Topsoil and subsoil bacterial community assemblies across different drainage conditions in a mountain environment.

BACKGROUND: High mountainous environments are of particular interest as they play an essential role for life and human societies, while being environments which are highly vulnerable to climate change and land use intensification. Despite this, our knowledge of high mountain soils in South America and their microbial community structure is strikingly scarce, which is of more concern considering the large population that depends on the ecosystem services provided by these areas. Conversely, the Central Andes, located in the Mediterranean region of Chile, has long been studied for its singular flora, whose diversity and endemism has been attributed to the particular geological history and pronounced environmental gradients in short distances. Here, we explore soil properties and microbial community structure depending on drainage class in a well-preserved Andean valley on the lower alpine vegetation belt (~2500 m a.s.l.) at 33.5˚S. This presents an opportunity to determine changes in the overall bacterial community structure across different types of soils and their distinct layers in a soil depth profile of a highly heterogeneous environment. METHODS: Five sites closely located (<1.5 km) and distributed in a well preserved Andean valley on the lower alpine vegetation belt (~2500 m a.s.l.) at 33.5˚S were selected based on a pedological approach taking into account soil types, drainage classes and horizons. We analyzed 113 soil samples using high-throughput sequencing of the 16S rRNA gene to describe bacterial abundance, taxonomic composition, and co-occurrence networks. RESULTS: Almost 18,427 Amplicon Sequence Variant (ASVs) affiliated to 55 phyla were detected. The bacterial community structure within the same horizons were very similar validating the pedological sampling approach. Bray-Curtis dissimilarity analysis revealed that the structure of bacterial communities in superficial horizons (topsoil) differed from those found in deep horizons (subsoil) in a site-specific manner. However, an overall closer relationship was observed between topsoil as opposed to between subsoil microbial communities. Alpha diversity of soil bacterial communities was higher in topsoil, which also showed more bacterial members interacting and with higher average connectivity compared to subsoils. Finally, abundances of specific taxa could be considered as biological markers in the transition from topsoil to subsoil horizons, like Fibrobacterota, Proteobacteria, Bacteroidota for shallower soils and Chloroflexi, Latescibacterota and Nitrospirota for deeper soils. CONCLUSIONS: The results indicate the importance of the soil drainage conditions for the bacterial community composition, suggesting that information of both structure and their possible ecological relationships, might be useful in clarifying the location of the edge of the topsoil-subsoil transition in mountainous environments.

AUTOSOMAL DOMINANT MÜLLER CELL SHEEN DYSTROPHY: Clinical, Histopathologic, and Genetic Assessment in an Extended Family With Long Follow-Up.

BACKGROUND: Autosomal dominant Müller cell dystrophy is a rare condition we described in 1991. It is characterized by a striking sheen appearance on the retinal surface with progressive retinal changes leading to disorganization and atrophy with a decreased b-wave electroretinograms. MATERIALS AND METHODS: We examined 45 members of a 4-generation family. Fifteen subjects from three generations were found with the disease, without gender predilection. Seven patients underwent ophthalmic examination including fundus examination, intravenous fluorescein angiogram, spectral-domain optical coherence tomography, and electroretinogram. Six patients have a 30-year follow-up. Histopathology examination was performed on eyes of the eldest patient. Whole exome sequencing was done in four affected subjects. RESULTS: Findings include a decreased visual acuity, abnormal cellophane-like sheen of the vitreoretinal interface, a "plush" nerve fiber layer, and characteristic macular changes. Electroretinogram showed a selective b-wave diminution. Intravenous fluorescein angiogram presented perifoveal hyperfluorescence and capillary leakage. Spectral-domain optical coherence tomography revealed cavitations involving inner and later outer retinal layers with later disorganization. Histopathologic findings included Müller cell abnormalities with cystic disruption of inner retinal layers, pseudoexfoliation in anterior segment, and amyloidosis of extraocular vessels. Pedigree analysis suggests an autosomal dominant inheritance with late onset. DNA analysis demonstrated a previously undescribed heterozygous missense p.Glu109Val mutation in transthyretin. CONCLUSION: To the best of our knowledge, this is the first family reported with this disorder. Our data support the hypothesis that autosomal dominant Müller cell dystrophy is a distinct retinal dystrophy affecting Müller cells. Mutations in transthyretin gene may manifest as a predominantly retinal disorder.

Embryonic stem cell trials for macular degeneration: a preliminary report.

