Hill Of Vision Research Articles

Retinal Characteristics of Female Choroideremia Carriers: Multimodal Imaging, Microperimetry, and Genetics

PurposeDescribe visual function and retinal features of female carriers of choroideremia (CHM), using multimodal imaging and microperimetry. DesignCross-sectional cohort study Participants and controlsCHM carriers seen in Australia (Melbourne or Perth) or United Kingdom (Oxford or Cambridge) between 2012 and 2023. Healthy age-matched controls seen in Melbourne, Australia, between 2022 and 2023. MethodsParticipants had visual acuity, fundus-tracked microperimetry, optical coherence tomography (OCT), and fundus autofluorescence (FAF) imaging performed. CHM carriers were either genetically and/or clinically confirmed (i.e., obligate carriers). CHM carriers were grouped according to their retinal phenotype and compared to healthy controls. Statistical analyses were performed on StataBE (v18.0). Main outcome measuresBest-corrected visual acuity (BCVA), low-luminance visual acuity (LLVA), average retinal sensitivity, volume of macular hill of vision (HoV), inner retinal thickness (IRT), and photoreceptor complex (PRC) thickness. ResultsEighty-six eyes of 43 CHM carriers and 60 eyes of 30 healthy controls were examined using multimodal imaging and microperimetry. Median age was 54 and 48.5 years for CHM carriers and controls, respectively (p=0.18). Most CHM carriers (86%) were genetically confirmed. CHM carriers and controls had strong inter-eye correlation between eyes for BCVA and average retinal sensitivity (p<0.001). LLVA and macular HoV tests were sensitive tests to detect changes in CHM carriers with mild phenotypes (i.e., fine and coarse). CHM carriers with geographic and/or male pattern phenotypes had reduced BCVA, LLVA, retinal sensitivity, and retinal thinning, compared to healthy controls. Retinal thickening of the inner retina was observed in the central 1 degree, despite generalised thinning of the PRC in the central 7 degrees, indicating retinal remodelling in CHM carriers, compared to controls. There were no genotype-phenotype correlations observed. ConclusionsFemale carriers of CHM with severe retinal phenotypes (i.e., geographic or male pattern) have significantly decreased visual function and retinal structural changes, when compared to age-matched controls and those carriers with milder phenotypes. LLVA and volumetric measures of the macular HoV were found to be the most sensitive functional tests to detect milder retinal disease (fine and coarse phenotypes) in CHM carriers.

Development and Validation of an Internet-Based Remote Perimeter (Perimouse).

We sought to validate the feasibility of Perimouse, an internet-based remote perimeter that allows for natural fixation and can be performed on most computers via a web page. In this cross-sectional study, Perimouse evaluated the visual field of 45 healthy people and 27 patients with primary open-angle glaucoma on a laptop. Participants used a mouse cursor to locate new dots on the screen that were determined by preset saccade vectors. A "click and confirm" strategy was used to eliminate the unwanted visual search. Dot brightness was either fixed at 12dB in the suprathreshold program (screening program) or variable in the threshold program. We compared Perimouse outcomes with the Humphrey Field Analyzer (HFA) 24-2 Swedish Interactive Testing Algorithm standard program. In the screening program, Perimouse showed moderate to high concordance with HFA. The intraclass coefficient ranged from 0.58 to 0.86 in different areas of Garway-Heath mapping. In the threshold program, normal subjects had threshold ranging from 19 to 16dB, presenting sensitivity changes according to the "hill of vision". The test-retest difference was 0.09dB. Habitual spectacle correction and environmental luminance (2-337 lux) had little impact on the central or peripheral threshold (P > 0.05). The correlation between Perimouse and HFA threshold sensitivity was strong (R = 0.950), although Perimouse mean defect was 4.40dB higher than the HFA mean defect. Perimouse is a reliable visual field test that correlates strongly with HFA. It shows potential for population screening and monitoring visual field defects. Perimouse assesses the visual field using saccade vectors without eye trackers, enhancing its accessibility via a web page.

