Periphery kinetic perimetry: clinically feasible to complement central static perimetry

Commentary: Rethinking 10-2 visual fields in early diagnosis of glaucoma for a glided glaucoma practice: The right choice to pick up a feeble noise?

Purpose To investigate whether peripheral and central visual field defects detected among epilepsy patients treated with vigabatrin are associated with reduced peripapillary retinal nerve fiber layer thickness as measured with optic coherence tomography (OCT). Methods Nine epilepsy patients with vigabatrin‐attributed visual field loss (group 1) and seven patients(age and sex matched) with epilepsy treated with other drugs(control group 2) were regularly examined with automated perimetry up to 60 degrees from fixation point (Humphrey Field Analyser). Peripapillary retinal nerve fiber layer thickness (RNFLT) was quantified by optic coherence tomography (OCT) using Fast RNFLT protocol, Stratus OCT (3.0). Five of the patients in group 1 had peripheral visual field defects, (group 1a), four had a central field defect(group 1b). All patients in control group 2 had normal visual field. Results Patients with vigabatrin‐attributed visual field loss had attenuated total RNFLT compared to controls (right eye : mean total RNFLT: group 1: 75.6 µm (SD 12.7); group 2: 103.5 µm (SD 9.7), mean difference 27.9 µm (CI 15.9‐39.9;P < 0.001). The nasal and inferior sectors RNFLT were more attenuated in patients with vigabatrin‐attributed visual field loss compared to controls, while no difference was detected in the temporal RNFLT. Both individuals with peripheral and central visual field losses had attenuated mean total RNFLT compared to controls (P = 0.006 and P= 0.002, respectively). Conclusion Vigabatrin‐attributed visual field defects are associated with reduced RNFLT. Combination of perimetry and OCT can efficiently detect vigabatrin induced retinal nerve fiber damage.

To explore the relationship between central corneal thickness (CCT) and visual field defect in open-angle glaucoma (OAG). In this cross-sectional study, we tested 344 eyes in 344 eligible patients, including 233 with normal-tension glaucoma (NTG) and 111 with primary open-angle glaucoma (POAG). The association among variables, especially that between visual field defect and CCT, was probed by multivariate regression in eyes with NTG or POAG, and in all eyes. All eyes were divided into early, moderate, or severe visual field defect groups according to Anderson's classification. Statistical analysis was performed for all cases, and for the three CCT groups. Multivariate regression analysis revealed an association between CCT and visual field defect in eyes with NTG but not in eyes with POAG or in all eyes. The eyes with early visual field defect had greater CCT than did those with severe visual field defect (533.2 versus 519.0 microm). The eyes with greater CCT had better visual field indices than did those with thinner CCT (-6.91 versus -9.17 dB). Central corneal thickness is a factor associated with the status of the visual field defect: a greater CCT is associated with a better visual field index. Other factors such as the glaucoma subtype play a role in the effect of CCT on visual field defect.

Disorders that specifically affect central and peripheral vision constitute invaluable models to study how the human brain adapts to visual deafferentation. We explored cortical changes after the loss of central or peripheral vision. Cortical thickness (CoTks) and resting-state cortical entropy (rs-CoEn), as a surrogate for neural and synaptic complexity, were extracted in 12 Stargardt macular dystrophy, 12 retinitis pigmentosa (tunnel vision stage), and 14 normally sighted subjects. When compared to controls, both groups with visual loss exhibited decreased CoTks in dorsal area V3d. Peripheral visual field loss also showed a specific CoTks decrease in early visual cortex and ventral area V4, while central visual field loss in dorsal area V3A. Only central visual field loss exhibited increased CoEn in LO-2 area and FG1. Current results revealed biomarkers of brain plasticity within the dorsal and the ventral visual streams following central and peripheral visual field defects.

To evaluate the difference of the peripapillary atrophy between two eyes of unilateral visual field defect in each of patient with primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG). This study included 40 eyes with unilateral visual field defect in patients with POAG (20 cases) and NTG (20 cases). Color stereo optic disc photographs were morphometrically evaluated by a video camera and a computer system. The refractive range (spherical equivalent) of all these subjects was between -3.00D and +3.00D. The cup areas (CA) and cup/disc areas (CA/DA) in eyes with visual field defect were significantly larger than in eyes with normal visual field (CA: t=5.332, P<0.01; CA/DA: t=5.126, P<0.01). The alpha zone areas (alphaA) of PPA were significantly enlarged in visual field defect eyes compared with visual field normal eyes (t=3.02, P=0.0045), while there is no significant difference in beta-zone area (betaA) between two eyes. (S=13.5, P=0.426). The frequency of the PPA (alpha-zone and beta-zone) occurrence were also similar in both eyes. (alphaA: chi(2)=0.00, P=1.000; betaA: chi(2)=1.2857, P=0.2568). The results suggest that either beta-zone area or the presence of PPA is not closely correlated to the visual field defect in POAG and NTG patients with exclusion of moderate or high myopia.

