Humphrey visual field and frequency doubling perimetry in the diagnosis of early glaucoma

PURPOSE: To compare Humphrey Visual Field Analyzer (HVF) and Frequency Doubling Perimetry (FDP) testing in the diagnosis of early glaucoma. METHODS: We performed HVF (24-2 standard full threshold) and FDP (N-30) evaluations in 34 consecutive patients with early primary glaucoma and 96 normal subjects. Early glaucoma was defined on the basis of disc changes of glaucoma; the mean deviation on white-on-white perimetry had to be no worse than 6 decibels. Glaucomatous optic neuropathy was defined as a combination of cup-disc asymmetry of more than 0.2, notching, excavation, thinning or pallor of superior or inferior neuroretinal rims, retinal nerve fibre layer defects of the wedge or diffuse type and neuroretinal rim haemorrhage. Both the glaucoma patients and normal subjects had vision better than 6/9 with correction. They had no media opacities other than early nuclear sclerosis and no fundus pathology. Further, normal subjects were free of systemic diseases known to affect the retina or optic nerve. The sensitivity and specificity of HVF and FDP were calculated. RESULTS: There were 44 eligible eyes among the 34 subjects. The glaucomatous disc findings included notch (n=8), pallor (n=21), thinning (n=23) and haemorrhage (n=1) of the neuroretinal rim. The sensitivity and the specificity of the HVF were 52.3% and 57.3% respectively. The sensitivity and the specificity of FDP were 65.9% and 61.5% respectively. CONCLUSION: The difference between FDP and HVF in the diagnosis of early glaucoma is not marked.     

Comparison of an automated confrontation testing device versus finger counting in the detection of field loss.

PURPOSE: The aim of this study was to compare an automated confrontation visual field testing (ACV) device with traditional finger-counting confrontation visual field testing (FCV). METHODS: Forty-five eyes of 45 subjects with glaucoma, 5 eyes of 5 subjects with neurologic disease and 15 eyes of 15 normal subjects (age matched to the subjects with glaucoma by frequency) were tested on both ACV and FCV. All subjects with glaucoma and neurologic disease had visual field loss on white-on-white Humphrey perimetry (HVF). The FCV was performed in 8 meridians in a normally lighted room, whereas ACV was performed in a darkened room. The ACV device consisted of a black rectangular box with 4 1.0-mm red light-emitting diodes at each corner and a fixation hole at the center. Four automated randomized presentations were presented, and the subject was asked to identify the number of red lights seen (from 1 to 4). Any point missed on any of the presentations on either test was recorded as a failure. RESULTS: All normal subjects passed both tests. FCV detected field loss in 33.0% of glaucomatous eyes, whereas ACV detected field loss in 58% of glaucomatous eyes (P < 0.001). Subjects with glaucoma who passed FCV but failed ACV had an average mean deviation of -7.77 dB on HVF, compared with subjects who failed both FCV and ACV, who had an average mean deviation of -19.74 dB on HVF (P < 0.001). All subjects with absolute visual field loss because of advanced glaucoma or neurologic disease failed both tests. No subject who passed ACV failed FCV. CONCLUSIONS: Gross confrontation visual field testing using an automated testing device has a greater sensitivity in the detection of moderate visual field loss than finger counting confrontation visual fields.     

Humphrey visual field findings in hydroxychloroquine toxicity

Purpose

To analyze Humphrey visual field (HVF) findings in hydroxychloroquine (HCQ) retinal toxicity.

Methods

HVF tests were interpreted retrospectively in this observational case series of 15 patients with HCQ toxicity. Patients seen at Lahey Clinic were identified by diagnosis coding search. Patients with age-related macular degeneration or glaucoma with visual field loss were excluded. HVFs done before the diagnosis were analyzed to see if earlier diagnosis could have been possible.

