Extent Of Visual Field Defects Research Articles

Visual field defects following different resective procedures for mesiotemporal lobe epilepsy

IntroductionOne of the most common side effects of mesiotemporal lobe resection in patients with medically intractable epilepsy are visual field defects (VFD). While peripheral defects usually remain unnoticed by patients, extended VFD influence daily life activities and can, in particular, affect driving regulations. This study had been designed to evaluate frequency and extent of VFD following different surgical approaches to the mesiotemporal area with respect to the ability to drive. Materials and methodsThis study comprises a consecutive series of 366 patients operated at the Epilepsy Center in Freiburg for intractable mesiotemporal lobe epilepsy from 1998 to 2016. The following procedures were performed: standard anterior temporal lobectomy (ATL: n=134; 37%), anterior temporal or keyhole resection (KH: n=53; 15%), and selective amygdalohippocampectomy via the transsylvian (tsAHE: n=145; 40%) and the subtemporal (ssAHE: n=34; 9%) approach. Frequency and extent of postoperative VFD were evaluated in relation to different surgical procedures. According to the German driving guidelines, postoperative VFD were classified as driving-relevant VFD with the involvement of absolute, homonymous central scotoma within 20° and driving-irrelevant VFD with either none or exclusively minor VFD sparing the center. ResultsPostoperative visual field examinations were available in 276 of 366 cases. Postoperative VFD were observed in 202 of 276 patients (73%) and were found to be driving-relevant in 133 of 276 patients (48%), whereas 69 patients (25%) showed VFD irrelevant for driving. Visual field defects were significantly less likely following ssAHE compared with other temporal resections, and if present, they were less frequently driving-relevant (p<0.05), irrespective of the side of surgery. ConclusionSubtemporal sAHE (ssAHE) caused significantly less frequently and less severely driving-relevant VFD compared with all other approaches to the temporal lobe, irrespective of the side of surgery.

Visual field loss in optic disc drusen patients correlates with central retinal artery blood velocity patterns

(1) To characterize the retrobulbar circulation in patients with optic disc drusen (ODD) using colour Doppler imaging; (2) to explore the differences in retrobulbar hemodynamics in patients with primary open-angle glaucoma (POAG). Retrospective analysis using three diagnostic groups: patients with ODD, age-matched healthy controls and age- and visual defect-matched patients with POAG. Subjects with history of ocular trauma or ocular diseases including vascular-related diseases were excluded. Kruskal-Wallis and Spearman's correlation tests were performed to compare and explore the correlations between the hemodynamic parameters and visual field damage. Sixty patients were included and equally divided between the three groups. Patients with ODD had lower systolic and diastolic flow velocities in the central retinal artery (CRA) when compared to healthy individuals, but no difference was found with the glaucoma group (p<0.005 versus healthy; p range 0.30-0.37 versus POAG). The systolic shift in flow patterns correlated with the extent of visual field defect in ODD patients (p<0.001, r=-0.78, confidence interval: -0.43 to -0.92), but not in POAG (p=0.73). Short ciliary arteries from ODD patients had lower mean systolic flow velocities when compared to both healthy individuals and patients with POAG (p<0.01 versus healthy; p≤0.04 versus POAG). The ophthalmic artery in ODD group had significantly higher mean blood velocities than in the POAG (p=0.04), while showing a significant overlap in Doppler waveform variables to the control group (p range 0.08-0.97). Similar to patients with glaucoma, individuals with ODD have low blood flow velocities in the vessels around the optic nerve head. Unlike patients with glaucoma, however, their CRA's blood flow velocity patterns correlate with the extent of the visual field defects.

