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Long-term studies of visual field changes by means of computerized perimetry (Octopus 201) in eyes with glaucomatous field defects after normalization of the intra-ocular pressure.

UNLABELLED: 126 eyes with open-angle glaucoma and defects of the visual field were studied over five years (+/-1.3) by repeated perimetries with Octopus Perimeter, Program 31, after the IOP had been normalized from 26.49 mm Hg to 19 mm Hg. All patients had suffered visual field defects in the period with increased pressure preceding our study and had many perimetric examinations before. The aim of the study was to check the behaviour of the visual field defects after pressure normalization. For evaluation of the visual fields, the upper most line of the test-points and the 6 test-points surrounding the blind spot were disregarded. The evaluation of each field and the comparison with preceding fields (no change, better, or worse) were done by the symmetry test of Bowker instead of the Delta Program, taking into account each of the 61 test-points with a significance level of 5%. In each patient the eye with the heavier field loss was evaluated. RESULTS: 67% of all eyes had no change during the observation time, 12% became better, and 21% worse. Improvement of the visual fields occurred even in old age: 10% became better in the age-group over 70 years. The total loss decreased in the 15 eyes which improved by 269 dB. In eyes which deteriorated, the total loss increased by 282 dB. The good news of this study is that normalization of IOP can stop the further decay of the visual-field in 67% and an improvement of the field loss is possible even in old age of with heavy field loss.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

Central corneal pachymetry and visual field progression in patients with open-angle glaucoma.

PURPOSE: To investigate the association between corneal pachymetry and visual field progression in patients with chronic open-angle glaucoma. DESIGN: Retrospective case-control study. PARTICIPANTS: Eighty-eight patients with primary open-angle glaucoma, pseudoexfoliative glaucoma, pigmentary glaucoma, or normal-tension glaucoma, followed for an average of 8 years, who had visual field loss and progression as defined by modified Anderson criteria. Cases with progression were matched for race, diagnosis, and age at pachymetry with controls who did not have progression. METHODS: Progression was defined by use of the modified Anderson criteria. Central corneal thickness (CCT) was determined by ultrasound pachymetry. MAIN OUTCOME MEASURES: Visual field progression and corneal pachymetry. RESULTS: The mean CCT in patients with visual field progression was significantly lower than the mean CCT in patients who did not progress (529+/-36 mum vs. 547+/-35 mum; P = 0.02). Those with thinner CCT were more likely to progress than those with thicker CCT as identified by Cox proportional hazards regression analysis (P = 0.01; hazard ratio, 1.44 for a 40-mum thinner CCT; 95% confidence interval, 1.12-1.80), and CCT was the only risk factor identified to be significantly associated with visual field progression. CONCLUSIONS: In this case-control patient population, visual field progression in patients with open-angle glaucoma was significantly associated with thinner CCT.

Adult↗

Electrode position and the multi-focal visual-evoked potential: role in objective visual field assessment.

PURPOSE/METHODS: To improve the performance of visual-evoked potentials (VEP) in the assessment of the human visual field, the multi-focal cortically scaled pattern VEP was recorded up to 250 of eccentricity in normal subjects. Monopolar and varying bipolar electrode positions were used. RESULTS: The monopolar response was strongly biased towards the lower hemifield. Bipolar leads straddling the inion (2 cm above and below) achieved approximately equal signals from the upper and lower visual field. Division into sectors of similar wave-form augments the analysis compared with summed full-field responses. CONCLUSION: With this technique, the multi-focal VEP can be used to objectively assess the visual field.

Cerebral Cortex↗

Visual-field map in the transcallosal sending zone of area 17 in the cat.

The representation of the visual field in the part of area 17 containing neurons that project axons across the corpus callosum to the contralateral hemisphere was defined in the cat. Of 1424 sites sampled along 77 electrode tracks, 768 proved to be in the callosal sending zone, which was identified by retrograde transport of horseradish peroxidase that had been deposited in the opposite hemisphere. The results show that the callosal sending zone has a fairly constant width of between 3 and 4 mm at most levels in area 17. However, the representation of the contralateral field at the different elevations of the visual field is not equal in this zone. The zone represents positions within 4 deg of the midline at the 0-deg horizontal meridian, and positions out to 15-deg azimuths in the upper hemifield and out to positions of 25-deg azimuth in the lower hemifield. The shape of the representation is approximately mirror-symmetric about the horizontal meridian, although there is a greater extent in the lower hemifield, which can be accounted for by the greater range of elevations (greater than 60 deg) represented there compared with the upper hemifield (approximately 40 deg). The representation in the sending zone of one hemisphere matches that present in the area 17/18 transition zone, which receives the bulk of transcallosal projections, in the opposite hemisphere. The observations on the sending zone show that callosal connections of area 17 are concerned with a vertical hour-glass-shaped region of the visual field centered on the midline. The observations suggest that in addition to interactions between neurons concerned with positions immediately adjacent to the midline, there are positions, especially high and low in the visual field, where interactions can occur between neurons that have receptive fields displaced some distance from the midline.