Results

A total of 66 HVFs were reviewed and categorized. Some abnormalities were subtle. Paracentral defects were seen on 10-2 tests whereas 24-2 tests, due to their compressed scale, showed central changes. The abnormalities were often more obvious on pattern deviation rather than the gray scale. Of those patients with prior HVFs available for review, 50% showed HVF abnormalities typical of HCQ toxicity present several months or years before diagnosis. HVF changes preceded fundus changes in nine patients.

Conclusion

HVF abnormalities indicating HCQ toxicity vary depending on the specific HVF test performed. Clinicians need to be aware of the subtle nature of HVF changes in early toxicity.     

Comparison of contrast sensitivity,visual acuity,and Humphrey visual field testing in patients with glaucoma

BACKGROUND: Despite their normal or near-normal Snellen visual acuity, patients with glaucoma often complain of "poor" vision. OBJECTIVE: To investigate the relationship between large-letter contrast sensitivity, high-contrast visual acuity, and visual field defects in patients with glaucoma who have 20/40 or better visual acuity. DESIGN :Prospective, cross-sectional case series. PATIENTS AND METHODS: We evaluated 250 eyes of 144 subjects from the Glaucoma Service at the University of Illinois at Chicago College of Medicine. Subjects with a diagnosis of glaucoma, suspected glaucoma, or ocular hypertension who met the 20/40 or better vision requirement were recruited. Visual acuity was measured using the rear-illuminated Lighthouse Visual Acuity Chart at 4 m. Contrast sensitivity was measured using the Pelli-Robson Chart in a front-illuminated box with even luminance across the chart. Visual fields of the patients were measured using the 24-2 full-threshold program on the Humphrey Visual Field Analyzer. RESULTS: A significant correlation (r = 0.57, P < 0.001, n = 127) was found between the visual field mean deviations and the contrast sensitivity scores. The correlation (r = -0.322, P < 0.001, n = 127) was less between the visual field mean deviation and the log MAR visual acuity values, as was the correlation between the contrast sensitivity scores and log MAR visual acuity values (r = -0.370, P < 0.001, n = 127). In the subgroup of patients with chronic open-angle glaucoma, the correlation between the mean visual field deviation and the contrast sensitivity score was higher at 0.689 (P < or = 0.001, n = 62). CONCLUSIONS: Reduced contrast sensitivity is significantly correlated with visual field losses in patients with glaucoma and a visual acuity of 20/40 or better. The study data support the conclusion that, compared with visual acuity, the disease process preferentially affects contrast sensitivity. In our previous work, contrast sensitivity was shown to be more related than visual acuity to real-world function in patients with early glaucomatous changes.     

Correlation of the binocular visual field with patient assessment of vision

PURPOSE: To determine which measures of the binocular visual field correlate best with the patient's assessment of vision. METHODS: Esterman binocular visual field testing and four other binocular visual field tests (designated peripheral 20 dB [p20], peripheral 22 dB [p22], central 24 dB [c24] and central 26 dB [c26]) were performed in 101 patients with glaucoma or suspected glaucoma. Scores from these five tests, as well as binocular visual field scores calculated from monocular testing (best-location summation and probability summation), were correlated with performance on the National Eye Institute's Visual Function Questionnaire (VFQ)-25 and Short-Form (SF)-36 quality of life instruments, as well as with the linear rating scale utility test. RESULTS: The mean percentage of correct responses was 87%, 69%, 59%, 78%, and 71% for the Esterman, p20, p22, c24, and c26 tests, respectively. The distribution of scores was much broader for the p20 and p22 tests than for the Esterman test. The mean decibels for the binocular visual fields calculated from the monocular visual fields were 21.5 +/- 7.7 dB for the best-location algorithm and 25.1 +/- 6.7 dB for the probability-summation algorithm. The binocular visual field score calculated with the best-location algorithm correlated better with the overall, general vision, distance activities, and peripheral vision domains of theVFQ-25 (partial correlation coefficients of 0.48, 0.48, 0.49, and 0.51, respectively) than did the probability-summation algorithm and all five binocular visual field tests. The best-location algorithm also had the strongest correlation with the linear rating scale utility test (partial correlation coefficient, 0.40). CONCLUSIONS: In this sample of clinic-based patients with glaucoma or suspected glaucoma, a global score derived from a combination of two monocular fields correlated better with patient assessment of vision than did the Esterman and four novel binocular visual field tests.     

