Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PERIMETRY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed1980

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.

Adult↗
PubMed2006

[Static fundus perimetry in normals. Microperimeter 1 versus SLO].

BACKGROUND: The Microperimeter 1 (MP-1) allows for fundus-controlled static perimetry of the central visual field. The purpose of this study was to compare MP-1 fundus perimetry with the already established scanning laser ophthalmoscope (SLO) fundus perimetry concerning detected threshold values of light increment sensitivity in normals. METHOD: In 31 eyes of 31 healthy volunteers a fundus controlled static threshold perimetry was carried out each with the MP-1 (Nidek Technologies) and the SLO (Rodenstock). In the central 21 degrees x 12 degrees visual field light increment sensitivity threshold values for 40 corresponding stimulus locations were compared in a rectangular 3 degree-grid. RESULTS: The average light increment sensitivity was 19.1+/-0.5 dB with the MP-1 and 17.2+/-0.9 dB with the SLO. On average the threshold values of the 40 corresponding test locations were 1.9+/-1.3 dB higher with the MP-1 than with the SLO. CONCLUSION: Both the MP-1 and SLO offer the possibility of a reproducible functional analysis of the central retina under simultaneous fundus control. For comparison of results of the MP-1 and SLO fundus perimetry, a correction factor of approximately 2 dB should be used.

Adult↗
PubMed2002

Multifocal objective perimetry in the detection of glaucomatous field loss.

PURPOSE: To test the ability of a new type of multifocal objective perimetry to identify glaucomatous visual field defects. METHODS: A multichannel visual evoked potential was recorded using the ObjectiVision Accumap perimeter. One hundred patients (age, 62.2 +/- 9.8 years, mean MD -6.5 +/- 4.17 dB) with open-angle glaucoma and confirmed glaucomatous visual field defects were tested and compared with the normal database of 100 normal subjects (age, 58.9 +/- 10.7 years). Both eyes were tested, but for determining sensitivity the eye with the lesser field defect was chosen if both qualified. The amplitude and intereye asymmetry coefficient for each zone of the field were calculated. A mean amplitude and multifocal objective perimetry severity index was calculated for each subject. RESULTS: In 95 of 100 (95%) patients with glaucoma Humphrey field defects were correlated with visual evoked potential amplitude reductions identifying a cluster of three or more abnormal zones. In two of five remaining patients with glaucoma the defect was detected on the intereye asymmetry analysis. Topographic location was well correlated with Humphrey fields. Mean amplitude was significantly reduced in 86 of the glaucoma cases (86%). The glaucoma severity index was abnormal in 93 glaucoma cases and showed a correlation with Humphrey MD (r = 0.67 right eyes, 0.69 left eyes). In 37 glaucoma cases with no scotoma by definition in the fellow eye, 22 (59.4%) had an abnormal multifocal objective perimetry, whereas only eight had some other aspect of their Humphrey visual field flagged as abnormal. CONCLUSIONS: Multifocal objective perimetry can assess the visual field and identify glaucomatous visual field defects. It may have the potential for identifying defects earlier than conventional perimetry.

Adult↗
PubMed2002

Learning effect for frequency doubling perimetry in patients with glaucoma.

PURPOSE: We studied the results obtained by repeated frequency doubling perimetry in patients with glaucoma and demonstrated a learning effect. METHODS: Prospective observational study. Thirty-three patients who had glaucoma and had never experienced frequency doubling perimetry participated in this study. The patients were examined by frequency doubling perimetry three times within 6 months. Mean deviation, pattern standard deviation, and intraocular pressure at examination were compared among three results. RESULTS: On frequency doubling perimetry, the mean deviation results of the first, second, and third tests were -7.96 dB, -7.29 dB, and -7.36 dB, respectively. The first and second results and the first and third results were significantly different (P = 0.029 and P = 0.049, respectively). No significant differences with regard to pattern standard deviation and intraocular pressure were noted. CONCLUSION: A positive learning effect was found for frequency doubling perimetry in the first and second mean deviation results of patients with glaucoma.

