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ABSTRACT Purpose: To longitudinally compare isolated structural parameters obtained using RTVue optical coherence tomography in patients with glaucoma and suspected glaucoma with stable visual fields. Methods: All patients were required to have a reliable SITA Standard 24-2 Humphrey Visual Field test. Visual field stability was defined as having <5 points with p<5% and/or having no points with p<1% and/or p<0.05% in the glaucoma progression analysis comparison graph. Furthermore, the glaucoma assessment strategy was used in optical coherence tomography. Results: The study included 75 eyes from 75 patients, 43 of which had glaucoma and 32 had suspected glaucoma. The mean visual field intervals were 29.57 ± 9.65 months between the first and third tests. No visual field parameter variations (mean deviation, pattern standard deviation, and visual field index) and no retinal nerve fiber layer or optic disk parameter variations between the first and third tests were observed (p>0.05 for all), and no retinal nerve fiber layer parameter variations throughout the study were observed, except for optic disk parameters presenting with cup volume changes (p=0.004). However, ganglion complex cells presented a progressively decreased average ganglion cell complex parameter, with a variability of -0.98% ± 3.71% (p=0.04) between the first and third tests. By contrast, the global loss volume progressively increased throughout the study, with a variability of 14.71% ± 44.52% (p=0.04) between the first and third tests. The inferior ganglion cell complex parameter was significantly decreased between the first and third tests (p=0.02). Conclusion: The present findings suggest that patients with glaucoma or suspected glaucoma with stable visual fields may present structural ganglion complex cell progression as assessed using RTVue optical coherence tomography.
RESUMO Objetivo: Comparar longitudinalmente os parâmetros estruturais isolados obtidos através da tomografia de coerência óptica RTVue em pacientes glaucomatosos e suspeitos de glaucoma com campos visuais estáveis. Métodos: Todos os incluídos deveriam ter Campimetria Computadorizada Humphrey Sita Standard 24-2 confiáveis. A estabilidade campimétrica foi definida se apresentassem menos de cinco pontos com p<5% e/ou nenhum ponto com p<1% e/ou p<0,05% no gráfico de comparação do Glaucoma Progression Analysis. Para a tomografia de coerência óptica, foi utilizado a estratégia de avaliação para glaucoma. Resultados: Foram incluídos 75 olhos de 75 pacientes: 43 com glaucoma e 32 suspeitos. A média dos intervalos do campo visual entre o 1o e 3o exame, foi de 29,57 ± 9,65 meses. Não houve variação para os parâmetros do campo visual (desvio médio, desvio padrão e índice da função visual) entre o primeiro e o último exame (p>0,05 para todos). Não houve variação dos parâmetros da camada de fibras nervosas da retina ao longo do estudo, enquanto que para os parâmetros do disco óptico, apenas cup volume apresentou mudança (p=0,004). Em relação à camada de células ganglionares da retina, notou-se uma redução progressiva na espessura média da Ganglionar Complex Cells com uma variabilidade entre o primeiro e último exame de -0,98 ± 3,71% (p=0,04). Quanto ao Global loss volume, houve um aumento progressivo ao longo do estudo com uma variabilidade entre o primeiro e último exame de 14,71 ± 44,52% (p=0,04). O parâmetro inferior do Ganglionar Complex Cells também reduziu significativamente entre o 1o e 3o exames (p=0,02). Os demais parâmetros da tomografia de coerência óptica RTVue se mantiveram estáveis entre o 1o e 3o exames. Conclusão: Os presentes achados sugerem que pacientes glaucomatosos ou com suspeita de glaucoma e com campos visuais estáveis, podem apresentar progressão estrutural na camada de células ganglionares da retina avaliada por meio da tomografia de coerência óptica RTVue.
