discomfort and corneal scar. Intracameral gas/air injection with or without corneal suturing, anterior segment ocular coherence tomography (ASOCT)-guided drainage of intrastromal fluid, and penetrating keratoplasty are some of the described surgical interventions to manage this condition. The purpose of our study was to assess the effect of full-thickness corneal suturing as a solo treatment in the management of acute hydrops. A total of five patients with acute hydrops received full-thickness corneal sutures perpendicular to their Descemet break. A complete resolution of symptoms and corneal oedema was observed between 8 to 14 days post-operation with no complications. This technique is simple, safe, and effective in the management of acute hydrops and saves patients from a corneal transplant in an inflamed eye. Full article

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15 pages, 2044 KiB

Open AccessArticle

Deficits in Face Recognition and Consequent Quality-of-Life Factors in Individuals with Cerebral Visual Impairment

by Corinna M. Bauer, Claire E. Manley, John Ravenscroft, Howard Cabral, Daniel D. Dilks and Peter J. Bex

Vision 2023, 7(1), 9; https://doi.org/10.3390/vision7010009 - 25 Jan 2023

Cited by 6 | Viewed by 1876

Abstract

Individuals with cerebral visual impairment (CVI) frequently report challenges with face recognition, and subsequent difficulties with social interactions. However, there is limited empirical evidence supporting poor face recognition in individuals with CVI and the potential impact on social–emotional quality-of-life factors. Moreover, it is [...] Read more.

Individuals with cerebral visual impairment (CVI) frequently report challenges with face recognition, and subsequent difficulties with social interactions. However, there is limited empirical evidence supporting poor face recognition in individuals with CVI and the potential impact on social–emotional quality-of-life factors. Moreover, it is unclear whether any difficulties with face recognition represent a broader ventral stream dysfunction. In this web-based study, data from a face recognition task, a glass pattern detection task, and the Strengths and Difficulties Questionnaire (SDQ) were analyzed from 16 participants with CVI and 25 controls. In addition, participants completed a subset of questions from the CVI Inventory to provide a self-report of potential areas of visual perception that participants found challenging. The results demonstrate a significant impairment in the performance of a face recognition task in participants with CVI compared to controls, which was not observed for the glass pattern task. Specifically, we observed a significant increase in threshold, reduction in the proportion correct, and an increase in response time for the faces, but not for the glass pattern task. Participants with CVI also reported a significant increase in sub-scores of the SDQ for emotional problems and internalizing scores after adjusting for the potential confounding effects of age. Finally, individuals with CVI also reported a greater number of difficulties on items from the CVI Inventory, specifically the five questions and those related to face and object recognition. Together, these results indicate that individuals with CVI may demonstrate significant difficulties with face recognition, which may be linked to quality-of-life factors. This evidence suggests that targeted evaluations of face recognition are warranted in all individuals with CVI, regardless of their age. Full article

(This article belongs to the Special Issue Cybervision: Investigating Vision and Visual Cognition through Web-Based Studies)

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12 pages, 414 KiB

Open AccessArticle

Delphi Study: Designing Training to Enable Visual Impairment Services to Promote Physical Activity

by Rosie K. Lindsay, Lee Smith and Peter M. Allen

Vision 2023, 7(1), 8; https://doi.org/10.3390/vision7010008 - 22 Jan 2023

Viewed by 1347

Abstract

Research suggests adults with visual impairment would increase their physical activity (PA) if they were advised to by a professional working in visual impairment services. However, there are no training programs which are targeted at enabling these professionals to promote PA. Therefore, this [...] Read more.