Efficacy of Frequency Doubling Technology Perimetry in Non-arteritic Anterior Ischaemic Optic Neuropathy with Altitudinal Visual Field Defects

The aim of the study was to evaluate the ability of frequency doubling technology perimetry to detect altitudinal hemifield defects in cases of non-arteritic anterior ischaemic optic neuropathy. Thirty eyes of 24 cases of the disorder with typical altitudinal visual field defects underwent standard automated (Humphrey 24-2) and frequency doubling technology (N-30 threshold) perimetry. For both techniques locations showing a defect of p < 5% were considered abnormal and the mean percentage defect of both the involved and uninvolved hemifields and global visual field parameters were compared. The mean percentage defects for the involved and uninvolved hemifields were comparable (p = 0.1 and p = 0.07, respectively) but there were statistically significant differences in fixation losses and in test duration (p < 0.001 and p < 0.001, respectively) for the two techniques. The authors conclude that frequency doubling technology perimetry is reliable and easily performed in patients with altitudinal visual field defects. The similarity of the extent of visual field defects found using the two techniques suggests that frequency doubling technology perimetry can be used for the rapid detection of altitudinal defects in anterior ischaemic optic neuropathy.

Management of strabismus with hemianopic visual field defects

Hemianopia and strabismus leads to severe disturbance of visual orientation and diplopia under binocular conditions if the deviated eye has a normal retinal localization. Four cases with homonymous (two) and bitemporal (two) hemianopia and strabismus will be described with respect to binocular visual field and diplopia/confusion. All of them were recommended for strabismus surgery. Preoperatively, prism adaptation test was carried out to analyze functional results and fusional competence. In three of the four cases, strabismus surgery was successfully performed to avoid diplopia/confusion. All three patients revealed normal retinal correspondence. Furthermore, in two cases surgery led to an extension of binocular visual field; in one case with a bitemporal hemianopia and hemifield-slide phenomenon, blurred central vision and reading problems reduced significantly postoperatively. In one patient with anomalous retinal correspondence due to early childhood trauma exotropia led to an extension of the binocular visual field. In this case, strabismus surgery would have been unfavourable. Case 1 showed a homonymous hemianopia to the left and acquired exotropia of the right eye, leading to binocular diplopia. Case 2 with homonymous hemianopia to the right and exotropia of right eye revealed anomalous retinal correspondence after history of perinatal brain injury, resulting in absence of diplopia and enlargement of visual field to the right. Cases 3 and 4 with bitemporal hemianopia suffered from sensory disturbances caused by additional acquired strabismus. The exodeviation of the right eye in case 3 led to a restriction of binocular visual field with overlap of the nasal parts causing diplopia, whereas the esodeviation of case 4 resulted in a "gap" between the nasal parts (blind area). Depending on the extent of visual field defects and on retinal correspondence, functional consequences for binocular vision and binocular visual field should be considered prior to surgery. In normal retinal correspondence, strabismus surgery will be indicated in most cases because of diplopia. However, surgery might result in a reduction of binocular visual field. Preoperatively, it is important to map monocular and binocular visual fields, to examine retinal correspondence, and to undertake prism adaptation test to imitate the postoperative functional result and risk of double vision.

Clinical efficacy of oral calcium dobesilate on diabetic optic neuropathy

Objective To evaluate the clinical efficacy of oral calcium dobesilate (CAD) on diabetic optic neuropathy (DON).Methods The clinical data of 235 eyes of 235 patients with DON diagnosed by examination of ocular fundus were retrospectively analyzed.The patients were divided into 3 groups according to the subtypes of DON:anterior ischemic optic neuropathy (AION) group (71 eyes of 71 patients),papilloedema group (71 eyes of 71 patients),and neovascularization of disc (NVD) group (93 eyes of 93 patients).The patients in each groups were randomly subdivided into CaD treating group and control group,in which the patients underwent oral administraion of CaD at a dose of 500 mg twice per day or Vie.E at a dose of 10 mg twice per day,respectively.The course of therapy was 6 months and consecutive 2 courses were performed with the 3-4 days interval between the courses,the courses lasted for 6 months.Several parameters (VFD/V),EA/d,NA/d,LA/d) were semi-quantitative analyzed 2,4,6,8 months after initial treatment.Repeated ANOVA measures and t test were used as statistical methods.Results In CaD group,VFD/V (0.25±0.10),EA/d (0.94±0.53),and LA/d (1.83±1.12) 2 months after initial treatment was obviously better than the results before the treatment (0.49±0.13,1.57±0.71,3.42±1.88) (P 0.05).Conclusion Oral administration of CaD can rapidly and remarkably decrease the extent of visual field defect,relieve optic disc edema and lessen the leakage of NVD. Key words: Diabetic retinopathy/drug therapy; Optic nerve diseases/ drug therapy; Calcium dobesilate/pharmacology; Treatment outcome