Adult↗
PubMed2001

The feasibility of short automated static perimetry in children.

OBJECTIVE: To evaluate the feasibility of short automated static perimetry using tendency-oriented perimetry in the pediatric population. DESIGN: Prospective observational case series. PARTICIPANTS: Fifty normal children age 6 through 12 years. TESTING: Subjects underwent testing with the Octopus TOP-32 program on the Octopus 1-2-3 automated perimeter. Testing was performed in a typical clinical setting without adaptations to the perimeter, prolonged training, or the use of custom seating. Each eye was tested twice. MAIN OUTCOME MEASURES: Ability to complete automated static perimetry tests with both eyes. Mean sensitivity, mean defect, and loss of variance; gray scale and numeric representations of the field; duration of each test and of the entire session; subjective assessment of each test as normal or abnormal; calculation of test specificity. Comparisons by age and test number were performed. RESULTS: All subjects successfully completed all four tests. The mean duration for each test was 2:30+/- 0.23 minutes. The average time for the whole session, including training, testing both eyes twice, and rest periods, was 25.8+/-4.87 minutes. Improvement in the specificity of the test (fewer abnormal tests in normal children) occurred in direct relation to subject age (R = 0.5). CONCLUSIONS: Automated static perimetry using short, tendency-oriented programs can be successfully performed in normal children age 6 through 12 years in a typical clinical setting. Age was the best predictor of the mean sensitivity, reproducibility, and accuracy of the test, with the most reliable results obtained after 7 years of age. In children 6 to 7 years old, significant interindividual variability was present, and testing success was more dependent on the child's maturity and ability to concentrate. Short automated perimetry seems to be a promising tool for the evaluation of peripheral vision in pediatric patients.

Automation↗
PubMed2002

Learning effects among perimetric novices in frequency doubling technology perimetry.

PURPOSE: To investigate learning effects, including improvements in reliability indices, in frequency doubling technology (FDT) perimetry in subjects without glaucoma who have not undergone previous automated perimetry. DESIGN: Prospective consecutive case series. PARTICIPANTS: Eighty-one normal subjects. METHODS: Normal subjects were recruited from the University of Washington Eye Clinic who had no history of automated visual field testing. All eyes underwent complete ophthalmic examination. The C-20-5 screening mode of FDT perimetry (Zeiss-Humphrey, San Leandro, CA) was performed after appropriate instruction, including a demonstration of the frequency doubling phenomenon. If any abnormal areas were identified or there were greater than 33% fixation losses or false-positive results, then the test was readministered up to three times or until a normal result was returned. MAIN OUTCOME MEASURES: Normal FDT test. RESULTS: The mean age was 54.8 years (range, 19-94). Sixty-nine subjects (85.2%) returned a normal test after a single test administration. Nine subjects (11.1%) required two administrations, and two subjects (2.5%) required three or more administrations to return a normal test. One subject still tested unreliably after four tests. The number or severity of abnormal locations did not predict the number of trials necessary to overcome learning effects. Fixation loss was the most common reliability problem. Subjects who demonstrated learning effects did not differ significantly in age, visual acuity, refraction, or test time from those who did not. CONCLUSIONS: Some perimetric novices demonstrate learning effects in C-20-5 screening-mode FDT perimetry. Learning effects in FDT perimetry must be considered during screening for glaucoma or other ocular disease.

Adult↗
PubMed2003

Corneal thickness measurements and frequency doubling technology perimetry abnormalities in ocular hypertensive eyes.