Animals↗

Multivariate analysis of the risk of glaucomatous visual field loss.

In a retrospective study, 92 patients with ocular hypertension, ie, intraocular pressure of 21 mm Hg or higher, and no evidence of glaucomatous visual field defects, were observed for five years. Visual field defects developed in one or both eyes of 33 patients during the five-year follow-up period, while none were detected in the remaining 59. Values for suspected risk factors, determined at the outset of the follow-up period, were subjected to a multivariate analysis with use of linear discriminant analysis and a multiple logistic function. Models of risk providing maximum separation of the two patient groups (visual field loss vs no visual field loss) found that the risk factors having the greatest significance for prediction of visual field loss included vertical estimates of cup/disc ratio, mean IOP during the period of observation, a positive family history of glaucoma, and age. Factors having the lowest predictive values included IOP response to topical dexamethasone, plasma cortisol suppression, and a history of systemic hypertension.

Glaucoma↗

Long-term follow-up of visual field progression after trabeculectomy in progressive normal-tension glaucoma.

OBJECTIVE: To evaluate the long-term effects of trabeculectomy on the progression of visual field damage in patients with progressive normal-tension glaucoma (NTG). DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: Twenty-three patients with NTG who had significant progression of visual field damage preoperatively and underwent trabeculectomy using antimetabolites. METHODS: Visual field testing using the Humphrey Visual Field Analyzer was periodically performed before and for at least 5 years after surgery (mean, 6 years). The time course of the mean deviation (MD) and mean of total deviations (TD(mean)) in four separate subfields, superior and inferior cecocentral and superior and inferior arcuate fields, were analyzed using a linear mixed effects model. MAIN OUTCOME MEASURES: Intraocular pressure (IOP), preoperative and postoperative regression coefficients of the time course of MD or TD(mean) in the four subfields, corresponding to the rate of progression of visual field damage. RESULTS: IOP significantly decreased from 16.2 +/- 1.8 mmHg preoperatively to approximately 11 mmHg during the postoperative follow-up period (P < 0.001). The preoperative regression coefficient of MD change was significantly negative (-1.05 [95% confidence interval, -1.28 to -0.82] dB/year, P < 0.001). After surgery, it increased significantly to -0.44 (95% confidence interval, -0.64 to -0.24) dB/year (P < 0.001), but the postoperative value was still significantly negative (P < 0.001). In the superior cecocentral, superior and inferior arcuate fields, preoperative regression coefficients of TD(mean) change were significantly negative (P < 0.001) and significantly increased after surgery (P < 0.01). In the inferior cecocentral field, the preoperative regression coefficient was not significantly different from 0 (P = 0.72) and did not change significantly after surgery (P = 0.15). CONCLUSIONS: Trabeculectomy was statistically associated with slowing further progression of visual field damage in patients with progressive NTG. The progression, however, did not completely stop over the 6-year postoperative follow-up period.

Disease Progression↗

Examining visual field defects in the paediatric population exposed to vigabatrin.

The antiepileptic drug, vigabatrin, has been linked to a specific pattern of visual field loss. The majority of studies have not included the paediatric population due to difficulties assessing visual field function. This is a particular problem as vigabatrin is effective against infantile spasms. A field-specific visual evoked potential was developed which consisted of a central stimulus (0-5 degrees radius) and a peripheral stimulus (30-60 degrees radius). Both stimuli consist of black and white checks which increase in size with eccentricity. Responses are recorded from occipital electrodes O2 and O1 referred to frontal electrode Fz. Electroretinograms and perimetry was performed were possible as a comparison. Thirty-nine children with epilepsy treated with vigabatrin aged from 3 to 15 years were included in the study; 35/39 children complied with the field-specific VEP, 26/39 complied with the ERG and 11/39 performed perimetry. Of these results, 18 children had normal ERG responses and eight had abnormal response. Visual field testing revealed four children had abnormal and seven had abnormal visual field results. The Field-specific VEP identified three of four abnormal perimetry results and six of seven normal perimetry results, giving a sensitivity of 75% and a specificity of 85.7%. When comparing perimetry results with the ERG parameters only the 30-Hz flicker amplitude, with a cut-off amplitude below 70 microV, gave a useful sensitivity of 75% and a specificity of 71%. The field-specific VEP is a useful alternative method that is both well tolerated by young children and gives a reliable indication of likely peripheral visual field loss associated with vigabatrin. The defect appears to have a similar prevalence in children as it does in adults.

