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Objective: To determine if patients with nonarteritic ischemic optic neuropathy (NAION) have sleep apnea syndrome (SAS), an entity characterized by repetitive upper airway obstructions during sleep, inducing hypoxia and sleep disruption. Methods: We recruited 17 patients with NAION and 17 age- and sex-matched controls from patients referred for treatment because of suspected restless legs syndrome. We performed overnight polysomnography and determined the respiratory disturbance index during night sleep, a value used to diagnose and grade SAS. We compared the proportions of patients with SAS among patients with NAION and matched controls using the [chi square] test. Additionally, we compared the proportions of patients with SAS among patients with NAION and a large SAS prevalence study using the binomial test. Results: Twelve (71%) of 17 patients with NAION had SAS. According to the respiratory disturbance index, 4 patients (24%) had mild, 4 patients (24%) had moderate, and 4 patients (24%) had severe SAS. Only 3 (18%) of 17 controls had SAS (P = .005). In the 45- to 64-year age group, 4 (50%) of 8 patients with NAION had SAS; 51 (11.9%) of 430 of the random sample in the prevalence study had SAS (P = .005). In the group older than 64 years, 8 (89%) of 9 patients with NAION had SAS; 18 (24%) of 75 of the random sample in the prevalence study had SAS (P Conclusions: We found a high prevalence of SAS in patients with NAION, which supports previous case reports suggesting that such an association exists. This association may explain why approximately 75% of all patients with NAION discover visual loss on first awakening or when they first use vision critically after sleeping. Our findings indicate that SAS may play an important role in the pathogenesis of NAION.

A biofilm electrode (BFE) was developed to measure the respiration activity of viable enteric viruses. The electrode consisted of a film of the infected cell sample deposited onto the surface of a dissolved oxygen electrode. A qualitative measurement of BFE current response was easily derived from steady-state oxygen diffusion models. BFE responses may be affected by the presence of contaminants in the test solution but the nature of the system is such that any interference with the BFE response is easily observed.

The mission of the Tear Film & Ocular Surface Society (TFOS) is to advance the research, literacy, and educational aspects of the scientific field of the tear film and ocular surface. Fundamental to fulfilling this mission is the TFOS Global Ambassador program. TFOS Ambassadors are dynamic and proactive experts, who help promote TFOS initiatives, such as presenting the conclusions and recommendations of the recent TFOS DEWS II™, throughout the world. They also identify unmet needs, and propose future clinical and scientific solutions, for management of ocular surface diseases in their countries. This meeting report addresses such needs and solutions for 25 European countries, as detailed in the TFOS European Ambassador meeting in Rome, Italy, in September 2019.

Purpose To describe the placement of a silicone shield to protect the optical cylinder following osteo-keratoprosthesis or osteo-odonto-keratoprosthesis (O/OKP) procedures in four patients.Methods In this retrospective observational study, we reviewed all patients who underwent O/OKP in our tertiary medical centre. We found four patients in whom a protective cellphone silicone shield (VisionGuard+, Zagg, Utah, USA) was cut with a 3 mm dermal punch and placed on the polymethyl methacrylate (PMMA) optical cylinder of an O/OKP 3–4 months after implantation to either correct or prevent abrasions.Results The first patient presented with a severely abraded OOKP optic that reduced BCVA from 6/6 to 6/20. The shield smoothed the optical surface and filled minor scratches, leading to BCVA improvement to 6/9. In the subsequent three patients, the optic was relatively clear, and the shield was used as a preventive measure. In two patients, the shield fell off after a few weeks and was replaced.Conclusions Placing a protective silicone shield on the optical cylinder of an O/OKP can prevent permanent abrasions and, in an already scratched polymethyl methacrylate (PMMA) optic cylinder, improve vision by smoothing the surface. This intervention can be clinically significant, considering that the optical cylinder cannot be removed after implantation.

ABSTRACTWe employ a dendrochronological approach to examine spatial variation in radial tree growth-climate relationships and responses to global climate oscillations across the geographic ranges of Picea glaucaand Picea engelmannii. Tree-ring chronologies were constructed for 77 sites and analyzed using correlation coefficients for monthly climatic variables. In general, for Picea glauca, stands in the western portion of its range had significant negative correlations with temperature during fall, winter, and spring; only summer temperature was positively correlated with tree growth. In eastern North America, Picea glaucagrowth was negatively correlated with winter and spring temperature. Across the north-south range of Picea engelmannii, growth of northern populations was positively correlated with temperature in most seasons except spring, which had negative correlations, and response to winter precipitation differed between northern and southern populations. However, some monthly values for both species correlations were altered due to decadal oscillation phase, especially for the Pacific Decadal Oscillation.