OBJECTIVE: It has been suggested that some patients currently diagnosed with ocular hypertension (OHT) may have thicker than average corneas that result in an overestimation of their true intraocular pressure. Consequently, patients with OHT with greater corneal thickness may be at a lower risk for functional glaucomatous damage, including visual field loss measured with frequency doubling technology (FDT) perimetry. The purpose of this study was to evaluate the frequency of FDT perimetry deficits in patients with OHT and to correlate these findings with central corneal thickness (CCT) measurements. DESIGN: Observational case control study. PARTICIPANTS AND CONTROLS: Sixty-five patients with OHT with normal optic discs and normal standard achromatic automated perimetry (SAP) visual fields and 52 normal control subjects. METHODS: All participants underwent SAP, FDT perimetry, and CCT measurements using ultrasound pachymetry. MAIN OUTCOME MEASURES: CCT measurements in patients with OHT with abnormal repeatable FDT test results were compared with CCT measurements in patients with OHT with normal FDT results. In addition, CCT measurements in patients with OHT were compared with CCT measurements in normal control subjects. RESULTS: Fourteen of 65 patients with OHT (21.5%) demonstrated repeatable FDT abnormalities. The mean CCT of patients with OHT with abnormal FDT results was significantly lower than the mean CCT of patients with OHT with normal FDT results (542+/-35 microm versus 575+/-35 microm; P = 0.003). The mean CCT in the normal control group was 556+/-36 microm. The mean CCT in patients with OHT with normal FDT results was significantly higher than in normal subjects (P = 0.008). No statistically significant difference was found between mean CCT in normal subjects and in patients with OHT with abnormal FDT results (P = 0.18). CONCLUSIONS: Patients currently diagnosed with OHT, but with visual field loss detected by FDT perimetry, had significantly lower CCT measurements than patients with OHT with normal FDT results. These findings suggest that patients with OHT with thinner corneas are more likely to develop early glaucomatous functional damage and that CCT measurements should be taken into account when assessing risk for the development of glaucoma among OHT subjects.

Case-Control Studies↗
PubMed1984

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.

Adult↗
PubMed1991

Intratest variability in conventional and high-pass resolution perimetry.

The authors studied the effects of threshold, age, and visual field location on intratest variability in 11 normal subjects between the ages of 15 and 50 years (mean, 35.37 years). The subjects were tested with a conventional manual (Tübinger) perimeter and a high-pass resolution (Ring) perimeter at the following locations: (0 degrees, 30 degrees), (0 degrees, 15 degrees), (0 degrees, -15 degrees), and (0 degrees, -30 degrees). Frequency-of-seeing curves were constructed to obtain accurate estimates of threshold and intratest variability. Although location did not have a significant effect on intratest variability in conventional perimetry, intratest variability increased with threshold (P = 0.031) and age (P = 0.012). The results with resolution perimetry contrasted sharply and showed that neither threshold, age, nor location had a significant effect on intratest variability (P greater than 0.225). Although the thresholds with the two types of perimetry were correlated, intratest variability was not. These results show that resolution perimetry may be able to bypass some of the limitations encountered in obtaining thresholds with conventional perimetry, thereby providing more reliable information.

Adolescent↗
PubMed1993

Comparison of reliability indices in conventional and high-pass resolution perimetry.

PURPOSE: The purpose of this study is to compare reliability indices in conventional (Humphrey) and high-pass resolution (Ring) perimetry in healthy subjects followed prospectively at 6-month intervals. METHODS: Of the 146 healthy subjects (mean age, 50.24 years; range, 30-84 years) enrolled in the study, 102 have been tested twice and 71 three times. The authors compared the reliability indices, fixation losses, false-positive rate, and false-negative rate between the two techniques, both cross-sectionally and serially. RESULTS: Fixation losses were slightly higher with high-pass resolution perimetry, whereas false-positive errors were higher with conventional perimetry. False-negative errors were uncommon with either technique. Of 319 fields, 30 (9.4%) conventional and 39 (12.2%) high-pass resolution perimetry fields were unreliable using the current suggested reliability criteria. Nearly all unreliable fields were due to high fixation errors. Using alternative criteria derived from baseline 95th percentile values, unreliable fields were attributed more equally to all three reliability parameters. In subjects tested three times, the reliability indices remained constant. CONCLUSION: The results of this study showed that healthy subjects have comparable reliability indices when tested with conventional and high-pass resolution perimetry.