Assessment of false positives with the Humphrey Field Analyzer II perimeter with the SITA Algorithm

PURPOSE: To evaluate the effects of false-positive (FP) response errors on mean deviation (MD), pattern standard deviation (PSD), glaucoma hemifield test (GHT), and test duration in the Humphrey Field Analyzer's (HFA II) Swedish Interactive Threshold Algorithm (SITA; Carl Zeiss Meditec, Inc., Dublin, CA). METHODS: Five individuals with glaucoma (ages 52, 63, 69, 77, and 78 years) and five individuals with normal, healthy eyes (ages 25, 34, 43, 45, and 52 years), participated in the study. Each subject was experienced in automated perimetry and performed multiple, monocular baseline SITA-standard (SITA-S) 24-2 visual field tests. In addition, normal subjects completed SITA-S 24-2 field examinations in which known frequencies of FP error were introduced (0%, 5%, 10%, 20%, or 33% frequency). Likewise, the subjects with glaucoma completed visual field examinations with 0%, 20%, and 33% error introduced during the test. RESULTS: Reported FP errors were significantly lower than the introduced frequency of error. The SITA algorithm more accurately identified FP errors when the MD and PSD diverged from normal. Test duration increased as introduced error frequencies increased. The Statpac single-field analyses indicated that two thirds of the tests with introduced errors produced a "low-patient-reliability" determination. CONCLUSIONS: HFA II SITA-S underestimates patients' FP errors, particularly among normal patients. High FP error frequencies can have adverse effects on MD and PSD, leading clinicians and researchers to an inaccurate determination of the amount and severity of visual field loss.     

Integrated visual fields: a new approach to measuring the binocular field of view and visual disability

Background We have developed a method of quantifying the central binocular visual field by merging results from monocular fields (Integrated visual field). This study aims to compare the new measure with the binocular Esterman visual field test in identifying patients with self-reported visual disability.Methods Forty-eight patients with glaucoma each recorded Humphrey 24-2 fields for both eyes and an Esterman on the same day, and each completed a binary forced-choice questionnaire relating to perceived visual disability. Computer software merged sensitivity values from monocular fields to generate an integrated visual field and a related score of the number of defects at the <10 dB and <20 dB level. Receiver operating characteristic (ROC) analysis was used to compare the integrated visual field score and the Esterman disability score with individual responses to the questions on perceived difficulty with visual tasks.Results Comparison of areas under ROC curves revealed that a score based on the integrated visual field was generally better (median area: 0.79) than Esterman scores (median area: 0.70) in classifying patients with or without a self-reported perceived difficulty with visual tasks.Conclusions The integrated visual field offers a rapid assessment of a glaucoma patients binocular visual field without extra perimetric testing. As compared to an actual binocular field test (Esterman), the integrated visual field provides a better prediction of a glaucoma patients perceived inability to perform certain visual tasks.     

Detection of visual field defects in patients after anterior temporal lobectomy for mesial temporal sclerosis-establishing eligibility to drive

AIMS: The aim of this study is to quantify visual field defects after temporal lobectomy for mesial temporal sclerosis and to establish eligibility for driving. METHODS: Automated static perimetry was performed on 14 patients who had undergone anterior temporal lobectomy for mesial temporal sclerosis. Perimetry consisted of monocular Humphrey Field Analyser (HFA) 30-2 test and a binocular Esterman 120 test. RESULTS: Of the 14 patients, three had no loss or non-specific loss, eight had partial homonymous quadrantanopia, one had complete homonymous quadrantanopia and two had concentric loss attributable to vigabatrin, which may have masked any loss occurring due to surgery. Of these, only seven passed the standardised DVLA visual fields. Of the seven who failed DVLA visual field, one had complete quadrantanopia, four had partial quadrantanopia and two had concentric loss (due to vigabatrin). CONCLUSIONS: Visual field defects contribute a great deal in the reduction of the quality of life in patients who have had surgery for mesial temporal sclerosis. Potential surgically induced visual field defects that could preclude driving need to be discussed with each patient preoperatively. In our study 50% of patients did not meet the required DVLA standards.     