Visual field loss from primary angle-closure glaucoma*1A comparative study of symptomatic and asymptomatic disease

Introduction: Normal Tension Glaucoma (NTG) is a spectrum of primary open angle glaucoma, characterised by optic nerve head change in the form of glaucomatous cupping, visual field defects despite Intraocular Pressure (IOP) &lt;21 mmHg. Patients remain asymptomatic until significant visual field loss occurs. An early sign of NTG is Retinal Nerve Fiber layer (RNFL) thinning. Although IOP is within normal range, further reduction can slow the disease progression. Early diagnosis of NTG is challenging due to absence of raised intraocular pressure, thus structural evaluation by optic disc, RNFL and functional evaluation by visual field indices helps in earlier diagnosis and disease progression. Aim: The aim of this study was to assess the relationship of optic nerve head and RNFL changes with visual field findings in NTG patients. Materials and Methods: The present prospective, interventional, hospital based study included 40 eyes with NTG conducted at SRM Medical College Hospital and Research Centre, Kattankulathur, Chennai, Tamil Nadu, India and duration of study was one year and six months. Thorough history, ophthalmic examination was done which includes visual acuity, anterior and posterior segment, IOP, Central Corneal Thickness (CCT), visual fields and Optical coherence Tomography (OCT). Patients started on 0.2% brimonidine eye drops twice a day and progression was tracked by repeat visual fields six months later. Data was analysed using independent samples t test and correlation was assessed using Pearson’s rank correlation. Statistical Package for Social Sciences (SPSS) software version 26 was used for the statistical analysis. Results: Forty eyes were studied. Mean age was 49.75 years with majority males 15 (56%). Average IOP was 14.825 mmHg, Average CCT was 528.58 micrometres. Correlation between IOP and Average RNFL was statistically insignificant (p=0.857). CCT had weak positive correlation with average RNFL, which was not significant statistically (p=0.659). Average CDR was 0.61. Average RNFL thickness was 81.4 μm. CDR weakly correlated to RNFL thickness (r=-0.179: p=0.269) but strongly correlated to visual field indices (Average Mean Deviation (MD) r=+0.955: p&lt;0.00001). RNFL correlated with Mean Sensitivity (MS). Followup after six months showed that only two eyes (7%) had visual field progression and was changed to latanoprost 0.005% eye drops once daily. Conclusion: CCT and Diurnal IOP variation tests play an important role in diagnosis of NTG. Hypoperfusion might be an etiological factor in NTG. OCT aids in identifying RNFL thinning even before field defects. The progression of field defects in NTG was reduced by lowering IOP.

Studies analysing biological motion perception based on reduced number of dots have demonstrated that biological motion can be perceived even when only the lower part of the body is visible or when the number of dots representing the object is reduced. What is the minimal amount of information that enables biological motion to be distinguished from its scrambled version? The results of the current experiment demonstrate that biological motion can be distinguished from its scrambled version when the object is formed of approximately 5 (4.7 ± 0.1) dots. Additionally, we also investigated whether the threshold value for biological motion perception differs in central and peripheral visual fields. By using stimulus magnification, we demonstrate that the number of dots sufficient for biological motion perception is similar in the central visual field and near periphery. Hence, stimulus magnification can compensate for reduced task performance in the peripheral visual field. The current results suggest that reduced performance of biological motion perception in the peripheral visual field (as demonstrated in other studies) is due to difficulties with the global perception of biological motion.

In a survey of methods for determining hemianopic visual field defects, a distinction is made between gross visual field screening and actual visual field examination with kinetic and automatic static perimetry. These methods may be arranged according to increasing the concentration required as well as to ability to cooperate, as follows: hand-movement stimulation of shifts of gaze, finger-counting with repetition by the patient, brightness and color comparison among the respective halves and quadrants of the visual field, then kinetic perimetry with the Goldmann perimeter, and, most exacting of all, automated perimetry. The advantages of kinetic perimetry in cases of incipient bitemporal visual field defects are discussed. For visual field examination with automated static perimeters, test programs are chosen which have their test-point pattern shifted with respect to the principal meridian. The diagnostic situations in which visual field testing may and must not be limited to 30 degrees are presented in tabular form. Guidelines and criteria for localizing lesions have been developed, i.e., the vertical and horizontal limits of the major axes which pass through the fixation point and the temporal crescent. Consideration of the course of the nerve fibers in the retina and of the fact that exact separation between superior and inferior may only be found temporal to the foveola with corresponding nasal defects enables horizontally limited visual field defects originating within the eye to be distinguished clearly from those originating in the visual cortex. Vertical limits due to semidecussation at the chiasma permit a differentiation between prechiasmic and postchiasmic lesions. In homonymous defects, consideration of further simple anatomic features of the visual pathway, namely the knee of Wilbrand and that portion of the optic radiation which extends anteriorly to the temporal lobes and which represents the inferior retinal halves with characteristic defects, also enables lesions in the visual pathway to be localized more accurately.

