PURPOSE: Multifocal visual evoked potential (mfVEP) is a newly introduced method used for objective visual field assessment. Several analysis protocols have been tested to identify early visual field losses in glaucoma patients using the mfVEP technique, some were successful in detection of field defects, which were comparable to the standard automated perimetry (SAP) visual field assessment, and others were not very informative and needed more adjustment and research work. In this study we implemented a novel analysis approach and evaluated its validity and whether it could be used effectively for early detection of visual field defects in glaucoma. METHODS: Three groups were tested in this study; normal controls (38 eyes), glaucoma patients (36 eyes) and glaucoma suspect patients (38 eyes). All subjects had a two standard Humphrey field analyzer (HFA) test 24-2 and a single mfVEP test undertaken in one session. Analysis of the mfVEP results was done using the new analysis protocol; the hemifield sector analysis (HSA) protocol. Analysis of the HFA was done using the standard grading system. RESULTS: Analysis of mfVEP results showed that there was a statistically significant difference between the three groups in the mean signal to noise ratio (ANOVA test, p < 0.001 with a 95% confidence interval). The difference between superior and inferior hemispheres in all subjects were statistically significant in the glaucoma patient group in all 11 sectors (t-test, p < 0.001), partially significant in 5 / 11 (t-test, p < 0.01), and no statistical difference in most sectors of the normal group (1 / 11 sectors was significant, t-test, p < 0.9). Sensitivity and specificity of the HSA protocol in detecting glaucoma was 97% and 86%, respectively, and for glaucoma suspect patients the values were 89% and 79%, respectively. CONCLUSIONS: The new HSA protocol used in the mfVEP testing can be applied to detect glaucomatous visual field defects in both glaucoma and glaucoma suspect patients. Using this protocol can provide information about focal visual field differences across the horizontal midline, which can be utilized to differentiate between glaucoma and normal subjects. Sensitivity and specificity of the mfVEP test showed very promising results and correlated with other anatomical changes in glaucoma field loss.
Adult ; Aged ; *Early Diagnosis ; Evoked Potentials, Visual/*physiology ; Female ; Follow-Up Studies ; Glaucoma/complications/*diagnosis/physiopathology ; Humans ; Intraocular Pressure/*physiology ; Male ; Middle Aged ; Reproducibility of Results ; Retrospective Studies ; Scotoma/*diagnosis/etiology/physiopathology ; Visual Field Tests/*methods ; Visual Fields/*physiology ; Young Adult

PURPOSE: Multifocal visual evoked potential (mfVEP) is a newly introduced method used for objective visual field assessment. Several analysis protocols have been tested to identify early visual field losses in glaucoma patients using the mfVEP technique, some were successful in detection of field defects, which were comparable to the standard automated perimetry (SAP) visual field assessment, and others were not very informative and needed more adjustment and research work. In this study we implemented a novel analysis approach and evaluated its validity and whether it could be used effectively for early detection of visual field defects in glaucoma. METHODS: Three groups were tested in this study; normal controls (38 eyes), glaucoma patients (36 eyes) and glaucoma suspect patients (38 eyes). All subjects had a two standard Humphrey field analyzer (HFA) test 24-2 and a single mfVEP test undertaken in one session. Analysis of the mfVEP results was done using the new analysis protocol; the hemifield sector analysis (HSA) protocol. Analysis of the HFA was done using the standard grading system. RESULTS: Analysis of mfVEP results showed that there was a statistically significant difference between the three groups in the mean signal to noise ratio (ANOVA test, p < 0.001 with a 95% confidence interval). The difference between superior and inferior hemispheres in all subjects were statistically significant in the glaucoma patient group in all 11 sectors (t-test, p < 0.001), partially significant in 5 / 11 (t-test, p < 0.01), and no statistical difference in most sectors of the normal group (1 / 11 sectors was significant, t-test, p < 0.9). Sensitivity and specificity of the HSA protocol in detecting glaucoma was 97% and 86%, respectively, and for glaucoma suspect patients the values were 89% and 79%, respectively. CONCLUSIONS: The new HSA protocol used in the mfVEP testing can be applied to detect glaucomatous visual field defects in both glaucoma and glaucoma suspect patients. Using this protocol can provide information about focal visual field differences across the horizontal midline, which can be utilized to differentiate between glaucoma and normal subjects. Sensitivity and specificity of the mfVEP test showed very promising results and correlated with other anatomical changes in glaucoma field loss.
Adult ; Aged ; *Early Diagnosis ; Evoked Potentials, Visual/*physiology ; Female ; Follow-Up Studies ; Glaucoma/complications/*diagnosis/physiopathology ; Humans ; Intraocular Pressure/*physiology ; Male ; Middle Aged ; Reproducibility of Results ; Retrospective Studies ; Scotoma/*diagnosis/etiology/physiopathology ; Visual Field Tests/*methods ; Visual Fields/*physiology ; Young Adult

STUDY DESIGN: Cross-sectional. PURPOSE: The purpose of the study was to determine the prevalence of low back pain (LBP) in the primary care setting with emphasis on the socio-demographic contributing factors and impact of LBP on lifestyle habits. OVERVIEW OF LITERATURE: LBP is one of the most common medical conditions seen in the Primary Health Care Clinic. METHODS: A representative sample of 2,600 patients were approached and 1,829 subjects agreed to participate in this study (70.0%). Data on socio-demographic characteristics, life style habits and type of treatment were collected through a questionnaire. RESULTS: The prevalence of LBP in the study sample was 56.5% (95% confidence interval, 54.2-58.8). LBP was more prevalent among women (53.9%) compared to men (46.1%). There was significant difference between male and female patients of LBP in terms of ethnicity (p<0.001), marital status (p=0.010), occupation (p<0.001), monthly household income (p=0.004), and cigarette/sheesha smokers (p<0.001). The percentages of different aspects of functional disabilities were statistically significantly higher among females compared to male patients with LBP. Almost a quarter of female patients with LBP (26%) and 18% male patients with LBP reported pain in the arms and legs (p=0.002). In addition, gastrointestinal complaints such as abdominal pain and food intolerance were significantly higher among female patients with LBP as compared to males (31% vs. 24.6%, p=0.018; and 25% vs. 18%, p=0.008, respectively). Complaints about headache and fainting were also significantly higher among female patients as compared to male LBP patients (43% vs. 36%, p=0.029; and 26% vs. 20%, p=0.016, respectively). The multivariate logistic regression revealed that being female, prolonged standing, prolonged sitting, heavy weight lifting, weakness in the legs, regular exercise, and cigarette/sheesh a smoking had a significant effect on the presence of LBP. CONCLUSIONS: LBP is highly prevalent among both genders and in older age. Also, weakness in the legs, smoking, prolonged standing and sitting had a significant effect on LBP. Furthermore, the current study findings support the fact that LBP continues to be an important clinical, social and economic, burden and a public health problem affecting the population of the entire world.
Abdominal Pain ; Arm ; Developing Countries* ; Epidemiology ; Family Characteristics ; Female ; Headache ; Humans ; Leg ; Life Style ; Logistic Models ; Low Back Pain* ; Male ; Marital Status ; Occupations ; Prevalence* ; Primary Health Care* ; Public Health ; Risk Factors ; Smoke ; Smoking ; Syncope ; Weight Lifting ; Surveys and Questionnaires