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INTRODUCTION: The Perception Sensory Threshold (ST) for sinusoidal current stimuli at 5, 250, and 2,000 Hz is commonly used in the assessment of peripheral nerve fibers (C, Aδ, and Aβ, respectively). However, the neuroselectivity of these frequencies is far from consensus. In addition, Reaction Time (RT) measurements suggest that 2,000 Hz stimuli excite Aβ-fibers, 250 Hz Aβ- or Aδ-fibers, as well as 5 Hz Aβ-, Aδ- or C-fibers. Therefore, we suppose that the sinusoidal current neuroselectivity may be better observed if ST and RT parameters are jointly evaluated. In addition, we have investigated whether there are other sets of frequencies that could be used. METHODS: Thus this work investigates ST and RT for stimuli with frequency ranging from 1 to 3,000 Hz, on 28 healthy subjects aged from 19 to 44 years old (27.1±5.49). ST and RT dissimilarity among different frequencies was evaluated applying bi-dimensional Fisher Quadratic Discriminant. RESULTS: The lowest classification error (3.6%) was obtained for 1, 250, and 3,000 Hz. Error for 5, 250, and 2,000Hz was 16.7%. Stimulation frequency at 1 Hz evoked more sensations related to C-fibers (53% of reports) than to Aβ-fibers (36%). However, this behavior did not repeat itself at 5 Hz (only 21% of perceptions were related to C-fibers against 64% to Aβ-fibers). Sensations related to Aβ-fibers prevailed for the highest frequencies presented to the subjects (2,000 Hz - 82% and 3,000 Hz - 93%). Mean RT values showed a decreasing trend with frequency. CONCLUSION: These results suggest that frequencies 1, 250, and 3,000 Hz are more neuroselective than 5, 250, and 2,000 Hz for the evaluation of peripheral sensitive fibers. Furthermore, they show RT usefulness.
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Las fibras de mielina intraoculares se presentan desde el nacimiento y suelen localizarse alrededor de la papila. El síndrome de mielinización de las fibras nerviosas retinales fue descrito por Virchow por primera vez en 1856. Este aparece como parches estriados, blanco o blanco grisáceos con los bordes imprecisos y plumosos siguiendo una configuración coincidente con la distribución de las fibras nerviosas retinales. Se presenta una paciente femenina de 4 años que es traída a consulta por desviación del ojo derecho. En el examen oftalmológico se detecta una agudeza visual con corrección de 0,1 y la oftalmoscopia confirma la mielinización de las fibras nerviosas retinales. En estos pacientes se asocia frecuentemente la miopía y ambliopía. A pesar de los pobres resultados visuales y ante la ausencia de otras terapias disponibles existe tendencia a tratamiento agresivo para la ambliopía, aunque en la literatura esto es aún controversial
The intraocular myelin fibers emerge since one's birth and it is usually located around the papilla. The syndrome of myelinated retinal nerve fibers was described for the first time by Virchow in 1856. This appears in the form of grooved patches, white or grayish white with imprecise and feathery borders following a coincident configuration with the distribution of the retinal nerve fibers. A four years-old girl who was taken to the doctor's office because she presented with right eye deviation. In the ophthalmologic exam, the best corrected visual acuity was 0.1 and the ophthalmoscopy confirmed myelinated retinal nerve fibers. Myopia and amblyopia were often associated in these patients. In spite of the poor visual results and the lack of other available therapies, specialists tend to apply aggressive treatment for amblyopia, although this procedure is still controversial in the medical literature
Subject(s)
Humans , Male , Child, Preschool , Amblyopia/diagnosis , Myopia/diagnosis , Nerve Fibers, Myelinated , Ophthalmoscopy/methods , Visual AcuityABSTRACT
The distribution of dopamine-immunoreactive endocrine cells and nerves in the digestive tract of guinea-pigs was examined with the ABC immunostaining technique. Dopamine-immunoreactive endocrine cells were observed in the pyloric antrum, small intestine and colon. The highest density of the positive ceils was found in the duodenum. From the jejunum to the colon the number of immunoreactive cells gradually decreased. A similar population of the positive cells was seen in the antrum and colon. Dopamine-immunoreactive nerve fibres were mainly located in the lamina propria and submucosa of the digestive tract. There were more positive fibres in the small intestine than in the stomach and colon. The dense networks of immunoreactive fibres were demonstrated in the villi. Some positive nerve fibres penetrated into the superficial and glandular epithelia. This representation indicated that the epithelial cells were directly innervated with the dopamine containing nerves.