Marmamula S, Mitchell W, Zebardast N, Locascio J, Barrenkala NR, Kumbham TR, Modepalli SB, Khanna RC, Friedman DS.
Impact of Vision Loss on Visual Function Among Elderly Residents in the "Home for the Aged" in India: The Hyderabad Ocular Morbidity in Elderly Study. Transl Vis Sci Technol 2020;9(13):11.
AbstractPurpose: The purpose of this study was to report the association between visual impairment (VI) and self-reported visual difficulty among the elderly in residential care using the Indian Vision Functioning Questionnaire (IND-VFQ-33) psychometrically validated questionnaire. Methods: Participants aged ≥ 60 years were recruited from 41 homes in Hyderabad in South India. All participants underwent detailed eye examination and interviews. Self-reported visual function was assessed using the IND-VFQ-33 questionnaire. Factor Analysis and Item Response Theory (IRT) models were used for analysis. Multivariable regression models were used to investigate associations between derived global difficulty scores versus severity and causes of VI. Presenting visual acuity worse than 6/18 in the better eye was considered as VI. Results: In total, 867 elderly participants completed the INDVFQ-33. Two latent traits ("daily activities" and "visual symptoms") were identified on factor analysis, each with uniquely loading questions. Participants with VI reported significantly higher daily activities difficulty (6 points higher) and visual symptoms difficulty (1.7 points higher) than those without VI ( < 0.05). Those with cataract reported the highest daily activities and visual symptoms difficulty (7.6 points and 2.2 points higher, respectively, < 0.05). Greater severity of VI was associated with increased self-reported difficulty for both factors, and for all causes of VI. Conclusions: We present a psychometrically validated visual questionnaire particularly suited to older adults in residential homes. We show a significant association between cause/severity of VI and difficulty with daily activities and visual symptoms after adjusting for sociodemographic and medical factors. Translational Relevance: Understanding the impact of vision loss on visual functions in the elderly will help in planning and resource allocation for developing early intervention programs for the elderly.
McKay TB, Guo X, Hutcheon AEK, Karamichos D, Ciolino JB.
Methods for Investigating Corneal Cell Interactions and Extracellular Vesicles In Vitro. Curr Protoc Cell Biol 2020;89(1):e114.
AbstractScience and medicine have become increasingly "human-centric" over the years. A growing shift away from the use of animals in basic research has led to the development of sophisticated in vitro models of various tissues utilizing human-derived cells to study physiology and disease. The human cornea has likewise been modeled in vitro using primary cells derived from corneas obtained from cadavers or post-transplantation. By utilizing a cell's intrinsic ability to maintain its tissue phenotype in a pre-designed microenvironment containing the required growth factors, physiological temperature, and humidity, tissue-engineered corneas can be grown and maintained in culture for relatively long periods of time on the scale of weeks to months. Due to its transparency and avascularity, the cornea is an optimal tissue for studies of extracellular matrix and cell-cell interactions, toxicology and permeability of drugs, and underlying mechanisms of scarring and tissue regeneration. This paper describes methods for the cultivation of corneal keratocytes, fibroblasts, epithelial, and endothelial cells for in vitro applications. We also provide detailed, step-by-step protocols for assembling and culturing 3D constructs of the corneal stroma, epithelial- and endothelial-stromal co-cultures and isolation of extracellular vesicles. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Isolating and culturing human corneal keratocytes and fibroblasts Basic Protocol 2: Isolating and culturing human corneal epithelial cells Basic Protocol 3: Isolating and culturing human corneal endothelial cells Basic Protocol 4: 3D corneal stromal construct assembly Basic Protocol 5: 3D corneal epithelial-stromal construct assembly Basic Protocol 6: 3D corneal endothelial-stromal construct assembly Basic Protocol 7: Isolating extracellular vesicles from corneal cell conditioned medium Support Protocol: Cryopreserving human corneal fibroblasts, corneal epithelial cells, and corneal endothelial cells.
Mitchell W, Hassall M, Henderson T.
Updating the model of eye care for Aboriginal populations in remote Central Australia. Clin Exp Ophthalmol 2020;48(9):1299-1306.
