High-pass Resolution Perimetry Research Articles

The role of optical coherence tomography in the detection of pituitary adenoma

To analyse retinal nerve fibre layer (RNFL) thickness in eyes with compression of the optic chiasm by a pituitary adenoma. RNFL thickness was analysed with optical coherence tomography (OCT) and compared to visual field measurements using high-pass resolution perimetry (HRP). Sixteen eyes from eight patients with pituitary adenoma were studied. All had bitemporal visual field depression caused by compression of the optic chiasm. Patients were submitted to an ophthalmic examination more than 14 months after surgery (seven patients had undergone trans-sphenoidal and one trans-cranial adenomectomy). The examination included HRP, fundus photography and measurement of the peripapillar RNFL thickness using OCT. In spite of temporal visual field depression, not all eyes showed reduced RNFL thickness by OCT. This was also true for some eyes in which RNFL was judged to be reduced on fundus photographs. Contrary to our expectations, RNFL thickness in the nasal quadrant was normal in nine of the 16 eyes. Corresponding figures for the superior, inferior and temporal quadrants were eight, six and five, respectively. The overall RNFL thickness, as measured by OCT, did not correlate well with neural capacity, which is an index of remaining retino-cortical neural channels in HRP. RNFL thickness as measured with OCT was reduced in most, but not all, eyes with temporal field depression caused by chiasmal compression. The pattern of RNFL loss did not correlate well with the visual field defect. Sensitivity of RNFL thickness measurement in OCT was low. The method has limited value in the diagnosis of pituitary tumour compression.

How robust is the optic chiasm? Perimetric and neuro-imaging correlations

Analysis of form and function relationships with tumour-mediated dislocations and deformations of the optic chiasm. Results of magnetic resonance tomography and two forms of quantitative, computerized perimetry were contrasted in 31 patients with pituitary adenomata impinging on the chiasm, prior to treatment. Perimetric abnormalities ranged from none to modest. High-pass Resolution Perimetry (HRP) produced abnormal results in 10 cases and RareBit perimetry (RBP) in 15 cases. Overall, field defects and qualitative stages of deformation and dislocation of the chiasm were well correlated. Among quantitative indices, the best correlations were obtained by a measure of the cranio-caudal position of the chiasm. On average, an elevation of the chiasm by 6 mm will be associated with abnormal visual fields in 50% of the cases. An additional elevation of 5 mm will raise the incidence of field defects to 90%.

Resolution visual fields in children surgically treated for congenital cataract

Abstract Purpose: To evaluate best‐corrected visual acuity (BCVA) and high‐pass resolution perimetry (HRP) visual fields in children surgically treated for congenital cataract. Methods: BCVA and HRP was recorded from 10 aphakic children, aged 10‐15 years and surgically treated for bilateral dense cataract before the age of nine months, and from six aphakic children, aged 10‐15 years and surgically treated for bilateral partial cataract at ages between 6 months and 9 years. Twenty‐three healthy children, 11 years of age, served as controls. Results: The aphakic children had significantly (p < 0.0001) lower BCVA in their best eye (range 0.1‐1.3) compared to controls (range 1.0‐1.6). Two aphakic children were visually disabled according to WHO. The children with previous dense bilateral cataract showed significantly (p < 0.05) lower sensitivity in their resolution visual fields (from their best eyes) compared to both controls and children with previous partial cataract. The dense cataract group also showed significantly (p<0.05) smaller difference between the innermost (5 deg) and the outermost (20‐30 deg) eccentricity locations in their visual fields than the other two groups. Conclusions: Dense cataract, even when surgically treated before the age of nine months, causes persistent impairment of spatial vision both in the fovea and the visual field. Partial cataract appears only to reduce visual acuity.

Influence of ageing on visual field defects due to stable lesions

Background:Knowledge about the effects of ageing on visual field defects is very sparse.Methods:Long-term follow-up records were examined from 28 patients with light-to-moderate visual field defects remaining after surgery for pituitary...

