Visual Field Characteristics Research Articles

Visual fields, foraging and collision vulnerability in gulls (Laridae)

Wide variation in visual field configuration has been recorded among avian species and it is hypothesized that this variation is driven primarily by foraging ecology and predator detection. It has also been shown that visual field configurations can render some species more vulnerable to collisions with human artefacts that extend into open airspace, such as power lines and wind turbines. Visual fields have three main components: the monocular fields describe the extent of the world seen by each eye, the binocular field describes the region where the monocular fields overlap, and the blind area describes the region in which no vision is provided. Among birds, the topography of the binocular field, and the extent and position of the blind area, show considerable interspecific variation. Although Laridae (gulls, terns, skimmers) are a large and cosmopolitan taxon, visual field characteristics of only one species, Black Skimmer Rynchops niger, have been determined. However, skimmers are distinct from other Laridae species because they use a specialized foraging technique based upon tactile cues. We determined visual fields in three species of gulls (European Herring Gulls Larus argentatus, Lesser Black‐backed Gulls Larus fuscus, Black‐legged Kittiwakes Rissa tridactyla), and found that they show the key characteristics associated with visually guided foraging. However, the binocular field does not extend through the full height of the frontal field. This results in a blind sector, which can project in the direction of flight when gulls pitch their heads sufficiently far forwards to visually search the surface below. This could render gulls vulnerable to collisions with anthropogenic structures (power lines, wind turbines) that extend into the open airspace. Photographs show that gulls in level flight do pitch their heads forward sufficiently to render them almost blind in the direction of travel, and further work on the head positions adopted by gulls in flight are recommended. The visual field of skimmers differs markedly from those of gulls. Their binocular field topography is interpreted as functioning in the control of bill position when skimming (flying just above the water surface with the elongated, blade‐like, rhamphotheca of the mandible extending through the water surface). Skimmers also have a blind area, which projects forwards in the direction of travel when skimming. This can be associated with the vulnerability of skimmers to collisions with objects that extend just above the water surface.

Driving Behavior Model for Multi-Vehicle Interaction at Uncontrolled Intersections Based on Risk Field Considering Drivers’ Visual Field Characteristics

Driving Behavior Model for Multi-Vehicle Interaction at Uncontrolled Intersections Based on Risk Field Considering Drivers’ Visual Field Characteristics

Glaucoma after penetrating keratoplasty and keratoprosthesis

To compare visual and glaucoma outcomes in patients with known glaucoma after a penetrating keratoplasty (PKP) or a Boston Keratoprosthesis Type 1 (KPro) as a second corneal replacement procedure. Retrospective interventional case series. Charts of 141 eyes that underwent either a PKP or KPro at the Centre hospitalier de l'Université de Montréal after one failed PKP from 2008 to 2020 were reviewed. Forty-six eyes with preoperative glaucoma were included. Data collected included demographics, indication for the initial surgery, best corrected visual acuity (BCVA), concurrent ocular disorders, number of glaucoma medications, need for glaucoma surgery, cup-to-disc ratios (CDRs), mean RNFL thickness, and visual field (VF) characteristics. Primary outcomes were glaucoma progression trends. Secondary outcomes were visual outcomes and need for additional procedures. Mean follow-up was 4.7years for the PKP and 7.3 for the KPro group (P<0.007). 30.6% of PKP compared to 70.5% of KPro patients were diagnosed with glaucoma preoperatively. Glaucoma worsened similarly in both groups; this is based on an analysis of the number of glaucoma medications, CDR, need for glaucoma surgery, and characteristic VF changes. Patients in the PKP group required significantly more regrafts than patients in the KPro group (31.8 vs. 8.3%; P=0.045). A preoperative diagnosis of glaucoma does not preclude KPro implantation. In glaucomatous eyes, the disease progressed similarly in both groups. Since both procedures increase the risk of worsening glaucoma, close follow-up is recommended. KPro may decrease the need for further corneal transplantation surgery.

FACTORS RELATED TO UNFAVORABLE VISUAL OUTCOME AFTER IDIOPATHIC EPIRETINAL MEMBRANE SURGERY IN PATIENTS WITH GLAUCOMA.

