Automated perimetry and neuro-ophthalmology. Topographic correlation

Visual fields continue to be a key exploration for the diagnosis and follow-up of patients in neuro-ophthalmology. The pattern of visual field defects helps, and in many cases allows, the identification of brain damage location. Manual kinetic perimetry has been replaced by automated methods. 24-2 SITA (Humphrey Visual Field Analyser) and TOP (Octopus) are regarded as the standard perimetric explorations in neuro-ophthalmology. Goldmann perimetry remains as an useful exploration for temporal crescent detection in occipital lobe diseases, and it could be more accurate and consistent for studying lesions in the post-geniculate pathway. Frequency doubling perimetry could be useful for detecting neuro-ophthalmic visual field defects, but does not provide an accurate characterisation of the lesions. From the neuro-ophthalmic point of view, visual field defects could be divided in pre-chiasmatics, chiasmatics and post-chiasmatics. Pre-chiasmatic defects are strictly unilateral, do not respect the vertical meridian, often have a nasal step associated and are usually accompanied by ocular pathology detectable in an ophthalmic examination. The characteristic perimetric pattern of chiasmal disease is bi-temporal hemianopsia. Homonymous contralateral defects are the characteristic perimetric pattern of post-chiasmal disease, and their congruency increases when the lesions are closer to the occipital lobe. Neuroimage studies are mandatory in all patients with a perimetric defect pattern compatible with chiasmal or post-chiasmal lesions. Magnetic Resonance Imaging may be normal in a patient with homonymous defects in Alzheimer's disease, the Heidenhain variant of Creutzfeldt-Jakobs disease, carbon monoxide poisoning and mild occipital ischemia demonstrated by SPECT or PET imaging (Arch Soc Esp Oftalmol 2002; 77: 413-428).     

Reliability in perimetry

As perimetric instrumentation becomes more sophisticated, patient reliability emerges as an important limiting factor in testing. Modern instrumentation for threshold and suprathreshold perimetry incorporate up to five separate indicators of patient reliability. For these perimetric methods, patient reliability is enhanced with specific techniques such as refractive correction, control of pupil size, and actively monitoring patient responses. With the manual (Goldmann) perimeter and the tangent screen, special statokinetic techniques help in both assessment and enhancement of patient reliability. In screening perimetry, reliability is assessed by analyzing the relative number, relative location, and repeatability of misses. Reliability in confrontation perimetry is both assessed and enhanced by using finger-counting and color-naming techniques. Review of the ophthalmic literature on perimetry shows how the various methods of patient reliability assessment and enhancement can be applied in the clinic.     

A clinical comparison of visual field testing with a new automated perimeter, the Humphrey Field Analyzer, and the Goldmann perimeter

Automated threshold static perimetry with the Humphrey field analyzer and kinetic and suprathreshold static perimetry with the Goldmann perimeter were performed on 171 eyes: 69 with glaucoma or ocular hypertension, 69 with "neurologic" disorders, and 33 normal. The two fields were similar or differed only slightly in 78% of eyes overall and in 88% when both fields appeared reliable. In general, defects were slightly more extensive using the Humphrey than the Goldmann perimeter. In 21% of the eyes with glaucoma or ocular hypertension, defects were found with the Humphrey perimeter that were not present with the Goldmann perimeter. Patient fixation was more difficult to maintain on the Humphrey than Goldmann perimeter. Poor fixation accounted for 9% of the automated fields being inadequate whereas only 2% of the manual fields were inadequate. The results indicate that the Humphrey Field Analyzer is capable of reliably detecting and quantitating visual field defects.     

