A Morphometric Study of the Pars Plana of the Ciliary Body in Human Cadaver Eyes.

This study aimed to determine the pars plana length in postmortem human eyes using advanced morphometric techniques and correlate demographics to ocular metrics such as age, sex, ethnicity, and axial length. Between February and July 2005, we conducted a cross-sectional observational study on 46 human cadaver eyes deemed unsuitable for transplant by the SBO Eye Bank. The morphometric analysis was performed on projected images using a surgical microscope and a video-microscopy system with a 20.5:1 correction factor. The pars plana length was measured three times per quadrant, with the final value being the mean of these measurements. Of the 46 eyes collected, 9 were unsuitable for the study due to technical constraints in conducting intraocular measurements. Overall, the average axial length was 25.20 mm. The average pars plana length was 3.8 mm in all quadrants, with no measurements below 2.8 mm or above 4.9 mm. There were no statistically significant variations across quadrants or with age, sex, axial length, or laterality. Accurately defining the pars plana dimensions is crucial for safely accessing the posterior segment of the eye and minimizing complications during intraocular procedures, such as intravitreal injections and vitreoretinal surgeries.

A subacute model of glaucoma based on limbal plexus cautery in pigmented rats.

Glaucoma is a neurodegenerative disorder characterized by the progressive functional impairment and degeneration of the retinal ganglion cells (RGCs) and their axons, and is the leading cause of irreversible blindness worldwide. Current management of glaucoma is based on reduction of high intraocular pressure (IOP), one of its most consistent risk factors, but the disease proceeds in almost half of the patients despite such treatments. Several experimental models of glaucoma have been developed in rodents, most of which present shortcomings such as high surgical invasiveness, slow learning curves, damage to the transparency of the optic media which prevents adequate functional assessment, and variable results. Here we describe a novel and simple method to induce ocular hypertension in pigmented rats, based on low-temperature cauterization of the whole circumference of the limbal vascular plexus, a major component of aqueous humor drainage and easily accessible for surgical procedures. This simple, low-cost and efficient method produced a reproducible subacute ocular hypertension with full clinical recovery, followed by a steady loss of retinal ganglion cells and optic axons, accompanied by functional changes detected both by electrophysiological and behavioral methods.

Neuroprotective effects of erythropoietin on rat retinas subjected to oligemia.

OBJECTIVES: Erythropoietin may have neuroprotective potential after ischemia of the central nervous system. Here, we conducted a study to characterize the protective effects of erythropoietin on retinal ganglion cells and gliotic reactions in an experimentally induced oligemia model. METHODS: Rats were subjected to global oligemia by bilateral common carotid artery occlusion and then received either vehicle or erythropoietin via intravitreal injection after 48 h; they were euthanized one week after the injection. The densities of retinal ganglion cells and contents of glial fibrillary acidic protein (astrocytes/Müller cells) and cluster of differentiation 68 clone ED1 (microglia/macrophages), assessed by fluorescence intensity, were evaluated in frozen retinal sections by immunofluorescence and epifluorescence microscopy. RESULTS: Retinal ganglion cells were nearly undetectable one week after oligemia compared with the sham controls; however, these cells were partially preserved in erythropoietin-treated retinas. The contents of glial fibrillary acidic protein and cluster of differentiation 68 clone ED1, markers for reactive gliosis, were significantly higher in retinas after bilateral common carotid artery occlusion than those in both sham and erythropoietin-treated retinas. CONCLUSIONS: The number of partially preserved retinal ganglion cells in the erythropoietin-treated group suggests that erythropoietin exerts a neuroprotective effect on oligemic/ischemic retinas. This effect could be related to the down-modulation of glial reactivity, usually observed in hypoxic conditions, clinically observed during glaucoma or retinal artery occlusion conditions. Therefore, glial reactivity may enhance neurodegeneration in hypoxic conditions, like normal-tension glaucoma and retinal ischemia, and erythropoietin is thus a candidate to be clinically applied after the detection of decreased retinal blood flow.