Retinal nerve fiber layer thickness in patients with retinitis pigmentosa

To study retinal nerve fiber layer (RNFL) thickness in patients with retinitis pigmentosa (RP). Cross-sectional observational study. One hundred and thirty-seven eyes of 137 patients with RP were examined. The effect of age, gender, laterality, inheritance trait, spherical equivalent refractive error, visual acuity, and the extent of visual field defect on RNFL thickness measured with optical coherence tomography were analyzed by a multiple linear regression model. The average RNFL thickness was 104.1+/-21.7 microm. The multiple R(2) for the model was 0.349. Among the variables studied, ageing and being male were significant risk factors for thinner RNFL thickness. RNFL thickness was not correlated with inheritance trait, laterality, refractive error, visual acuity, or the extent of visual field defect. RNFL thickness in RP patients was not correlated with visual function but ageing as in the normal subjects. Currently proposed therapies, including photoreceptor rescue/transplantation and visual prosthesis, are based on the premise that the inner retinal structures are relatively retained despite the profound loss of photoreceptors. The present result supports this notion.

The Impact of Visual Field Loss on Driving Performance: Evidence From On-Road Driving Assessments

The purpose of this study was to investigate the relationship between visual field loss and driving performance as determined by on-road driving assessments. We reviewed the files of 1350 patients enrolled in a rehabilitation program at the Bloorview MacMillan Rehabilitation Centre, Toronto, Canada. We identified 131 patients with visual field loss who had undergone an on-road driving assessment. These patients had a primary diagnosis of visual impairment or a primary diagnosis of cerebral vascular accident (CVA) with a secondary diagnosis of visual impairment. None of these patients had documentation of neglect, substantial motor or cognitive deficits. We report the data obtained from 13 hemianopics, 7 quadrantanopics, 25 patients with monocular vision, 10 patients with moderate peripheral losses (<135 degrees of horizontal visual field measured at the midline), and 76 patients with mild peripheral losses (between 135 degrees and 186 degrees of horizontal visual field). The on-road assessment consisted of driving in the area surrounding the rehabilitation center, and the outcome was based on performance on a number of tasks commonly encountered in daily driving. For the purposes of this study, the assessment outcomes were classified as safe, unknown, or unsafe. Overall, the extent of visual field loss did not have a significant impact on driving performance (chi2 = 4.37, p = 0.358). However, hemianopia tended to have a worse impact on driving performance than quadrantanopia with a marginally significant result (chi2 = 3.33, p = 0.068). Overall, the location of the visual loss was not significantly related to driving fitness (chi2 = 1.05, p = 0.30). However, localized defects in the left hemifield (chi2 = 9.561, p = 0.002) and diffuse visual loss in the right hemifield (chi2 = 10.395, p = 0.001) seemed to be associated with driving impairments. A large proportion of monocular drivers were safe drivers and the location of their deficit had no significant impact. Although the extent of visual field defects appears to be related to driving performance as determined by an on-road driving assessment, large individual differences were observed. This highlights the need for individualized on-road assessments for patients with visual field defects.

Frequency-doubling technology perimetry.

