Assessing Strategies to Reduce the Carbon Footprint of the Annual Meeting of the American Academy of Ophthalmology.

Importance: Greenhouse gas emissions associated with medical conferences have been associated with climate change, and the effects of climate change have been associated with an increased incidence of ophthalmic diseases. Identifying practical strategies associated with reducing these emissions may be warranted. Objective: To assess greenhouse gas emissions associated with in-person and virtual meetings of the American Academy of Ophthalmology (AAO) and to conduct mitigation analyses to suggest strategies to reduce future emissions. Design, Setting, and Participants: Quality improvement study in which attendee and conference data were used to estimate emissions from in-person (October 12 to October 15, 2019, San Francisco, California) and virtual (November 13 to November 15, 2020) AAO annual meetings for 35 104 attendees. The data were also used to perform mitigation analyses to assess whether meeting format alterations could be used to reduce future emissions. Data were analyzed from December 21, 2021, to April 18, 2022. Exposures: Attendance at a selected meeting. Total attendance was 23 190 participants in 2019 and 11 914 participants in 2020. Main Outcomes and Measures: Greenhouse gas emissions produced by the in-person meeting were estimated by calculating the equivalent metric tons of carbon dioxide (CO2) associated with attendee transportation, attendee accommodations, and the conference venue. Emissions produced by the virtual meeting were estimated by calculating the equivalent metric tons of CO2 associated with attendees' computer use, network data transfer, and video-conferencing server use. Mitigation analyses simulated the association of changing the meeting location and format with reductions in emissions. Results: In this analysis, the 2019 in-person meeting produced 39 910 metric tons of CO2 (1.73 metric tons of CO2 per capita), and the 2020 virtual meeting produced 38.6 metric tons of CO2 (0.003 metric tons of CO2 per capita). Mitigation analyses showed that holding a single in-person meeting in Chicago, Illinois, rather than San Francisco, California, could be associated with transportation-related emissions reductions of 19% (emissions for the San Francisco meeting, 38 993 metric tons of CO2; for the Chicago meeting, 31 616 metric tons of CO2). Holding multiple in-person meetings in separate regions could be associated with transportation-related emissions reductions of as much as 38% (emissions for the San Francisco meeting, 38 993 metric tons of CO2; for multiple meeting scenario 2, 24 165 metric tons of CO2). Conclusions and Relevance: This study found that the AAO's 2019 in-person meeting was associated with substantially higher greenhouse gas emissions compared with the 2020 virtual meeting, primarily due to transportation-related emissions. Increasing the proportion of virtual participants, holding the meeting in locations chosen to minimize transportation-related emissions, or offering multiple regional meeting locations may reduce the carbon footprint of future meetings.

A Review of the Role of the Intestinal Microbiota in Age-Related Macular Degeneration.

Blindness from age-related macular degeneration (AMD) is an escalating problem, yet AMD pathogenesis is incompletely understood and treatments are limited. The intestinal microbiota is highly influential in ocular and extraocular diseases with inflammatory components, such as AMD. This article reviews data supporting the role of the intestinal microbiota in AMD pathogenesis. Multiple groups have found an intestinal dysbiosis in advanced AMD. There is growing evidence that environmental factors associated with AMD progression potentially work through the intestinal microbiota. A high-fat diet in apo-E-/- mice exacerbated wet and dry AMD features, presumably through changes in the intestinal microbiome, though other independent mechanisms related to lipid metabolism are also likely at play. AREDS supplementation reversed some adverse intestinal microbial changes in AMD patients. Part of the mechanism of intestinal microbial effects on retinal disease progression is via microbiota-induced microglial activation. The microbiota are at the intersection of genetics and AMD. Higher genetic risk was associated with lower intestinal bacterial diversity in AMD. Microbiota-induced metabolite production and gene expression occur in pathways important in AMD pathogenesis. These studies suggest a crucial link between the intestinal microbiota and AMD pathogenesis, thus providing a novel potential therapeutic target. Thus, the need for large longitudinal studies in patients and germ-free or gnotobiotic animal models has never been more pressing.

Visual Impairment in Fungal Versus Bacterial Corneal Ulcers 4 Years After Successful Antimicrobial Treatment.