Functional Vision in Patients With Biallelic USH2A Variants

To describe functional vision (FV) and investigate the relationship between FV, visual acuity (VA), and hill of vision (VTOT) at baseline in patients with biallelic USH2A variants. Multicenter, international, cross-sectional study. In individuals with biallelic disease-causing variants in USH2A, clinical diagnosis of Usher syndrome type 2 (USH2) or autosomal recessive nonsyndromic retinitis pigmentosa (ARRP) was based on history of hearing loss and audiology examinations. The VALVVFQ-48 was administered verbally to participants ≥18 years old. VA was measured in both eyes; VTOT was determined from static perimetry in the study eye (better VA). FV scores were calculated using Rasch analysis. Median age of 121 participants (76 with USH2, 45 with ARRP) was 41 years (range: 19-80); 54% were female. FV scores varied from -2.0 to 7.6 logits (median [interquartile range (IQR)]: 2.8 [1.5-3.8]). ARRP and USH2 participants had similar FV scores, both before [mean (95% CI): 2.8 (2.3-3.4) and 2.7 (2.3-3.2), respectively], and after [mean (95% CI): 2.5 (2.1-3.0) and 2.9 (2.6-3.3), respectively; P = .24] adjusting for age, VA, disease duration, and VTOT. VA and VTOT accounted for 29% and 26% of the variance in FV scores, respectively (P < .001 for each). Together, they accounted for 36% of variance observed. Biallelic USH2A variants were associated with a large range of FV, yet similar in ARRP and USH2, despite hearing loss in USH2. The modified VALVVFQ-48 we evaluated is not ideal for detecting the impact of USH2A-associated retinal degenerations on activities of daily living.

Improved Rod Sensitivity as Assessed by Two-Color Dark-Adapted Perimetry in Patients With RPE65-Related Retinopathy Treated With Voretigene Neparvovec-rzyl.

The purpose of this study was to evaluate rod-mediated function with two-color dark-adapted perimetry (2cDAP) in patients with RPE65-related retinopathy treated with voretigene neparvovec-rzyl. Following dilation and dark adaptation, 2cDAP and FST were performed. The 2cDAP was measured on an Octopus 900 perimeter (Haag-Streit) with cyan (500 nm wavelength) and red (650 nm wavelength) stimuli. Hill of vision (HOV) analysis was performed on 2cDAP perimetry with Visual Field Modeling and Analysis (VFMA). Full field threshold stimulus testing (FST) was also measured as a secondary measure of rod-mediated function, and assessed on a Diagnosys Espion with the ColorDome stimulator (Diagnosys LLC). Eight eyes from 4 patients who were treated with voretigene bilaterally had rod function assessed by 2cDAP testing at least 1 year after treatment. There was statistically significant improvement in 2cDAP following gene augmentation therapy. HOV VFMA analysis showed widespread improvements that extended beyond the treatment bleb and statistically significant improvement in HOV analysis volumetric measurements post-treatment to cyan and red stimuli. FST testing performed in six eyes from three patients demonstrated statistically significant improvement to all chromatic stimuli following treatment. These findings demonstrated statistically significant improvement in 2cDAP and FST following treatment with voretigene. These findings provide a sensitive method of assessing rod-mediated function in a topographic manner that may be useful in future clinical trials for inherited retinal dystrophies.

Gaze tracker parameters have little association with visual field metrics of intrasession frontloaded SITA-Faster 24-2 visual field results.

PurposeTo determine the usefulness of Humphrey Field Analyser (HFA) SITA‐Faster 24–2 gaze tracker outputs on interpreting intra‐visit visual field (VF) result pairs.MethodsAnalysis of 1380 right–left eye pairs and 1432 pairs of test 1‐test 2 intrasession VF results of patients seen within a university‐based glaucoma service was undertaken to understand gaze deviation distributions. Output gaze tracker results were aggregated into total ticks, sum of amplitudes and average amplitudes. Correlations between visual field indices (mean deviation [MD], “events” and overall hill of vision) and independent variables (age and test order) were performed using one eye from each subject.ResultsThere was no association of test order (right–left, test 1‐test 2) with eye movements. There was a significant, but weak correlation between eye movements and age (r = 0.16). Correlations of eye movements with MD were driven by more severe MD values. There were no significant correlations between intrasession difference in eye movements and the change in MD, number of “events” and hill of vision, or in the root mean square of sensitivity and total deviation values. There was also no significant correlation between gaze tracker outputs and another commonly used “reliability” metric, false positive rate.ConclusionsEye movement parameters as currently reported by the HFA do not appear to be correlated with key sensitivity parameters when considering the repeatability of intrasession SITA‐Faster 24–2 VF results. Thus, current gaze tracker outputs do not appear to provide clinically meaningful information for interpretation of intra‐visit visual field results that cannot already be garnered using other strategies.