Binocular summation in the peripheral visual field

Purpose: To investigate binocular summation for a light detection task in the central and peripheral retina along 4 meridians. Methods: 10 young subjects aged 22-30 years (mean 26 years) with healthy eyes and normal visual fields participated in the study. A custom-designed program on a Humphrey Visual Field Analyser measured thresholds at the fovea and at 5°, 10°, 15°, 25°, 40° and 55° along the horizontal meridian, and at 5°, 10°, 15°, 25°, 40° along the vertical, 45° oblique and 135° oblique meridians. Right and left monocular fields and binocular fields were measured on each subject using white spot stimuli (Goldmann sizes I and III). Binocular summation ratios were calculated for each eccentricity by dividing binocular sensitivity be the better monocular sensitivity. Results and conclusion: As expected, binocular and monocular sensitivities decreased with increasing eccentricity. The mean binocular summation ratio at the fovea was 1.38 for size I stimulus and 1.42 for size III. Binocular summation was demonstrated in the peripheral retina along all meridians and is of similar magnitude to foveal binocular summation. ANOVA showed that binocular summation was significantly higher in the vertical meridian than horizontal meridian for both size I and III stimuli. There was no significant variation in binocular summation ratios with eccentricity along any of the 4 meridians examined.     

Screening for glaucomatous visual field loss. The effect of patient reliability

Eighty-eight glaucoma patients and 252 normal subjects underwent C-30-2 testing on the Humphrey Field Analyzer. The effect of fixation losses, high false-positive and false-negative response rates on visual field test results was assessed using the mirror image method of detecting asymmetry across the horizontal meridian, and the Humphrey STATPAC pattern standard deviation (PSD) and mean deviation (MD). Glaucoma patients with poor fixation (greater than or equal to 20%) had less depressed fields and fewer localized defects than those with good fixation. Fixation loss did not affect measures of localized defects or generalized depression among normal subjects. High false-positive rates (greater than or equal to 10%) were associated with less-depressed visual fields among glaucoma patients and normal subjects. Visual fields were depressed by an average of 9 dB for glaucoma patients and 7 dB for normal subjects with high false-negative rates (greater than or equal to 33%), when compared with those with low false-negative rates. Apparent localized defects were observed among normal subjects with high false-negative rates. Most of these defects were located in the superior nasal and adjacent arcuate area.     

Comparison of Humphrey MATRIX and Swedish interactive threshold algorithm standard strategy in detecting early glaucomatous visual field loss

Purpose:

The aim of this study was to compare the Humphrey MATRIX visual field (frequency doubling technology threshold) and Swedish interactive threshold algorithm (SITA) standard strategy white on white perimetry in detecting glaucomatous visual field loss.

Material and Methods:

Twenty-eight adult subjects, diagnosed to have glaucoma at a tertiary eye care hospital, who fulfilled the inclusion criteria, were included in this prospective study. All subjects underwent a complete ophthalmic examination. Subjects with glaucomatous optic disc changes underwent repeat perimetric examination on the same day with the Humphrey visual field analyzer (HFA II) and Humphrey MATRIX, the order of testing being random. Only reliable fields, where the HFA results corresponded to the disc changes were considered for analysis. A cumulative defect depth in each hemifield in both HFA and MATRIX reports was calculated.

