A pressure indicator for the impact of Iberian wild goat on moss and soils in a Mediterranean climate

In the Sierra de Guadarrama National Park (central Spain), the population of Iberian wild goat, also known as Spanish ibex (Capra pyrenaica) has grown strongly since its reintroduction three decades ago. The plant community is now under heavy browsing pressure due to this high population. A study of the presence of moss on rocks was used herein as the basis for the design of an indicator, named impact on mosses (im), to describe the environmental pressure exerted by the Iberian wild goat in terms of moss removal. Granite and gneiss zones at medium altitudes with continental Mediterranean climate are the most suitable areas for successful application of the indicator. The hypotheses to test are: (1) the indicator will discriminate between areas with different wild goat pressure levels, (2) wild goat pressure will explain a high proportion of moss loss variance, and (3) the im indicator will be useful to establish a mathematical model between wild goat pressure and moss loss. The proposed indicator was analyzed using both statistical and data science techniques. The results support the mentioned hypotheses. Specifically, statistically significant differences were found regarding the impact on mosses between areas with different levels of Iberian wild goat pressure. Thus, a high proportion of the variance was associated with wild goat pressure (80% for high-pressure areas, 56% for low-pressure areas). A modified parabolic function was fit to express the relationship between Iberian wild goat pressure and impact on mosses. In conclusion, the im indicator was shown to be a useful tool to assess pressure due to Iberian wild goat. Therefore, im can help assess and manage Iberian wild goat populations and determine their sustainable levels.

Standard automated perimetry using size III and size V stimuli in advanced stage glaucoma: an observational cross-sectional comparative study

ObjectivesIn this study, we sought to evaluate the extent of further visual field that could be assessed when using stimulus size V in standard automated perimetry compared with size III in advanced stage glaucoma and whether cut-off values could be determined for when to switch from size III to size V.DesignProspective cross-sectional study.SettingSingle-centre outpatient eye clinic in India (New Delhi).ParticipantsAdvanced stage glaucoma defined as stages 3–4.InterventionCentral static perimetry with Octopus 900 G programme (size III stimulus dynamic strategy) and low vision central programme (size V stimulus dynamic strategy).Primary and secondary outcome measuresVisual field assessment for right and left eyes with both sizes III and V were undertaken within one clinic visit.ResultsWe recruited 126 patients (170 eyes). Mean patient age at assessment was 55.86 years (SD 15.15). Means (SD) for size III versus size V, respectively, were 6.94 dB (5.58) and 12.98 dB (7.77) for mean sensitivity, 20.02 dB (5.67) and 19.22 dB (7.74) for mean deviation, 5.89 dB (2.29) and 7.69 dB (2.78) for standard loss variance and 3.32 min (1.07) and 6.40 min (1.43) for test duration. All except mean deviation were significantly different between size III and V tests.ConclusionUseful visual field information was obtained with size V stimuli which allowed continued monitoring of these patients that was not possible with size III. Increased test duration, standard loss variance and mean sensitivity were found with size V, as expected, given that more visual responses were obtained with the increased target size. A switch from size III to V may be considered when mean sensitivity reaches 10 dB and/or mean deviation reaches 18 dB.

Evaluation of Visual Field and Balance Function Alterations in Patients Who Underwent Dermatochalasis Surgery

Purpose. To compare perioperative visual field (VF), balance functions (BF), and changes in the other ocular parameters in patients undergoing upper eyelid dermatochalasis (DC) surgery. Methods. One hundred and fifty-eight eyes of 79 patients who underwent DC surgery were included in the study. The VF, BF, intraocular pressure (IOP), pachymetry (PM), macular, and optic nerve measurements were recorded. Measurements were repeated at postoperative month 1. The preoperative and postoperative ocular measurements and the balance data were compared. Results. Nineteen of 79 (24.05%) patients were male and 60 of 79 (75.95%) were female, while the mean age of the patients was 58.65 ± 7.38 years. There were statistically significant differences in terms of VF and macular thickness between the preoperative and postoperative values. The improvements in mean defect, standard loss variance, and mean sensitivity values of global VF parameters in both eyes were statistically significant after surgery. Central macular thickness, mean macular thickness, and macular volume decreased significantly in all eyes after surgery (p<0.05). Conclusions. Although a marked improvement was observed in VF and peripheral vision after surgery, no significant change was found in BF parameters including primarily falling risk. The significant change in the macular parameters was only remarkable, and we think that the decrease was due to subtle vasospasm. There is a need for further comprehensive studies including especially patients older than 65 with a view to understanding the effect of DC surgery on BF.