An Open-source Static Threshold Perimetry Test Using Remote Eye-tracking (Eyecatcher): Description, Validation, and Preliminary Normative Data.

PurposeTo describe, validate, and provide preliminary normative data for an open-source eye-movement perimeter (Eyecatcher).MethodsVisual field testing was performed monocularly in 64 normally sighted young adults, using (i) a Humphrey Field Analyzer (HFA) and (ii) the novel Eyecatcher procedure. Eyecatcher used a remote eye-tracker to position stimuli relative to the current point of fixation, and observers responded by looking towards the stimulus. In both tests, Goldman III stimuli were sampled from a 24-2 grid, and were presented against a 10 cd/m2 background. Participants completed each test twice to assess test–retest repeatability.ResultsMean Sensitivity (MS) did not differ between Eyecatcher and the HFA (P = 0.086), and both tests exhibited similar test–retest repeatability (CoREyecatcher = ±1.86 dB; CoRHFA = ±1.95 dB). Eyecatcher was also able to detect changes in sensitivity across the normal visual field (the “Hill of Vision”), and could differentiate the physiological blind spot from adjacent retinal locations. Mean sensitivities and 95% limits of agreement are described for each pointwise location.ConclusionsEyecatcher can use eye movements to assess visual fields in young, normally sighted adults. In such observers, it provides results similar to the current gold standard clinical device (HFA).Translational RelevanceGiven further development, eye movement perimeters such as Eyecatcher could be particularly useful for individuals unable to perform traditional perimetric assessments, such as young children or stroke patients. Full technical details and information on how to freely acquire the source code are included.

Pattern noise (PANO): a new automated functional glaucoma test.

To present a newly developed visual field device (pattern noise: PANO) designed to be sensitive to glaucoma defects, cost-effective, material-practical and easy to repair and therefore particularly suited for low-income countries, where glaucoma can be highly prevalent (e.g. sub-Saharan Africa). This is primarily a descriptive paper, but it also includes a prospective matched case-control pilot study. Hardware, stimulus, target configuration, testing strategy and result sheet are described. The main outcome measure is the contrast level (range 2-64). Targets are composed of bright/dark pixels flickering with 18Hz and have a size of 5°. Pixel size is approximated to the hill of vision. Average luminance of targets is constant and equals background luminance.The study was performed in the West Region in Cameroon. Twenty eyes of 20 newly presenting patients with glaucomatous optic disc cupping on funduscopy were compared with 20 eyes of 20 normal patients matched in age and laterality of eye. Mean age was 32.9±18.8 years for glaucoma patients and 32.2±15.6 years for healthy subjects. Mean contrast threshold was significantly higher in eyes with abnormal disc (16.2±14.3 vs. 4.4±0.8, P=0.002). Correlation of mean contrast thresholds and cup-to-disc ratio was significant (r=0.59; P=0.006). Average examination time was significantly longer for glaucoma eyes compared to healthy eyes (8.2 vs. 6.1min, P<0.001), whereas error rate did not differ (4.8±2.5% vs. 4.1±1.8%, P=0.33). PANO demonstrated visual field defects in patients with glaucomatous optic disc. Defects correlated significantly with glaucomatous optic nerve head morphological alterations. Healthy eyes obtained normal results. More studies are needed to establish PANO.

Test-Retest Variability of Functional and Structural Parameters in Patients with Stargardt Disease Participating in the SAR422459 Gene Therapy Trial.