Discordance between subjective perimetric visual fields and objective multifocal visual evoked potential-determined visual fields in patients with hemianopsia

PURPOSE: To investigate the concordance between subjectively and objectively acquired visual fields in patients with subjectively determined hemianopsia. DESIGN: Retrospective observational study. METHODS: Ten patients, six men and four women, ranging in age from 28 to 68 years, were studied. Goldmann or Humphrey perimeters were used to obtain the subjectively determined visual fields for up to 25 degrees of eccentricity, and the VERIS Scientific System (Electro-Diagnostic Imaging, San Francisco, California, USA) was used to record multifocal visual evoked potential [VEPs] (mfVEPs) to obtain the objective visual fields. Each of the 60 black-and-white segments of the checkerboard stimulus was alternated according to a binary m sequence. The first slices of the second-order kernels were extracted and analyzed. RESULTS: In five cases, the visual field loci where the mfVEPs were within normal limits corresponded to the scotomatous areas obtained by conventional perimetry. In these discordant cases, the lesions (e.g., arteriovenous malformation) were located in the occipital lobe. Two of these cases had a complete recovery of the subjective visual field. The lesions of the concordant cases were located outside the occipital lobe (e.g., pituitary adenoma). In these cases, no visual field improvement was seen. The temporal crescent syndrome was ruled out in patients with posterior lesions by computed tomography (CT) or magnetic resonance imaging (MRI) findings. CONCLUSIONS: In some patients with occipital lesions, the subjective and objective visual field results are discordant, and some of them will show a recovery of the visual field deficits.     

Efficiency of Rarebit perimetry in the evaluation of homonymous hemianopia in stroke patients

AIMS: To compare the efficiency of Rarebit perimetry and the Humphrey field analyser (HFA) in detecting the homonymous hemianopia in stroke patients with occipital lobe infarcts. METHODS: 40 patients who suffered from visual complaints caused by acute occipital lobe infarcts underwent visual field analysis on the same day, in random order-first with either Humphrey perimetry 30-2, SITA standard program (Zeiss Humphrey Systems) or Rarebit perimetry. A visual field was classified into four quadrants for right and left eyes: superior temporal, superior nasal, inferior temporal, and inferior nasal. The entire mean hit rate numbers (MHR) and mean deviation and pattern standard deviation (PSD) values were compared for each quadrant of each eye. RESULTS: The results of Rarebit MHR and HFA mean deviation values for each quadrant of the right and left eyes were highly correlated in all patients with homonymous hemianopia (Pearson's r correlation coefficients for superior temporal, superior nasal, inferior temporal and inferior nasal quadrants of right and left eyes were 0.827, 0.833, 0.843, 0851 and 0.746, 0821, 0882, 0.824, respectively (p<0.001 for all quadrants)). There was a strong correlation between Rarebit MHR and HFA PSD for each quadrant of both eyes. CONCLUSIONS: Rarebit perimetry is rapid, reliable, and easily performed in patients with homonymous hemianopia. It can be done using a simple software program and simple hardware and it readily detects severe visual loss in patients with occipital lobe lesions.     

Relationship between visual acuity and nasal field thresholds in patients with temporal hemianopia.

The area of nasal field found with Goldmann static perimetry and the sum of decibels by Humphrey threshold 30/2 was calculated in normal subjects and in subjects with chiasmatic lesions, temporal field loss, and normal or abnormal visual acuity. There was a significant reduction of the mean of the area of the nasal field by static Goldmann perimetry and of the mean of decibels in the nasal field on Humphrey perimetry in patients with temporal field loss and chiasmatic lesions, as compared with normal controls. There were significant correlations of nasal field depression (Goldmann) and visual acuity and for sums of nasal field decibels (Humphrey) and visual acuity. Thus, a generally depressed nasal field was found in patients with chiasmatic lesions and temporal field loss when accompanied by lowering of visual acuity. This would appear to be the earliest stage of nasal field involvement.     

Evaluation of sensitivity and specificity of spatial resolution and Humphrey automated perimetry in pseudotumor cerebri patients and normal subjects.