Neuroprotective effects of erythropoietin on rat retinas subjected to oligemia

OBJECTIVES: Erythropoietin may have neuroprotective potential after ischemia of the central nervous system. Here, we conducted a study to characterize the protective effects of erythropoietin on retinal ganglion cells and gliotic reactions in an experimentally induced oligemia model. METHODS: Rats were subjected to global oligemia by bilateral common carotid artery occlusion and then received either vehicle or erythropoietin via intravitreal injection after 48 h; they were euthanized one week after the injection. The densities of retinal ganglion cells and contents of glial fibrillary acidic protein (astrocytes/Müller cells) and cluster of differentiation 68 clone ED1 (microglia/macrophages), assessed by fluorescence intensity, were evaluated in frozen retinal sections by immunofluorescence and epifluorescence microscopy. RESULTS: Retinal ganglion cells were nearly undetectable one week after oligemia compared with the sham controls; however, these cells were partially preserved in erythropoietin-treated retinas. The contents of glial fibrillary acidic protein and cluster of differentiation 68 clone ED1, markers for reactive gliosis, were significantly higher in retinas after bilateral common carotid artery occlusion than those in both sham and erythropoietin-treated retinas. CONCLUSIONS: The number of partially preserved retinal ganglion cells in the erythropoietin-treated group suggests that erythropoietin exerts a neuroprotective effect on oligemic/ischemic retinas. This effect could be related to the down-modulation of glial reactivity, usually observed in hypoxic conditions, clinically observed during glaucoma or retinal artery occlusion conditions. Therefore, glial reactivity may enhance neurodegeneration in hypoxic conditions, like normal-tension glaucoma and retinal ischemia, and erythropoietin is thus a candidate to be clinically applied after the detection of decreased retinal blood flow.

Comparative electrophysiological responses in anisometropic and strabismic amblyopic children.

PURPOSE: To compare anisometropic hypermetropic amblyopic and strabismic amblyopic responses to pattern electroretinogram (PERG) and pattern visual evocated potential (PVEP). MATERIALS AND METHODS: Fifty-six patients - 18 hypermetropic anisometropic amblyopic children (mean age 9.70±2.5 years), 19 strabismic amblyopic children (mean age 10.30±2.6 years) and 19 normal emetropic subjects (mean age 10.10±2.2 years) - were enrolled in this study. After routine ophthalmic examination, PERG and PVEP were recorded in response to checks reversed at the rate of two reversals/second stimulating macular area. RESULTS: The difference between hypermetropic anisometropic amblyopia and strabismus amblyopia with respect to P100/P50/N95 wave latencies (P=0.055/0.855/0.132) and P100/P50/N95 amplitudes (P=0.980/0.095/0.045) was not statistically significant. However, there was a significant statistical difference between strabismic amblyopia group and controls for P100/P50/N95 latencies (P=0.000/0.006/0.004). CONCLUSION: Our findings indicated that despite clinical differences between anisometropic amblyopic and strabismic amblyopic patients, no differences were found in the responses of PVEP and PERG. The abnormal components of the PVEP and PERG in amblyopic subjects could reflect a retinal dysfunction in the visual pathway.

Brimonidine tartrate effect on retinal spreading depression depends on Müller cells / O efeito do tartarato de brimonidina sobre a depressão alastrante retiniana depende das células de Müller

Objective: Demonstrate the Brimonidine effect over Retinal Spreading Depression (SD). Brimonidine is an alpha-2–adrenergic receptor agonist, used in the management of glaucoma. Alpha2-agonists have been shown to be neuroprotective in various experimental models, however the molecular and cellular targets leading to these actions are still poorly defined. The SD of neuronal electric activity is a wave of cellular massive sustained depolarization that damages the nervous tissue. Local trauma, pressure, ischemic injuries and other chemical agents as high extracellular potassium concentration or glutamate, can trigger SD, leading to exaggerated focal electrical followed by an electrical silence. Methods: Using chicken retina as model, we performed alpha2-receptor detection by Western Blotting and Immunohistochemistry. After that we obtained electrical signals of SD by microelectrodes on retina in the absence or presence of Brimonidine. For in vivo visualization we observed retina with optical coherence tomography on normal state, with SD passing, and with SD + Brimonidine. Results: Our data demonstrated that: (1) alpha2-adrenergic receptors are present in Müller cells, (2) the treatment with Brimonidine decreases the SD‘s velocity as well as the voltage of SD waves and (3) OCT revealed that SD creates a hyper reflectance at inner plexiform layer, but on retinal treatment with brimonidine, SD was not visualized. Conclusions: Our study about brimonidine possible pathways of neuroprotection we observed it reduces SD (a neuronal damage wave), identified a new cellular target – the Müller cells, as well as, firstly demonstrated SD on OCT, showing that the inner plexiform layer is the main optically affected layer on SD. .