AbstractEye disease is the third-highest contributor towards health inequality for Aboriginal Australians. Understanding how the Central Australian ophthalmology service addresses complexities of remote eye care is crucial in understanding how expansion can meet current and future needs. The present study analyses findings from the MEDLINE database and Governmental reports, and descriptive information from stakeholders in Central Australia and the Australian Department of Health. We describe the current Central Australian ophthalmology model at three levels; (a) the healthcare service level (specialized primary care, local/outreach optometry and ophthalmology services, and intensive extended surgical weeks), (b) the community level (local community staff, clinics and initiatives, and eye "champions" and mutual support), and (c) the healthcare system level (federal and state government, and private funding). We conclude that building full-time specialist availability, and system-wide approaches to increase patient utilisation, will facilitate overcoming barriers of remoteness, and create enduring improvements in Central Australian eye care and health-inequality.
Moharrer M, Tang X, Luo G.
With Motion Perception, Good Visual Acuity May Not Be Necessary for Driving Hazard Detection. Transl Vis Sci Technol 2020;9(13):18.
AbstractPurpose: To investigate the roles of motion perception and visual acuity in driving hazard detection. Methods: Detection of driving hazard was tested based on video and still-frames of real-world road scenes. In the experiment using videos, 20 normally sighted participants were tested under four conditions: with or without motion interruption by interframe mask, and with or without simulated low visual acuity (20/120 on average) by using a diffusing filter. Videos were down-sampled to 2.5 Hz, to allow the addition of motion interrupting masks between the frames to maintain video durations. In addition, single still frames extracted from the videos were shown in random order to eight normally sighted participants, who judged whether the frames were during ongoing hazards, with or without the diffuser. Sensitivity index d-prime (d') was compared between unmasked motion ( = 20) and still frame conditions ( = 8). Results: In the experiment using videos, there was a significant reduction in a combined performance score (taking account of reaction time and detection rate) when the motion was disrupted ( = 0.016). The diffuser did not affect the scores ( = 0.419). The score reduction was mostly due to a decrease in the detection rate ( = 0.002), not the response time ( = 0.148). The d' of participants significantly decreased ( < 0.001) from 2.24 with unmasked videos to 0.68 with still frames. Low visual acuity also had a significant effect on the d' ( = 0.004), but the change was relatively small, from 2.03 without to 1.56 with the diffuser. Conclusions: Motion perception plays a more important role than visual acuity for detecting driving hazards. Translational Relevance: Motion perception may be a relevant criterion for fitness to drive.
Moon JY, Miller JB, Katz R, Ta T, Szypko C, Garg I, Lorch AC, Gardiner MF, Armstrong GW.
The Impact of the COVID-19 Pandemic on Ophthalmic Care at an Eye-Specific Emergency Department in an Outbreak Hotspot. Clin Ophthalmol 2020;14:4155-4163.
AbstractPurpose: During the COVID-19 pandemic, there is growing concern that patients are forgoing necessary care. Emergency departments (ED) represent an important site of eye care. We analyzed patterns of ED visits at an eye-specific ED since the declaration of the public health crisis. Materials and Methods: In this retrospective, cross-sectional single center study, medical records of 6744 patients who presented to the Massachusetts Eye and Ear ED between March 1st and April 30th in 2018, 2019, and 2020 were studied. The primary outcome measures were total volume of ED visits, proportion of urgent ED visits, and proportion of surgical visits. Results: Overall, the median number of daily visits to the ED decreased by 18 visits per day since the declaration of public health guidelines (interquartile range, 9-24, p < 0.001). This accounted for a 32% decrease in the total volume of ED visits in 2020 compared to prior years during the study period (p < 0.001). There was a 9% increase in the proportion of primary diagnoses considered urgent (p = 0.002). The proportion of visits requiring urgent surgery increased by 39% (p = 0.004). Conclusion: The total number of eye-specific ED visits dropped compared to prior years while the proportion of urgent visits increased. Patients were likely more reluctant to seek eye care, deferring less urgent evaluation.