Intraocular pressure before and after visual field examination

To evaluate the influence of visual field (VF) examinations using modern techniques with short examination times on the intraocular pressure (IOP). Sixty-one consecutive patients, aged 28-90 years, 40 women and 21 men, were examined. Forty patients were treated for glaucoma and 21 were untreated patients with ocular hypertension or suspected glaucoma. Twenty-one subjects were examined using the Humphrey Field Analyzer, using SITA programs, and 40 with high-pass resolution perimetry (HRP). Goldmann applanation tonometry was performed immediately before and after the VF examinations. A difference in IOP of more than 2 mm Hg before and after the VF examination was observed in 14 of the 61 patients (23%). The maximum change in each direction was 4 mm Hg. The mean differences were not significant. All eight subjects with increasing IOP after VF examinations were examined using the HRP technique (P=0.04). Modern VF techniques with short examination time do not seem to significantly influence IOP.

Identifying Glaucomatous Vision Loss with Visual-Function–Specific Perimetry in the Diagnostic Innovations in Glaucoma Study

To compare the diagnostic results of four perimetric tests and to identify useful parameters from each for determining abnormality. One hundred eleven eyes with glaucomatous optic neuropathy (GON), 31 with progressive optic neuropathy (PGON) 53 with ocular hypertension, and 51 with no disease were included (N = 246). Visual field results were not used to classify the eyes. Short-wavelength automated perimetry (SWAP), frequency-doubling technology perimetry (FDT), high-pass resolution perimetry (HPRP), and standard automated perimetry (SAP) were performed. Receiver operating characteristic (ROC) curves were used to compute the areas under the curves (AUC) and sensitivity levels at given specificities for a variety of abnormality criteria. The agreement among tests for abnormality, location, and extent of visual field deficit were assessed. AUC analysis: When the normal group was compared with the GON group, the FDT pattern SD (PSD) area was larger than the HPRP PSD (P = 0.020), and the FDT area of total deviation (TD) <5% was larger than the HPRP mean deviation (MD; P = 0.004). When the normal group was compared with the PGON group, the FDT area of pattern deviation (PD) <5% was larger than the SWAP PSD (P = 0.020). A difference from previous work was that AUCs for PSD or the best SAP were not significantly poorer than those in the function-specific tests. At set specificities, FDT yielded higher sensitivities than all other tests for all parameters. The agreement among tests for abnormality was fair to moderate (kappa = 247-0.563). When loss was present on more than one test, the quadrant of the visual field affected was the same in 95% (79/83) of eyes. The number of eyes identified and number of abnormal quadrants increased across groups with increasing certainty of glaucoma. At equal specificity, no single perimetric test was always affected, whereas others remained normal. Several parameters at suggested criterion values provided good sensitivity and specificity. FDT showed the highest sensitivity overall, with SAP performing better than in prior reports. Of note, the same area of the retina was identified as damaged in all tests.

Glaucoma follow-up by the Heidelberg Retina Tomograph

The Heidelberg Retina Tomograph (HRT) is a commercially available instrument for the detection of glaucomatous damage by analysis of optic nerve head topography. The main purpose of the study was to investigate the ability of HRT to detect changes in optic disc topography indicating progression of optic neuropathy in eyes with open-angle glaucoma or, in eyes with ocular hypertension, conversion to open-angle glaucoma. Fifty-nine subjects (34 with ocular hypertension, 25 with glaucoma) from the glaucoma service at Sahlgrenska University Hospital were included in this study. One eye of each patient was selected. All participants underwent thorough clinical examination, including HRT, high-pass resolution perimetry (HRP), and optic disk photography. After a mean follow-up time of 50 months, patients were re-examined. Based on analyses of optic disc photographs and HRP, eyes were classified into one of two groups: progressive or stable. The differences between baseline and follow-up HRT parameters in the two groups were analysed. The topographic HRT change images were also compared after digital image processing. A pixel ratio was calculated defined as the ratio between the area of pixels representing deepening of the disc surface and the total disc area. Receiver operating characteristic (ROC) curves for HRT parameters and pixel ratio were compared. In the group judged to have progressive optic neuropathy, a statistically significant change between baseline and follow-up examination was found for the following HRT parameters: cup shape measurement, classification index, the third moment in contour, cup/disc ratio, cup area, rim area, and area below reference). In the stable group no HRT parameters had changed significantly. A well-defined distinction between the two groups was found by comparing digitally processed HRT change images. The area under the ROC curve was larger for pixel ratio than for any of the HRT parameters. The HRT is a useful tool for long-term follow-up of glaucomatous optic neuropathy. Digital image processing of HRT change images could facilitate the detection of progressive change.

