Diagnosis Of Optic Nerve Diseases Research Articles

Neuropatía óptica en imagen

The aim of this work is to provide a diagnostic approach to the potential causes of optic neuropathy, focusing on the radiological findings associated with this pathology. Various etiologies have been identified, including inflammatory and demyelinating optic neuritis, developmental and hereditary diseases, neurodegenerative disorders, infectious conditions, post-traumatic causes, ischemic optic neuropathy (with anterior ischemic optic neuropathy being the most common form), and neoplastic etiologies. Optical coherence tomography and magnetic resonance imaging play a fundamental role in the diagnosis of optic neuropathy, allowing to distinguish patterns of optic nerve involvement. These studies are essential to locate and characterize the different pathologies, increasing the precision of the diagnosis in diseases presenting optic neuropathy as the main symptom. In conclusion, the findings obtained from magnetic resonance imaging are essential in the differential diagnosis of optic nerve diseases, aiding in the localization and characterization of various pathologies affecting either the optic pathway alone or multiple levels of the central nervous system and thereby increasing diagnostic accuracy.

Diagnostic performance of multifocal photopic negative response, pattern electroretinogram and optical coherence tomography in glaucoma

The photopic negative response of the electroretinogram reflects retinal ganglion cell function and consequently aids diagnosis of optic nerve diseases including glaucoma. In this study, we assessed the efficacy of stimulation parameters for electroretinographic recordings of the multifocal photopic negative response (mfPhNR) for the detection of glaucoma and compared the diagnostic accuracy of electrophysiological, structural and functional measures of glaucoma. We compared the diagnostic performance of the mfPhNR for 6 different stimulation rates in a cohort of 24 controls, 10 glaucoma suspects (GLAS ) and 16 glaucoma participants (GLAG). A cross-modal comparison of the mfPhNR/b wave ratio was performed with the pattern electroretinogram (PERG), and the peripapillary retinal nerve fiber layer (pRNFL) thickness. These analyses were based on area under curves (AUC) obtained from receiver-operating-characteristics (ROC) and step-wise regression analyses. We found that compared to the other mfPhNR-conditions, the PhNR/b-wave ratio for the fastest stimulation condition had the highest AUC for GLAS (0.84, P = 0.008, 95%CI: 0.71- 0.98), while the other modalities, i.e., PERG-amplitude and pRNFL had AUCs of 0.78 (P= 0.039), and 0.74 (P < 0.05), respectively. For GLAG , the respective AUCs were 0.78 (P= 0.004), 0.85 (P< 0.001) and 0.87 (P< 0.001). pRNFL was the significant predictor for both mfPhNR/b-wave ratio [t (48) = 4, P = 0.0002] and for PERG amplitude [t (48) = 3.4, P = 0.001]. In conclusion, fast mfPhNR protocols outperform other multifocal PhNR protocols in the identification of glaucomatous damage especially for GLAS and thus aid the early detection of glaucoma, indicating its value as a surrogate marker of early stage ganglion cell dysfunction.

Follow‐up of glaucomatous eyes with optic disc haemorrhages: the Beijing Eye Study

Editor, Optic disc haemorrhages play an important role in the ophthalmoscopic diagnosis of optic nerve diseases (Airaksinen et al. 1981). Previous hospital-based studies and population-based investigations have shown that disc haemorrhages are highly significantly associated with glaucoma (Airaksinen et al. 1981; Leske et al. 2003; Ramakrishnan et al. 2003; Budenz et al. 2006). The present study set out to assess how often disc haemorrhages are followed by glaucoma progression in a population-based setting. The Beijing Eye Study 2001, a population-based study on subjects aged ≥ 40 years in Greater Beijing, included 4439 of the 5324 subjects invited to participate. Glaucoma was defined by the appearance of the optic nerve head (‘optic disc glaucoma’ [ODG]) or according to the presence of additional visual field defects (‘perimetric glaucoma’ [PG]), as has recently been described in detail (Xu et al. 2007). In 2001, 221 (2.5%) eyes fulfilled the criteria for the diagnosis of ODG and 134 (1.5%) fulfilled the criteria for PG. In the same year, an optic disc haemorrhage was detected on optic disc photographs in 16 (7.2%) of the 221 eyes with ODG and in 11 (8.2%) of the 134 eyes with PG. Of the 16 eyes with ODG and an optic disc haemorrhage diagnosed in 2001, 11 (69%) returned for re-examination in 2006. Examinable photographs were obtained in nine (56%) of these eyes. In seven (78%) of these eyes, glaucoma had progressed as shown by neuroretinal rim loss and enlargement of the beta zone of peripapillary atrophy. In two (22%) eyes, optic disc appearance appeared unchanged at the 5-year follow-up. Of the 11 eyes with PG and an optic disc haemorrhage diagnosed in 2001, eight (73%) eyes returned for re-examination in 2006 and photographs were obtained in six (55%) of them. In four (66%) eyes, a change in the appearance of the optic disc indicated that glaucoma had progressed, and in two (33%) eyes the optic disc appeared to be unchanged. These results suggest that, in a population-based setting, optic disc haemorrhages in glaucomatous eyes in an adult Chinese population may be followed by a progression of glaucomatous optic nerve damage with a probability of about 70–80%. These results contrast with those of the Ocular Hypertension Treatment Study, which found that although ocular hypertensive subjects with optic disc haemorrhages during follow-up were six times more likely to experience a primary open-angle glaucoma end-point, 87% of study participants with an optic disc haemorrhage did not experience a glaucoma end-point by a median follow-up of 96 months (Budenz et al. 2006). The discrepancy in findings between the studies may reflect the facts that the majority of patients in the present study were not under treatment and that the Ocular Hypertension Treatment Study did not primarily include glaucomatous eyes. This research was supported by the National Key Laboratory Fund, Beijing, China.