To determine the sensitivity and specificity of high-pass resolution perimetry ("ring test"), 18 patients with pseudotumor cerebri (PTC) and 18 age-matched controls were examined with the Humphrey program 24-2 and the ring test. Goldmann perimetry also was done to determine if defects found with the ring test were present with another method. Testing with Humphrey perimetry revealed defects in 15 PTC patients and four control subjects; with the ring test, 13 PTC patients and two control subjects had abnormalities. The disturbed areas in the control subjects with both automated tests were not reproducible. Humphrey perimetry had a sensitivity of 83% and the ring test, 72%. The specificities were Humphrey perimetry, 78% and the ring test, 89%. These differences were not statistically significant. Qualitative assessment of the presence and extent of damage using the pointwise probability plots and graphically displayed raw data showed good correlation of the tests in 11 of the 18 patients. The lack of correlation in four of the patients was caused by the presence of a generalized depression or a peripheral contraction on the Humphrey test; this defect, not present on retesting, may have been related to fatigue or poor motivation. The ring test is a sensitive and specific perimetric technique in patients with PTC.     

Visual field assessment and the Austroads driving standard

Purpose: To compare the conventional (Humphrey 24‐2) automated visual field testing with the Goldmann standard visual field test for driving, and to predict how many patients with glaucoma may not meet the Australian driving standard with respect to visual fields. Methods: Four patients (retinitis pigmentosa, glaucoma or vigabatrin treatment) with marked visual field defects as determined by uniocular static computerized perimetry (conventional testing) were re‐evaluated with binocular kinetic Goldmann IV4e target field test (Australian driving standard). A series of 48 consecutive patients seen by the Glaucoma Inheritance Study in Tasmania were assessed with both static computerized perimetry and the Goldmann IV4e target test. Results: The four patients with severe visual field defects (on computerized perimetry) were found to meet the driving standard on the binocular Goldmann IV4e target test. On computerized perimetry, 15 of 48 patients from the Glaucoma Inheritance Study in Tasmania were found to have visual field defects of sufficient severity that they may not meet the driving standard. However, only five of these patients failed the driving standard for visual fields, two of whom were still driving. Conclusions: Patients with severe field defects on conventional uniocular automated perimetry may still meet the Goldmann standard visual field test for driving. Approximately 30% of glaucoma patients would have visual field loss shown on Humphrey 24‐2 test of a severity that requires further testing to determine if they meet the driving standard. Ten per cent of glaucoma patients tested did not meet the driving standard for visual fields.     

Color perimetry of glaucomatous visual field defects

A color video tangent screen has been devised, using microcomputer control of a video display to produce colored perimetric test objects matched in luminance to a white surround at 10-foot lamberts . Perimetric isopters for varying degrees of color saturation were determined by kinetic perimetry. This form of color perimetry was used to examine one eye of each of 40 patients with open-angle glaucoma as well as 20 glaucoma-suspect patients. For the first 23 eyes with manifest glaucomatous visual field defects, a masked comparison was made between the results of color perimetry and conventional perimetry with a Goldmann perimeter. For these 23 eyes, color perimetry did as well as luminance perimetry in 14, was less sensitive in 2, and was more sensitive in 7. All defects that were detectable by conventional perimetry were successfully demonstrated by the color method. Such defects often appeared to be greater in extent when mapped by the color method as compared to conventional luminance perimetry.     

Occipital lobe infarction after open heart surgery

The most common permanent neuro-ophthalmologic complication of cardiopulmonary bypass surgery is visual loss. Bilateral lower altitudinal visual field defects were documented in a patient who noted blurred vision following open heart surgery. A difference of opinion existed as to whether the field defects were due to retina-optic nerve or occipital lobe lesions. Two points are emphasized in this report: 1) the field defects were much easier to define on the tangent screen than on Goldman perimetry, and 2) occipital coronal high resolution CT scan confirmed bilateral upper bank calcarine cortex infarctions in this patient. Occipital coronal, thin-section, high-resolution computed tomographic scans are helpful in studying patients with occipital lobe visual field defects.     