The relation between resolution measurements and numbers of retinal ganglion cells in the same human subjects

Limiting factors of resolution have previously only been investigated by using resolution data and retinal ganglion cell spacing data from different individuals. We report on our unique opportunity to study the intra-individual relationship in three human subjects between retinal ganglion cell separations and resolution thresholds, measured with high-pass resolution perimetry. Our data show that resolution is directly proportional to half the midget population, in accordance with the hypothesis that a dichotomous midget ON/OFF population mediates resolution.

Longitudinal changes in the visual field and optic disc in glaucoma

The nature and mode of functional and structural progression in open-angle glaucoma is a subject of considerable debate in the literature. While there is a traditionally held viewpoint that optic disc and/or nerve fibre layer changes precede visual field changes, there is surprisingly little published evidence from well-controlled prospective studies in this area, specifically with modern perimetric and imaging techniques. In this paper, we report on clinical data from both glaucoma patients and normal controls collected prospectively over several years, to address the relationship between visual field and optic disc changes in glaucoma using standard automated perimetry (SAP), high-pass resolution perimetry (HRP) and confocal scanning laser tomography (CSLT). We use several methods of analysis of longitudinal data and describe a new technique called "evidence of change" analysis which facilitates comparison between different tests. We demonstrate that current clinical indicators of visual function (SAP and HRP) and measures of optic disc structure (CSLT) provide largely independent measures of progression. We discuss the reasons for these findings as well as several methodological issues that pose challenges to elucidating the true structure-function relationship in glaucoma.

Visual field of high-pass resolution perimetry in normal subjects.

To investigate the properties of the visual field of high-pass resolution perimetry in normal subjects. Four centers collected normative data for high-pass resolution perimetry. In two of the centers the subjects were stratified by age. One eye was tested per subject using high-pass resolution perimetry (Ophthimus). We tested 640 normal subjects and describe their visual field results by test location. We also analyzed the data by concentric zone, age, and by testing center. The individual test location averages confirmed a reduction in resolution with eccentricity. Resolution thresholds increased with age by 0.025 dB per year (P < 0.001). The mean ring size increased by about 1 dB from age 20 to 70. Among centers there were significant differences in the means and the change in threshold with age (P = 0.009). The normal visual field of high-pass resolution perimetry is characterized by an increase in threshold with eccentricity. We found significant differences among the centers that were likely due to multiple factors including differences in subject selection criteria. Whether such differences occur with other perimetric techniques is unknown.

Peripheral and Central Visual Fields in 11-Year-Old Children Who Had Been Born Prematurely and At Term

To examine the peripheral and central visual fields in children who had been born prematurely and at term. Four groups of 11-year-old children were examined: group 1 included 24 children who had been born at term (control group); group 2 included 20 children who had been born prematurely without ROP; group 3 included 22 children who had been born prematurely with untreated ROP (stages 2 and 3); and group 4 included 21 children who had been born prematurely and underwent cryotreatment for severe ROP. Their peripheral visual fields were examined with Goldmann perimetry. Static high-pass resolution perimetry was used to evaluate their central visual fields within 30 degrees. The peripheral visual fields were constricted in children who had undergone cryotreatment (group 4), as compared with the other groups (1 to 3). We found no difference between the groups of children who had been born prematurely with or without ROP (groups 2 and 3) and the control group. The function of the central visual fields, expressed as neural capacity, was reduced in the children who had been born prematurely compared with the controls, significantly in their left eyes only. The children who underwent cryotreament did not differ from the other children who had been born prematurely in this respect. The peripheral visual fields were constricted in children who had undergone cryotreatment. It is uncertain whether this was caused by the treatment or by severe ROP. The central visual fields showed a tendency of reduced neural capacity in the children who had been born prematurely, reflecting a reduced density of retinocortical neural channels. However, this was not related to ROP or cryotreatment.