BACKGROUND: It has been 13 years since the discovery of human embryonic stem cells (hESCs). Our report provides the first description of hESC-derived cells transplanted into human patients. METHODS: We started two prospective clinical studies to establish the safety and tolerability of subretinal transplantation of hESC-derived retinal pigment epithelium (RPE) in patients with Stargardt's macular dystrophy and dry age-related macular degeneration--the leading cause of blindness in the developed world. Preoperative and postoperative ophthalmic examinations included visual acuity, fluorescein angiography, optical coherence tomography, and visual field testing. These studies are registered with ClinicalTrials.gov, numbers NCT01345006 and NCT01344993. FINDINGS: Controlled hESC differentiation resulted in greater than 99% pure RPE. The cells displayed typical RPE behaviour and integrated into the host RPE layer forming mature quiescent monolayers after transplantation in animals. The stage of differentiation substantially affected attachment and survival of the cells in vitro after clinical formulation. Lightly pigmented cells attached and spread in a substantially greater proportion (>90%) than more darkly pigmented cells after culture. After surgery, structural evidence confirmed cells had attached and continued to persist during our study. We did not identify signs of hyperproliferation, abnormal growth, or immune mediated transplant rejection in either patient during the first 4 months. Although there is little agreement between investigators on visual endpoints in patients with low vision, it is encouraging that during the observation period neither patient lost vision. Best corrected visual acuity improved from hand motions to 20/800 (and improved from 0 to 5 letters on the Early Treatment Diabetic Retinopathy Study [ETDRS] visual acuity chart) in the study eye of the patient with Stargardt's macular dystrophy, and vision also seemed to improve in the patient with dry age-related macular degeneration (from 21 ETDRS letters to 28). INTERPRETATION: The hESC-derived RPE cells showed no signs of hyperproliferation, tumorigenicity, ectopic tissue formation, or apparent rejection after 4 months. The future therapeutic goal will be to treat patients earlier in the disease processes, potentially increasing the likelihood of photoreceptor and central visual rescue. FUNDING: Advanced Cell Technology.

Early-Phase Perceptions of COVID-19's Impact on Ophthalmology Practice Patterns: A Survey from the Pan-American Association of Ophthalmology.

Purpose: The COVID-19 pandemic affected medical practice worldwide due to interventions to prevent spreading. Its effect on ophthalmology practices in Latin America has not yet been explored. We aimed to assess the perceptions about the pandemic from countries' ophthalmological national and subspecialty retina societies affiliated to the Pan-American Association of Ophthalmology (PAAO). Patients and Methods: A survey-based study of leaders of national ophthalmological and retinal societies was conducted. The survey was sent by email to 30 societies, from which 20 responded (12 countries, 66.6% response rate). It included closed- and open-ended questions about (1) operational capacity and precautions, (2) telemedicine and virtual care, (3) procedures, and (4) post-pandemic considerations. Results: There was a marked decline in ophthalmology patient visits (80-95%) and elective surgeries (90%) during 2020 compared to before the pandemic. Precautions like temperature checks, mask usage, and social distancing were widely implemented while personal protective equipment (PPE) availability varied. Telemedicine use was limited due to lack of experience with it. Reopening plans focused on maintaining precautions and gradually resuming activities. Economic and security concerns were raised, and adherence to guidelines was emphasized. Respondents acknowledged the need to adapt to a "new normal". Long duration drugs, fewer imaging studies, and shorter wait times were preferred; however, availability of long duration drugs was limited. Conclusion: The pandemic impacted ophthalmology in Latin America, with reduced patient visits, procedures, and surgeries. Delayed treatment and complications were likely the result of the pandemic.

Evolutionary and terminological analysis of the flexor digitorum superficialis, interflexorii and palmaris longus muscles in kinkajou (Potos flavus) and crab-eating racoon (Procyon cancrivorus).

The kinkajou (Potos flavus) and crab-eating raccoon (Procyon cancrivorus) are carnivores belonging to the family Procyonidae, but both species are characterized by different types of locomotion. Differences can be found in the adaptations that these two species present in the forearm muscles, such as the flexor digitorum superficialis (FDS), palmaris longus (PL) and interflexorii (IF), which have been described confusingly in previous studies. Therefore, the aim of this study was to describe these muscles in both species together with their innervations to carry out an evolutionary and terminological analysis among carnivorans. Both thoracic limbs were dissected from five P. flavus and three P. cancrivorus that had died of natural causes in Wildlife Care Centers. Two PL muscles (m. palmaris longus lateralis, PLL, and m. palmaris longus medialis, PLM) were found in P. flavus, and the IF were the only superficial flexors of the digits, whereas P. cancrivorus presented the IF and two bellies homologous to the two PLs of P. flavus, where the homologous belly of the PLM sent tendons to digits II-IV. Therefore, it was considered as the FDS due to its similarity to other carnivorans, and the lateral belly is the only PL present in P. cancrivorus. The topology, attachments and innervation of these muscles in P. flavus and P. cancrivorus allowed homologies to be established, hypothesizing their evolutionary derivation from the FDS. It also allowed the differences among PL, FDS and IF muscles to be described, concluding that most carnivorans do not have a PL.