Utilization of Discretization method on the diagnosis of optic nerve disease

The optic nerve disease is an important disease that appears commonly in public. In this paper, we propose a hybrid diagnostic system based on discretization (quantization) method and classification algorithms including C4.5 decision tree classifier, artificial neural network (ANN), and least square support vector machine (LSSVM) to diagnose the optic nerve disease from Visual Evoked Potential (VEP) signals with discrete values. The aim of this paper is to investigate the effect of Discretization method on the classification of optic nerve disease. Since the VEP signals are non-linearly-separable, low classification accuracy can be obtained by classifier algorithms. In order to overcome this problem, we have used the Discretization method as data pre-processing. The proposed method consists of two phases: (i) quantization of VEP signals using Discretization method, and (ii) diagnosis of discretized VEP signals using classification algorithms including C4.5 decision tree classifier, ANN, and LSSVM. The classification accuracies obtained by these hybrid methods (combination of C4.5 decision tree classifier-quantization method, combination of ANN-quantization method, and combination of LSSVM-quantization method) with and without quantization strategy are 84.6–96.92%, 94.20–96.76%, and 73.44–100%, respectively. As can be seen from these results, the best model used to classify the optic nerve disease from VEP signals is obtained for the combination of LSSVM classifier and quantization strategy. The obtained results denote that the proposed method can make an effective interpretation and point out the ability of design of a new intelligent assistance diagnosis system.

Ensemble adaptive network-based fuzzy inference system with weighted arithmetical mean and application to diagnosis of optic nerve disease from visual-evoked potential signals

This paper presents a new method based on combining principal component analysis (PCA) and adaptive network-based fuzzy inference system (ANFIS) to diagnose the optic nerve disease from visual-evoked potential (VEP) signals. The aim of this study is to improve the classification accuracy of ANFIS classifier on diagnosis of optic nerve disease from VEP signals. With this aim, a new classifier ensemble based on ANFIS and PCA is proposed. The VEP signals dataset include 61 healthy subjects and 68 patients suffered from optic nerve disease. First of all, the dimension of VEP signals dataset with 63 features has been reduced to 4 features using PCA. After applying PCA, ANFIS trained using three different training-testing datasets randomly with 50-50% training-testing partition. The obtained classification results from ANFIS trained separately with three different training-testing datasets are 96.87%, 98.43%, and 98.43%, respectively. And then the results of ANFIS trained with three different training-testing datasets randomly with 50-50% training-testing partition have been combined with three different ways including weighted arithmetical mean that proposed firstly by us, arithmetical mean, and geometrical mean. The classification results of ANFIS combined with three different ways are 98.43%, 100%, and 100%, respectively. Also, ensemble ANFIS has been compared with ANN ensemble. ANN ensemble obtained 98.43%, 100%, and 100% prediction accuracy with three different ways including arithmetical mean, geometrical mean and weighted arithmetical mean. These results have shown that the proposed classifier ensemble approach based on ANFIS trained with different train-test datasets and PCA has produced very promising results in the diagnosis of optic nerve disease from VEP signals.