IMPORTANCE: Cataract is associated with a progressive decline in light transmission due to the clouding and yellowing of the natural crystalline lens. While the downstream effects of aging lenses include long-term disruption of circadian rhythms, cognitive function, and sleep regulation, it remains unknown whether there is an association of intraocular cataract lens (IOLs) replacement with circadian rhythms, cognition, and sleep. OBJECTIVE: To test whether IOL replacement (blue blocking [BB] or ultraviolet [UV] only blocking) in older patients with previous cataract is associated with the beneficial light effects on the circadian system, cognition, and sleep regulation. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study at the Centre for Chronobiology, University of Basel in Switzerland from February 2012 to April 2014, analyzed between June 2012 and September 2018. Sixteen healthy older controls and 13 patients with previous cataract and IOL replacement participated without medication and no medical and sleep comorbidities. EXPOSURES: Three and a half hours of prior light control (dim-dark adaptation), followed by 2 hours of evening blue-enriched (6500 K) or non–blue-enriched light exposure (3000 K and 2500 K), 30 minutes in dim post–light exposure, 8 hours of sleep opportunity, and 2 hours of morning dim light following sleep. MAIN OUTCOMES AND MEASURES: Salivary melatonin, cognitive tests, and sleep structure and electroencephalographic activity to test the association of IOLs with markers of circadian rhythmicity, cognitive performance, and sleep regulation, respectively. RESULTS: The participants included 16 healthy older controls with a mean (standard error of the mean [SEM]) of 63.6 (5.6) years; 8 women and 13 patients with previous cataract (mean [SEM] age, 69.9 [5.2] years; 10 women); 5 patients had UV IOLs and 8 had BB IOLs. Patients with previous cataract and IOLs had an attenuated increase in melatonin levels during light exposure (mean [SEM] increase in the BB group: 23.3% [2.6%] and in the UV lens group: 19.1% [2.1%]) than controls (mean [SEM] increase, 48.8% [5.2%]) (difference between means, 27.7; 95% CI, 15.4%-41.7%; P < .001). Cognitive function, indexed by sustained attention performance, was improved in patients with UV lens (mean [SEM], 276.9 [11.1] milliseconds) compared with patients with BB lens (mean [SEM], 348.3 [17.8] milliseconds) (difference between means, 71.4; 95% CI, 29.5%-113.1%; P = .002) during light exposure and in the morning after sleep. Patients with UV lens had increased slow-wave sleep (mean [SEM] increase, 13% [3.4%]) compared with controls (mean [SEM] increase, 5.2% [0.8%]) (percentage of total sleep time; difference between means, 7.9; 95% CI, 2.4%-13.4%; P = .02) and frontal non–rapid eye movement slow-wave activity (0.75-4.5 Hz) during the first sleep cycle (mean [SEM], 79.9 [13.6] μV2/Hz) compared with patients with BB lens (mean [SEM], 53.2 [10.7] μV2/Hz) (difference between means, 26.7; 95% CI, 9.2-48.9; P = .03). CONCLUSIONS AND RELEVANCE: These in-laboratory empirical findings suggest that optimizing the spectral lens transmission in patients with previous cataract may minimize the adverse age-related effects on circadian rhythms, cognition, and sleep.

Targeting genes to specific neuronal or glial cell types is valuable for both understanding and repairing brain circuits. Adeno-associated viruses (AAVs) are frequently used for gene delivery, but targeting expression to specific cell types is an unsolved problem. We created a library of 230 AAVs, each with a different synthetic promoter designed using four independent strategies. We show that a number of these AAVs specifically target expression to neuronal and glial cell types in the mouse and non-human primate retina in vivo and in the human retina in vitro. We demonstrate applications for recording and stimulation, as well as the intersectional and combinatorial labeling of cell types. These resources and approaches allow economic, fast and efficient cell-type targeting in a variety of species, both for fundamental science and for gene therapy. Targeting genes to specific cell types is valuable for basic science and gene therapy. The authors describe a collection of AAVs containing synthetic promoters targeting a broad range of neuronal cell types in mice, non-human primates and humans.