PurposeThe goal of this analysis was to determine the test–retest variability of functional and structural measures from a cohort of patients with advanced forms of Stargardt Disease (STGD) participating in the SAR422459 (NCT01367444) gene therapy clinical trial.MethodsTwenty-two participants, aged 24 to 66, diagnosed with advanced forms of STGD, with at least one pathogenic ABCA4 mutation on each chromosome participating in the SAR422459 (NCT01367444) gene therapy clinical trial, were screened over three visits within 3 weeks or less. Functional visual evaluations included: best-corrected visual acuity (BCVA) Early Treatment Diabetic Retinopathy Study (ETDRS) letter score, semiautomated kinetic perimetry (SKP) using isopters I4e, III4e, and V4e, hill of vision (HOV) calculated from static visual fields (SVF) by using a 184n point centrally condensed grid with the stimulus size V test target. Retinal structural changes such as central macular thickness and macular volume were assessed by spectral-domain optical coherence tomography (SD-OCT). Repeatability coefficients (RC) and 95% confidential intervals (CI) were calculated for each parameter using a hierarchical mixed-effects model and bootstrapping.ResultsCriteria for statistically significant changes for various parameters were found to be the following: BCVA letter score (8 letters), SKP isopters I4e, III4e, and V4e (3478.85; 2488.02 and 2622.46 deg2, respectively), SVF full volume HOV (VTOT, 14.62 dB-sr), central macular thickness, and macular volume (4.27 μm and 0.15 mm3, respectively).ConclusionsThis analysis provides important information necessary to determine if significant changes are occurring in structural and functional assessments commonly used to measure disease progression in this cohort of patients with STGD. Moreover, this information is useful for future trials assessing safety and efficacy of treatments in STGD.Translational RelevanceDetermination of variability of functional and structural measures in participants with advanced stages of the STGD is necessary to assess efficacy and safety in treatment trials involving STGD patients.

Comparison of nonparametric methods for static visual field interpolation

Visual field testing with standard automated perimetry produces a sparse representation of a sensitivity map, sometimes called the hill of vision (HOV), for the retina. Interpolation or resampling of these data is important for visual display, clinical interpretation, and quantitative analysis. Our objective was to compare several popular interpolation methods in terms of their utility to visual field testing. We evaluated nine nonparametric scattered data interpolation algorithms and compared their performances in normal subjects and patients with retinal degeneration. Interpolator performance was assessed by leave-one-out cross-validation accuracy and high-density interpolated HOV surface smoothness. Radial basis function (RBF) interpolation with a linear kernel yielded the best accuracy, with an overall mean absolute error (MAE) of 2.01 dB and root-mean-square error (RMSE) of 3.20 dB that were significantly better than all other methods (p ≤ 0.003). Thin-plate spline RBF interpolation yielded the best smoothness results (p < 0.001) and scored well for accuracy with overall MAE and RMSE values of 2.08 and 3.28 dB, respectively. Natural neighbor interpolation, which may be a more readily accessible method to some practitioners, also performed well. While no interpolator will be universally optimal, these interpolators are good choices among nonparametric methods.

Structure-Function Modeling of Optical Coherence Tomography and Standard Automated Perimetry in the Retina of Patients with Autosomal Dominant Retinitis Pigmentosa.

PurposeTo assess relationships between structural and functional biomarkers, including new topographic measures of visual field sensitivity, in patients with autosomal dominant retinitis pigmentosa.MethodsSpectral domain optical coherence tomography line scans and hill of vision (HOV) sensitivity surfaces from full-field standard automated perimetry were semi-automatically aligned for 60 eyes of 35 patients. Structural biomarkers were extracted from outer retina b-scans along horizontal and vertical midlines. Functional biomarkers were extracted from local sensitivity profiles along the b-scans and from the full visual field. These included topographic measures of functional transition such as the contour of most rapid sensitivity decline around the HOV, herein called HOV slope for convenience. Biomarker relationships were assessed pairwise by coefficients of determination (R2) from mixed-effects analysis with automatic model selection.ResultsStructure-function relationships were accurately modeled (conditional R2>0.8 in most cases). The best-fit relationship models and correlation patterns for horizontally oriented biomarkers were different than vertically oriented ones. The structural biomarker with the largest number of significant functional correlates was the ellipsoid zone (EZ) width, followed by the total photoreceptor layer thickness. The strongest correlation observed was between EZ width and HOV slope distance (marginal R2 = 0.85, p<10−10). The mean sensitivity defect at the EZ edge was 7.6 dB. Among all functional biomarkers, the HOV slope mean value, HOV slope mean distance, and maximum sensitivity along the b-scan had the largest number of significant structural correlates.ConclusionsTopographic slope metrics show promise as functional biomarkers relevant to the transition zone. EZ width is strongly associated with the location of most rapid HOV decline.