Adult↗
PubMed2005

Peristat: a computer-based perimetry self-test for cost-effective population screening of glaucoma.

PURPOSE: Peristat is a virtual perimetry system that allows self-testing on any standard computer monitor via Internet connection. The sensitivity and specificity of Peristat to detect visual-field defects were compared to standard Humphrey Visual Field Analyzer data. MATERIALS AND METHODS: In this prospective, comparative observational case series, 58 eyes of 33 patients were examined. Semiquantitative analyses compared Peristat and Humphrey Visual-Field scores. The study evaluated patients with an established glaucoma diagnosis, as well as glaucoma suspects who had undergone comprehensive ophthalmologic examinations including prior office perimetry evaluation (Humphrey Field Analyzer). Inclusion criteria were (1) diagnosis or suspicion of glaucoma, (2) BCVA better than 20/200, (3) reliable performance on prior standardized office perimetry, and (4) CDR greater than 0.5. Computer literacy was not required, and more than 40% of the patients tested were computer illiterate, with no previous computer or Internet experience. A total of 58 eyes of 33 patients were tested with the Humphrey and the Peristat systems: 10 eyes of 5 patients without documented glaucomatous field loss and 48 eyes of 23 patients with mild-to-severe scotomas by standard 24-2 office perimetry. A standard computer setup was used with a 17" monitor, and the Peristat system was enabled through a remote connection with a server. RESULTS: All patients completed the Peristat test without difficulty. Testing time varied between 2 and 5 min, tending to be longer with more severe visual-field defects. Test results were reviewed, in a masked fashion, by two glaucoma specialists and one general ophthalmologist. The Peristat demonstrated a high degree of correlation with the Humphrey system. Among the three reviewers, sensitivity ranged from 80% to 83%. In a second subanalysis in which cases with mild defects were excluded, the Peristat's sensitivity increased to 84%-86% while specificity remained between 94% and 97% for all three reviewers. Patients performed the Peristat test with similar facility to their Humphrey test. Fixation losses and test reliability were comparable for both tests. CONCLUSIONS: Peristat is a reliable self-test perimetry system that demonstrates high clinical utility for the detection of visual-field defects from glaucoma. Peristat could be a valuable public health tool for cost-effective screening of glaucoma.

Algorithms↗
PubMed1999

Normal aging effects for frequency doubling technology perimetry.

PURPOSE: To determine the influence of normal aging on contrast sensitivity for frequency doubling technology (FDT) perimetry. METHODS: Contrast sensitivity measures were obtained for frequency-doubled stimuli (0.25 cycles per degree sinusoidal gratings undergoing 25 Hz counterphase flicker) at 17 target locations (4 per quadrant plus the central 5 degrees ) using a prototype of the Welch Allyn (Skaneateles, NY)/Humphrey Systems FDT perimeter (Humphrey Systems, Dublin, CA). A total of 407 normal subjects (761 eyes) between the ages of 15 and 85 years were tested. RESULTS: Between the ages of 15 and 60 years there was an approximately linear decrease in contrast sensitivity of 0.6 dB per decade. After the age of 70, there was a slightly greater sensitivity loss with age. There were no meaningful differences in sensitivity loss as a function of age for different visual field locations. A small but consistent reduction in contrast sensitivity (approximately 0.7 dB) was found at all visual field locations for the second eye tested that may be due to a central adaptation process. CONCLUSIONS: Normal aging effects for FDT perimetry are similar to those obtained for conventional automated perimetry, except that the FDT perimetry aging effects do not appear to be eccentricity dependent. These normative data provide a basis for establishing a statistical analysis procedure and probability plots for FDT perimetry.

Adolescent↗
PubMed2002

Recent developments in automated perimetry in glaucoma diagnosis and management.