Corneal topography allows the assessment of the cornea’s refractive power which is crucial for diagnostics and surgical planning. The use of optical coherence tomography (OCT) for corneal topography is still limited. One limitation is the susceptibility to disturbances like blinking of the eye. This can result in partially corrupted scans that cannot be evaluated using common methods. We present a new scanning method for reliable corneal topography from partial scans. Based on the golden angle, the method features a balanced scan point distribution which refines over measurement time and remains balanced when part of the scan is removed. The performance of the method is assessed numerically and by measurements of test surfaces. The results confirm that the method enables numerically well-conditioned and reliable corneal topography from partially corrupted scans and reduces the need for repeated measurements in case of abrupt disturbances.

Many factors in the domains of mental, physical, and social health have been associated with various ocular surface diseases, with most of the focus centered on aspects of dry eye disease (DED). Regarding mental health factors, several cross-sectional studies have noted associations between depression and anxiety, and medications used to treat these disorders, and DED symptoms. Sleep disorders (both involving quality and quantity of sleep) have also been associated with DED symptoms. Under the domain of physical health, several factors have been linked to Meibomian gland abnormalities, including obesity and face mask wear. Cross-sectional studies have also linked chronic pain conditions, specifically migraine, chronic pain syndrome and fibromyalgia, to DED, principally focusing on DED symptoms. A systematic review and meta-analysis reviewed available data and concluded that various chronic pain conditions increased the risk of DED (variably defined), with odds ratios ranging from 1.60 to 2.16. However, heterogeneity was noted, highlighting the need for additional studies examining the impact of chronic pain on DED signs and subtype (evaporative versus aqueous deficient). With respect to societal factors, tobacco use has been most closely linked to tear instability, cocaine to decreased corneal sensitivity, and alcohol to tear film disturbances and DED symptoms.

ABSTRACTUsing modeled geographic range and importance projections of 133 tree species in the eastern United States we compare regional scale patterns of forest species diversity, similarity, evenness and community composition under present conditions with two future climate change scenarios. Overall, there is an increase in tree species richness on a pixel-by-pixel basis under future conditions, with a general shift to higher diversity in the northern portion of the United States. Percent similarity in species composition between current forest composition and future species composition under the low scenario averages 53.1%, and is lower for the high climate change scenario (45%), with the lowest similarity occurring in northern forests and the northern United States forest-prairie ecotone. In the future, species evenness increases over a large portion of the study area compared with current conditions. Forest community composition is stable in the southeastern United States, lower Great Lakes region and western extent of the eastern forests. Novel species assemblages develop in northern Wisconsin and Michigan, the northeastern United States, the southern forest-prairie ecotone and the southern coastal plain. Our study highlights geographic regions likely to experience substantial shifts in species composition and forest structure that should be monitored for early signs of forest change.

The aim of this study was to investigate the feasibility and effectiveness of cone-beam computed tomography (CBCT) in the planning, assessment, and follow-up for osteo-odonto-keratoprosthesis (OOKP).

Cone beam CT–based dacryocystography (DCG) is a good alternative to conventional DCG or CT-based DCG (CT-DCG), allowing imaging in an upright position with a lower radiation dose but similar image quality as CT-DCG.

Abstract:We evaluated the effects of varying bulk seed mix weight (kg/ha) applications on species diversity and species composition of a tallgrass prairie planting established at Nachusa Grasslands (north-central Illinois). Following the application of five seed sowing weights (0, 11.2, 33.6, 56.0, and 78.5 kg/ha) containing seeds from 128 species, we censused plot species richness, stem density, and percent cover of each species in the treatment and control plots (0 kg/ha). Overall there were significant differences in vegetation composition between seed weight treatments. Low seed density plots had low species evenness, while densities of 56.0 and 78.5 kg/ha showed significantly greater evenness. Based on germination and growth, the floristic quality index (FQI) was significantly lower in the control and lighter seed weight treatments. Detrended Correspondence Analysis (DCA) ordination suggests that 56.0 kg/ha yields compositionally similar results to 78.5 kg/ha. Considering all ecological metrics analyzed, there were few differences between the 56.0 and 78.5 kg/ha treatments. The applications of 33.6 kg/ha and below led to outcomes such as greater weed abundance and lower overall vegetation cover, potentially creating future management concerns. Our findings, two years post-planting, suggest that seed weights of at least 56.0 kg/ha should be used whenever possible to maximize diversity and increase presence of species with high conservation value.