Quantification of the Visual Field Loss in Retinitis Pigmentosa Using Semi-Automated Kinetic Perimetry

ABSTRACT Purpose: To assess quantitatively the natural course of the visual field (VF) loss in patients with retinitis pigmentosa (RP) during 2-year period of observation. Methods: VFs were obtained by semi-automated kinetic perimetry (SKP) during four examinations of 16 patients suffering from RP. Three stimulus conditions (V4e, III4e and I4e) with a constant stimulus angular velocity of 3°/s were used to assess the hill of vision in both eyes of each patient. The area of each isopter was measured in square degrees and corrected for the individual reaction time (RT). Results: There were four patients with mild restriction of VF, six with ring scotomas and six with advanced concentric constrictions of VF. Only I4e isopter area decreased significantly from the first to the last session (p = 0.006), the difference was 154 deg2 being 13% of initial isopter area. The difference was not significant for V4e and III4e isopters. RT values did not differ significantly between four sessions. Conclusions: Only I4e isopter’s area was decreased significantly during two years of observation. SKP provides a method of assessment of progression of the VF loss in patients suffering from RP by measurement of the isopters’ area over time.

VFMA: Topographic Analysis of Sensitivity Data From Full-Field Static Perimetry.

To analyze static visual field sensitivity with topographic models of the hill of vision (HOV), and to characterize several visual function indices derived from the HOV volume. A software application, Visual Field Modeling and Analysis (VFMA), was developed for static perimetry data visualization and analysis. Three-dimensional HOV models were generated for 16 healthy subjects and 82 retinitis pigmentosa patients. Volumetric visual function indices, which are measures of quantity and comparable regardless of perimeter test pattern, were investigated. Cross-validation, reliability, and cross-sectional analyses were performed to assess this methodology and compare the volumetric indices to conventional mean sensitivity and mean deviation. Floor effects were evaluated by computer simulation. Cross-validation yielded an overall R2 of 0.68 and index of agreement of 0.89, which were consistent among subject groups, indicating good accuracy. Volumetric and conventional indices were comparable in terms of test-retest variability and discriminability among subject groups. Simulated floor effects did not negatively impact the repeatability of any index, but large floor changes altered the discriminability for regional volumetric indices. VFMA is an effective tool for clinical and research analyses of static perimetry data. Topographic models of the HOV aid the visualization of field defects, and topographically derived indices quantify the magnitude and extent of visual field sensitivity. VFMA assists with the interpretation of visual field data from any perimetric device and any test location pattern. Topographic models and volumetric indices are suitable for diagnosis, monitoring of field loss, patient counseling, and endpoints in therapeutic trials.

The prediction error of the visual field sensitivity is large at the steep ‘border’ of glaucomatous scotoma

AbstractPurpose To create a method to identify the edge of visual field (VF) scotoma and to investigate the relationship between the steepness of the ‘border’ of scotoma and the prediction error of VF sensitivity.Methods Twenty‐two glaucomatous patients with reliable VFs were recruited. Then, using the latest VFs (Humphrey 24‐2) of these patients, the gradient of the plane on the hill of vision is calculated from the sensitivity of adjacent four/three points, so that the ‘border’ of VF damage is identified. Next, VF measurement was carried out, adding ten test points at the centre of adjacent four/three points where the gradient of the plane is largest (Full threshold, Custom mode). The VF measurements were performed using two approaches; random target presentation of 62 test points together and showing ten added points following or prior (randomly selected) to 52 (24‐2) points. Each measurement with each approach was repeated twice in a same visit. Then, the absolute value of the difference between the measured sensitivity of the added ten test points and the average of the sensitivities of surrounding three/four test points were calculated. Finally, the relationship between the gradient of sensitivity plane and the absolute difference was investigated using the multilevel modeling (MLM).Results MLM revealed significant positive relationship between the absolute difference and the gradient of plane with all of the four measurements (p&lt;0.01).Conclusion It may be advantageous to increase the spatial information by carrying out additional measurement at the gap where the border of scotoma is steep.