Objetivo: Demonstrar o efeito do Tartarato de Brimonidina, um alfa2-agonista usado no manejo do glaucoma, sobre a depressão alastrante (DA) retiniana. Esses agonistas têm demonstrado ser neuroprotetores em vários modelos experimentais, contudo seus alvos celulares e moleculares continuam indefinidos. A DA da atividade elétrica neuronal é uma onda de despolarização celular massiva e sustentada que leva ao dano no tecido nervoso. Trauma local, pressão, isquemia e outros agentes químicos como o aumento do potássio extracelular e o glutamato podem disparar a DA, levando a uma atividade elétrica exagerada seguida de silêncio elétrico. Métodos: Usando a retina de pinto como modelo, realizamos a detecção do alfa2-receptor por Western Blotting e ensaio Imunohistoquímico. Após isso, obtivemos os sinais elétricos da DA através de microeletrodos inseridos na retina durante sua passagem na presença ou ausência de Brimonidina. Para visualização do tecido utilizamos o tomógrafo de coerência optica (OCT), analisando como é a retina no seu estado de repouso, durante a passagem da DA, e a DA + brimonidina. Resultados: Nossos dados demonstraram que: (1) os receptores alfa adrenérgicos presentes na retina são do subtipo-2A e estão localizados nas células de Müller; (2) o tratamento com Brimonidina diminui a velocidade e a voltagem da onda de DA; (3) A OCT demonstrou que a DA retiniana possui um sinal óptico de maior reflectância na camada plexiforme interna, fato não observado quando foi associada à Brimonidina. Conclusão: A Brimonidina foi capaz de reduzir a DA (uma onda de lesão neuronal) e identificamos um novo possível alvo celular – a célula de Müller e demonstramos pela primeira vez uma OCT da DA, visualizando a camada plexiforme interna como a mais afetada opticamente pelo fenômeno. .

Axonal electrovisiogram as an electrophysiological test to evaluate optic nerve and inner retina electrical potentials: findings in normal subjects.

PURPOSES: To standardize and validate the technique of axonal electrovisiogram (AxEvg), defining its normative values and parameters and characterizing its findings in normal individuals. METHODS: We enrolled 140 normal individuals (280 eyes) divided into seven groups according to age, each one with 10 males and 10 females. The technique was based on monocular visual stimulation by a 0 dB intensity bright flash on Ganzfeld bowl at a presentation rate of 1.4 Hz. Golden cup electrodes were used and electrical waves were acquired after artifact rejection. For each amplitude and implicit time peak we calculated the mean, median, pattern deviation, minimum and maximum values and 95% confidence interval. RESULTS: Monocular visual stimulation with bright flash under mesopic conditions was the standard technical procedure established. The normal AxEvg waveform consists of an initial positive wave (named P1, with mean amplitude of 2.0 mV and mean implicit time peak of 23.1 ms) followed by a negative wave (named N1, with mean amplitude of -3.9 mV and mean implicit time peak of 41.4 ms). No significant differences were observed between males and females or between right and left eyes, but there was an increased P1 and N1 implicit time peaks according to age. Implicit time characteristics suggest that P1 wave represents an optic nerve electrical potential and N1 wave represents an inner retinal layers potential. CONCLUSIONS: AxEvg can be considered a pre-chiasmatic visual evoked potential capable to reliably record the electrical activity of optic nerve and inner retina. The findings suggest that AxEvg may be useful as an electrophysiological test in the diagnosis of neuroretinal diseases.