To evaluate the visual outcomes after idiopathic epiretinal membrane surgery in glaucomatous and nonglaucomatous eyes and factors related to unfavorable outcomes in glaucomatous eyes. This was a retrospective cohort study including patients undergoing idiopathic epiretinal membrane surgery with ≥12-month follow-up. Final visual acuity at pseudophakic status was compared among groups of glaucoma, glaucoma suspect, and nonglaucoma and correlated with optical coherence tomography and visual field characteristics in patients with glaucoma. Of the 314 patients enrolled, 31 had glaucoma and 22 were glaucoma suspect. Baseline visual acuity and central foveal thickness were similar across the groups. Most patients had improved/stable visual acuity postoperatively, with a lower proportion of 83.9% with glaucoma than 96.9% and 100% without glaucoma and glaucoma suspect, respectively (P = 0.002). The mean visual acuity did not change in the glaucoma group (from 6/29 to 6/23), but it improved from 6/25 to 6/12 (a gain of 16.7 approxETDRS letters) in nonglaucoma and 6/26 to 6/14 in glaucoma suspect (a gain of 14.0 approxETDRS letters) (both P < 0.001). The change of visual acuity was correlated with preoperative visual field defects (P < 0.001, r2 = 0.554). Patients with glaucoma with more advanced, fixation-threatening defects or temporally located inner nuclear layer microcysts were more likely to have worsened visual acuity. Visual field testing is imperative for patients with glaucoma before idiopathic epiretinal membrane surgery for outcome assessment.

Visual Field Characteristics in East Asian Patients With Occult Macular Dystrophy (Miyake Disease): EAOMD Report No. 3.

PurposeThe purpose of this study was to investigate the perimetric features and their associations with structural and functional features in patients with RP1L1-associated occult macular dystrophy (OMD; i.e. Miyake disease).MethodsIn this international, multicenter, retrospective cohort study, 76 eyes of 38 patients from an East Asian cohort of patients with RP1L1-associated OMD were recruited. Visual field tests were performed using standard automated perimetry, and the patients were classified into three perimetric groups based on the visual field findings: central scotoma, other scotoma (e.g. paracentral scotoma), and no scotoma. The association of the structural and functional findings with the perimetric findings was evaluated.ResultsFifty-four eyes (71.1%) showed central scotoma, 14 (18.4%) had other scotomata, and 8 (10.5%) had no scotoma. Central scotoma was mostly noted in both eyes (96.3%) and within the central 10 degrees (90.7%). Among the three perimetric groups, there were significant differences in visual symptoms, best-corrected visual acuity (BCVA), and structural phenotypes (i.e. severity of photoreceptor changes). The central scotoma group showed worse BCVA often with severe structural abnormalities (96.3%) and a pathogenic variant of p.R45W (72.2%). The multifocal electroretinogram (mfERG) groups largely corresponded with the perimetric groups; however, 8 (10.5%) of 76 eyes showed mfERG abnormalities preceding typical central scotoma.ConclusionsThe patterns of scotoma with different clinical severity were first identified in occult macular dystrophy, and central scotoma, a severe pattern, was most frequently observed. These perimetric patterns were associated with the severity of BCVA, structural phenotypes, genotype, and objective functional characteristics which may precede in some cases.

Driving Behavior Model for Multi-Vehicle Interaction at Uncontrolled Intersections Based on Risk Field Considering Drivers' Visual Field Characteristics

Driving Behavior Model for Multi-Vehicle Interaction at Uncontrolled Intersections Based on Risk Field Considering Drivers' Visual Field Characteristics

Eye-tracking-based visual field analysis (EFA): a reliable and precise perimetric methodology for the assessment of visual field defects

ObjectiveSeveral studies report evidence for training-related neuroplasticity in the visual cortex, while other studies suggest that improvements simply reflect inadequate eye fixation control during perimetric prediagnostics and postdiagnostics.Methods and analysisTo...