Research suggests adults with visual impairment would increase their physical activity (PA) if they were advised to by a professional working in visual impairment services. However, there are no training programs which are targeted at enabling these professionals to promote PA. Therefore, this study aims to inform a UK-based training program which facilitates PA promotion within visual impairment services. A modified Delphi technique was used, consisting of a focus group and two rounds of surveys. The panel included 17 experts in round one, and 12 experts in round two. Consensus was defined as equal to or greater than 70% agreement. The panel agreed training should: educate professionals on PA benefits, injury prevention, and wellbeing, address myths associated with PA, address health and safety concerns, help professionals to find local PA opportunities, and include a networking session for professionals in visual impairment services and local PA providers. The panel agreed training should also target PA providers and volunteers for visual impairment services, and that training should be delivered online and in-person. In conclusion, training should provide professionals with the capability to promote PA and to establish stakeholder partnerships. The present findings can inform future research which tests the panel’s recommendations. Full article

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3 pages, 236 KiB

Open AccessEditorial

Acknowledgment to the Reviewers of Vision in 2022

by Vision Editorial Office

Vision 2023, 7(1), 7; https://doi.org/10.3390/vision7010007 - 19 Jan 2023

Viewed by 904

Abstract

High-quality academic publishing is built on rigorous peer review [...] Full article

23 pages, 4233 KiB

Open AccessReview

An Overview of the Penguin Visual System

by Peter W. Hadden and Jie Zhang

Vision 2023, 7(1), 6; https://doi.org/10.3390/vision7010006 - 17 Jan 2023

Cited by 1 | Viewed by 5568

Abstract

Penguins require vision that is adequate for both subaerial and submarine environments under a wide range of illumination. Here we provide a structured overview of what is known about their visual system with an emphasis on how and how well they achieve these [...] Read more.

Penguins require vision that is adequate for both subaerial and submarine environments under a wide range of illumination. Here we provide a structured overview of what is known about their visual system with an emphasis on how and how well they achieve these goals. Amphibious vision is facilitated by a relatively flat cornea, the power in air varying from 10.2 dioptres (D) to 41.3 D depending on the species, and there is good evidence for emmetropia both above and below water. All penguins are trichromats with loss of rhodopsin 2, a nocturnal feature, but only deeper diving penguins have been noted to have pale oil droplets and a preponderance of rods. Conversely, the diurnal, shallow-diving little penguin has a higher ganglion cell density (28,867 cells/mm²) and f-number (3.5) than those that operate in dimmer light. In most species studied, there is some binocular overlap, but this reduces upon submergence. However, gaps in our knowledge remain, particularly with regard to the mechanism of accommodation, spectral transmission, behavioural measurements of visual function in low light, and neural adaptations to low light. The rarer species also deserve more attention. Full article

(This article belongs to the Special Issue Vision in Aquatic Environment)

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Graphical abstract

10 pages, 889 KiB

Open AccessArticle

Improving Visual Comfort during Computer Gaming with Preservative-Free Hyaluronic Acid Artificial Tears Added to Ergophthalmological Measures

by Fernando Trancoso Vaz, Ester Fernández-López, María José Roig-Revert, Alicia Martín and Cristina Peris-Martínez

Vision 2023, 7(1), 5; https://doi.org/10.3390/vision7010005 - 11 Jan 2023

Cited by 1 | Viewed by 2732

Abstract

Digital asthenopia (DA) or Computer Vision Syndrome can occur after prolonged use of digital devices and is usually managed with ergophthalmological measures and the use of artificial tears. This prospective, controlled study evaluated the use of hyaluronic acid artificial tears on the signs [...] Read more.