Metamorphopsia Score and Central Visual Field Outcomes in Diabetic Cystoid Macular Edema

Aim. To detect abnormality of the visual function in naïve patients with cystoid diabetic macular edema (DME) using M-charts, Amsler test, and white on white (W/W) and blue on yellow (B/Y) perimetry. Methods. There were 64 eyes included in the study: 30 eyes with DME, 22 eyes with diabetes without DME, and 12 eyes of normal subjects. Conventional W/W perimetry and B/Y perimetry were performed within the central 10° of the visual field. To assess metamorphopsia, Amsler test and M-charts were used. Results. The rate of detection of metamorphopsia was 37% with Amsler test examination and 50% with M-charts. Specificity of both tests was 100%. We found a significant difference between vertical scores of M-charts in all groups, but not in horizontal scores (p<0.0001). Mean defect (MD) was 8.9 dB and 3.6 dB and loss variance (LV) 4.8 dB and 3.3 dB (p<0.0001). Conclusions. M-chart is more sensitive than Amsler test method for detection of metamorphopsia. The MD and LV are higher in b/y in comparison to W/W perimetry. B/Y perimetry and M-charts are more sensitive than conventional methods for detecting the visual function loss in cystoid DME.

Visual field indices and patterns of visual field deficits in mesopic and dark-adapted two-colour fundus-controlled perimetry in macular diseases

Background/AimsTo analyse the retest reliability of visual field indices and to describe patterns of visual field deficits in mesopic and dark-adapted two-colour fundus-controlled perimetry (FCP) in macular diseases.MethodsSeventy-seven eyes (30 eyes with macular diseases and 47 normal eyes) underwent duplicate mesopic and dark-adapted two-colour FCP (Scotopic Macular Integrity Assessment, CenterVue). Non-weighted (mean defect, loss variance), variability-weighted (mean deviation, pattern standard deviation (PSD)) and graphical (cumulative defect (Bebie) curves) indices were computed. Reproducibility (coefficient of repeatability, CoR) of these indices was assessed. Cluster analysis was carried out to identify patterns of visual field deficits.ResultsThe intrasession reproducibility was lower for the mean defect as compared with the mean deviation (CoR (dB) 2.67 vs 2.57 for mesopic, 1.71 vs 1.45 for dark-adapted cyan, 1.94 vs 1.87 for dark-adapted red testing) and lower for the square-root loss variance as compared with the PSD (CoR (dB) 1.48 vs 1.34, 0.77 vs 0.65, 1.23 vs 1.03). Hierarchical cluster analysis of the indices disclosed six patterns of visual field deficits (approximately unbiased P value>0.95) with varying degrees of global versus focal defect and rod versus cone dysfunction. These were also reflected by the cumulative defect curves.ConclusionFCP with mesopic and dark-adapted two-colour testing allows for reproducible assessment of different types of retinal sensitivity, whereby mean deviation and PSD exhibited the better retest reliability of the tested indices. Distinct patterns of retinal dysfunction can be identified using this setup, reflecting variable degrees of rod and cone dysfunction in different macular diseases. Dark-adapted two-colour FCP provides additional diagnostic information and allows for refined structure–function correlation in macular diseases.