If current temperature trends continue and increase as predicted by general circulation models, the persistence and migration of sugar maple (Acer saccharum) at its northern limit will become crucial to its continued existence in North America. Specifically, anthropogenic warming may affect germination success and growth of sugar maple. To evaluate this potential limitation, our study addresses two questions. The first involves a growth chamber: Do temperatures at and above (1°, 7°, and 14° C) sugar maple's optimal germination temperature affect its germination? The second involves a common garden: Do sugar maple germination and subsequent growth and mortality rates show evidence of geographic variation under current climatic conditions? While sugar maple germinated successfully at 7° C in the lab, field results suggest that other environmental variables may limit its future establishment as climate changes. Germination of seeds from sugar maple's northern range limit was significantly reduced under warmer conditions, and subsequent seedling mortality rates were significantly increased when grown at a more southerly latitude. Local adaptation was evident with respect to germination, survival, and growth in the field. Ultimately, results from this study further the understanding of how predicted anthropogenic climate change may affect the regeneration of sugar maple in the future.

The ability to model forest distributions in light of anthropogenic disturbance requires a thorough understanding of how trees respond to their physical and climatic environment. The primary objective of this study is to determine how four environmental variables (elevation, latitude, slope angle, and slope aspect) affect the distribution of seven common tree species (Acer saccharum, Betula alleghaniensis, Betula papyifera, Abies balsamea, Picea glauca, Thuja occidentalis, and Acer spicatum) using both regression tree analysis (RTA) and canonical correspondence analysis (CCA) techniques. In general, within the study area, Acer saccharum, Abies balsamea, and Thuja occidentalisabundance was controlled by elevation and latitude, whereas the other species showed limited response to the measured environmental variables. While CCA and RTA showed similar patterns, RTA allows for a more nuanced evaluation of species-environment interactions. Given that the study area encompasses Acer saccharum'snorthern limit, there were differences in the response of Abies balsameato environmental conditions in the absence of Acer saccharum.

OBJECTIVE To evaluate a new surgical method, using calvarial bone graft combined with a wedge of irradiated homologous costal cartilage, for the revision repair of posttraumatic enophthalmos. METHODS This retrospective study was performed from January 1, 2003, through December 31, 2007. Eight patients were diagnosed as having unilateral posttraumatic enophthalmos. All the patients had previously undergone insufficient primary repair of their orbital fractures. In the revision surgery a calvarial bone graft was placed in the area of the defect using a transconjunctival approach. In combination with this technique, a wedge of irradiated rib cartilage was placed on the bone graft behind the globe. Patients were assessed preoperatively and postoperatively by ophthalmologists and maxillofacial surgeons. Standard follow-up examinations were performed at 2 and 4 weeks and at 3 and 6 months after surgery. Computed tomographic scans were obtained preoperatively and postoperatively from all patients. RESULTS For all 8 corrected orbits, favorable cosmetic results were obtained regarding the position of the globe. The mean preoperative Hertel exophthalmometer showed a difference of 3.1 mm and 0.7 mm postoperatively. Improvement of ocular motility and reduction of diplopia were achieved in only 1 patient; in the others, motility and diplopia remained unchanged. No postoperative complications were observed. CONCLUSION The bone and cartilage wedge technique seems to be a useful surgical technique for the cosmetic correction of posttraumatic enophthalmos.Arch Facial Plast Surg. 2010;12(5):305-310--

Ecotones have been subject to significant attention over the past 25 years as a consensus emerged that they might be uniquely sensitive to the effects of climate change. Most ecotone field studies and modeling efforts have focused on transitions between forest and non‐forest biomes (e.g. boreal forest to Arctic tundra, forest to prairie, subalpine forests to alpine tundra) while little effort has been made to evaluate or simply understand forest–forest ecotones, specifically the deciduous forest – boreal forest ecotone. Geographical shifts and changes at this ecotone because of anthropogenic factors are tied to the broader survival of both the boreal and deciduous forest communities as well as global factors such as biodiversity loss and dynamics of the carbon cycle. This review summarizes what is known about the location, controlling mechanisms, disturbance regimes, anthropogenic impacts, and sensitivity to climate change of the deciduous forest – boreal forest ecotone.

The potential impact of climate change on agricultural production has frequently been evaluated at national and regional scales. This study considers the potential county-scale impact of climate change on corn (Zea maysL.) and soybean (Glycine max[L.] Merr.) yield in the important agricultural state of Illinois, USA. By identifying specific monthly climate variables (mean daily temperature and precipitation) to which corn and soybean yield is sensitive, this study compares monthly regional General Circulation Model (GCM) predictions with the monthly climate variables to which corn and soybean yield is sensitive to predict crop yield under future climate. Corn yield is negatively correlated with July and August temperature in much of the state, and positively correlated with precipitation from the previous September (in the central portion of the state) and July and August precipitation in most of northern and southern Illinois, respectively. Soybean yield is negatively correlated with mean monthly temperature in central and southern Illinois during the summer, and positively correlated with July and August precipitation in the same regions. Given the regional GCM prediction for increased summer temperatures and summer drought, both corn and soybean yield will likely decrease under future climate conditions. This is likely to be most pronounced in the central and southern portions of Illinois. Additionally, given higher summer temperatures, the risk of summer drought is more pronounced.