Digital asthenopia (DA) or Computer Vision Syndrome can occur after prolonged use of digital devices and is usually managed with ergophthalmological measures and the use of artificial tears. This prospective, controlled study evaluated the use of hyaluronic acid artificial tears on the signs and symptoms of DA in participants of a videogame convention. Subjects (n = 56) were randomized into a control group (CG, n = 26), which followed ergophthalmological measures, and a study group (SG, n = 30), which followed ergophthalmological measures and instilled 1 drop of artificial tears with hyaluronic acid 0.15% four times a day. Subjects were evaluated before and after playing for three consecutive days for eye dryness (SPEED questionnaire), conjunctival hyperemia, corneal fluorescein staining, conjunctival lissamine green staining, tear breakup time, Schirmer I test, near convergence and accommodation, and using questionnaires for DA symptoms. After 3 days of intense videogaming, the SPEED score of CG increased significantly (p = 0.0320), while for the SG it was unchanged. Similarly, the CG presented significant increases in ocular fatigue (p = 0.0173) and dryness (p = 0.0463), while these parameters decreased significantly in the SG (p = 0.0149 and p = 0.00427, respectively). This study confirms the protective effect of hyaluronic acid artificial tears against DA symptoms associated with prolonged visual display terminal use. Full article

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15 pages, 6065 KiB

Open AccessArticle

Confocal and Electron Microscopic Structure of the Cornea from Three Species of Penguin

by Peter W. Hadden, Akilesh Gokul, Satya Amirapu, Ratish Kurian, Charles N. J. McGhee and Jie Zhang

Vision 2023, 7(1), 4; https://doi.org/10.3390/vision7010004 - 03 Jan 2023

Viewed by 1552

Abstract

Corneal confocal microscopy has not previously been performed in penguins, despite recognition of its unusually flat shape. To identify features that the penguin shares with other birds and or mammals and those specific to penguins, we undertook confocal microscopic examination of two little [...] Read more.

Corneal confocal microscopy has not previously been performed in penguins, despite recognition of its unusually flat shape. To identify features that the penguin shares with other birds and or mammals and those specific to penguins, we undertook confocal microscopic examination of two little (Eudyptula minor), four gentoo (Pygoscelis papua) and five king (Aptenodytes patagonicus) penguin corneas. Transmission electron microscopy was performed on one gentoo and one king penguin, for finer details. Features shared with other higher vertebrates included a five-layered cornea and a similar limbus. Typically avian were a lower density of stromal cells, a more regular arrangement of collagen bands and an absent basal nerve plexus. Features unique to penguins included a flattened superficial epithelium (king penguin), stromal myofibroblasts (all) and an irregular endothelium (little penguin). Other features uniquely identified by confocal microscopy in birds include epithelial and stromal nerves, guttata and stromal imprints on Descemet’s membrane. Transmission electron microscopy identified a lack of wing cells (king penguin), greater posterior collagen lamellae thickness (gentoo penguin) and significantly less interlacing of collagen lamellae in the central cornea (king and gentoo). Most of these unique features are yet to be explained, but some could be adaptations to diving. Full article

(This article belongs to the Special Issue Vision in Aquatic Environment)

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10 pages, 675 KiB

Open AccessArticle

The Relation between Ensemble Coding of Length and Orientation Does Not Depend on Spatial Attention

by Melanie Kacin, Oakyoon Cha and Isabel Gauthier

Vision 2023, 7(1), 3; https://doi.org/10.3390/vision7010003 - 28 Dec 2022

Viewed by 1257

Abstract

Most people are good at estimating summary statistics for different features of groups of objects. For instance, people can selectively attend to different features of a group of lines and report ensemble properties such as the mean length or mean orientation and there [...] Read more.

Most people are good at estimating summary statistics for different features of groups of objects. For instance, people can selectively attend to different features of a group of lines and report ensemble properties such as the mean length or mean orientation and there are reliable individual differences in such ensemble judgment abilities. Our recent study found decisive evidence in support of a correlation between the errors on mean length and mean orientation judgments (r = 0.62). The present study investigates one possible mechanism for this correlation. The ability to allocate spatial attention to single items varies across individuals, and in the recent study, this variability could have contributed to both judgments because the location of lines was unpredictable. Here, we replicate this prior work with arrays of lines with fully predictable spatial locations, to lower the contribution of the ability to distribute attention effectively over all items in a display. We observed a strong positive correlation between errors on the length and orientation averaging tasks (r = 0.65). This provides evidence against individual differences in spatial attention as a common mechanism supporting mean length and orientation judgments. The present result aligns with the growing evidence for at least one ensemble-specific ability that applies across different kinds of features and stimuli. Full article

