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Background: To identify vitreoretinal practice patterns in the months following the initial 2020 national shutdown due to the COVID-19 pandemic in the United States (US). Study Design: Retrospective analysis of vitreoretinal practice patterns from multiple retinal centers across the US from January 1, 2018 to December 31, 2020. Results: The lowest utilization of retina care occurred during the week of March 23, 2020, after which utilization returned to pre-pandemic levels by July 2020. Patients with retinal detachments (RDs) presented with worse visual acuity during March, April, and May 2020 compared to the same time periods of 2018 and 2019 ( P values < 0.05). However, only comparing eyes that presented in March 2018 to March 2020, was the year 1 vision significantly worse ( P = 0.008). Conclusion: The COVID-19 pandemic significantly impacted vitreoretinal care. The vision of patients with RDs may not have been affected by the delayed presentation. [ Ophthalmic Surg Lasers Imaging Retina 2023;54:15–23.]

To describe the prevalence, management, and outcomes of rhegmatogenous retinal detachment (RRD) after incisional glaucoma filtering surgery.All patients with a history of trabeculectomy or glaucoma drainage device surgery who were subsequently diagnosed with an RRD from January 1, 2016, to January 1, 2021, at the Wills Eye Hospital were identified.Forty-six eyes met the inclusion criteria. The mean age was 60.7 ± 19.6 years, and 15 patients (32.6%) were female. Of all eyes, 34 (73.9%) were diagnosed with primary open-angle glaucoma. The mean time from most recent incisional glaucoma surgery to RRD diagnosis was 1,133 ± 1,644 days. There were 19 eyes (41.3%) with preoperative proliferative vitreoretinopathy (9 eyes [19.6%] with Grade C proliferative vitreoretinopathy) and 35 eyes (76.1%) had macula-off RRD at the time of presentation. At RRD presentation, 4 eyes (8.7%) had concomitant endophthalmitis, 5 (10.9%) had concurrent choroidal detachment, and 2 (4.7%) had concurrent vitreous hemorrhage. Primary vitrectomy was performed in most (91.3%) cases. Silicone oil tamponade was often required (71.1%). The single surgery success rate was 65.2% (30 of 46). The mean preoperative logarithm of the minimum angle of resolution visual acuity was 1.72 ± 0.78 (Snellen acuity 20/1,050), and the mean final postoperative logarithm of the minimum angle of resolution was 1.59 ± 0.89 (20/778, P = 0.2853). Of glaucoma surgeries performed, the 5-year prevalence of RRD was 0.71% (26 of 3,664, 95% Poisson confidence interval 0.48%-1.04%).The 5-year prevalence of RRDs after trabeculectomy or glaucoma drainage device was 0.71%. Most patients presented with macula-involving detachments, often with proliferative vitreoretinopathy. Anatomical and visual outcomes were poor.

Objective To investigate optical coherence tomography (OCT)-based biomarkers of visual acuity (VA) in eyes with idiopathic epiretinal membranes (ERM) undergoing surgical intervention. Purpose To assess surgical outcomes of pars plana vitrectomy (PPV) and membrane peel (MP) surgery in eyes with idiopathic ERM and identify potential imaging-based biomarkers of vision outcomes. Methods Retrospective, consecutive case series of eyes with idiopathic ERM that underwent PPV and MP surgery between 1/1/2017 and 1/1/2019. A previously described ERM grading scale was utilized for OCT analysis. The primary outcome was VA at post-operative month 6 and final follow-up. A secondary outcome was the association of OCT structural features, including ectopic inner foveal layers (EIFL), inner microcystoid changes, and ellipsoid zone (EZ) disruption, with VA outcomes. Results A total of 322 eyes with idiopathic ERM were included. Mean (± SD) follow-up was 506.6 ± 324.6 days after MP surgery. VA improved from logMAR 0.49 ± 0.27 (Snellen 20/61) pre-MP to 0.41 ± 0.30 (Snellen 20/51, p Conclusions VA improvement was noted after surgery in eyes with idiopathic ERM across all stages. Pre-operative stage 4 characteristics were associated with worse VA at 6 months. Post-operative inner microcystoid changes and EZ disruption at month 3 were additional OCT biomarkers associated with worse 6 month and final VA outcomes.

This paper provides four theorems on the existence of a free-disposal equilibrium in a Walrasian economy: the first with an arbitrary set of agents with compact consumption sets, the next highlighting the trade-offs involved in the relaxation of the compactness assumption, and the last two with a countable set of agents endowed with a weighting structure. The results generalize theorems in the antecedent literature pioneered by Shafer–Sonnenschein in 1975, and currently in the form taken in He–Yannelis 2016. The paper also provides counterexamples to the existence of non-free-disposal equilibrium in cases of both a countable set of agents and an atomless measure space of agents. One of the examples is related to one Chiaki Hara presented in 2005. The examples are of interest because they satisfy all the hypotheses of Shafer’s 1976 result on the existence of a non-free-disposal equilibrium, except for the assumption of a finite set of agents. The work builds on recent work of the authors on abstract economies, and contributes to the ongoing discussion on the modelling of “large” societies.