Noninvasive intraocular pressure (IOP) measurement in mice is critically important for understanding the pathophysiology of glaucoma. Rebound tonometry is one of the methods that can be used for obtaining such measurements. We evaluated the ability of the rebound tonometer (RT) to determine IOP differences among various mouse strains and whether differences in corneal thickness may affect IOP measurements in these animals.

Abstract: Background: We wished to investigate the toxicity of four immunosuppressant and antimetabolic drugs, which are known to influence postoperative wound healing, on three different human ocular cell lines. Methods: Acute toxicity to cyclosporin A, azathioprine, mitomicyn C and daunorubicin was assessed in Chang cells by monitoring their uptake of propidium iodide during a 3-h period. Chronic toxicity was assessed by monitoring the proliferation and viability of subconfluent cultures of Chang cells, human corneal endothelial cells (HCECs) and retinal pigmented epithelial (RPE) cells after continuous exposure to the drugs for 7 days. Results: Acute toxicity testing revealed no obvious effects. However, the chronic toxicity tests disclosed a narrow concentration range over which cell proliferation decreased dramatically but calcein metabolism was sustained. Although the three lines reacted similarly to each agent, HCECs were the most vulnerable to daunorubicin and mitomycin. At a daunorubicin concentration of 0.05 μg/ml, a 75% decrease in calcein metabolism (P<0.001) and a ≥95% cell loss (P<0.001) were observed. At a mitomycin concentration of 0.01 μg/ml, cell density decreased by 61% (P<0.001) without a change in calcein metabolism, but at 0.1 μg/ml, the latter parameter decreased to 12% (P=0.00014). At this concentration the proliferation of Chang and RPE cells decreased by more than 50%, whilst calcein metabolism was largely sustained. Cyclosporin inhibited cell proliferation moderately at lower concentrations (<5 μg/ml; P=0.05) and substantially at higher ones, with a corresponding decline in calcein metabolism. Azathioprine induced a profound decrease in both parameters at concentrations above 5 μg/ml. Conclusion: Daunorubicin, cyclosporin and azathioprine could be used to inhibit excessive intraocular scarring after glaucoma and vitreoretinal surgery without overly reducing cell viability. The attributes of immunosuppressants lie in their combined antiproliferative and immunomodulatory effects.

Abstract: Purpose: To evaluate the potential of the vitamin E compound α-tocotrienol as antifibrotic agent in vitro. Methods: Using human Tenon’s capsule fibroblast cultures, the antiproliferative and cytotoxic effects of the different vitamin E forms α-tocopherol, α-tocopheryl acetate, α-tocopheryl succinate and α-tocotrienol were compared with those of mitomycin C. To mimic subconjunctival and regular oral application in vivo, exposure time of serum-stimulated and serum-restimulated fibroblasts (SF and RF, respectively) to vitamin E forms was set at 6 days. Cultures were only exposed for 5 min to mitomycin C due to its known acute toxicity and to mimic the short-time intraoperative administration. Proliferation (expressed as % of control) was determined by DNA content quantification on days 2, 4 and 6, whereas cytotoxicity was assessed by cell morphology and glucose 6-phosphate dehydrogenase (G6PD) release after 24 h. Results: α-Tocopherol and α-tocopheryl acetate stimulated growth of SF, but not RF. Reduction of fibroblast content by α-tocopheryl succinate was accompanied by increased G6PD release and necrosis. Contrary to α-tocopheryl succinate, 50 μM or repeatedly 20 μM of α-tocotrienol significantly inhibited proliferation without causing cellular toxicity (maximal effect: 46.8%). RF were more sensitive to this effect than SF. Mitomycin C 100–400 μg/ml showed a stronger antiproliferative effect than α-tocotrienol (maximal effect: 13.8%). Morphologic characteristics of apoptosis were more commonly found under treatment with mitomycin C. Conclusions: Of the vitamin E forms tested, only α-tocotrienol significantly inhibited growth at non-toxic concentrations. In this in vitro study, antiproliferative effects of mitomycin C were stronger than those of α-tocotrienol.