The foveal avascular zone (FAZ) - with perimeter and acircularity index (AI) and surrounding vessel density - are measured in glaucomatous eyes in comparison to healthy eyes - with additional subdivision into visual field defects in different locations (central vs. peripheral). The data from 128 eyes were evaluated. Firstly, glaucomatous eyes (n = 74) were compared with healthy eyes (n = 54). In addition, glaucomatous eyes with a central visual field defect (ZGD, n = 19) and eyes with peripheral visual field defect (PGD, n = 34) were differentiated. The FAZ area, its perimeter and roundness, as well as the parafoveal vessel density (VD), were calculated by means of optical coherence tomography angiography in the superficial and deep vascular plexus. Glaucomatous eyes have no significant change in FAZ, its perimeter or the AI compared to healthy eyes. However, dividing the glaucomatous eye by visual field defect reveals that the eyes with a central defect have a significantly larger FAZ than those with a peripheral defect and the perimeter is also significantly larger. The AI shows no significant difference depending on the localisation of visual field defects. The macular/foveal VD is significantly lower in the ZDG group. In glaucoma, the FAZ enlarges when the visual field defect is centralised and VD decreases significantly in the area of fovea.

Objective To observe the changes in visual field defect before and after treatment in patients with acute solitary occipital lobe cerebral infarction. Methods From January 2017 to May 2019, 59 patients with hemianopsia who were diagnosed as acute occipital lobe cerebral infarction in Henan Provincial People's Hospital were selected. There were 35 males (59.3%) and 24 females (40.7%); aged from 50 to 72 years, with an average age of 62.86±6.10 years. There were 23 patients of right occipital cerebral infarction and 36 patients of left occipital cerebral infarction. Lesions involved 41 patients in the striated area, 8 patients involved the occipital pole, and 23 patients involved visual radiation. All patients underwent standard medical treatment. All patients underwent visual field examination before treatment, and modified rankin scale (mRS) was used to evaluate the level of visual disability after cerebral infarction. At 1, 3, and 6 months after treatment,54 patients underwent at least one visual field examination in outpatient or inpatient follow-up visits, and 5 patients were lost to follow-up; 49 patients received repeated mRS scores. The visual field defect and mRS score of patients before and after treatment were compared and analyzed. The improvement of visual field defect in the horizontal direction exceeding 10°or the vertical direction exceeding 15°was defined as improvement, otherwise it was defined as no improvement. According to the type of visual field defect, the patients were divided into two groups: complete homonymous hemianopia and incomplete homonymous hemianopia. The cumulative visual field improvement rate of the two groups of patients was calculated. An mRS score of 0 to 2 was defined as a good prognosis, and >2 was defined as a poor prognosis. Results Before treatment, of the 59 patients, 47 were complete homonymous hemianopsia and 12 were incomplete. Of the 47 patients with complete homonymous hemianopia, 26 patients had hemianopia on the right side of both eyes, 21 patients had hemianopia on the left side of both eyes; 32 patients with macular avoidance (72.3%). Among the 12 patients of incomplete homonymous hemianopia, 10 patients of quadrant blindness included 6 patients of upper quadrant and 4 patients of lower quadrant; 2 patients of partial isotropic hemianopia on one side. Of the 54 patients reviewed after treatment, the visual field improved at the last follow-up of 25 patients (46.3%), and there was no improvement in 29 patients (53.7%). The cumulative visual field improvement rate of 47 patients with complete hemianopia hemianopia before treatment was 37.2% (16/43). The cumulative visual field improvement rate of 11 patients with incomplete isotropic hemianopia before treatment was 81.8% (9/11). There was a statistically significant difference in cumulative visual field improvement between the two groups of patients (χ2 = 7.011, P<0.05). Before treatment, 59 patients had mRS scores of 1 to 2 points in 15 patients (25.4%), and 44 patients with 2 points or more (74.6%). Of the 49 patients reviewed after treatment, 28 (57.1%) had a good prognosis and 21(42.9%) had a poor prognosis. Conclusions The visual field defect of patients with homonymous hemianopsia after acute occipital infarction may be improved after treatment. The improvement mostly occurs within 1 m after treatment, and patients with incomplete homonymous hemianopsia have more significant improvements than those with complete homonymous hemianopsia. Key words: Occipital lobe; Cerebral infarction; Visual fields; Hemianopsia