视觉刺激功能磁共振成像在枕叶病变患者中的初步应用

目的 观察枕叶病变患者患侧与健侧的功能磁共振成像（fMRI）特点，评价fMRI在视觉中枢功能性病变检查、枕叶肿瘤定位、手术入路选择以及切除范围方面的临床应用价值。设计 病例系列。研究对象 伴有同侧偏盲的视觉中枢功能性病变及单侧枕叶肿瘤患者各1例。方法 对上述2例患者应用自行设计的双眼棋盘格刺激（5Hz）行脑fMRI检查。所得数据应用SPM软件处理（P〈0．01），与Goldmann视野计检查结果相比较，验证视野损害与其大脑皮层投影改变的一致性。主要指标 统计参数图，脑激活图，激活脑区信号变化的时间曲线，与标准化T1像叠加的脑激活图。结果 在视觉刺激on时，枕叶视功能区激活；off时无信号；2例患者fMRI检查右侧视功能区激活明确，左侧视功能区无信号与视野检查双眼右半视野缺损相一致。结论 视觉刺激程序能够很好地引出视觉中枢fMRI；fMRI的检查结果与视野结果一致性较好；fMRI在视觉中枢功能性检查、枕叶肿瘤范围定位的确定方面有良好的临床应用前景。     

Coffee and doughnut maculopathy: a cause of acute central ring scotomas

AIMS: To report the clinical features of five patients with non-progressive central ring scotomas of acute onset associated with excellent retained visual acuity. METHODS: Complete neuro-ophthalmological examinations were performed. Visual fields were performed by tangent screen, Goldmann, or Humphrey perimetry. In some cases further testing was carried out including fundus photography, fluorescein angiography, ERG, VEP, and neuroimaging. RESULTS: The patients were three women and two men whose ages ranged from 25 to 57 years. Four patients were heavy caffeine consumers while the fifth patient experienced an episode of hypotension. Vision loss was acute in all cases. The onset of vision loss was bilateral/simultaneous in three cases, bilateral/sequential in one case, and unilateral in one case. All affected eyes retained visual acuities of 20/25 or better. Colour vision was subnormal in three of four cases. Visual field defects were characterised by a central ring scotoma having an outer diameter less than 10 degrees. Fundus examination demonstrated temporal optic nerve pallor in three patients (five of 10 affected eyes) and reddish, petaloid macular lesions in one patient. Good visual acuity was maintained for the duration of follow up in all five patients. CONCLUSION: Central ring scotomas with excellent retained visual acuity may present as an acute, bilateral syndrome in patients who are heavy caffeine consumers. The configuration of visual field loss and its location, combined with the presence of temporal pallor in five eyes, suggest that the defect localises to the inner layers of the macula. While these cases could be considered an expansion of the clinical spectrum of acute macular neuroretinopathy, some may represent a distinct entity.     

Automated and manual perimetry-a six-year overview. Special emphasis on neuro-ophthalmic problems

Between August 1976 and September 1982, more than 34,000 manual and automated visual fields have been analyzed in the Department of Ophthalmology, University of California, Davis. Approximately 27% of these tests consisted of manual kinetic visual fields performed on the Goldmann perimeter, while 73% were conducted using automated perimetry. Automated testing alone, or a combination of automated perimetry and manual kinetic testing (Goldmann perimeter) was usually employed to monitor progression or regression of visual field loss. This paper provides an overview of two aspects of automated suprathreshold static perimetry that have not been emphasized in our previous studies: (1) methodologic difficulties and problem patients in automated suprathreshold static perimetry, and (2) examples of automated suprathreshold static perimetry in neuro-ophthalmologic patient populations.     