Adolescent↗

[Unilateral visual field defect due to optic nerve compression by sclerotic internal carotid artery: a case report].

A case of unilateral visual field defect due to optic nerve compression by a sclerotic internal carotid artery was reported. A 71-year-old woman was admitted to our department because of constricted visual field of the right eye. MRI showed elevation of the right optic nerve compressed by an internal carotid artery. The right carotid angiography revealed elevation and distortion of the C1-2 portion. Frontal craniotomy was carried out and the optic nerve was visualized on this side. The right optic nerve was found to have been compressed by the sclerotic internal carotid artery. The optic canal was then unroofed. The post-operative course was uneventful. The visual field was improved. When last seen 6 months after surgery, her visual field remained in the improved condition. Nasal field abnormalities are most frequently encountered in retinal and anterior optic nerve pathology. Our success in improving the visual field disturbance may be accounted for by the fact that the preoperative period was short and the operation was performed before atrophy of ocular fundi occurred. Nasal field loss caused by intracranial lesions of the optic pathway is rare. It is probably impossible to determine degree of the symptomatology caused by direct-pressure compression as opposed to that caused by ischemia secondary to occlusion of small arterial supply branches. Vascular compressive neuropathy of optic nerve should not be diagnosed simply by the radiological finding of the optic nerve dislocation. However, optic nerve compression by surrounding arteries should be remembered as one of the possible causes of visual field defect which needs to be treated surgically.

Aged↗

Visual fields in a successfully radiated retinoblastoma patient.

1. Computerized visual fields have recently been used to study patients before and after treatment of choroidal melanoma with plaque therapy. Such information is unavailable for patients diagnosed with retinoblastoma. 2. There is no information on the long term visual fields of successfully treated retinoblastoma; therefore, no comparisons can be made between the effects of photocoagulation, cryotherapy, plaques, and external beam radiation on the visual field defects. 3. External beam radiation to tumors around the optic nerve caused widespread patchy sparing because of partial destruction of the nerve fiber layer. Whether the destruction was related to the position of the tumors or the effect of the radiation is unknown.

Eye↗

Pupillary anomaly masquerading as a glaucomatous visual field defect: a case report.

BACKGROUND: Patients are often referred to ophthalmologists with focal visual field defects on routine testing, possibly related to a potential diagnosis of glaucoma. However, examination of the individual patient's ocular characteristics as well as facial characteristics may often reveal a cause of the visual field defect. CASE PRESENTATION: We describe a patient who was found to have a superior visual field defect on routine testing by the optician. Repeat perimetry with pharmacological dilatation of the pupil revealed that the cause of the field defect was related to an eccentric inferiorly displaced pupil, secondary to trauma some years previously. DISCUSSION: Individual patient characteristics, including both ocular, as well as facial, need to be considered, when interpreting any visual field defect.

Aged↗

[Objective evaluation of visual field loss in a patient with branch retinal artery occlusion and brain infarction].

PURPOSE: To evaluate visual field loss using multifocal ERG(m-ERG), multifocal VEP(m-VEP), and Heidelberg Retina Flowmeter(HRF) in a patient with branch retinal artery occlusion(BRAO) and brain infarction. CASE: A 38-year-old man noticed inferior-nasal visual field loss in the left eye, and was referred to Keio University Hospital. He suffered from paralysis in the left leg due to brain infarction at the age of 24. However, he had not noticed visual field loss due to the brain infarction. His left fundus showed retinal edema in the area of a superior-temporal retinal artery occulusion. He was diagnosed as having BRAO. The Goldmann and Humphry perimetric examinations revealed homonymous quadrantanopia in the upper left field as well as inferior visual field defect in the left eye. RESULTS: Both m-ERG and m-VEP, especially second-kernel responses, were reduced in the affected retinal area of BRAO. But only m-VEP was affected in the corresponding area of homonymous quadrantanopia in the upper left field. The retinal flow in the area with BRAO evaluated by HRF was decreased in some areas and not in others, suggesting that retinal function was not necessarily consistent with retinal circulation. CONCLUSIONS: m-ERG and m-VEP are useful To differentiate retinal lesions from brain lesions in visual field loss.