Assessment of Ischemic Index in Retinal Vascular Diseases Using Ultra-Wide-Field Fluorescein Angiography: Single Versus Summarized Image.

BACKGROUND AND OBJECTIVE: To compare a single image with a computer-generated summarized image from the ultra-wide-field fluorescein angiogram (UWFFA) sequence for evaluation of ischemic index (ISI). MATERIALS AND METHODS: UWFFA sequences from patients with diabetic retinopathy (DR) (n=5), branch retinal vein occlusion (BRVO) (n=5), and central retinal vein occlusion (CRVO) (n=5) were evaluated by six graders. A single image best illustrating retinal non-perfusion was compared to a summarized image generated by computerized superimposition of angiograms. Non-perfused and ungradable retinal areas were outlined and the ISI between the single and summarized images was compared. RESULTS: The mean ISI in the single versus (vs) summarized images was 17% vs 15% in BRVO (p=0.12), 48% vs 48% in CRVO (p=0.67), and 25% vs 23% in DR (p=0.005). Inter-grader agreement of ISI in single versus summarized images was 0.43 vs 0.40 in BRVO, 0.69 vs 0.71 in CRVO, and 0.53 vs 0.34 in DR. CONCLUSION: Computer-generated summarized images were similar to single images for grading ISI in BRVO and CRVO, but underestimated it in DR.

Decadelong profile of women in ophthalmic publications.

IMPORTANCE: In recent decades, there has been an increase in the number of women practicing medicine. We believe this shift may be reaching academic publications in ophthalmology and changing gender trends. OBJECTIVE: To determine whether there has been an increase in women publishing academic articles and editorials in ophthalmology during the past decade. DESIGN, SETTING, AND PARTICIPANTS: In this observational retrospective study, 3 ophthalmology journals were sampled from 2000 and 2010 for at least 100 articles per journal, per year, and all editorials published in both years. Data reviewed included the authors' gender, number of authors, number of references, subspecialty, and country of origin. EXPOSURE: Publication by women authors. MAIN OUTCOMES AND MEASURES: The primary outcome measure was an increase in women publishing in ophthalmology. The hypothesis was formulated before data collection. RESULTS: Our analysis included 671 original articles (336 from 2000 and 335 from 2010) and 89 editorials. The percentage of original articles with a woman as first author increased from 23.2% in 2000 to 32.5% in 2010, a difference of 9.3% (95% CI, 23.3%-32.5%; P = .005). The percentage of original articles with a woman last author increased from 16.4% in 2000 to 24.2% in 2010, a difference of 7.8% (95% CI, 16.4%-24.2%; P = .01). The percentage of original articles with a woman first author increased in Asia from 1.2% in 2000 to 8.4% in 2010, a difference of 7.2% (95% CI, 1.2%-8.4%; P < .001). The percentage of articles with a woman last author increased in Europe from 2.2% in 2000 to 7.5% in 2010, a difference of 5.3% (95% CI, 2.2%-7.5%; P < .001) and in Asia from 0% in 2000 to 6.0% in 2010, a difference of 6.0% (95% CI, 0%-6%; P < .001). Editorials were written predominantly by men: 33 of 38 editorials (87%) in 2000 and 46 of 51 (90%) in 2010, a difference of 3% (95% CI, 87%-90%; P = .62), showing a trend toward decreased editorial authorship by women during the past decade. CONCLUSIONS AND RELEVANCE: Our data suggest an increase in women publishing original investigations in ophthalmic literature, but no increase in editorial authorship.

Pediatric retinal conditions imaged by ultra wide field fluorescein angiography.

BACKGROUND AND OBJECTIVE: Ultra wide field technology was originally designed for use in children. The purpose of this study was to evaluate ultra wide field fluorescein angiography (UWFFA) in children. PATIENTS AND METHODS: Retrospective case series of patients younger than 13 years who underwent UWFFA. Angiographic findings and their impact on diagnosis and management were assessed. UWFFA quality was evaluated, including phases of the angiogram available in each study, field of view, and artifacts. RESULTS: Forty images of 16 patients with a mean age of 9.3 years were included. Peripheral angiographic findings such as vasculitis, telangiectasia, and neovascularization were present in 12 of 16 patients (75%). Seven of 16 patients (43.8%) had images during the arterial phase, and 16 of 16 patients (100%) had venous and recirculation phases captured. CONCLUSION: UWFFA was successfully performed in this group of children. The macula and periphery were adequately imaged, obtaining important information for documentation, diagnosis, and management.