Results:

Thirty-seven eyes of 24 subjects had reliable fields corresponding to optic disc changes. The mean age of the subjects was 56 ± 12 years. There were 12 males and 12 females. The test duration was significantly less on the MATRIX, mean difference in test duration was −81 ± 81.3 sec (p < 0.001). The mean deviation and the pattern standard deviation between the two instruments showed no significant difference (p = 0.55, p = 0.64 respectively) and a positive correlation coefficient of 0.63 and 0.72 respectively. Poor agreement was found with the glaucoma hemifield test.

Conclusion:

The Humphrey MATRIX takes less time in performing the test than SITA Standard and shows good correlation for mean deviation and pattern standard deviation. However, the glaucoma hemifield test showed poor agreement. The Humphrey MATRIX diagnoses were similar to established perimetric standards.     

Baseline visual field characteristics in the ocular hypertension treatment study

PURPOSE: The Ocular Hypertension Treatment Study (OHTS) seeks to evaluate the safety and efficacy of topical ocular hypotensive medication in preventing or delaying the onset of visual field loss and/or optic nerve damage in ocular hypertensive subjects at risk for developing primary open-angle glaucoma. This study evaluates the baseline visual field test characteristics (visual field status, reliability properties, etc.) of patients who underwent eligibility visual field testing for entry to the OHTS. DESIGN: Cross-sectional study of baseline data as part of a longitudinal randomized clinical trial. PARTICIPANTS: Two thousand eight hundred nineteen ocular hypertensive individuals, aged 40 to 80 (mean age, 55). METHODS: Subjects underwent at least two Humphrey Field Analyzer Program 30-2 Full Threshold visual field examinations in both eyes for study eligibility. A third examination was performed if a prior test was abnormal, questionable, or unreliable. For final eligibility, two sets of visual field examinations had to meet OHTS criteria for reliability and had to be classified as "normal." All OHTS visual field tests of potential subjects were submitted for eligibility assessment to the OHTS Visual Field Reading Center. MAIN OUTCOME MEASURES: The percentage of visual fields that were normal and reliable according to OHTS criteria. RESULTS: Of the subset of 2304 subjects who completed the eligibility assessments, 1828 (79%) were OHTS-eligible based on visual field test requirements. A third eligibility test was required for 11% of all eyes because of unreliable, questionable, or abnormal test results. With the 33% fixation loss cutoff in the OHTS, 97% of all eligibility visual field examinations were reliable and 3% were unreliable. The most frequent cause (69.5%) of unreliability was excessive fixation losses. CONCLUSIONS: Permitting one repeat test after an abnormal or unreliable test allowed an extra 560 patients to be "eligible" for the study based on visual field tests. A clinical screening review of otherwise normal and reliable tests was not restrictive. The adoption of a 33% fixation loss cutoff significantly reduced the number of required retests and prevented study rejection of 89 patients.     

Simulating binocular visual field status in glaucoma

AIMS—To simulate the central binocular visual field using results from merged left and right monocular Humphrey fields. To assess the agreement between the simulation and the binocular Humphrey Esterman visual field test (EVFT).
METHOD—59 consecutive patients with bilateral glaucoma each recorded Humphrey 24-2 fields for both eyes and binocular EVFT on the same visit. EVFT results were used to identify patients exhibiting at least one defect (<10 dB) within the central 20° of the binocular field. This criterion is relevant to a patient''s legal fitness to drive in the UK. Individual sensitivity values from monocular fields are merged to generate a simulated central binocular field. Results are displayed as a grey scale and as symbols representing defects at the <10 dB level. Agreement between patients failing the criterion using the simulation and the EVFT was evaluated.
RESULTS—Substantial agreement was observed between the methods in classifying patients with at least one defect (<10 dB) within the central binocular field (kappa 0.81; SE 0.09). Patients failing this criterion using the EVFT results were identified by the binocular simulation with high levels of sensitivity (100%) and specificity (86%).
CONCLUSIONS—Excellent agreement exists between the simulated binocular results and EVFT in classifying glaucomatous patients with central binocular defects. A rapid estimate of a patient''s central binocular field and visual functional capacity can be ascertained without extra perimetric examination.