Ineffectiveness of light emitting diodes as underwater deterrents for Long-tailed Ducks Clangula hyemalis

Gillnet bycatch accounts for over 400,000 bird mortalities worldwide every year, affecting a wide variety of species, especially those birds that dive when foraging. Technological solutions to improve gillnet visibility or deter birds from approaching nets, such as LED lights, are essential for aiding diving birds to perceive nets as a hazard. Designing such solutions requires obtaining visual and behavioural ecology information from species to assess their ability to see the warning devices, and to examine their behavioural responses to them. Seaducks, particularly Long-tailed Ducks Clangula hyemalis, have high bycatch mortality rates. We examined the visual fields of four Long-tailed Ducks to understand their three-dimensional view around the head. The visual field characteristics of this species indicate a reliance on visual guidance for foraging associated with their capture of varied, mobile prey in their generalist diet. We subsequently conducted dive tank trials to test the effectiveness of 12 different LED treatments as visual deterrents to the underwater foraging behaviour of 8 Long-tailed Ducks. During each trial, ducks were offered food rewards from a specific underwater location in a dive tank, having the choice of whether to take the food or not. At the same time, they were exposed to either one LED light or the control (no light) to determine whether the presence of each light affected the foraging success rate of dives compared to the control. Exposure of ducks to all 13 treatment combinations was randomised over the trial period. White lights with an increasing flash rate were shown to have a significant positive effect on foraging success, and likely acted as a visual attractant, rather than as a deterrent. No light treatment significantly reduced the foraging success of ducks. LED lights did not inhibit the feeding of Long-tailed Ducks. Such lights may be ineffective as underwater visual deterrents when deployed on gillnets, while white flashing lights may make foraging sites more attractive to Long-tailed Ducks.

Clinically Nonfunctioning Pituitary Incidentalomas: Characteristics and Natural History

Introduction: Available data on pituitary incidentalomas mostly derive from small-scale studies, with heterogeneous inclusion criteria and limited follow-up. No paper has focused specifically on clinically nonfunctioning pituitary in­cidentalomas (CNFPIs). Objective: To describe the charac­teristics and the natural history of patients diagnosed with CNFPIs. Methods: Retrospective multicenter cohort study evaluating hormonal, imaging, and visual field characteristics at diagnosis and during follow-up of CNFPIs investigated in 2 Pituitary Centers. Results: Three hundred and seventy-one patients were included (50.9% microadenomas, 35.6% males). Men were older and more likely to have a macroadenoma (p < 0.01). Totally, 23.7% of patients presented secondary hormonal deficits (SHDs), related to tumor size (higher in macroadenomas; p < 0.001) and age (higher in older patients; p < 0.001). Hypogonadism was the most frequent SHD (15.6%). Two hundred and ninety-six patients had follow-up data, 29.1% required surgery after first evaluation, and 97 had at least 3 years of follow-up. In total, 15.3% adenomas grew (more macroadenomas), but only in microadenomas patients with longer follow-up showed a higher growth trend. Totally, 5.2% of patients developed new SHDs (micro- vs. macroadenomas p = 1.000), and in 60% of them this was not associated with an increase in tumor size. Thirteen additional patients required surgery during follow-up (1 microadenoma at diagnosis). Conclusions: Macroadenomas and age are risk factors for SHD in CNFPIs, which occur at diagnosis in a quarter of patients. During follow-up, macroadenomas tend to grow more often, but microadenomas display higher growth trend as follow-up increases. Deterioration of pituitary function is not always related to adenoma growth.