Visualizing the hill of vision in 3D using the free programming language ‘R’

Visualizing the hill of vision in 3D using the free programming language ‘R’

K-Train–a computer-based, interactive training program with an incorporated certification system for practicing kinetic perimetry: evaluation of acceptance and success rate

To evaluate, in an experimental study, an interactive, computer-based teaching procedure for kinetic perimetry that incorporates an evaluation system for scoring examination technique. K-Train was developed and based on the original user interface of the new semi-automated kinetic perimetry (SKP) feature of the OCTOPUS 101 perimeter (HAAG-STREIT, Koeniz, Switzerland). The trainer creates a 3D individual "hill of vision" for a specific pathology and the trainee can individually select target characteristics and independently define origin, end and direction of each kinetic stimulus with the help of vectors. Quality of the perimetric examination can be quantitatively assessed by the ratio of intersection area and union area of the trainee's result and the related trainer-defined original isopter. This ratio and other parameters are used to define a score of "perimetric quality". The general acceptance of K-Train was assessed in 30 participants in two perimetric courses. The success rate was examined by comparing the scores before and after a perimetric training session. The K-Train course was graded by the participants with an average score of 1.35 (range 1-3) in a scoring system ranging from 1=excellent to 6=unsatisfactory. The average perimetric quality score increased from 48 before to 59 (max. 100) after the training (27 trainees) indicating that K-Train was able to achieve and also verify a considerable success rate. The acceptance of K-Train, a computer-based, interactive tool that allows for certification, education and quality control of kinetic perimetry, is high. K-Train is capable of improving a trainee's individual performance in kinetic perimetry and of verifying this by an appropriate scoring system.

Normal Isopter Position in the Peripheral Visual Field in Goldmann Kinetic Perimetry

Purpose: Often in young patients the question arises if a disease state has contracted their peripheral boundary of the visual field. Since the ‘hill of vision’ is steeper in the periphery, kinetic perimetry is more sensitive in detecting peripheral visual field abnormalities than static perimetry. In order to be able with kinetic perimetry to detect mild peripheral visual field constrictions, we determined the normal position of 4 isopters in the peripheral visual field. Subjects and Methods: Intraindividual sensitivity variations of the isopters in the peripheral visual field were determined in 3 normal subjects by one perimetrist. Then, in 22 subjects (19–42 years old) the position of the isopters V4e, III4e, I4e and I3e has been determined by one perimetrist. Visual fields were registered using a Goldmann kinetic perimeter. Results: The intraindividual sensitivity variations (measured as 1 standard deviation) for the isopter V4e was 0.98° and for the isopter I4e 1.13°. To visualize the normal isopter positions in the peripheral visual field, the average positions ± 2 standard deviations were plotted for the isopters V4e, III4e, I4e and I3e. Conclusion: In this study, we determined the normal position of 4 isopters frequently used to plot the peripheral visual field. The plots have been printed in a scale of 1:4 in order to facilitate its use. Photocopying the figures on transparencies by scaling them with a factor 4 will allow to superpose the transparencies on individual Goldmann kinetic visual fields in order to easily determine whether the individual isopters are inside or outside the normal range.

