The objective assessment of visual contrast sensitivity by pattern reversal visual evoked potentials in diabetes

Martinelli, Vittorio; Lacerenza, Marco; Merenda, M. L.; Meschi, Franco; Somazzi, L; Comı, Gıancarlo

doi:10.1016/0891-6632(88)90028-1

Cited by 7 publications

(4 citation statements)

References 7 publications

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“…Previous studies demonstrated that in patients with diabetes mellitus (DM) and good visual acuity there is a dissociation between the CSF and Snellen acuity [26,34,42]. These studies have suggested that when the Snellen acuity of patients with diabetes and retinal disease is slightly affected, the contrast sensitivity is strongly altered.…”

Section: Introductionmentioning

confidence: 95%

Neurovisual abnormalities preceding the retinopathy in patients with long-term type 1 diabetes mellitus

Faria

Katsumi

Cagliero

et al. 2001

Graefe's Arch Clin Exp Ophthalmol

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Patients with type 1 DM without retinopathy showed significant lower amplitude of the visual evoked responses at all spatial frequencies tested, with the saturation phenomena observed at lower level of contrast stimuli. In addition, there was a dissociation between the sweep visual evoked responses and the Snellen acuity measurements. A significant and nonselective neuronal visual loss involving the visual pathway precedes the ophthalmoscopically detectable retinopathy in patients with type 1 DM.

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Section: Introductionmentioning

confidence: 95%

Neurovisual abnormalities preceding the retinopathy in patients with long-term type 1 diabetes mellitus

Faria

Katsumi

Cagliero

et al. 2001

Graefe's Arch Clin Exp Ophthalmol

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“…Since the first use of the white-black chessboard reversal pattern and the grating pattern to study vision and the revealing of tight correlations between components of the VEP and visual acuity [1,2] , researchers have attempted to apply the technique to clinical evaluation and ophthalmological assessment [3][4][5] . Because of the method-ological advantages of VEPs (simple waveform, repeatability, and small inter-individual variation), increasing attention has been paid to the study of diseases involving visual problems, such as in the field of oculopathy (amblyopia [6,7] , refractive errors, field defects, diseases of the optic nerve, glaucoma [8] and color blindness), in diseases with latent impairment of vision (multiple sclerosis [9] , diabetes [10] ), and in psychological dysfunctions (schizophrenia, dementia, epilepsy) [11][12][13][14] . So far only some changes in the early components (especially the P100) have been associated with certain diseases.…”

Section: Introductionmentioning

confidence: 99%

Visual acuity evaluated by pattern-reversal visual-evoked potential is affected by check size/visual angle

Chen

Liu

et al. 2012

Neurosci. Bull.

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Objective To systemically explore the range of visual angles that affect visual acuity, and to establish the relationship between the P1 component (peak latency ~100 ms) of the pattern-reversal visual-evoked potential (PRVEP) and the visual acuity at particular visual angles. Methods Two hundred and ten volunteers were divided into seven groups, according to visual acuity as assessed by the standard logarithmic visual acuity chart (SLD-ii). For each group, the PRVEP components were elicited in response to visual angle presentations at 8°, 4°, 2°, 1°/60´, 30´, 15´, and 7.5´, in the whiteblack chess-board reversal mode with a contrast level of 100% at a frequency of 2 Hz. Visual stimuli were presented monocularly, and 200 presentations were averaged for each block of trials. The early and stable component P1 was recorded at the mid-line of the occipital region (oz) and analyzed with SPSS 13.00. Results (1) oz had the maximum P1 amplitude; there was no significant difference between genders or for interocular comparison in normal controls and subjects with optic myopia. (2) The P1 latency decreased slowly below 30´, then increased rapidly. The P1 amplitude initially increased with check size, and was maximal at ~1° and ~30´. (3) The P1 latency in the group with visual acuity ≤0.2 was significantly different at 8°, 15´ and 7.5´, while the amplitude differed at all visual angles, compared with the group with normal vision. Differences in P1 for the groups with 0.5 and 0.6 acuity were only present at visual angles <1°. (4) Regression analysis showed that the P1 latency and amplitude were associated with visual acuity over the full range of visual angles. There was a moderate correlation at visual angles <30´. Regression equations were calculated for the P1 components and visual acuity, based on visual angle. Conclusion (1) Visual angle should be taken into consideration when exploring the function of the visual pathway, especially visual acuity. A visual angle ~60´ might be appropriate when using PRVEP components to evaluate poor vision and to identify malingerers. (2) increased P1 amplitude and decreased P1 latency were associated with increasing visual acuity, and the P1 components displayed a linear correlation with visual acuity, especially in the range of optimal visual angles. Visual acuity can be deduced from P1 based on visual angle.