Lifestyle shapes bird of prey binocular visual field

Swooping toward a victim with its vicious talons extended, a bird of prey homes in for the kill with meticulous precision. ‘Birds, particularly birds of prey [raptors], are believed to forage primarily using visual cues’, says vision scientist Simon Potier from Lund University, Sweden, who was inspired by his father's love of birds of prey to take up falconry as a small child. Yet, Potier explains that it was not clear how the birds use the region where the views from the two eyes overlap (the binocular zone) during their rapier-like attacks. As the hunting strategies of birds of prey span low-speed scavenging to high-speed aerial and ground prey capture, Potier, Francesco Bonadonna and Olivier Duriez from Université de Montpellier, France, and an international team of collaborators wondered whether the binocular vision of these precision hunters might vary depending on their lifestyle.Potier turned to his own collection of almost 60 birds at Les Ailes de l'Urga theme park in France and other birds from Le Grand Parc du Puy du Fou to measure the binocular visual fields of birds ranging from carrion-feeding vultures to predatory Cooper's hawks and eagles that target victims on the ground. ‘We used a non-invasive procedure to measure visual field characteristics in alert birds’, says Potier, recalling the difficulty of holding the large eagles steady for 20 min while measuring the limit of the view from each eye in order to calculate the binocular region where the visual fields overlapped. ‘The experience of the falconers who helped was essential’, he says. In addition, he had to custom build individual bill holders for each species to keep their heads in place, ‘which took me quite some time to fit perfectly’, he laughs. However, Potier was relieved when the birds appeared unfazed after they were released: ‘Directly after the experiment, they still flew to me, which indicates that they were not stressed’, he smiles.Initially, Potier and his colleagues had anticipated that the binocular visual fields of the hunters would be wider than those of the scavengers, as the hunters have to precisely target a moving victim with their talons while the scavengers’ aim may not need to be as precise. However, the width of the binocular visual fields was remarkably similar. The contrasts were more apparent when the team plotted the full projections of the binocular region, showing that the zone above the beak where the view from the two eyes overlapped tapered more rapidly in the ground-hunting eagles than it did in Cooper's hawks (which target birds on the wing) and the scavenging vultures. There was also an extensive blind zone above the heads of the ground predators – which do not have to outmanoeuvre agile targets on the wing. Considering the various hunting strategies and differences in the head shapes of the 15 species, Potier and his colleagues suspect that the ridge of bone that shades the eyes of the ground-hunting species could partially obscure the upper portion of their binocular field to produce the large blind zone. In addition, their short, but wide, powerful beaks appear to shade the lower portion of their view.‘Our results show that the binocular field configuration is specialized to foraging tactics in raptors’, says Potier, who is keen to scrutinise the vision of the almost exclusively terrestrial secretary bird. ‘They have very large eyes… I would love to estimate their visual field’, he muses.

Reversal of Glaucoma Hemifield Test Results and Visual Field Features in Glaucoma

To develop a visual field (VF) feature model to predict the reversal of glaucoma hemifield test (GHT) results to within normal limits (WNL) after 2 consecutive outside normal limits (ONL) results. Retrospective cohort study. Visual fields of 44 503 eyes from 26 130 participants. Eyes with 3 or more consecutive reliable VFs measured with the Humphrey Field Analyzer (Swedish interactive threshold algorithm standard 24-2) were included. Eyes with ONL GHT results for the 2 baseline VFs were selected. We extracted 3 categories of VF features from the baseline tests: (1) VF global indices (mean deviation [MD] and pattern standard deviation), (2) mismatch between baseline VFs, and (3) VF loss patterns (archetypes). Logistic regression was applied to predict the GHT results reversal. Cross-validation was applied to evaluate the model on testing data by the area under the receiver operating characteristic curve (AUC). We ascertained clinical glaucoma status on a patient subset (n= 97) to determine the usefulness of our model. Predictive models for GHT results reversal using VF features. For the 16 604 eyes with 2 initial ONL results, the prevalence of a subsequent WNL result increased from 0.1% for MD <-12 dB to 13.8% for MD ≥-3 dB. Compared with models with VF global indices, the AUC of predictive models increased from 0.669 (MD ≥-3 dB) and 0.697 (-6 dB ≤ MD <-3 dB) to 0.770 and 0.820, respectively, by adding VF mismatch features and computationally derived VF archetypes (P < 0.001 for both). The GHT results reversal was associated with a large mismatch between baseline VFs. Moreover, the GHT results reversal was associated more with VF archetypes of nonglaucomatous loss, severe widespread loss, and lens rim artifacts. For a subset of 97 eyes, using our model to predict absence of glaucoma based on clinical evidence after 2 ONL results yielded significantly better prediction accuracy (87.7%; P < 0.001) than predicting GHT results reversal (68.8%) with a prescribed specificity 67.7%. Using VF features may predict the GHT results reversal to WNL after 2 consecutive ONL results.