Recently, there have been several new developments in automated perimetry that have contributed to enhanced diagnosis and management of glaucoma. This paper will briefly review four of the latest advances in automated perimetry: (1) efficient test strategies that reduce the testing time and variability of automated perimetric testing, in particular, the Swedish Interactive Threshold Algorithm (SITA) and Tendency Oriented Perimetry (TOP) test strategies will be described; (2) Frequency Doubling Technology (FDT) perimetry, which has been shown to be a rapid, effective method of detecting glaucomatous visual field loss; (3) Short Wavelength Automated Perimetry (SWAP), which has demonstrated the ability to predict the onset and progression of glaucomatous visual field deficits; (4) The Multifocal Electroretinogram (mfERG) and the Multifocal Visual Evoked Potential (mfVEP), which provide an objective measurement of the visual field. Each of these techniques has presented distinct advantages for the diagnosis and management of glaucoma.

Glaucoma↗
PubMed2004

How well does color perimetry isolate responses from individual cone mechanisms?

PURPOSE: Over the past two decades there has been renewed interest in the use of color perimetry as a means of detecting early functional defects resulting from glaucomatous optic neuropathy and other forms of ophthalmic and neurologic pathology. The most popular form of color perimetry employs a colored background that selectively desensitizes two of the cone mechanisms, while the wavelength of the test target is selected to favor detection by the remaining, relatively unadapted, cone mechanism. While there are data to support the assertion that blue on yellow perimetry adequately isolates the short wavelength sensitive (SWS) cone mechanism, the only estimates of isolation of the other two cone mechanisms are for the region of the visual field corresponding to the fovea. The purpose of this experiment was thus to determine the amount of cone mechanism isolation that is afforded by automated perimetry when using yellow, blue, and magenta adapting backgrounds. METHODS: To estimate cone mechanism isolation, we determined spectral sensitivity for a range of narrow-band stimuli using a standard 30-2 program on a modified Humphrey perimeter. Targets were presented against three different backgrounds of different luminance; yellow at 2.1 log cd.m-2, magenta at 1.3 log cd.m-2, and blue at 1 log cd.m-2. Sensitivity values for each background at each stimulus position were plotted as a function of wavelength, normalized, and then fitted with cone sensitivity templates to determine the relative sensitivity of the three cone mechanisms. RESULTS: The maximum relative isolation of an individual cone mechanism was achieved with a yellow background, where there was an average relative isolation of 0.94 for the SWS cone mechanism; the blue background provided a relative isolation of 0.89 for the long wavelength sensitive (LWS) cone mechanism. The magenta background proved poor at isolating the medium wavelength sensitive (MWS) cone mechanism, where a relative isolation of only 0.51 was obtained. CONCLUSION: Although color perimetry is capable of isolating individual cone mechanisms, the magnitude of isolation in normal observers may be small under certain circumstances. Therefore, when the technique is used to examine pathologic states, it may be necessary to employ at least two target wavelengths to determine the cone mechanism that is performing target detection. Furthermore, we suggest that MWS cone mechanism isolation may be improved through the combination of the so-called silent substitution technique with that of selective adaptation.

Adult↗
PubMed2007

Frequency doubling technology perimetry in open-angle glaucoma eyes with hemifield visual field damage: comparison of high-tension and normal-tension groups.

PURPOSE: To evaluate the performance of frequency doubling technology (FDT) perimetry in open-angle glaucoma eyes with hemifield visual field damage and to compare it between open-angle glaucoma with high pressure [high-tension glaucoma (HTG)] and those with normal pressure [normal-tension glaucoma (NTG)] groups. METHODS: FDT perimetry with the N-30 full threshold protocol and standard automated perimetry (SAP) using the Humphrey Field Analyzer with the 30-2 full threshold protocol were performed in 20 eyes of 20 HTG patients and 36 eyes of 36 NTG patients with visual field damage confirmed with SAP in only one hemifield. RESULTS: There was no significant difference in demographics, the Heidelberg Retina Tomography indices, and the Humphrey Field Analyzer indices between HTG and NTG groups. Regarding the FDT perimetry results, mean deviation in the global field (P=0.009) and mean sensitivity in the SAP-spared (P=0.001) and SAP-impaired (P=0.011) hemifields were lower; the numbers of FDT abnormal test points (probability of abnormality <5%) in the SAP-spared hemifield were significantly greater (P=0.005) in HTG than in NTG groups. Eyes in which FDT results of the SAP-spared hemifield were judged as abnormal was more frequent in HTG groups (P=0.007). CONCLUSIONS: The performance of FDT perimetry to detect early or preperimetric glaucomatous functional changes should be different between HTG and NTG eyes.