Henry James’s Apprenticeship by W.R. Martin and Warren U. Ober

offer a special instance of prophetic utterance. “The Lamb,” for exam­ ple, clearly portrays the adamic power of naming (though also, I suspect, the arguably “socio-political” mode of catechizing). Children are especially vulnerable to coercive and exploitative impositions from the socio-political sphere. The term “imposition,” a key word in The Marriage of Heaven and Hell and elsewhere in Blake, becomes an important dimension of Esterhammer ’s theory in her analysis of the prophecies. In The Marriage of Heaven and Hell, for example, Blake’s Isaiah claims the authority to impose upon his audience, and hence to effect changes in individuals and in society, through his sense of a “firm perswasion” and the voice of “honest indigna­ tion.” Blake’s sense of “imposition” enriches Esterhammer’s description of the tensions between the poet-prophet and society. In the final chapter on Jersualem, text and theory merge in a critical state­ ment that affirms, in a provocative reading of the final line of the poem, the authority of the visionary poet: “Jerusalem, as a social and spiritual entity, is brought into existence by the verbal pronouncement of the visionary poet” (216). The culminating integration of text and theory achieved in the final chapter leads me to comment on the structure of the entire book. Esterham­ mer’s study enacts the process of vision through its carefully orchestrated dialectic structure. The book also consists of seven chapters, the paradig­ matic number of vision. Esterhammer’s use of the structure and number of vision may show her debt to Northrop Frye, who used similar techniques and who is clearly an important influence on her work. If these assumptions are correct, then one can conclude with a metaphoric comparison of her work to the visionary prospects it examines: the way up the hill of vision in Esterhammer’s study is instructive, and the view of Jerusalem at the top is superb. d a v id g a y / University of Alberta W.R. Martin and Warren U. Ober, Henry James’s Apprenticeship (Toronto: P.D. Meany, 1994). xiv, 213. 2 illustr. $45.00 cloth. The task undertaken here by W.R. Martin and Warren U Ober may initially seem fairly clear and straightforward, but, as soon becomes evident, it is by no means without difficulty. They attempt not only to offer an analysis of each of the thirty-eight tales written in the first fifteen years of James’s career but also to show how these tales prepared for the writing of James’s first masterpiece, The Portrait of a Lady. The most immediate problem is how to cope with those tales that James himself decided not to include in the New York Edition of his work. One, 349 “A Tragedy of Error,” was never even acknowledged by James as his (14); another, “Professor Fargo,” has been dismissed by Leon Edel as “one of James’s recurrent potboilers” (112); still another, “Rose-Agathe,” is cer­ tainly not done any injustice by Edel’s description of it as a “trifle.” 1 And there are other tales — many others — that could slow down the metabolism of any critical intelligence stubbornly plodding toward what would soon ap­ pear, with every additional page of dullness, as an impossibly distant finish line. What fortifies the reader for the journey is the sudden, and seemingly inexplicable, appearance of tales that are head and shoulders above the rest, tales like “The Madonna of the Future,” “Madame de Mauves,” and “An International Episode.” And, miraculously, towering above all these is the nouvelle that has gathered about it the mantle of greatness, “Daisy Miller.” But how does one trace the lines of development that accurately delineate this evolution? James himself obliquely hints that the nature of such a progression can indeed be traced. For James writes, in two separate passages quoted by Martin and Ober, that he was “ ‘the fond observer of the footsteps of genius’ ” (3), and that he would “ ‘follow in the footsteps’ of Stendhal and Balzac” (159); Leon Edel adds that, in James’s journey through Europe, James himself “knew ... there were moments when he distinctly felt as if he were following in the footsteps of Nathaniel Hawthorne.” 2...

Asymmetry and Variation in the Normal Hill of Vision

This analysis describes the symmetry and variation in the shape and height of the "hill of vision" obtained from automated static visual field testing of 146 normal eyes of 81 people aged 20 to 78 years. Threshold values dropped from the center to the 30 degrees periphery, with the greatest decrease occurring in the superior quadrant. Variability also increased with distance from the center of fixation, with the greatest variability occurring in the superior quadrant. Threshold values were lower throughout the field in individuals over age 60 years compared with those who were younger, with the greatest decrease in thresholds occurring in the superior quadrant. This age effect was not explained by differences in pupil diameter or central acuity. Variability was higher in the older group, but only in the periphery (greater than 24 degrees from fixation).

The Hill of Vision: A Forecast of the Great War and of Social Revolution with the Coming of the New Race Gathered from Automatic Writings obtained between 1909 and 1912, and also, in 1918, through the Hand of John Alleyne under the Supervision of the Author

The Hill of Vision: A Forecast of the Great War and of Social Revolution with the Coming of the New Race Gathered from Automatic Writings obtained between 1909 and 1912, and also, in 1918, through the Hand of John Alleyne under the Supervision of the Author