A Study on Layout of Combiner Head-up Display on the basis of Visual Field Characteristics

A Study on Layout of Combiner Head-up Display on the basis of Visual Field Characteristics

Homonymous hemianopia: challenges and solutions.

Stroke is the most common cause of homonymous hemianopia (HH) in adults, followed by trauma and tumors. Associated signs and symptoms, as well as visual field characteristics such as location and congruity, can help determine the location of the causative brain lesion. HH can have a significant effect on quality of life, including problems with driving, reading, or navigation. This can result in decreased independence, inability to enjoy leisure activities, and injuries. Understanding these restrictions, as well as the management options, can aid in making the best use of remaining vision. Treatment options include prismatic correction to expand the remaining visual field, compensatory training to improve visual search abilities, and vision restoration therapy to improve the vision itself. Spontaneous recovery can occur within the first months. However, because spontaneous recovery does not always occur, methods of reducing visual disability play an important role in the rehabilitation of patients with HH.

Spatiotemporal flow of information in the early visual pathway

The spatial components of a visual scene are processed neurally in a sequence of coarse features followed by fine features. This coarse-to-fine temporal stream was initially considered to be a cortical function, but has recently been demonstrated in the dorsal lateral geniculate nucleus. The goal of this study was to test the hypothesis that coarse-to-fine processing is present at earlier stages of visual processing in the retinal ganglion cells that supply lateral geniculate nucleus (LGN) neurons. To compare coarse-to-fine processing in the cat's visual system, we measured the visual responses of connected neuronal pairs from the retina and LGN, and separate populations of cells from each region. We found that coarse-to-fine processing was clearly present at the ganglion cell layer of the retina. Interestingly, peak and high-spatial-frequency cutoff responses were higher in the LGN than in the retina, indicating that there was a progressive cascade of coarse-to-fine information from the retina to the LGN to the visual cortex. The analysis of early visual pathway receptive field characteristics showed that the physiological response interplay between the center and surround regions was consistent with coarse-to-fine features and may provide a primary role in the underlying mechanism. Taken together, the results from this study provided a framework for understanding the emergence and refinement of coarse-to-fine processing in the visual system.

Retinal ganglion cell topography in juvenile Pacific bluefin tuna Thunnus orientalis (Temminck and Schlegel)

The retinal ganglion cell distribution, which is known to reflect fish feeding behavior, was investigated in juvenile Pacific bluefin tuna Thunnus orientalis. During the course of examination, regularly arrayed cells with a distinctive larger soma, which may be regarded as motion-sensitive cells, were found. The topographical distribution of ordinary-sized ganglion cells, which is usually utilized to estimate fish visual axis and/or visual field characteristics, showed that the highest-density area, termed the area centralis, was localized in the ventral-temporal retina. The retinal topography of ordinary-sized ganglion cells seems to reflect the bluefin tuna's foraging behavior; while cruising, cells in the area centralis may signal potential prey, such as small schooling pelagic fishes or squids, that are present in the upward-forward direction. Judging from morphological characteristics, the large ganglion cells localized in the small temporal retinal area seem to be equivalent to physiologically categorized off-center Y-cells of cat, which are stimulated by a transient dark spot in a bright visual field. It was inferred that presumed large off-center cells in the temporal retina detect movements of agile prey animals escaping from bluefin tuna as a silhouette against environmental light.

A prospective comparison of chronic primary angle-closure glaucoma versus primary open-angle glaucoma in Singapore