Peripheral fluorescein angiographic findings in fellow eyes of patients with branch retinal vein occlusion.

Introduction. Branch retinal vein occlusion (BRVO) is a common retinal vascular condition that results in intraocular inflammatory changes. Ultra wide field fluorescein angiography (UWFFA) is a retinal imaging device that can capture peripheral retinal findings. The purpose of this study was to look for peripheral findings in the fellow eye of patients with BRVO using UWFFA. Methods. Retrospective imaging review of patients diagnosed with BRVO that had both eyes imaged with UWFFA. Images were graded for peripheral findings in other quadrants of the same eye as well as in all quadrants of the fellow eye. Results. Of 81 patients, 14 (17%) patients had late vascular leakage in a quadrant other than the BRVO distribution. Five (6%) findings were in the same eye, 8 (10%) findings were in the fellow eye, and 1 (1%) finding was in both the same eye and the fellow eye. Of these 14 patients, 11 (80%) patients had hypertension. Conclusion. Late peripheral retinal leakage in the fellow eye of patients with BRVO was detected in this cohort of patients with UWFFA. This novel finding may represent underlying systemic inflammation, hypertension, or bilateral BRVOs.

Subretinal perfluorocarbon liquid for dissection of proliferative vitreoretinopathy.

Proliferative vitreoretinopathy (PVR) is a frequent condition following complex retinal detachments or trauma, and subretinal PVR is a common cause of retinal redetachment. Subretinal PVR removal is challenging and may require creating multiple or large retinotomies, making manipulation of the retina difficult and sometimes hazardous. We propose a novel surgical technique that may facilitate subretinal removal of PVR. After peripheral retinotomy of 180 degrees or greater, perfluorocarbon liquid (PFCL) is carefully introduced into the subretinal space as a single bubble which provides space to perform the maneuvers. The PFCL serves as a second hand which folds the retina over, thereby allowing better visualization for safer and easier subretinal PVR removal. PFCL in then removed by direct aspiration as a single bubble while still under balanced salt solution, taking advantage of its high surface tension which prevents leaving bubbles behind. The described technique allows adequate exposure of the subretinal space for proper dissection of difficult-to-reach subretinal PVR. We applied this technique in five patients with chronic retinal detachment, extensive subretinal PVR and poor visual potential. The utilization of subretinal PFCL can assist dissection of subretinal PVR and may be useful in eyes with complicated retinal detachment and poor visual prognosis.

Ultra wide field fluorescein angiography can detect macular pathology in central retinal vein occlusion.

The purpose of this study was to evaluate whether ultra wide field fluorescein angiography (UWFFA), a tool established for the detection of peripheral non-perfusion, can also detect macular pathology. A retrospective imaging review was performed on patients with central retinal vein occlusion. UWFFA was graded for angiographic leakage (petalloid and/or diffuse leakage) and presence of abnormalities in the foveal avascular zone and was then correlated to spectral-domain optical coherence tomography (SD-OCT). Sixty-six eyes met inclusion criteria. Intergrader agreement was highly reliable for grading macular leakage on UWFFA (kappa = 0.75) and moderately reliable for the evaluation of an abnormal foveal avascular zone (kappa = 0.43). Angiographic leakage on UWFFA correlated to macular edema on SD-OCT (P > .0001), and abnormalities in the foveal avascular zone on UWFFA correlated to ganglion cell layer atrophy on SD-OCT (P = .0002). Intergrader reliability in grading UWFFA was better when assessing macular leakage than when assessing macular ischemia. UWFFA findings correlated to macular edema and signs of macular ischemia on SD-OCT.

A modified technique for extracting a dislocated lens with perfluorocarbon liquids and viscoelastics.

The authors describe a modified technique for extraction of a dislocated crystalline lens or large and hard lens fragments displaced into the vitreous cavity. An ophthalmic viscosurgical device was used around and on top of the heavy liquid bubble to keep the lens centered and less mobile for easier phacofragmentation or removal by the cutting-suction probe. This technique was used in 10 eyes, including cases of traumatic dislocation and Marfan syndrome, with excellent anatomical results and no complications that could be attributed to the surgical technique. The technique has also been used to retrieve and reposition dislocated intraocular lenses.