Visual field and optic disc progression in patients with different types of optic disc damage: A longitudinal prospective study

Objective To evaluate the incidence of visual field and optic disc progression in glaucoma patients with distinct patterns of optic disc damage. Design Prospective, observational case series. Participants One hundred five patients with open-angle glaucoma. Methods Baseline optic disc photographs of 105 study eyes of 105 patients were reviewed by 2 masked observers and classified according to patterns of disc damage into the following categories: focal, myopic, senile sclerotic, and generalized disc damage. Patients were followed up every 6 months with standard automated perimetry (SAP), high-pass resolution perimetry (HRP), and scanning laser tomography (SLT) with the Heidelberg Retina Tomograph. Main outcome measures Visual field (SAP and HRP) and optic disc (SLT) progression were determined according to predefined criteria. Results Twenty-four eyes were classified into the focal, 8 into the myopic, 12 into the senile sclerotic, and 28 into the generalized group. Eyes from 33 patients could not be classified by the observers into any of these groups and were excluded from further analysis. Although intraocular pressure during follow-up was similar among the four groups, some differences in frequency of progression were observed. Patients with senile sclerotic discs had the lowest rates of visual field progression (both with SAP and HRP) and optic disc progression, although the differences were significant only for optic disc progression ( P = 0.05). Conclusions Patients with senile sclerotic discs showed a tendency towards less visual field and optic disc progression when compared with patients with other types of disc damage.

Eccentric correction for off-axis vision in central visual field loss.

Subjects with absolute central visual field loss use eccentric fixation and magnifying devices to utilize their residual vision. This preliminary study investigated the importance of an accurate eccentric correction of off-axis refractive errors to optimize the residual visual function for these subjects. Photorefraction using the PowerRefractor instrument was used to evaluate the ametropia in eccentric fixation angles. Methods were adapted for measuring visual acuity outside the macula using filtered optotypes from high-pass resolution perimetry. Optical corrections were implemented, and the visual function of subjects with central visual field loss was measured with and without eccentric correction. Of the seven cases reported, five experienced an improvement in visual function in their preferred retinal locus with eccentric refraction. The main result was that optical correction for better image quality on the peripheral retina is important for the vision of subjects with central visual field loss, objectively as well as subjectively.

Detection of glaucomatous visual field defect by nonconventional perimetry

PurposeTo report the correlations among Humphrey Field Analyzer 750 (HFA), high-pass resolution perimetry (HRP), and frequency-doubling technology (FDT) perimetry in glaucoma patients and ocular hypertensive patients. DesignCross-sectional study. MethodsEighty-two eyes of 82 consecutive patients with primary open-angle glaucoma (POAG) or ocular hypertension were included in this study. One eye of each patient was randomly selected for data analysis. Visual fields were assessed by HFA, HRP, and FDT perimetry. HRP global deviation (HRP-GD), HRP local deviation (HRP-LD), FDT-mean deviation (FDT-MD), and FDT-pattern standard deviation (FDT-PSD) were considered for the analysis. Clinical agreement between HRP and FDT was evaluated. All data were analyzed by Pearson r coefficient when the distribution of the data was normal and by Spearman coefficient correlation when the distribution of the data was not normal. A P < .05 was considered statistically significant. ResultsFifty-two eyes (52 patients) were classified as glaucoma and 30 eyes (30 patients) as ocular hypertension. In the entire group, a significant (P > .001) correlation was found between the HFA indices and those of either HRP or FDT. A significant (P < .001) correlation was found between HRP-GD and FDT-MD as well as between HRP-LD and FDT-PSD. In 14% of the glaucomatous patients and in 33% of the subjects with ocular hypertension, FDT and HRP showed different clinical features. ConclusionsOur data suggest that FDT and HRP are useful for detection of early glaucomatous visual field damage.

Are high-pass resolution perimetry thresholds sampling limited or optically limited?