Groundwater resources have become an important fresh water supply due to its increasing demandsfor agricultural, drinking and industrial uses. Groundwater is often contaminated by the process ofindustrial development and suburbanization that has gradually advanced over time without anyconcern for environmental consequences. The objective of this study is to analyse the groundwaterquality of shallow dug wells in parts of Tanah Merah district by conducting quality assessment ofgroundwater using WHO and MHO guide lines. Groundwater samples were collected from dugwells uniformly spread out across the study area to investigate the major ion chemistry of thegroundwater as well as physical parameter. The major ion being investigated are sodium,magnesium, calcium, potassium, sulphate, nitrate, chloride and bicarbonates. Various methods havebeen were employed to determine the major ions concentration in the samples such as atomicabsorption spectrophotometer for cations, gravimetric method for sulphates, titration method forchloride and bicarbonates and colorimetric method for nitrate ion. From the analysed data’s, mostwells are safe for drinking purpose although quite a small amount of ion concentration has surpassedthe permissible limit set by WHO and MOH. The graphical presentation of major ion chemistryaids in identifying two types of groundwater. Ionic species such as Na-K-HCO3 and mixed typewaters are likely to occur in the groundwater system. The analysed major ions concentrationsindicates that majority of the shallow dug wells reported adequate or lower values compared topermissible limit which are safe and can be utilized for various domestic purposes includingdrinking. Several recommendations has been suggested to proliferate the groundwater quality suchas strictly monitoring and supervising the dissipation of waste such as pesticides, industrial effluentand domestic sewage into the aquifer.

In this review article, I read a book that revolves around two papers published in 1954, one by Lionel McKenzie, and the other by Kenneth Arrow and Gérard Debreu—Till Düppe and E. Roy Weintraub’s Finding Equilibrium: Arrow, Debreu, McKenzie and the Problem of Scientific Credit (2014). Under a tripartite categorization of people, context, and credit, this book advances the claim that “by being applied, interpreted, shaped, and reshaped, [these] proofs came to symbolize a new intellectual culture in American economics and help reconstruct the body of economic knowledge” (Düppe and Weintraub 2014, p. 204). My reading leads me to contest this claim, and also to contest whether a history of economic analysis, much less a history of economic thought, can be written by taking refuge in the vernacular of ancillary discourses orthogonal to the subject matter whose history is being written, and without the disciplinary criteria that these discourses operate under. An unintended consequence of my reading is the identification of lacunae in the reception of these proofs, an underscoring of Paul A. Samuelson’s panoramic vision, and a reemphasis of the sterling contributions of David Gale, Thomas Kuhn, Hukukane Nikaido, and Hirofumi Uzawa. (JEL A14, B23, B30, C60)

This paper considers the neglected case of a capital-intensive investment-good sector in the two-sector Robinson-Shinkai-Leontief (RSL) model of discrete-time optimal economic growth. We find the optimal policy to be surprisingly simple and uniform between the discounted and undiscounted cases. The “straight-down-the-turnpike” policy, first identified by Winter and Shell, entails unemployment or excess supply of capital throughout the optimal transition dynamics. We extend our analysis to the case of circulating capital and find the optimal policy to have the same property. We also briefly indicate possibilities for application to topical concerns.

We root this tribute to Nicholas Yannelis in Chapter II of his 1983 Rochester Ph.D. dissertation, and in his 1983 paper with Prabhakar: this work strengthens the lower semicontinuity assumption of Michael’s continuous selection theorem to open lower sections, and leads to correspondences defined on a paracompact space with values on a Hausdorff linear topological space. We move beyond the literature to provide a necessary and sufficient condition for upper semi-continuous local and global selections of correspondences, and apply our result to four domains of Yannelis’ contributions: Berge’s maximum theorem, the Gale–Nikaido–Debreu lemma, the Sonnenschein–Shafer non-transitive setting, and the Anderson–Khan–Rashid approximate existence theorem. The last also resonates with Chapter VI of Yannelis’ dissertation, and allows a more general framing of the pioneering application of the paracompactness condition to his current and ongoing work in mathematical economics.