     

Comparison of visual field sensitivities between the Medmont automated perimeter and the Humphrey field analyser

Background: Two commonly used perimeters in Australia and in many parts of Asia are the Humphrey field analyser II (HFA) and the Medmont automated perimeter (MAP). Each device maps the incremental light threshold of the visual field and describes the sensitivity at each point in ‘decibels’ (dB); however, these values are not interchangeable between devices. This study was designed to compare directly the sensitivity values of HFA and MAP visual fields. Methods: Sixty‐three subjects who had suspected glaucoma, ocular hypertension or glaucoma, or were normal controls were recruited selectively. One eye from each patient was tested with the MAP and HFA in random order on the same day. Corresponding points between the two tests were identified and their sensitivities were compared. Results: Sensitivities between MAP and HFA were strongly correlated (r² = 0.45; P < 0.0001), with the relationship between them being described by the linear equation: MAP = 0.75*(HFA) ? 0.87. On average, across the entire field MAP sensitivities were 7.4 dB (standard deviation 4.6 dB) lower than HFA. However, this relationship was modified by eccentricity and field sensitivity loss. Conclusion: Visual field sensitivities for MAP and HFA may be related by a linear relationship. Theoretical and clinical predictions that this difference may be on average approximately 5 dB have been confirmed.     

单眼视野损伤程度对青光眼患者双眼视野的影响

目的：探讨单眼视野丢失严重程度对原发性闭角型青光眼、原发性开角型青光眼和正常眼压性青光眼患者双眼视野缺损的影响。

方法：根据双眼单眼视野缺损的阶段,将120例青光眼患者和30例健康参与者分为正常、早期、中度或重度四个阶段。通过整合视野和Esterman双眼视野评估确定双眼视野。在组内和组间比较单眼和双眼视野参数。

结果：对于一只眼睛处于正常或早期阶段而另一只眼睛处于严重阶段的患者,双眼综合视野平均偏差分别为-2.8±1.1、-5.5±1.9dB,以及Esterman的平均得分分别为99.1%±1.7%和95.6%±4.7%。当双眼发展为中度或重度损伤(中度/中度,中度/重度或重度/重度)时,双眼综合视野平均偏差低于-6dB,中度/中度和中度/严重损伤组Esterman的平均得分分别为94.2%±6.0%、94.3%±4.9%,但当双眼处于重度损伤阶段时,Esterman的平均得分迅速从大于90%下降到68.4%±26.3%。

结论：如果一只眼睛处于正常或早期阶段,双眼视野可以保持相对完整。当双眼进展到中度或重度阶段时,通过双眼综合视野平均偏差测量的双眼视野缺损是显著的,并且仅当双眼进入严重阶段时才检测到显著的Esterman双眼视野缺损。     

Predicting binocular visual field sensitivity from monocular visual field results

PURPOSE: To compare methods of predicting binocular visual field sensitivity of patients with glaucoma from monocular visual field data. METHODS: Monocular and binocular visual fields were obtained for 111 patients with varying degrees of glaucomatous damage in one or both eyes, using the Humphrey 30-2 full-threshold procedure. Four binocular sensitivity prediction models were evaluated: BEST EYE, predictions based on individual values for the most sensitive eye, defined by mean deviation (MD); AVERAGE EYE, predictions based on the average sensitivity between eyes at each visual field location; BEST LOCATION, predictions based on the highest sensitivity between eyes at each visual field location; and BINOCUIAR SUMMATION, predictions based on binocular summation of sensitivity between eyes at each location. Differences between actual and predicted binocular sensitivities were calculated for each model. RESULTS: The average difference between predicted and actual binocular sensitivities was close to zero for the BINOCULAR SUMMATION and BEST LOCATION models, with 95% of all predictions being within +/-3 dB of actual binocular sensitivities. The best eye (MD) prediction had an average error of 1.5 dB (95% confidence limits [CL], +/-3.7 dB). The average eye prediction was the poorest, with an average error of 3.7 dB (95% CL, +/-4.6 dB). CONCLUSIONS: The BINOCULAR SUMMATION and BEST LOCATION models provided better predictions of binocular visual field sensitivity than the other two models, with a statistically significant difference in performance. The small difference in performance between the BINOCULAR SUMMATION and BEST LOCATION models was not statistically significant. For evaluations of functional visual field influences on task performance, daily activities, and related quality-of-life issues, either the BINOCULAR SUMMATION or BEST LOCATION model provides good estimates of binocular visual field sensitivity.     