It has been reported that high-pass resolution perimetry (HRP) provides a means of noninvasively determining retinal ganglion cell density. However, there is evidence to suggest that this may not be true. The purpose of the present study was to determine whether HRP thresholds are sampling limited, which is a necessary condition for being able to determine retinal ganglion cell density psychophysically. This study measured resolution and detection performance for a range of grating-based stimuli under the testing conditions that HRP uses and compared these with performance of the ring stimulus. The results show that detection and resolution acuity under HRP test conditions were often equivalent, in accordance with previous investigations. However, the results also show that the thresholds underestimated the true level of resolution acuity in the periphery because increasing stimulus contrast increased performance. These findings suggest that HRP thresholds cannot be regarded as sampling limited, but rather they are optically limited. We therefore conclude that HRP thresholds cannot be regarded as a direct measure of the underlying ganglion cell density.

New, sensitive window on abnormal spatial vision: rarebit probing

Clinical tests have a poor sensitivity to low to moderate degrees of neuro-visual damage, possibly because their test targets involve numerous receptive fields. A new test used briefly exposed microdots of high contrast. Multiple visual field areas were probed repeatedly, with ever-new microdot positions. Normal subjects responded to a median 96.0% of probes. Patients with different visual field defects missed larger numbers of probes within defects and the deeper the defects, the larger the number of misses. Patients with minor chiasmal lesions averaged 1.8 times larger defects in microdot perimetry than in high-pass resolution perimetry, indicating superior sensitivity to minor damage.

The value of high-pass resolution perimetry in glaucoma.

High-pass resolution perimetry (HRP) is a perimetric technique that relies on low-contrast, high-spatial-frequency-filtered, ring-shaped test targets. It was devised as a quick and user-friendly technique that reflects the status of the retino-corneal pathway. Since its introduction in 1987, HRP has undergone substantial investigation, primarily in cross-sectional studies on patients with glaucoma, though it is also used in patients with neuro-ophthalmologic disorders. HRP has a shorter test time compared with conventional perimetry. Currently, evidence suggests that HRP is a viable test for the evaluation of the glaucomatous visual field.

Intraocular pressure and progression of glaucomatous visual field loss

PURPOSE: To evaluate the relationship between intraocular pressure and visual field progression in patients with primary open-angle glaucoma. METHODS: We prospectively followed 113 patients with early to moderate glaucomatous field damage. Conventional automated static perimetry, high-pass resolution perimetry, and intraocular pressure measurements were carried out at 6-month intervals. The mean and the highest intraocular pressure in the follow-up were compared in stable and progressing patients with each perimetric technique. RESULTS: The mean (± SD) follow-up was 4.5 ± 0.9 years. The mean (± SD) intraocular pressure in patients remaining stable with conventional perimetry [18.2 ± 3.3 mm Hg, n = 81 (71.7%)] was not significantly different ( P =.65) from those in whom it progressed (17.9 ± 3.3 mm Hg, n = 32 [28.3%]). The mean intraocular pressure in patients remaining stable with high-pass resolution perimetry (17.9 ± 3.5 mm Hg, n = 63 [55.8%]) was not significantly different ( P = .33) from those in whom it progressed (18.5 ± 3.0 mm Hg, n = 50 [44.2%]). The mean (± SD) of the highest (single or three highest) pressure during follow-up for stable and progressing patients with conventional perimetry was not significantly different (22.6 ± 5.0 and 23.0 ± 4.6 mm Hg, respectively, P = .76). However, for high-pass resolution perimetry, the difference was highly significant (21.6 ± 4.5 and 24.1 ± 4.9 mm Hg, respectively, P < .01). Furthermore, patients who progressed with high-pass resolution perimetry had more damaged baseline fields compared with those who remained stable ( P < .01). CONCLUSIONS: The mean level of intraocular pressure does not differentiate glaucoma patients with progressive visual field loss from ones who remained stable. Baseline visual field status and peak intraocular pressure of patients who progress with high-pass resolution perimetry are significantly different from those who remain stable.

Measurement of retinal nerve fibre layer by scanning laser polarimetry and high pass resolution perimetry in normal tension glaucoma with relatively high or low intraocular pressure

AIMSTo determine whether any differences may exist in the relation between the neural capacity as determined by high pass resolution perimetry and the thickness of the retinal nerve fibre layer...

Course of exfoliation and simplex glaucoma after primary trabeculectomy

AIMTo study the course of exfoliation and simplex glaucoma with respect to intraocular pressure (IOP) regulation and visual field survival after primary trabeculectomy.METHODSPostoperative IOP regulation and complications were analysed prospectively...