PURPOSE: To compare longitudinal outcomes of visual acuity after fungal corneal ulcers with those of bacterial ulcers. DESIGN: Prospective cohort study. METHODS: This study was conducted in a tertiary eye hospital in South India. The population consisted of 100 of 152 individuals whose fungal or bacterial keratitis had been diagnosed 4 years prior and had been enrolled in 1 of 2 concurrent randomized trials. Causative organisms of infectious keratitis were either bacterial or fungal. Presenting visual acuity consisted of best spectacle corrected visual acuity (BSCVA) and hard contact lens-corrected visual acuity (CLVA). RESULTS: Fifty study participants with prior fungal keratitis and 50 with prior bacterial keratitis were enrolled. Four years after treatment for keratitis, participants' presenting vision in the better eye was worse than 20/60 for 12 individuals (24.0%) in the fungal group and 10 individuals (20.0%) in the bacterial group. Median BSCVA in the affected eye at the 4-year visit in the fungal group was similar to that in the bacterial group (Snellen equivalent, 20/32 for each), although vision worse than 20/400 was more common in the fungal ulcer group after spectacle correction (odds ratio [OR] 4.19; 95% confidence interval [CI], 1.11-15.8) and contact lens correction (OR, 5.74; 95% CI, 1.37-24.1). CONCLUSIONS: In this South Indian population with a previous episode of fungal or bacterial keratitis, correctable bilateral visual impairment was common. Although long-term visual outcomes were, on average, similar between fungal and bacterial ulcers, fungal ulcers were more likely to produce severe visual impairment.

Quantitative Evaluation of Choroidal Neovascularization under Pro Re Nata Anti-Vascular Endothelial Growth Factor Therapy with OCT Angiography.

PURPOSE: To use optical coherence tomography angiography (OCTA) derived quantitative metrics to assess the response of choroidal neovascularization to pro-re-nata (PRN) anti-endothelial growth factor (anti-VEGF) treatment in neovascular age-related macular degeneration (AMD). DESIGN: Prospective longitudinal cohort study. PARTICIPANTS: Fourteen eyes from 14 study participants with treatment-naïve neovascular AMD were enrolled. METHODS: Subjects were evaluated monthly and treated with intravitreal anti-VEGF agents under a PRN protocol for one year. At each visit, two 3×3 mm2 OCTA scans were obtained. Custom image processing was applied to segment the outer retinal slab, suppress projection artifact, and automatically detect CNV. CNV membrane area (mm2) and CNV vessel area (mm2) was calculated. MAIN OUTCOMES: Individual and mean CNV membrane area and CNV vessel area at each visit; within-visit repeatability determined by coefficient of variation. RESULTS: Eight eyes had entire CNV within 3×3 mm2 scanning area and had adequate image quality for CNV quantification. One case (case #2) was excluded from analysis due to the presence of a large subretinal hemorrhage overlying the CNV membrane. In the remaining cases, CNV vessel area was reduced by 39%, 50%, 43%, and 41% at months 1, 3, 6, and 12 respectively. CNV membrane area was reduced by 39%, 51%, 54%, and 45% at months 1, 3, 6, and 12. At month 6, mean change from baseline was not statistically significant for CNV vessel area, while it was statistically significant for CNV membrane area. Neither metric was significantly different compared to baseline at month 12. Individual analyses revealed each CNV had a unique response under PRN treatment. Within-visit repeatability was was 7.96% (coefficient of variation) for CNV vessel area and 7.37% for CNV membrane area. CONCLUSIONS: In this small exploratory study of CNV response to PRN anti-VEGF treatment, both CNV vessel area and membrane area were reduced compared to baseline after three months. After one year of follow-up, these reductions were no longer statistically significant. When anti-VEGF treatment was held, increasing CNV vessel area over time often resulted in exudation, but it was not possible to exactly when exudation occurs.

Detection of pigment epithelial detachment vascularization in age-related macular degeneration using phase-variance OCT angiography.

PURPOSE: To demonstrate the use of phase-variance optical coherence tomography (PV-OCT) angiography for detection of pigment epithelial detachment (PED) vascularization in age-related macular degeneration (AMD). PATIENTS AND METHODS: Patients with PEDs and exudative AMD were evaluated by the Retina Services at the University of California, Davis, and the University of California, San Francisco. Each subject underwent fluorescein angiography and structural optical coherence tomography (OCT). Phase-variance OCT analysis was used to create angiographic images of the retinal and choroidal vasculature. PV-OCT-generated B-scans were superimposed on structural OCT B-scans to allow easy identification of perfused vascular structures. RESULTS: Three patients with vascularized PEDs were imaged with PV-OCT, and each was found to have a vascular signal extending from the choroid into the hyperreflective substance of the PED. Two patients who had no evidence of PED vascularization on fluorescein angiography did not have vascular signals within their PEDs on PV-OCT. CONCLUSION: Structural OCT and PV-OCT images can be combined to create composite B-scans that offer high-resolution views of the retinal tissue along with dynamic vascular visualization. This technique offers a fast, noninvasive method for detecting vascularization of PEDs in AMD and may aid in the early detection of neovascular disease.