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7 pages, 239 KiB

Open AccessArticle

Risk Profile of Keratoconus among Secondary School Students in the West Region of Cameroon

by Enowntai Nkongho Ayukotang, Vanessa Raquel Moodley and Khathutshelo Percy Mashige

Vision 2023, 7(1), 2; https://doi.org/10.3390/vision7010002 - 23 Dec 2022

Viewed by 1416

Abstract

This study determined the risk factors of keratoconus (KC) among secondary school students in the West Region of Cameroon. A stratified, random sampling technique was used to select the 3015 secondary school students, 8 years and older, within the West Region of Cameroon. [...] Read more.

This study determined the risk factors of keratoconus (KC) among secondary school students in the West Region of Cameroon. A stratified, random sampling technique was used to select the 3015 secondary school students, 8 years and older, within the West Region of Cameroon. Selected school students completed the validated Keratoconus Risk Investigative Survey (KRIS) and a structured demographic questionnaire to determine the risk profile of KC. Descriptive analysis, logistic regression and p-values were used to provide an overview of the demographic findings and the risk factors of KC. Estimates were made as the proportion of affected school students and presented with a 95% confidence interval (CI). Multivariate logistic regression analysis was performed to explore the association between KC and the independent predictors that were found significant in the univariate analysis. The ages of the majority (93.2%) of students ranged from eight years to 18 years (mean = 13.18 ± years) and were mostly female (59.7%). Gender (OR 2.024, p < 0.001), eye rubbing (OR 3.615, p < 0.001), exposure to sunlight (OR 2.735, p < 0.001), blood relations with KC (OR 41.819, p < 0.001) and allergic experience (OR 1.070, p < 0.001) were considered. Eye rubbing was the most significant risk factor of keratoconus followed by refractive error, allergic experiences and sunlight exposure. These findings support the evidence that the etiology of KC is multifactorial, with eye rubbing being the most significant factor in this cohort. There is a need to address eye rubbing among students to minimize the risk of KC. Furthermore, 34.46% of students in Cameroon were at risk of developing KC. Hence the risk profile is that one engages in eye rubbing, has a family member with KC, spends more than eight hours per week in the sun and is prone to allergies. It will therefore be prudent for these risk factors for keratoconus to be included in the school health education programs. Full article

14 pages, 2086 KiB

Open AccessArticle

Binocular Information Improves the Reliability and Consistency of Pictorial Relief

by Paul B. Hibbard, Rebecca L. Hornsey and Jordi M. Asher

Vision 2023, 7(1), 1; https://doi.org/10.3390/vision7010001 - 22 Dec 2022

Cited by 1 | Viewed by 1445

Abstract

Binocular disparity is an important cue to three-dimensional shape. We assessed the contribution of this cue to the reliability and consistency of depth in stereoscopic photographs of natural scenes. Observers viewed photographs of cluttered scenes while adjusting a gauge figure to indicate the [...] Read more.

Binocular disparity is an important cue to three-dimensional shape. We assessed the contribution of this cue to the reliability and consistency of depth in stereoscopic photographs of natural scenes. Observers viewed photographs of cluttered scenes while adjusting a gauge figure to indicate the apparent three-dimensional orientation of the surfaces of objects. The gauge figure was positioned on the surfaces of objects at multiple points in the scene, and settings were made under monocular and binocular, stereoscopic viewing. Settings were used to create a depth relief map, indicating the apparent three-dimensional structure of the scene. We found that binocular cues increased the magnitude of apparent depth, the reliability of settings across repeated measures, and the consistency of perceived depth across participants. These results show that binocular cues make an important contribution to the precise and accurate perception of depth in natural scenes that contain multiple pictorial cues. Full article

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