ABSTRACTCandida albicansis the most frequent cause of fungal keratitis in temperate regions. Caspofungin has potent activity against Candidaspp. in a variety of clinical settings. Little is known, however, about its activity against fungal keratitis. We compared the efficacy of topical caspofungin with that of topical amphotericin B (AMB) in a rabbit model of experimental keratomycosis. Keratitis was induced with a standardized inoculum of Candida albicans(SC 5314) placed on the debrided cornea. Twenty-four hours after infection, animals were randomly assigned to treatment with 0.15% caspofungin, 0.5% caspofungin, 0.15% AMB, and a saline control (n= 12 rabbits in each group). For the first 12 h, treatment was repeated every 30 min and, after a 12-h pause, was resumed at hourly intervals for another 12 h. The animals were examined and killed 12 h after administration of the last dose. Treatment effects were evaluated by clinical assessment, fungal culture, and histopathology. Drug treatment significantly reduced corneal fungal recovery from 3.78 log10CFU in saline-treated animals to 2.97, 1.76, and 1.18 log10CFU in animals treated with 0.15% caspofungin, 0.5% caspofungin, and 0.15% AMB, respectively. By histopathology, the mean hyphal density was significantly lower in the corneas of treated animals than in those of the controls; there was no difference in hyphal densities between the different treatment groups. The depth of corneal invasion was not significantly reduced by the antifungal treatments. By clinical assessment, keratitis progressed in animals treated with saline, whereas disease progression was inhibited by all drug treatment regimens. In our rabbit model, 0.5% caspofungin was as effective as 0.15% AMB for the topical treatment of Candidakeratitis. The potential clinical efficacy of caspofungin awaits further investigation.

Background:Amphotericin B (AmB) and various lipid formulations of AmB are available for the treatment of fungal infections of the eye. Currently, the recommended route of administration for the treatment of fungal keratitis is by topical application. Nevertheless, because of the risk of a difficult to treat exogenous fungal endophthalmitis, a combined topical and systemic treatment is frequently given when treating deep fungal keratitis. To date, little is known about the pure corneal availability of these drugs following systemic treatment. In this study, the corneal concentration following 7 daily doses of parenteral AmB lipid complex (ABLC) or liposomal AmB (L-AmB) was compared to that of AmB deoxycholate (D-AmB) in a rabbit model. Methods:Following induction of uveitis in one rabbit eye by intravitreal injection of endotoxin, daily doses of D-AmB (1 mg/kg), ABLC (5 mg/kg) or L-AmB (5 mg/kg) were given intravenously on 7 consecutive days. Five or more rabbits per treatment were used. AmB concentrations were determined by high-performance liquid chromatography (HPLC) in corneas collected at autopsy 24 h after the 7th and final dose. Data were analyzed using the Mann-Whitney U test. Results:After 7 days of treatment, mean corneal concentrations of AmB in the inflamed eyes were significantly higher (2.38 ± 1.47 µg/g; p < 0.01) following treatment with L-AmB compared with ABLC (<0.1 µg/g) and D-AmB (0.46 ± 0.2 µg/g). No AmB could be detected in the corneas of the non-inflamed eyes. Conclusion:In our rabbit model, AmB penetration into the cornea was significantly higher after systemic administration of L-AmB compared with conventional D-AmB or ABLC.

The transition from deciduous to boreal forest is abrupt regionally and topographically in Lake Superior Provincial Park, Ontario, Canada. The northern range limit of Acer saccharumis coincident with the forest transition to boreal forest. The goal of our study was to characterize the distribution of A. saccharumseedlings at the transition zone to determine variability in seedling demographics and genetics with topographic position and along a short north-south gradient. Seedling density, size, age, and growth were evaluated in permanent plots across the regional transition zone, and at the south-facing, ridge top and north-facing limits across the topographic transition. Growth over 5 yrs. was determined by measuring the distance between terminal bud scars, and compared with regional climate data. Genetic material was collected and analyzed from two of these sites. No significant differences were detected in density or growth of Acer saccharumacross the regional transition but mean age increased and height decreased as the limit was approached. Across the topographic transition, ridge top seeding densities were greater than the south-facing or north-facing limits. Genetic variability is great with no cohort preference for topographic position detected.