Solitary albinotic spot of the retinal pigment epithelium: a functional and imaging study

PURPOSE: The presence or absence of functional changes associated with solitary, congenital, hypopigmented lesions of the retinal pigment epithelium (RPE) have been a matter of controversy. This case report describes retinal and functional findings in a young patient with such a lesion. METHODS: A 10-year-old Hispanic female with a solitary congential hypopigmented spot of the RPE was examined using fundus photography, fluorescein angiography, autofluorescence imaging (AF) and optical coherence tomography (OCT). Functional analyses were performed using the Humphrey 24 - 2 visual field, Goldmann perimetry and the multifocal ERG (mfERG). RESULTS: A small visual field defect was demonstrated on both Goldmann perimetry (I/ 2e test object) and on Humphrey 24 - 2 visual field testing (significant at the 0.5 % level for pattern deviation). The multifocal ERG response amplitudes were decreased in the corresponding area and increased in implicit time. Autofluorescence imaging showed an absence of fluorescence corresponding to the area of the lesion. OCT findings were indicative of a small amount of subretinal fluid or schisis-like changes overlying the RPE anomaly. CONCLUSION: The results indicate that solitary, albinotic spots of the RPE can be associated with visual field defects and outer retinal deficits; these may be related to impaired RPE function and/or chronic exudative changes.     

A comparison of Goldmann and Humphrey automated perimetry in patients with glaucoma.

Humphrey automated threshold perimetry (Program 30-2) was performed on 42 eyes of 25 patients with glaucoma to determine both the sensitivity and specificity of automated perimetry in detecting glaucomatous visual field defects. Automated perimetry sensitivity was 90.38%, while automated perimetry specificity was 91%. Fifty-two patients and a technician took part in a survey to determine their preference for either test. Patients generally preferred having Goldmann perimetry. The technician favoured Humphrey automated perimetry. Program 30-2 on the automated perimeter took 25% longer to perform than Goldmann perimetry.     

Clinical comparison of frequency doubling technology perimetry and Humphrey perimetry

AIM: To determine the number of missed points on frequency doubling technology (FDT) perimetry that optimise the sensitivity and specificity of the test and to determine the topographical accuracy of the test in a clinical setting. METHODS: In a prospective study, the perimetric data from 99 patients who underwent both FDT perimetry in the screening mode and Humphrey 24-2 (H24-2) were used to determine the sensitivity and specificity of the FDT perimetry compared with the full threshold H24-2 as the gold standard. RESULTS: Missed points on the FDT perimetry correlated with both the mean deviation and the corrected pattern standard deviation on the Humphrey perimetry. A score assigned to abnormal points on the FDT perimetry and the Humphrey total deviation plot showed a significant correlation for both the location and the depth of the defect. In comparing the Humphrey hemifield test with the FDT perimetry results, if at least one missed point on the frequency doubling test was considered as abnormal then the overall sensitivity of the test was 78.1% and the specificity was 89.1%. CONCLUSION: FDT perimetry in the screening mode performed in a clinical setting was highly specific, exhibited reasonable sensitivity, and accurately determined the location and depth of scotomas when compared with the full threshold Humphrey 24-2.     

Visual field testing in the management of cytomegalovirus retinitis.

BACKGROUND: Sequential visual field testing is an extremely helpful adjunct to ophthalmoscopy and fundus photography in the management of cytomegalovirus (CMV) retinitis with the antiviral agents ganciclovir or foscarnet in patients with the acquired immune deficiency syndrome (AIDS). The authors studied the visual field defects found in a series of 110 patients with AIDS and CMV retinitis. METHODS: Ophthalmoscopy and fundus photography were performed on all patients. Visual field analysis was performed with either tangent screen, Goldmann kinetic, or Humphrey automated static perimetry. RESULTS: Of 166 eyes in 110 patients with CMV retinitis, visual field defects were present initially in 92 (55%) eyes of 78 (70%) patients, and ultimately in 97 (53%) eyes of 90 patients in whom follow-up was available. Stabilization of visual field defects was indicative of controlled retinitis. CONCLUSION: Sequential visual field testing will confirm ophthalmoscopic evidence of successful antiviral treatment of CMV retinitis and will corroborate very early progression of previously controlled retinitis.     