The effect of generalized discriminate analysis (GDA) to the classification of optic nerve disease from VEP signals

In this paper, we have investigated the effect of generalized discriminate analysis (GDA) on classification performance of optic nerve disease from visual evoke potentials (VEP) signals. The GDA method has been used as a pre-processing step prior to the classification process of optic nerve disease. The proposed method consists of two parts. First, GDA has been used as pre-processing to increase the distinguishing of optic nerve disease from VEP signals. Second, we have used the C4.5 decision tree classifier, Levenberg Marquart (LM) back propagation algorithm, artificial immune recognition system (AIRS), linear discriminant analysis (LDA), and support vector machine (SVM) classifiers. Without GDA, we have obtained 84.37%, 93.75%, 75%, 76.56%, and 53.125% classification accuracies using C4.5 decision tree classifier, LM back propagation algorithm, AIRS, LDA, and SVM algorithms, respectively. With GDA, 93.75%, 93.86%, 81.25%, 93.75%, and 93.75% classification accuracies have been obtained using the above algorithms, respectively. These results show that the GDA pre-processing method has produced very promising results in diagnosis of optic nerve disease from VEP signals.

Utilization of artificial neural networks in the diagnosis of optic nerve diseases

This research is concentrated on the diagnosis of optic nerve disease through the analysis of pattern electroretinography (PERG) signals with the help of artificial neural network (ANN). Multilayer feed forward ANN trained with a Levenberg Marquart (LM) backpropagation algorithm was implemented. The designed classification structure has about 96.4% sensitivity, 90.4% specifity and positive prediction is calculated to be 94.2%. The end results are classified as healthy and diseased. Testing results were found to be compliant with the expected results that are derived from the physician's direct diagnosis. The end benefit would be to assist the physician to make the final decision without hesitation.

Electrophysiological assessment of optic nerve disease

The electrophysiological findings in optic nerve and primary ganglion cell dysfunction are reviewed. The value of the pattern reversal visual-evoked potential (VEP) in the diagnosis of optic nerve disease, and the pattern appearance VEP in the demonstration of the intracranial misrouting associated with albinism, are discussed. The pattern electroretinogram (PERG) is used in the direct assessment of ganglion cell function. The use of PERG or multifocal electroretinography (mfERG), to enable the distinction between VEP delay due to optic nerve disease and that due to macular dysfunction, is described.

Quantitative Pupillometry of Relative Afferent Defects in Glaucoma

To the Editor. —A relative afferent pupillary defect usually indicates a disorder in the anterior visual pathway anterior to the optic chiasm. Its detection is helpful in the diagnosis of optic nerve diseases. It has generally been evaluated using Kestenbaum's number 1 or the swinging flashlight test and neutral-density filters that were calibrated in logarithmic units of light attenuation and percentage of light transmittance. 2 We measured the relative afferent pupillary defect employing the infrared video camera of the OCTOPUS perimeter 201 (Interzeag AG, Switzerland). The study included 10 healthy subjects (mean ± SD age, 41.6 ± 16.7 years; refractive error, +0.27 ± 1.81 diopters [spherical equivalent]) and 17 patients suffering from primary open angle glaucoma (mean age, 53.0 ± 11.9 years; refractive error, −0.15 ± 2.22 diopters). The mean difference in refractive error between the two eyes of the same individual was 0.01 diopter. Since in the control group

Anatomy and Physiology of Visual Evoked Potentials and Electroretinograms

ERGs are electrical potentials originating in the retina and recorded directly from the corneal surface of the eyes. Flash ERGs are elicited by high intensity flashes either on scotopic or photopic conditions. The origin of the A and B waves of ERG are a combination of photoreceptor potentials, K+ mediated current flow and DC potentials within Müller cells, whereas the C waves are altered K+ fluxes induced by light in the pigment epithelia. Oscillatory potentials are probably related to feedback circuits of the inner layer of the retina. Electroretinograms evoked by pattern are mostly originated in ganglion cells. The use of various visual stimuli allow the selective activation of different retinal structures. Flashes selectively activate retina luminance and color detectors, whereas small pattern stimuli preferentially activate contrast and edge detectors. Visual evoked potentials recorded from the scalp probably originate from multiple cortical visual areas. P-100 response of the visual evoked potential to pattern stimulation is a cortically originated wave either produced exclusively by area 17 or 18 or by a multiplicity of cortical neuronal pools. Visual evoked potentials have important application for the diagnosis of optic nerve disease, assessment in conjunction with pattern ERG of the prognosis of recovery of visual function, and the evaluation of visual physiology and physiopathology.

The Value of Visual Changes in the Diagnosis of Optic Nerve Disease Due to Latent Morbid Conyyditions of the Nasal Accessory Sinuses

The Value of Visual Changes in the Diagnosis of Optic Nerve Disease Due to Latent Morbid Conyyditions of the Nasal Accessory Sinuses