The FDT perimeter is a compact and relatively inexpensive perimeter whose transportability, tolerance to refractive errors, and rapid test times (less than 1 minute per eye) make it a suitable candidate for visual field screening. It is a uniform finding that the C-20-1 screening protocol of the FDT perimeter provides good sensitivity and specificity for the detection of moderate and severe losses in glaucoma. Sensitivity can be increased by use of the C-20-5 screening protocol. In addition, the FDT perimeter demonstrates good sensitivity and specificity for detecting the presence of neuro-ophthalmic disorders, though it may have a limited ability to determine whether a field defect is hemianopic. There is only limited evidence that the FDT can appropriately detect retinal disease. Despite some evidence that the current FDT perimeter may be suitable for staging and monitoring the progression of visual field damage, the large targets used in the test make this of limited practicability. The development of a frequency-doubling test with smaller targets spaced over narrower intervals would improve the ability of FDT perimetry to determine the spatial extent of visual field defects.

Automatische Perimetrie bei Ptose und Blepharochalase

First, we were looking if a correlation between the extent of ptosis and superior visual field defect exists. In a second step visual fields in blepharochalasis were compared with those in ptosis. Pre- and postoperative visual fields in 20 patients with blepharochalasis, 6 patients with congenital and 9 with acquired ptosis were tested using program 7 of Octopus 500 automated perimeter. The degree of ptosis was separated in mild, medium and severe. According to the extent of visual field defect the same parameters as in ptosis were used also grading blepharochalasis in mild, medium and severe. We found that the amount of upper visual field defect clearly correlated with the extent of ptosis. In addition, patients with congenital ptosis showed less visual field defect compared to those with acquired ptosis. Comparable to ptosis surgery blepharoplasty also lead in severe and medium cases to a clear gain of upper visual field. Using perimetry and the same grading system as for ptosis makes it possible to study the functional defect occurring to the blepharochalasis patient.

Subclinical visual field defects in multiple sclerosis. Demonstration and quantification with automated perimetry, and comparison with visually evoked potentials.

Fourteen patients with definite but inactive multiple sclerosis (MS) and 17 normal controls were examined with the automated perimeter octopus. Most of the patients had subclinical visual field defects, typically consisting of patchy, shallow scotomata located mostly in an area of between 15 degrees and 30 degrees eccentricity. In 8 patients, more than 15% of the tested visual field of at least one eye was abnormal. The severity and extent of the defects was unrelated to a history of optic neuritis. When visually evoked potentials (VEPs) of these subjects were examined using a reversing pattern, no correlation was found in the MS patients between prolonged VEP latencies and the location, depth or extent of visual field defects. Since subclinical visual field defects may be found in MS patients with normal VEP latencies, automated perimetry can be helpful in diagnosing some cases.

TEMPORAL LOBE EPILEPSY AND NEURO‐OPHTHALMOLOGY

A survey is presented of the ophthalmological findings in 74 patients with drug-resistant temporal lobe epilepsy, who underwent unilateral anterior temporal lobectomy 1960-1969 at Rigshospitalet, Copenhagen. At follow-up, 1970-1971, one to ten years following the operation, 81% of the patients had no or only few seizures. Preoperatively 11% of the patients suffered from strabismus as compared to an expected frequency of 5%, but this trend just falls short of statistical significance. The visual acuity remained unchanged in all patients following the operation. Preoperatively a visual field defect was observed in 2 patients. At follow-up 51 patients had homonymous hemianopias, in 38 of them this was limited to the upper quadrants, and in 13 patients also included the lower quandrants, but was characterized as a total homonymous hemianopia in only 6 patients. The presence and extent of the visual field defects were correlated to surgical results, age at onset of epilepsy, age at operation, preoperative duration of epilepsy, presence of grand mal, preoperative complications, and neuropathological findings, but without observing any statistically significant conclusions. On the other hand, the extent of the postoperative visual field defect was significantly influenced by the side of the operation, with more and larger defects following right-sided lobectomies. In the 51 patients with postoperative hemianopias, this defect was either unobserved by the patient or regarded as a considerably less important handicap than the frequent and socially invalidating preoperative seizures...