Adult↗

The visual field representation of the rat ventral lateral geniculate nucleus.

The representation of the visual field in the ventral lateral geniculate nucleus (LGNv) was studied in rats anesthetized with urethane by recording the response of single units to visual stimulation. Receptive fields of LGNv units were plotted on a campimeter, 60 cm in diameter, which was placed 30 cm from the contralateral eye. LGNv neurons responded mainly to stimulation of the contralateral eye with on-tonic characteristics. Few neurons responded only to stimulation of the ipsilateral eye and no binocular interaction was observed. Retinotopic organization was clearly seen in the LGNv; the nasal visual fields were represented dorsally, the temporal fields ventrally, and the upper to lower visual fields were in the rostrolateral to caudomedial parts of the LGNv. A given point in the visual field is represented along a line running through the LGNv in a rostrocaudal direction. Almost the entire horizontal extent of the contralateral visual field was represented in the LGNv, whereas vertically the visual field between 40 degrees above and 20 degrees below the distribution axis was represented. The major axis of the strip of the visual field containing all the RF centers, which is referred to as the distribution axis, inclined nasally up and temporally down at an angle of 10.4 degrees to the 0 degree horizontal meridian line. The representation of the distribution axis in the retina was in accordance with the major axis of retinal ganglion cell distribution (Fukuda, '77; Schober and Gruschka, '77).

Animals↗

Retention of practice effects on simple reaction time for peripheral and central visual fields.

Previous researchers reported that EMG Reaction Time (RT) for a key press in peripheral and central visual fields decreases with practice. The practice effects on the RT for peripheral visual field transferred to the RT for the central visual field, and vice versa. The present study investigated whether practice effects on the RT for peripheral and central visual fields and the corresponding transfer effects lasted 3 wk. or not. 16 male subjects were divided into two groups, one practicing using peripheral vision, the other practicing using central vision. Each group practiced RT tasks for 3 wk. 3 wk. after practice terminated, the practice effects and the transfer effects were maintained as a significant decrease in RT was found over the 3-wk. retention interval, suggesting that once the neural correlates of responding quickly are improved, the improved performances are remarkably stable for at least 3 wk.

Adult↗

Kinetics of visual field loss in Usher syndrome Type II.

PURPOSE: To characterize the kinetics of visual field decay in Usher syndrome type II. METHODS: The area of 137 Goldmann visual fields (GVFs) delimited with the I4e and V4e targets was measured in each eye of 19 patients with an established diagnosis of Usher syndrome type II, and the average interocular GVF area for each patient at each time point was calculated. The average follow-up was 5.58 years. Symptomatic disease duration was defined as years elapsed after symptoms were first noted. The data set (n = 67 for the I4e target; n = 70 for the V4e target) was analyzed with a random coefficient mixed model to identify the best-fit model describing the decay of visual field size over time. The half-life of the residual visual field area (t(0.5)) was also calculated. RESULTS: The variable that best explained the decay of the GVF area was the duration of symptomatic disease. In an exponential model, the slope estimate for the natural log of the GVF area was -0.172 for the I4e target and -0.136 for the V4e target for each year of symptomatic disease. Accordingly, t(0.5) was approximately 4 years for the I4e target and 5 years for the V4e target. These estimates are very similar to those in previous studies of nonsyndromic retinitis pigmentosa (RP). CONCLUSIONS: This study suggests that the kinetics of GVF decline in Usher syndrome type II are, on average, very similar to other forms of RP and that, once the disease becomes symptomatic, GVF deterioration follows stereotyped kinetics, even in patients with late-onset retinal disease.

Adolescent↗

Importance of visual field score and asymmetry in the detection of glaucoma.