Quantitative optical coherence tomography angiography of vascular abnormalities in the living human eye.

Retinal vascular diseases are important causes of vision loss. A detailed evaluation of the vascular abnormalities facilitates diagnosis and treatment in these diseases. Optical coherence tomography (OCT) angiography using the highly efficient split-spectrum amplitude decorrelation angiography algorithm offers an alternative to conventional dye-based retinal angiography. OCT angiography has several advantages, including 3D visualization of retinal and choroidal circulations (including the choriocapillaris) and avoidance of dye injection-related complications. Results from six illustrative cases are reported. In diabetic retinopathy, OCT angiography can detect neovascularization and quantify ischemia. In age-related macular degeneration, choroidal neovascularization can be observed without the obscuration of details caused by dye leakage in conventional angiography. Choriocapillaris dysfunction can be detected in the nonneovascular form of the disease, furthering our understanding of pathogenesis. In choroideremia, OCT's ability to show choroidal and retinal vascular dysfunction separately may be valuable in predicting progression and assessing treatment response. OCT angiography shows promise as a noninvasive alternative to dye-based angiography for highly detailed, in vivo, 3D, quantitative evaluation of retinal vascular abnormalities.

Tissue necrosis following diode laser-assisted transcanalicular dacryocystorhinostomy.

Advantages of transcanalicular laser-assisted dacryocystorhinostomy (TCDCR) over conventional, external, and endonasal dacryocystorhinostomy (DCR) have been purported to include decreased operating time, reduced morbidity, enhanced cosmesis, avoidance of general anesthesia, and a shorter recovery time. However, 1 case of skin necrosis has recently been reported to have occurred following diode laser-assisted TCDCR, and the authors now report 3 additional cases that were evaluated by the Ophthalmic Plastic Surgery services at the University of North Carolina, North Carolina, and the University of California, San Francisco. Three patients developed full-thickness tissue necrosis over the medial canthus following TCDCR, and 2 of these patients experienced persistent tissue breakdown at the site following reconstructive repair.

Visual outcomes in treated bacterial keratitis: four years of prospective follow-up.

PURPOSE: We described the change in visual acuity experienced by eyes successfully treated for bacterial keratitis. METHODS: This was a prospective cohort study of a subset of study participants who had previously enrolled in the Steroids for Corneal Ulcers Trial (SCUT). All study participants had been diagnosed with culture-proven bacterial keratitis before enrollment in SCUT and subsequently were randomized to adjunctive topical corticosteroids or placebo. During SCUT, we monitored study participants at enrollment, 3 weeks, 3 months, and 12 months. We invited a subset to complete a comprehensive eye examination approximately 4 years after enrollment in SCUT. Certified refractionists assessed best spectacle-corrected visual acuity (BSCVA) using the same protocol at each study visit. RESULTS: We examined 50 SCUT participants at 4 years after enrollment. Among those in this cohort, mean logMAR BSCVA at enrollment was 0.85 (Snellen equivalent, 20/160; 95% confidence interval [CI], 0.71-0.99). On average, visual acuity improved by 2.9 logMAR lines from enrollment to 3 weeks (P < 0.001), 1.2 lines from 3 weeks to 3 months (P = 0.002), and 0.8 lines from 3 to 12 months (P = 0.01). The BSCVA did not change significantly between 12 months and 4 years (0.04-line improvement, P = 0.88). After controlling for visual acuity at enrollment, BSCVA was not significantly different between the corticosteroid and placebo groups at 4 years (P = 0.53). CONCLUSIONS: Cases of bacterial keratitis may continue to demonstrate improvements in visual acuity up to 12 months following diagnosis, but further improvements are unlikely. These findings may guide the appropriate timing of surgical intervention in these patients. (ClinicalTrials.gov number, NCT00324168.).