To describe the optic disc, visual field and ocular characteristics of a consecutive cohort of Asian patients with chronic primary angle-closure glaucoma (CPACG), and compare them with those having primary open-angle glaucoma (POAG). In a prospective comparative case series of new patients with POAG or CPACG in Singapore, all patients underwent visual acuity assessment, slit-lamp examination, tonometry, gonioscopy, refraction, Heidelberg Retina Tomograph (HRT) and Humphrey visual field (HVF) assessment. 98 patients were enrolled (POAG n = 48; CPACG n = 50). CPACG patients were significantly older (66.5 ± 9.2 years vs. 64.1 ± 13.5 years; p = 0.027) and mostly female (p = 0.004). CPACG eyes had significantly higher intraocular pressure (26.9 ± 6.9 mmHg vs. 24.5 ± 3.3 mmHg; p = 0.03), shorter axial length (22.89 ± 0.97 mm vs. 24.26 ± 1.79 mm; p < 0.001) and shallower anterior chamber depth (2.60 ± 0.25 mm vs. 3.16 ± 0.48 mm; p < 0.001). HVF mean deviation or pattern standard deviation (PSD) did not differ significantly between POAG and CPACG eyes, but the latter had a lower PSD for a given mean deviation. HRT parameters between the two groups were not significantly different. In this study, CPACG eyes had significantly higher presenting intraocular pressure than POAG eyes, but there were no significant differences in optic disc topography. A majority of the patients in both groups had moderate field defects at the time of presentation, followed by severe and then mild defects. The field loss in CPACG eyes was more diffuse than that in POAG eyes.

Visual field characteristics in neuromyelitis optica in absence of and after one episode of optic neuritis

PurposeOptic neuritis (ON) observed during neuromyelitis optica (NMO) is in most cases very severe and with poor prognosis. This study’s objective was to analyze visual field (VF) abnormalities observed in the absence of ON and post-ON episode.MethodsTwenty-seven cases of both NMO and multiple sclerosis (MS) were selected. Thorough ophthalmologic exam was performed at least 6 months post-ON attack. The VF was collected using the Humphrey 750 perimeter. We used the central threshold tests 24-2 with FASTPAC strategy. The abnormalities were categorized based on the Optic Neuritis Treatment Trial classification.ResultsAfter one ON, 40% of the NMO group’s eyes showed total VF loss (P = 0.01), 21% showed abnormalities of neurologic aspect, and 27% showed fascicular abnormalities of which 12% were altitudinal. Given the total VF loss, the positive predictive value in favor of an NMO was 92.8% and the negative predictive value was 47.3%.ConclusionAlterations of the VF during the NMO differ from those observed in the course of the MS. One ON, blinding from the first attack, must call to mind an NMO. The altitudinal deficits point to a vascular mechanism.

A study of peripheral visual field characteristics at intersections with unobstructed visibility

AbstractThis paper describes a basic experiment and simulation of two peripheral visual field characteristics that are related to major factors in rural district accidents, namely, collision course relationships, and presence of objects in the peripheral visual field. The quantitative recognition threshold for shape changes (stimulus) in the peripheral visual field is studied. It is found that such critical dimensions as the diameter of a circle, the side length of a square or triangle, and the axis length of an oval are important in recognizing vehicles moving on a perpendicular course. It is shown that a similar principle applies to aircraft moving in three‐dimensional space, not just to vehicles moving on a two‐dimensional plane. This paper identifies the limit of the peripheral visual field characteristic, one of the human visual characteristics, and also shows that there is no dependence on figure shape for other figures whose maximum side size is the same as the diameter of the circle. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 96(1): 25–32, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11428