The impact of sociodemographic factors on the presentation and outcomes of rhegmatogenous retinal detachment (RRD) in the United States has not been described. We analyzed the impact of these factors on the presenting fovea-on or off status of RRD, single operation anatomic success (SOAS) of repair, and postoperative visual acuity (VA).Retrospective, single-center, cohort study.Participants included 4061 patients from Wills Eye Hospital/Mid Atlantic Retina from February 2015 to February 2020.Sociodemographic factors including age, gender, race, and regional mean household income (MHI) as determined by ZIP code were recorded. The VA at baseline and 12 months post-RRD repair was recorded. Multiple regression analysis was used to evaluate the relationship between sociodemographic factors to fovea-on or off presentation of RRD, SOAS, and 12-month VA.Foveal attachment at presentation of RRD, SOAS, and 12-month VA.Older age (odds ratio [OR], 1.34 per decade, 95% confidence interval [CI], 1.27-1.41, P0.001), male gender (OR, 1.27, 95% CI, 1.11-1.45, P0.001), non-White race (OR, 2.41, 95% CI, 1.92-3.03, P0.001), and lower MHI (OR, 0.94 per $10 000, 95% CI, 0.91-0.98, P = 0.005) were independent risk factors for fovea-off presentation of RD. The need for reoperation to repair RRD within 90 days was independently associated with fovea-off presentation (OR, 1.47, 95% CI, 1.24-1.74, P0.001) and non-White race (OR, 1.72, 95% CI, 1.27-2.39, P0.001). Finally, 12-month postoperative VA was worse in patients who were fovea-off (P0.001), older (P = 0.041), male (P = 0.038), and non-White (P = 0.007) but was not related to MHI (P = 0.24).These findings reveal associations between the sociodemographic factors and the presentation and outcomes of RRD. Physicians should be aware that socioeconomic disparities can negatively impact the prognosis of patients with RRD. Further study confirming these findings and efforts to mitigate their effects are warranted and will be of interest to the greater ophthalmology community.

Gene therapy offers the potential to treat inherited retinal disorders and deliver sustained therapy for acquired retinal diseases. In the latter case, host cells can be harnessed to produce non-native proteins that have beneficial properties, such as antivascular endothelial growth factor activity, transforming the eye into an ocular "biofactory." Several gene therapy programs have entered clinical testing for delivery to the vitreous, subretinal, and suprachoroidal space. Improved viral vectors and refined surgical techniques are critical to successful delivery of therapeutic products to the target tissue. In this review, we discuss the development of gene therapy products aimed at acquired retinal diseases and the surgical techniques utilized to achieve targeted delivery.

This paper presents necessary and sufficient conditions for 3-period cycles in the two-sector Robinson–Solow–Srinivasan (RSS) model, taking as its point of departure an independently-(and simultaneously-) discovered exact discount-factor restriction for a general class of growth models by Mitra and Nishimura–Yano (MNY) in 1996. Our investigation of this remarkable result in the specificity of the RSS model enables a broadened inquiry that goes beyond the discount factor to parameters of labor-productivity and capital-depreciation. Since the RSS model, despite its concrete simplicity, is not covered by the general MNY model, the exact discount-factor restriction presented here does not follow from the MNY theorem, and necessitates new argumentation. Furthermore, we present a novel exact parametric region as our second result.

This paper investigates the well-known phenomenon of eventual periodicity of Li–Yorke chaos in the context of the two-sector Robinson–Shinkai–Leontief model of economic growth. It locates its (i) presence under specific parameter restrictions that include the extreme classical saving specification, and its (ii) absence in savings generated by the optimization of an infinitely-lived representative agent with perfect foresight. These results in which rare events, chaos and stability are all brought together under the rubric of upward and downward inertia, while of substantive economic interest of their own, also highlight phenomena in economic dynamics that may go towards a clearer definitional understanding of chaotic systems.

Subjects in diabetic macular edema clinical trials in the United States are disproportionately White and male, compared with the population undergoing treatment for diabetic macular edema.

Oil pollution is considered one of the main contributors to marine pollution. The threat that oil pollution poses to the marine environment is extremely dangerous to its ecosystem. The South China Sea is an important route for various activities, including fishing, recreational and marine activities, and oil and gas exploration. Tarballs are a common byproduct of oil spills, which arise when the sun, wind, and water break down the oil. Tarballs are clumps or blobs of oil and hydrocarbon that have been weathered and displaced from the main body of oil by ocean currents can be found along the shorelines of the Eastern, South China Sea, and Western, Selat Malacca coasts.. The beaches at Chendering in Kuala Terengganu, which face the South China Sea, are also affected by tarball pollution. The geochemical study of tar balls and surface sediments of Chendering area is located at Chendering beach coastal plain area, 103° 11’ 09” E, 5° 16’ 09” N. In this study, The Inductive Couple Plasma-Optimal Emission Spectroscopy (ICP-OES) was used to analyse 12 soil samples (contaminated with tarballs) for heavy metal components. The ICP-OES result shows that average concentrations of heavy metal of beach sediments display the following ascending pattern Cu < Pb < Ni < Cr < Zn < Mn with the value of range 0.100, 0.331, 0.633, 0.905 and 3.226 ppm respectively.