26 Jahre Erlanger Glaukomregister: demografische und perimetrische Charakteristika der Patienten im Wandel der Zeit

Zusammenfassung Hintergrund Das Erlanger Glaukomregister kann im Jahre 2017 auf sein nun 26-jähriges Bestehen zurückblicken. Wir möchten mit dieser Arbeit die demografischen sowie perimetrischen Daten der Patienten mit okulärer Hypertension (OHT), präperimetrischem (präPOWG) und perimetrischem primärem Offenwinkelglaukom (POWG), Normaldruckglaukom (NDG) sowie sekundärem Offenwinkelglaukom (SOWG) bei Erstvorstellung in dem Register beschreiben und mit den aktuellsten vorliegenden perimetrischen Werten vergleichen. Material und Methoden 1406 Augen (754 Patienten) des Erlanger Glaukomregisters (EGR; NTC00494923) wurden zwischen 1991 und 2016 retrospektiv analysiert betreffend: demografische Daten (Alter, Visus, intraokularer Druck [IOD]), Diagnose sowie perimetrische Charakteristika (Mean Defekt [MD], Loss Variance [LV]) bei Erstvorstellung sowie die aktuellsten vorliegenden perimetrischen Befunde. Ergebnisse (1) 558 Augen von Patienten mit OHT, 347 präPOWG, 236 POWG, 161 NDG und 104 SOWG wurden zwischen 1991 und 2007 in das Erlanger Glaukomregister eingeschlossen. (2) Bei der Erstuntersuchung lag das mittlere Alter für Patienten mit OHT (43,79 ± 13,64) signifikant niedriger als das der perimetrischen Offenwinkelglaukome (NDG: 54,46 ± 11,41, p < 0,001; POWG: 54,00 ± 11,27, p < 0,001; SOWG: 47,92 ± 12,37, p = 0,008). Patienten mit präPOWG (48,62 ± 11,98 Jahre) waren zudem signifikant jünger als Patienten mit POWG (p < 0,001) sowie NDG (p < 0,001). (3) Die bestkorrigierte Sehschärfe lag bei Patienten mit OHT (1,04 ± 0,14, p < 0,001) sowie präPOWG (1,05 ± 0,15, p < 0,001) signifikant höher als bei Patienten mit POWG (0,95 ± 0,16), SOWG (0,93 ± 0,23) und NDG (0,93 ± 0,18). (4) Der IOD war mit 19,08 ± 2,25 mmHg (OHT), 19,18 ± 3,90 mmHg (präPOWG), 18,29 ± 4,11 mmHg (POWG) und 18,57 ± 5,34 mmHg (SOWG) signifikant höher als bei den Patienten mit NDG (15,23 ± 2,83 mmHg, p < 0,001). (5) Seit dem Jahre 1991 wurde bei Erstvorstellung in dem Register zunehmend die Diagnose eines POWG oder SOWG gestellt. (6) MD- und LV-Verlauf zwischen 1991 und 2016: Ein ansteigender Trend für die MD-Werte bei Erstvorstellung war für Patienten mit präPOWG und POWG sowie ein abfallender Trend für Patienten mit OHT, NDG und SOWG zu beobachten. Eine perimetrische Progression war bei allen Patientengruppen zu beobachten. Schlussfolgerung Seit der Gründung des Erlanger Glaukomregisters im Jahre 1991 zeigten alle Patientengruppen bis 2016 eine perimetrische Progression, obwohl eine Therapieoptimierung bei Nichteinhalten des individuellen Zieldrucks erfolgte.

Visual Field Damage and Progression in Glaucomatous Myopic Eyes

Purpose To make a visual field retrospective analysis on a group of patients with primary open angle glaucoma (POAG) and to evaluate whether different refractive errors could have different progression of the 30° central sensitivity. Methods A total of 110 patients with POAG (52 men and 58 women) were included in the study. All the patients were divided into four subgroups based on the refractive error. The visual field of all the included patients was assessed by an Octopus 30° central visual field every 6 months, for a total of 837 visual fields examined. The resulting data were analyzed by PERIDATA for Windows 1.7 TREND function. Mean defect (MD) and loss variance (LV) were considered for the analysis. Results At the first examination, 82% of eyes showed a global decrease of differential light sensitivity (MD >2 dB) and in 67% the distribution of the defect was nonhomogeneous (LV >6 dB). The analysis of variance for subgroups showed a more significant decrease of MD in highly myopic patients. A linear regression analysis highlighted a statistically significant change in time of MD in 36% and of LV in 34% of the eyes studied. Highly myopic patients had the highest (p<0.01) percentage of change of MD and LV (46% and 42%, respectively). Among the four subgroups, there was no difference in progression of MD decrease in time. Conclusions These results showed that after 5 years of glaucoma, the visual field was altered in most of the eyes examined (82%) and that in 67% of cases, its defect was nonhomogeneous and worsened with the increase of myopia. The regression linear analysis of visual field changes in time showed a progressive increase of MD and LV in approximately one third of all the eyes examined.