ABSTRACTLittle is known about the ocular penetration of amphotericin B (AMB) and its lipid formulations, the current drug of choice in fungal endophthalmitis. The ocular distribution of AMB lipid complex (ABLC), liposomal AMB (L-AMB), and AMB deoxycholate (D-AMB) was studied in a rabbit model. D-AMB (1 mg/kg of body weight/day), ABLC (5 mg/kg/day), or L-AMB (5 mg/kg/day) was given intravenously to rabbits as a single dose or as repeated daily doses on 7 consecutive days after induction of unilateral uveitis by intravitreal injection of endotoxin. AMB concentrations in aqueous humor, vitreous humor, and plasma were determined by high-pressure liquid chromatography 16 h after administration of a single dose or 24 h after the last of seven doses. After single-dose administration, L-AMB achieved at least eightfold-higher AMB concentrations in the aqueous of inflamed eyes than ABLC or D-AMB (1.21 ± 0.58 μg/ml versus 0.14 ± 0.04 and 0.11 ± 0.09 μg/ml, respectively). At that time point no drug was detectable in the vitreous. After 7 days of treatment, the concentration of AMB in the vitreous was higher after treatment with L-AMB (0.47 ± 0.21 μg/ml) than after treatment with ABLC (0.27 ± 0.18 μg/ml) and D-AMB (0.16 ± 0.04 μg/ml). Similarly, AMB concentration in the aqueous was higher after repeated doses of L-AMB (0.73 ± 0.43 μg/ml) than after repeated doses of ABLC (0.03 ± 0.02 μg/ml) or D-AMB (0.13 ± 0.06 μg/ml). No AMB was detected in noninflamed eyes. Following systemic administration, AMB distribution to the eye is inflammation dependent and occurs sequentially, first to the aqueous and then to the vitreous. Compared to D-AMB and ABLC, L-AMB reaches higher drug concentrations in both ocular compartments.

Abstract Background. The reproducibility and accuracy of the induction/impact (I/I) probe device (rebound tonometer) and the TonoPen XL electronic tonometer were compared through the measurement of intraocular pressure (IOP) differences between contralateral rat eyes. Methods. IOP was measured in 18 female Wistar rats with variable, modest elevations of IOP in one eye. Mean IOP from five measurements on each of the 36 eyes was determined using the rebound tonometer, followed by the TonoPen XL. Following cannulation, true (manometrically determined) IOP was recorded with a calibrated pressure transducer. Differences between the operated and normal eye of each animal for each tonometric method of measurement were correlated with the true difference in IOP. Results. IOP differences between the operated and contralateral normal eye ranged from +5.9 to -1.7 mmHg (mean +1.7 mmHg) when measured by cannulation and from +7.2 to -1.4 mmHg (mean +2.4 mmHg) and +9.8 to -3.2 mmHg (mean +3.6 mmHg) when measured with the rebound tonometer and TonoPen XL respectively. Differences between eyes recorded by rebound tonometer (y) correlated with those determined by cannulation (x) in a linear fashion (y=0.8243x+1.0721; R²=0.6603). Correlation for the TonoPen XL was much weaker (y=0.8675x+2.1672; R²=0.2077). IOP measurements using the rebound tonometer did not differ significantly from true IOP, whereas TonoPen XL increasingly underestimated IOP with increasing IOP (9-20 mmHg). Conclusion. The rebound tonometer displayed greater accuracy and less variability than TonoPen XL in measuring the IOP of the rat eye (range 9-20 mmHg).

AbstractIntroduction:In normal-tension glaucoma, optic nerve damage occurs without elevated intraocular pressures, hence vascular and pathogenic mechanisms other than intraocular pressure effects have been postulated. However, the exact cause(s) remain unknown. We have looked for an association between normal-tension glaucoma and sleep apnea syndrome, a disease characterized by repetitive upper airway obstructions during sleep, inducing hypoxia and sleep disruption with the risk of late cardiovascular and neurological sequelae. Methods:We performed overnight polysomnography in 16 consecutive Caucasian patients with normal-tension glaucoma. The respiratory disturbance index (RDI) during night sleep was used to diagnose and grade obstructive sleep apnea. Patients with an RDI of 10 or more were diagnosed as having obstructive sleep apnea. Results:We observed the following prevalences of obstructive sleep apnea in normal-tension glaucoma patients: 0 (0 of 2) for the group of patients younger than 45 years, 50 (3 of 6) for the age group 45–64 years, and 63 (5 of 8) for the group older than 64 years. Prevalences in the middle and older age group were significantly higher than in a historic control group (p < 0.025 for both, binomial test). Conclusion:Normal-tension glaucoma patients constitute a high-risk population for sleep apnea syndrome. Therefore, they should be screened for sleep apnea syndrome, and, if necessary, be treated to avoid late cardiovascular and neurological sequelae.Copyright © 2002 S. Karger AG, Basel