Learning effect of Humphrey Matrix perimetry

BACKGROUND: Humphrey Matrix perimetry is a recent development in automated perimetry that uses frequency-doubling technology (FDT). We evaluated the learning effect of Humphrey Matrix perimetry with a full-threshold 30-2 strategy. METHODS: Twenty-four patients with primary open-angle glaucoma and early visual field defects as assessed by standard automated perimetry and 24 healthy control subjects participated. All subjects had no prior experience with FDT visual field tests. Humphrey Matrix perimetry using a full-threshold 30-2 strategy was performed 3 times within 1 month. Various visual field indices were compared across multiple tests. RESULTS: Mean deviation (MD) showed a larger defect at the first test than at the second and third tests (p < 0.001), and the mean total improvement of the MD was 2.80 decibels (dB) in the glaucoma group and 1.71 dB in the control group. Pattern standard deviations (PSDs) were decreased as the tests were repeated, but test duration, fixation losses, and false-positive or false-negative rate were not changed significantly. Additionally, the Glaucoma Hemifield Test (GHT) showed unstable results. INTERPRETATION: In patients naive to the FDT test, Humphrey Matrix perimetry showed a large learning effect on MD and PSD among the various visual field indices. The GHT results of Humphrey Matrix perimetry showed a large instability.     

Dichoptic stimulation improves detection of glaucoma with multifocal visual evoked potentials

PURPOSE: To determine whether simultaneous binocular (dichoptic) stimulation for multifocal visual evoked potentials (mfVEP) detects glaucomatous defects and decreases intereye variability. METHODS: Twenty-eight patients with glaucoma and 30 healthy subjects underwent mfVEP on monocular and dichoptic stimulation. Dichoptic stimulation was presented with the use of virtual reality goggles (recording time, 7 minutes). Monocular mfVEPs were recorded sequentially for each eye (recording time, 10 minutes). RESULTS: Comparison of mean relative asymmetry coefficient (RAC; calculated as difference in amplitudes between eyes/sum of amplitudes of both eyes at each segment) on monocular and dichoptic mfVEP revealed significantly lower RAC on dichoptic (0.003 +/- 0.03) compared with monocular testing (-0.02 +/- 0.04; P = 0.002). In all 28 patients, dichoptic mfVEP identified defects with excellent topographic correspondence. Of 56 hemifields (28 eyes), 33 had Humphrey visual field (HFA) scotomas, all of which were detected by dichoptic mfVEP. Among 23 hemifields with normal HFA, two were abnormal on monocular and dichoptic mfVEP. Five hemifields (five patients) normal on HFA and monocular mfVEP were abnormal on dichoptic mfVEP. In all five patients, corresponding rim changes were observed on disc photographs. Mean RAC of glaucomatous eyes was significantly higher on dichoptic (0.283 +/- 0.18) compared with monocular (0.199 +/- 0.12) tests (P = 0.0006). CONCLUSIONS: Dichoptic mfVEP not only detects HFA losses, it may identify early defects in areas unaffected on HFA and monocular mfVEP while reducing testing time by 30%. Asymmetry was tighter among healthy subjects but wider in patients with glaucoma on simultaneous binocular stimulation, which is potentially a new tool in the early detection of glaucoma.