Purpose: To evaluate the accuracy of confrontation visual field testing with regard to the density of the visual field defect and its location in the peripheral visual field. Methods: A prospective comparison of confrontation visual field testing with fullthreshold Humphrey automated static perimetry C24-2 or C30-2 was conducted at a university eye center over a 3-month period. Seventy-two patients with a variety of neurologic and ophthalmologic conditions underwent confrontation visual field testing and automated perimetry as a part of their evaluation. One visual field from each patient was analyzed for this study. Results: Confrontation visual field testing yielded an overall sensitivity for detecting an abnormal visual field (full-field analysis) of 63%, when sensitivity of confrontation testing rested on the detection of just one abnormal quadrant. The sensitivity of confrontation testing varied depending on the type of visual field loss present: 51 % for arcuate scotomas, 67% for visual field constriction, 78% for attitudinal scotomas, and 90% for hemianopias. The sensitivity of detecting abnormal visual field quadrants, rather than the full-field analysis, was, however, poor at 38%. The sensitivity of confrontation testing was lower for superior quadrant defects and higher for inferior quadrant defects. The estimated probability of detecting an abnormal visual field quadrant occurring at a —26-decibel sensitivity loss from age-matched healthy patients for superior quadrant defects and a —19-decibel sensitivity loss for inferior quadrant defects was 50%. The increased sensitivity noted for visual field defects and for inferior quadrant defects appears to be related, in part, to the density of the visual field loss present. Conclusion: Confrontation visual field testing is relatively insensitive unless a moderate to dense defect is present, and as such is a poor screening test. However, when visual field defects are identified with confrontation visual field testing, the defects often are real as per the high specificity (97%)and high positive predictive value (96%).

The contribution of peripheral and central vision in the control of movement amplitude

PURPOSE:Age-related macular degeneration (ARMD) is the leading cause of irreversible blindness worldwide and Nepal is one among them. We aimed to determine the relationship between outer retinal layer thickness parameters with central visual field indices in early dry ARMD cases among Nepalese population.MATERIALS AND METHODS:The subjects for this descriptive, cross-sectional study comprised 40 patients with early dry ARMD from the ophthalmology department of a tertiary level hospital of Nepal. The retinal layer thickness was measured with spectral-domain optical coherence tomography (SD-OCT), and the visual field indices were assessed using the 10-2 protocol of Humphrey visual field analyzer (HFA). Thus, the retinal layer structures correlated with visual field indices among our population.RESULTS:Among our early dry ARMD population, the foveal threshold (FT) was found to be significantly correlated with retinal pigment epithelium (RPE) elevation (P < 0.01, r = −0.541), outer segment (OS) length (P = 0.02, r = 0.465), and inner segment ellipsoid (ISe) band disruption (P = 0.01, r = −0.499), but not with presence of hyperreflective foci (P = 0.464), RPE thickness (P = 0.612), and central macular thickness (P = 0.214). However, no significant correlation between mean deviation and pattern standard deviation of visual field with retinal layer thickness parameters was identified.CONCLUSION:In early dry ARMD, a reduced FT is significantly correlated with the integrity of the ISe band, thinning of OS length, and drusen-associated RPE elevation. The results highlight the utility of both SD-OCT retinal layer measurement and central visual field testing by HFA in ARMD to monitor the progression of the disease.

To determine if motion automated perimetry can identify early glaucomatous visual field defects in patients with suspected glaucoma (by disc), those with ocular hypertension, and those with primary open-angle glaucoma. Motion automated perimetry, a foveally centered motion test, and standard visual field tests were conducted on one randomly selected eye of normal patients (n = 38), patients with suspected glaucoma (by disc) (n = 28), patients with ocular hypertension (n = 18), and patients with primary open-angle glaucoma (n = 21). Subjects' performance on both motion tests were compared with their performance on standard perimetry. Perimetric motion thresholds significantly distinguished the groups (P< or =.001), while the foveally centered motion test was unable to separate them (P< or =.32). Of the total patients, 90.5% of those with glaucoma, 39.3% of those with suspected glaucoma, 27.8% of those with ocular hypertension, and 5.3% of the normal subjects had abnormal results on motion automated perimetry testing. Perimetric motion thresholds were significantly correlated with standard visual field thresholds (P< or =.001). Motion automated perimetry identifies visual field defects in patients who already show standard visual field loss as well as in a moderate percentage of those with suspected glaucoma and ocular hypertension, indicating that the testing of discrete locations might be necessary for increased diagnostic utility.