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“…Long before loss of visual acuity is apparent to patients they may suffer from other disturbances of visual function such as waviness, blurring, relative scotoma, loss of fixation and decrease of contrast sensitivity, which are not assessed and quantified in routine examination [3, 4, 5, 6]. In patients with diabetic maculopathy evaluation of visual acuity alone may not represent visual function and the severity of diabetic maculopathy sufficiently, especially in the early stage of the disease [7, 8, 9].…”

Section: Introductionmentioning

confidence: 99%

Fixation Stability and Macular Light Sensitivity in Patients with Diabetic Maculopathy: A Microperimetric Study with a Scanning Laser Ophthalmoscope

et al. 2005

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Background: In patients with diabetic maculopathy, evaluation of visual acuity alone may not represent central retinal function sufficiently. Despite good visual acuity, patients may suffer from visual disturbances like waviness, relative scotoma, loss of fixation and decrease of contrast sensitivity. The aim of the study was to assess localized light sensitivity in the central visual field and to determine fixation stability in patients with diabetic maculopathy with moderate visual loss in comparison to healthy controls. Methods: Twenty-seven patients (mean age: 54 ± 15; range 17–81 years) with diabetic maculopathy and 61 controls (mean age: 45 ± 22; range 18–85 years) were included in the study. Light sensitivity was quantified by presenting stimuli with different light intensity with simultaneous real-time monitoring of the retina (intensity: 0–27.9 dB; size: Goldmann III, wavelength: 633 nm). Eye movements were controlled by semiautomatic fundus tracking. Fixation stability was quantified by measuring the area within 75% of all points of fixation. Results: Fixation stability was significantly decreased in diabetic patients in comparison to controls (43 ± 22 vs. 31 ± 16 arc min, p < 0.01). There was a significant difference in macular light sensitivity in diabetic patients compared to controls (19.6 ± 0.5 dB), both in mean difference (15.6 ± 1.4 dB) and if affected with macular edema (16.1 ± 4.5 dB), hard exudates (13.3 ± 6.7 dB), nonperfusion areas (10.3 ± 7.9 dB) and laser burns (3.0 ± 6.1 dB). Temporal parts of the macula were more affected than other parts. No correlation was found between visual acuity and foveal light sensitivity and foveal fixation, respectively. Conclusion: Macular light sensitivity decreased progressively with the kind and severity of retinal alteration independent of visual acuity. The assessment of macular light sensitivity and stability of fixation with automatic threshold microperimetry may help to identify patients with diabetic maculopathy and could improve the management of diabetic maculopathy.

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The objective assessment of visual contrast sensitivity by pattern reversal visual evoked potentials in diabetes

Cited by 7 publications

References 7 publications

Neurovisual abnormalities preceding the retinopathy in patients with long-term type 1 diabetes mellitus

Neurovisual abnormalities preceding the retinopathy in patients with long-term type 1 diabetes mellitus

Visual acuity evaluated by pattern-reversal visual-evoked potential is affected by check size/visual angle

Fixation Stability and Macular Light Sensitivity in Patients with Diabetic Maculopathy: A Microperimetric Study with a Scanning Laser Ophthalmoscope

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