The visual fields and intraocular pressures (IOP's) of 115 normal volunteers and 107 suspect/diagnosed early glaucoma subjects were recorded by Friedmann static perimetry and noncontact tonometry or applanation tonometry. The visual field data were analyzed statistically and quantified numerically by a microcomputer. The readings obtained from the suspect/diagnosed early glaucoma subjects were compared to those from an age-matched control group according to four criteria: highest field score; field score asymmetry; highest IOP; and IOP asymmetry. A combined field score and asymmetry analysis was found to be more sensitive, 86%, than a combined IOP and IOP asymmetry analysis, 56%. The combined field score and field score asymmetry analysis also gave a clear bimodal separation of subjects with early visual field defects from those with normal visual function.

Adult↗

[Conventional techniques of visual field examination: part 4 Static perimetry: interpretation--perimetric indices--follow-up--perimetry in childhood].

Visual field examination with fixed stimuli was first realized in manual static profile perimetry. The transition from a linear stimulus alignment along a profile section towards a two-dimensional arrangement introduced the era of static grid perimetry. Application of computer technology nowadays allows automation and standardization of this procedure, which enables the examiner to select the necessary visual field area, the adequate grid, and the optimal strategy for an estimation of differential luminance sensitivity. Furthermore, the computer independently takes over the recording, visualization, and processing of the perimetric procedure. This contribution discusses conventional static visual field examinations since these are widely used, easily accessible, well established for practical application, and standardized. This paper (part 4) explicitly focuses on the correct interpretation of automated static strategies of visual field examinations. Furthermore the classification and scoring of visual field defects as well as quality control, progression analysis, and perimetry in childhood are addressed. This manuscript is based on three preceding parts, which were published in previous issues of this journal [27, 28, 29].

Child↗

Randomised controlled trial comparing the effect of brimonidine and timolol on visual field loss after acute primary angle closure.

AIM: To compare the effect of brimonidine and timolol in reducing visual field loss in patients with acute primary angle closure (APAC). METHODS: In addition to standard acute medical treatment, patients presenting with APAC were randomised to either brimonidine 0.2% or timolol 0.5% upon diagnosis, then twice daily for 4 weeks. After laser peripheral iridotomy (LPI), subjects underwent three baseline perimetry tests during the first week, and then at weeks 4, 8, 12, and 16. Pointwise linear regression analysis was applied to the field series of each of these subjects starting with the third test (total of five tests per subject). Progression was defined as a significant regression slope (p<0.05) showing 1 dB per year or more of sensitivity loss at the same test location in the series. Patients were also compared for prevalence of abnormal fields at 16 weeks, which was defined as an abnormal glaucoma hemifield test result and/or corrected pattern standard deviation outside the 95% confidence limits. RESULTS: 59 subjects (31 in the brimonidine group; 28 in the timolol group) completed the study. There were 47 females (79.7%), the majority of subjects (94.9%) were Chinese and the mean age was 59.2 (SD 7.2) years. There were no significant differences between the two groups with respect to demographic features, presenting intraocular pressure (IOP), duration of symptoms, time from presentation to LPI, or mean IOP at each study visit. Over the 16 week study period, despite adequate statistical power, no difference was found between groups in terms of the number of patients with progressing locations, the mean number of progressing locations per subject, or the mean slope of the progressing locations. Nine (29%) subjects in the brimonidine group and 10 (35.7%) in the timolol group were found to have significant visual field defects at 16 weeks (p = 0.58). 15 out of these 19 subjects (78.9%) already had these visual field defects in the first week. CONCLUSIONS: In the first 16 weeks after APAC, there was no difference in the prevalence of visual field defects or rate of visual field progression between brimonidine and timolol treated groups.

Acute Disease↗

[Perimetry findings and driving performance. "How much visual field" does a motorist need?].

OBJECTIVE: On 01-01-99 the new driving licence regulations came into force. Are the visual field criteria mentioned there sufficient for an adequate evaluation of driving fitness? METHODS: Typical (binocular) visual field defects were digitally superimposed onto photographs of traffic scenes to show the influence of such scotomata on visual perception. RESULTS: Exemplary cases clearly show that evaluation of visual field borders alone is not sufficient for evaluating driving fitness. They also prove that binocular scotomata affecting the (para-)central region of the visual field are of special importance to driving performance. The actual guidelines given by the traffic commission of the German Ophthalmological Society (DOG) and the legally defined limits will be critically discussed. CONCLUSION: From the ophthalmological point of view the actual visual field criteria of the new driving licence regulations do not seem to be sufficient for the evaluation of driving fitness: An additional consideration of (para-)central scotoma is mandatory. This publication provides recommendations for execution and interpretation of perimetric examinations for traffic ophthalmological purposes.

Automobile Driver Examination↗