Preferred Retinal Loci Relationship to Macular Scotomas: A10-Year Comparison

Age-related maculopathy is the leading cause of vision loss among adults in developed countries, and its prevalence is expected to double over the next decade (Congdon et al., 2004; Friedman et al., 2004). The two forms of age-related maculopathy--exudative and nonexudative--are capable of affecting the macula, with potential symptoms including decreased contrast sensitivity, decreased visual acuity, abnormal adaptation to the dark, and central or pericentral scotomas (Jager, Mieler, & Miller, 2008). When a central scotoma impairs the ability of the fovea to distinguish detail, one or more preferred retinal loci (PRL) (Schuchard & Raasch, 1992; von Noorden & Mackensen, 1962; White & Bedell, 1990), also known as pseudo-foveas (Guez, Le Gargasson, Rigaudiere, & O'Regan, 1993), naturally develop at eccentric retinal locations and become the new points of fixation. The location of the PRL varies from person to person, as does the ability to maintain steady fixation with the PRL and to use it for reading and activities of daily living (Dalgleish & Naylor, 1963; Fletcher, Schuchard, & Watson, 1999; Timberlake et al., 1986; Whittaker, Budd, & Cummings, 1988). Fletcher and Schuchard (1997) reported the results of a study examining patterns of PRL ability and location relative to macular scotomas. They mapped dense scotomas and determined the location of the PRL in 1,339 eyes in 825 persons with a scanning laser ophthalmoscope during a standard low vision rehabilitation evaluation. Fletcher and Schuchard created a scoring system to measure the pursuit ability, fixation stability, and saccadic ability of the PRL. They determined the characteristics of dense scotomas within 2.5 degrees of the PRL or fovea. Of the 1,339 eyes, 84% (1,130) demonstrated an established PRL, ranging in size from 1.0 degrees to 9.0 degrees in diameter, and 82.5% had a central dense scotoma. The PRL had no dense scotomas on any border in 14.8% of the eyes. It had one, two, or three borders with a dense scotoma in 39.7%, 19.0%, and 9.0% of the eyes, respectively. Ring scotomas, bordering the PRL on four borders, were present in 17.4% of the eyes. Of the eyes with one scotomatous border, most had a field defect located either superior (39.0%) or to the right (33.7%). It was less common for the eyes to have field defects to the left or inferior, with 19.9% and 7.5% of the eyes, respectively. This report presents a 10-year comparison of these previous findings. It examines whether the PRL characteristics of persons with low vision remained steady over the ensuing decade. Changes in PRL and visual field characteristics among persons with low vision over time could have implications for the approaches of low vision rehabilitation professionals to training in eccentric viewing and other rehabilitation techniques. METHODS The study used 271 persons who were referred to the Frank Stein and Paul S. May Center for Low Vision Rehabilitation at California Pacific Medical Center (CPMC) in San Francisco between 2005 and 2007. All consecutive patients with low vision were included in the study, regardless of age, gender, race, and other demographic variables. Participants were excluded only if they lacked the cognitive or physical ability to complete a macular perimetry examination, as determined by the clinical impression of the ophthalmologist. Approval from the institutional review board was obtained from CPMC for the retrospective analyses of charts. As part of the standard low vision rehabilitation evaluation, an ophthalmologist measured visual acuity with the Early Treatment of Diabetic Retinopathy System chart (Ferris, Kassoff, Bresnick, & Bailey, 1982). The characteristics of the scotoma and PRL were measured with a Scanning Laser Ophthalmoscope (SLO; SLO-101, Rodenstock, Dusseldorf, Germany). The SLO was outfitted with a smart microperimetry (MacKeben & Gofen, 2007) program with a gaze-contingent display that automatically monitors eye movements, blinks, and other factors. …

Visual Field Characteristics in Normal-Tension Glaucoma Patients With Autonomic Dysfunction and Abnormal Peripheral Microcirculation

To elucidate the visual field (VF) characteristics of normal-tension glaucoma (NTG) patients with either autonomic dysfunction or abnormal peripheral microcirculation. Prospective, observational study. participants: Sixty NTG patients. procedures: All subjects underwent a complete ophthalmic examination and were then referred to a rheumatology department, where they were subjected to heart rate variability (HRV) assessment and nailfold capillaroscopy. Subjects with VF defect clusters confined to the central 10 degrees or outside the central 10 degrees (defined as peripheral) in 1 hemifield were selected (n = 60). The central and peripheral regions were divided further into superior and inferior sectors. Patients were classified into low, middle, and high HRV groups using HRV assessment or normal and abnormal capillaroscopy groups using nailfold capillaroscopy findings. The VF characteristics of the groups were compared. main outcome measures: Location of the VF defect, depth of the VF defect, mean deviation, and the pattern standard deviation of the VF. The VF defect was more frequent and deepest in the superior central sector in both the low HRV and abnormal capillaroscopy groups. The mean deviation was similar between groups, but the pattern standard deviation was significantly higher in eyes with central defects than in eyes with peripheral defects among those in the low HRV group or abnormal capillaroscopy group. Logistic regression analysis revealed that the group classified by the HRV assessment and the presence of abnormalities in the capillaroscopy were related to the location of the VF defect. NTG patients with low heart rate variability or abnormal nail capillaroscopy may present as central VF defects. Therefore, vascular risk factors need to be considered when NTG patients have central VF defects.