Automatic (Octopus) and manual (Goldmann) perimetry in glaucoma

Of 115 patients with chronic open angle glaucoma or suspected glaucoma 115 eyes were subjected to a visual field examination with the manual Goldmann perimeter and the automatic Octopus perimeter. In 84.4 ±8.9% the automaton detected more visual field loss, including 27.8±10.9% of the eyes where no visual field loss was found by the manual perimetry. Since some eyes with normal fields on manual perimetry and abnormal fields detected by automatic perimetry remained abnormal on retesting, it is assumed that scotomas found by automatic perimetry and not shown by manual perimetry constitute false-negative manual fields rather than false-positive automatic fields.Presented in part at the First International Meeting on Automated Perimetry, System OCTOPUS, in Zurich, April 6–7, 1979 and at the ARVO Spring Meeting in Sarasota, Florida, 1979 Offprint requests to: Professor B. Gloor, Universitäts-Augenklinik, Mittlere Strasse 91, CH-4056 Basel, Switzerland     

Loss of stereopsis with optic chiasmal lesions and stereoscopic tests as a differential test

OBJECTIVE: To identify and characterize the loss of stereopsis observed in patients with lesions of the optic chiasm. STUDY DESIGN: Cross-sectional study. PARTICIPANTS: Forty-three patients who had good visual acuity with orthophoria and without strabismologic histories were divided into two groups. Group 1 consisted of 13 patients with lesions involving the optic chiasm (regardless of their visual field loss) diagnosed by magnetic resonance imaging findings. Group 2 (control group) consisted of 30 patients who had large absolute visual field defects as a result of other causes, including 11 intracranial disorders other than optic chiasmal lesions, 11 cases of open-angle glaucoma, and 8 patients with lesions of the retina. METHODS: The stereoacuity and visual field in each case in group 1 (before and after surgery) and group 2 were assessed, and the results were compared. MAIN OUTCOME MEASURES: Stereoacuity was assessed by the Titmus stereo test (normal value for circle, 6/9; 80 seconds of arc) and by Lang-stereotest (normal value for circle, 3/3; 350 seconds of arc). Visual field was evaluated by Goldmann and Humphrey perimetry (conventional perimetry), the starlight test (binocular visual field test), and scanning laser ophthalmoscopic microperimetry (microperimetry). RESULTS: Before surgery, 11 of 13 cases (85%) in group 1 failed stereo tests, and after surgery, 5 of 13 cases (38%) in group 1 failed stereo tests. Before surgery, four patients who failed stereo tests showed no absolute scotoma by Humphrey or Goldmann analysis; after surgery, one patient who failed stereo tests showed no absolute scotoma by Humphrey or Goldmann analysis. However, starlight testing showed complete bitemporal hemianopsia only under binocular conditions, and microperimetry demonstrated a relative bitemporal hemianopsia at the fixating point. No patient failed in the Titmus circle test, but one patient in group 2 failed the Lang test (3%). The patients with chiasmal lesions significantly lost the ability of stereopsis compared with other diseases (group 1 [before or after surgery] vs. group 2, P < 0.001, Fisher's exact test). Conventional perimetry was unable to measure scotomas within 3 degrees of the fixation point, which is the key area for acute foveal stereopsis, because of an attached observational mirror. CONCLUSIONS: The difficulty with stereopsis in patients with lesions of the optic chiasm is most likely caused by the compression of the decussating optic nerve fibers resulting in the loss of an overlapping visual field at the fixation point. Stereo tests were demonstrated to be simple and effective adjunctive tests for suspected chiasmal compression.     

Perimetry yesterday and today

The historical development of perimetry, from the first technical devices for testing the visual field (arc perimeter) through the manual hemispherical perimeters (Tübingen and Goldmann perimeters) to the latest developments in automated, computer-controlled perimeters, is described with reference to the basic measuring methods and strategies on the one hand and technical realization on the other. The future development of perimetry will be characterized by a refinement of measured value statistics and the testing of perimetric procedures that test more complex physiological functions than sensitivity to differences (e.g., analysis of temporal transmission characteristics in flicker perimetry.