Neurospecific acetylcholinesterase inhibitors have been shown to lower intraocular pressure (IOP) in normal rabbits and might have additional neuroprotective effects. This study was set out to explore and compare the toxicity of two selective acetylcholinesterase inhibitors, rivastigmine and donepezil, on two standardized cell lines of epithelial origin. Chang and Vero cells were incubated with various concentrations of rivastigmine or donepezil. Acute toxicity (4 h) was assessed by monitoring the permeability of cells to propidium iodide. Chronic toxicity (7 days) was determined by monitoring the effect of the two drugs on esterase activity and cell proliferation. The viability of cells was also assessed morphologically by microscopic inspection. Signs of acute toxicity became manifest at a rivastigmine concentration of 50 mg/ml in both Chang and Vero cells. Indications of chronic toxicity became obvious at concentrations of as low as 1 × 10–5 mg/ml. In contrast, degenerative morphological changes became manifest only at a concentration of as high as 1 mg/ml. In donepezil-treated cells, acute toxicity was not observed in the concentration range tested, whereas chronic toxicity was detected at 1 × 10–1 mg/ml in both Chang and Vero cells, a concentration at which degenerative morphological changes became evident as well. In contrast to rivastigmine, donepezil elicited no signs of acute or chronic toxicity in either Chang or Vero cells at the IOP-lowering concentration of 1 × 10–4 mg/ml. At this dose, the drug is therefore unlikely to evoke deleterious effects on ocular surface tissues in the clinical setting.

Sugar maple reaches its northern limit along the eastern shore of Lake Superior marking the transition from the deciduous forest of eastern North America to a predominantly boreal forest community. In light of regional warming trends over the past 100 years and projections for even warmer conditions in the future, we sought to characterize the current age structure and regeneration status of both sugar maple and boreal tree species within this ecotone zone. Within Lake Superior Provincial Park (Ontario, Canada), a series of east-west trending hills create numerous deciduous-boreal transition zones as sugar maple occupies uplands and boreal species occupy valley bottoms; then, once north of the sugar maple limit, boreal species dominate all topographic positions. Unlogged forest stands were sampled in the transition zone on ridges and slopes both north and south of the sugar maple limit. Overall tree density and basal area in sugar maple and boreal stands were similar across the ecotone, but seedling density was significantly higher in plots dominated by sugar maple. Moreover, sugar maple seedlings, but not saplings, were found slightly beyond the adult sugar maple tree hillside limit, indicating that the potential for range expansion may be limited by microclimatic variables, namely cold air drainage.

Non-invasive intraocular pressure (IOP) measurement in rats can be performed with a variety of methods, none of which seems appropriate for scaling down for the mouse eye. In an attempt to develop such a method for non-invasive IOP measurement in mice, an alternative concept, that of rebound tonometry, was explored using an induction/impact (I/I) tonometer probe. IOP measurement using the rebound concept is based on bouncing a probe onto the eye and detecting its motion. Motion parameters of the probe, which vary according to eye pressure, are used to calculate the IOP.

AbstractIntroduction:The etiology of primary open-angle glaucoma remains unclear. Various risk factors, including vascular abnormalities, have been associated with this disease. Sleep-associated diseases, like sleep apnea syndrome, might also represent a risk factor. Sleep apnea syndrome is characterized by repetitive upper airway obstructions during sleep, inducing hypoxia and sleep disruption with the risk of cardiovascular and neurological sequelae. In this study, we determined the prevalence of sleep apnea syndrome in primary open-angle glaucoma patients. Methods:Overnight transcutaneous finger oximetry was performed in 30 consecutive patients having primary open-angle glaucoma. We assessed the oximetry disturbance index during night sleep, a parameter used to diagnose sleep apnea syndrome and to grade its severity. Results:Sleep apnea syndrome was more prevalent among primary open-angle glaucoma patients compared to normal historic controls of the same age and sex distribution (=χ2= 9.35, d.f. = 3, p < 0.025). The oximetry disturbance index grade was significantly larger in the primary open-angle glaucoma group compared to normal controls (U = 3,352, p = 0.01). According to the oximetry disturbance index, 20% (6/30) of primary open-angle glaucoma patients had sleep apnea syndrome. Conclusion:Primary open-angle glaucoma is associated with sleep apnea syndrome. Early recognition and treatment of sleep apnea syndrome are important to avoid cardiovascular and neurological complications.Copyright © 2000 S. Karger AG, Basel

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