Cross-Sectional Studies↗
PubMed2005

Scaling the structure--function relationship for clinical perimetry.

PURPOSE: The full ranges of glaucomatous visual field defects and retinal ganglion cell losses extend over several orders of magnitude and therefore an interpretation of the structure-function relationship for clinical perimetry requires scaling of both variables. However, the most appropriate scale has not been determined. The present study was undertaken to compare linear and logarithmic transformations, which have been proposed for correlating the perimetric defects and neural losses of glaucoma. METHODS: Perimetry, by behavioural testing, and retinal histology data were obtained from rhesus monkeys with significant visual field defects caused by experimental glaucoma. Ganglion cell densities were measured in histologic sections of retina that corresponded to specific perimetry test locations for the treated and control eyes. The linear (percentage) and logarithmic (decibel) relationships for sensitivity loss as a function of ganglion cell loss were analysed. RESULTS: With decibel scaling, visual sensitivity losses and ganglion cell densities were linearly correlated with high coefficients of determination (r(2)), although the parameters of the functions varied with eccentricity. The structure-function relationships expressed as linear percentage-loss functions were less systematic in two respects. Firstly, the relationship exhibited considerable scatter in the data for small losses in visual sensitivity and, secondly, visual sensitivity losses became saturated with larger losses in ganglion cell density. The parameters of the percentage-loss functions also varied with eccentricity, but the variation was less than for the decibel-loss functions. CONCLUSIONS: Linear scaling of perimetric defects and ganglion cell losses might potentially improve the structure-function relationship for visual defects associated with small amounts of cell loss, but the usefulness of the relationship is limited because of the high variability in that range. With log--log co-ordinates, the structure--function relationship for clinical perimetry is relatively more accurate and precise for cell losses greater than about 3 dB. The comparatively greater accuracy and precision of decibel loss functions are a likely consequence of the logarithmic scale of stimulus intensities for perimetry measurements and because the relationship between visual sensitivity and the number of neural detectors is a form of probability summation.

Animals↗
PubMed2005

Central visual field changes using flicker perimetry in type 2 diabetes mellitus.

PURPOSE: To evaluate the efficacy of flicker perimetry compared with that of static perimetry in determining central visual field losses in participants with type 2 diabetes mellitus. METHODS: Flicker and static perimetry were performed using the Medmont field analyser on 20 participants with type 2 diabetes mellitus and 24 age-matched control participants. RESULTS: Flicker, but not static, perimetry demonstrated significant reductions in thresholds in those participants who had a recent diagnosis of diabetes or who had no or only minimal diabetic retinopathy compared to the control group at eccentricities close to fixation. CONCLUSION: Flicker perimetry is recommended for the evaluation of visual field losses in participants with recent onset of diabetes and minimal diabetic retinopathy.

Aged↗
PubMed1977

A note of fixation during perimetry.

Small eye movements in the direction of the disappearing stimulus can be observed at kinetic perimetry when the test object enters a scotomatous area. These may be responsible for the fact that several field defects, missed at routine manual perimetry, are spotted at automatic perimetry. In the latter case the patient cannot predict the position of next test light, since these are illuminated at random, whereas at kinetic perimetry they are exposed in systematic order. By using two specially designed logics in automatic perimetry, it was shown that there may be a reduction of the scotoma size if the lights are exposed in an ordered sequence. This effect is avoided by using a logic with randomly exposed stimuli. It is most likely that the difference can be attributed to "malfixation".

Adult↗