Axonal electrovisiogram as an electrophysiological test to evaluate optic nerve and inner retina electrical potentials: findings in normal subjects / Eletrovisuograma axonal como teste eletrofisiológico na avaliação dos potenciais de ação do nervo óptico e da retina interna: achados em indivíduos normais

PURPOSES: To standardize and validate the technique of axonal electrovisiogram (AxEvg), defining its normative values and parameters and characterizing its findings in normal individuals. METHODS: We enrolled 140 normal individuals (280 eyes) divided into seven groups according to age, each one with 10 males and 10 females. The technique was based on monocular visual stimulation by a 0 dB intensity bright flash on Ganzfeld bowl at a presentation rate of 1.4 Hz. Golden cup electrodes were used and electrical waves were acquired after artifact rejection. For each amplitude and implicit time peak we calculated the mean, median, pattern deviation, minimum and maximum values and 95 percent confidence interval. RESULTS: Monocular visual stimulation with bright flash under mesopic conditions was the standard technical procedure established. The normal AxEvg waveform consists of an initial positive wave (named P1, with mean amplitude of 2.0 mV and mean implicit time peak of 23.1 ms) followed by a negative wave (named N1, with mean amplitude of -3.9 mV and mean implicit time peak of 41.4 ms). No significant differences were observed between males and females or between right and left eyes, but there was an increased P1 and N1 implicit time peaks according to age. Implicit time characteristics suggest that P1 wave represents an optic nerve electrical potential and N1 wave represents an inner retinal layers potential. CONCLUSIONS: AxEvg can be considered a pre-chiasmatic visual evoked potential capable to reliably record the electrical activity of optic nerve and inner retina. The findings suggest that AxEvg may be useful as an electrophysiological test in the diagnosis of neuroretinal diseases.

OBJETIVOS: Padronizar e validar a técnica de realização do eletrovisuograma axonal (EVA), definir seus valores normativos e caracterizar os achados em indivíduos normais. MÉTODOS: Estudo descritivo com 140 indivíduos (280 olhos) normais. Os participantes foram divididos em sete grupos de acordo com a idade, cada qual com 10 indivíduos do sexo masculino e 10 do sexo feminino. Definiu-se como técnica de exame a estimulação monocular por flash luminoso com intensidade de 0 dB na cúpula de Ganzfeld a uma frequência de 1,4 Hz. Foram utilizados eletrodos com cúpula de ouro e foram analisados os traçados elétricos obtidos após rejeição de artefatos. Para cada amplitude e tempo de culminação foram calculados a média, a mediana, o desvio-padrão, os valores mínimo e máximo e o intervalo de confiança de 95 por cento representando uma faixa de normalidade para os valores. RESULTADOS: A técnica de exame padronizada foi a estimulação visual monocular por flash em condições mesópicas. O traçado normal do eletrovisuograma axonal consistiu numa onda positiva inicial (P1, com amplitude média de 2,0 mV e tempo de culminação médio de 23,1 ms) seguida de uma onda negativa (N1, com amplitude média de -3,9 mV e tempo de culminação médio de 41,4 ms). Não foram observadas diferenças significativas entre os sexos e entre os olhos direito e esquerdo, mas os tempos de culminação de P1 e de N1 aumentaram proporcionalmente com a idade. CONCLUSÕES: O eletrovisuograma axonal é um exame de potencial visual evocado pré-quiasmático, capaz de registrar de forma confiável e reprodutível a atividade elétrica do nervo óptico e da retina interna, podendo ser utilizado na propedêutica eletrofisiológica na investigação de lesões neurorretinianas.

Avaliação da onda b do eletrorretinograma na Athene cunicularia / Evaluation of the b-wave electroretinogram in Athene cunicularia

OBJETIVO: Avaliar a onda b do eletrorretinograma da coruja buraqueira (Athene cunicularia), diferenciando a resposta elétrica retiniana em ambiente fotópico e escotópico. MÉTODOS: Foi realizado estudo observacional transversal, com o registro do eletrorretinograma full field de quatorze olhos, sendo sete estimulados em ambiente fotópico e sete em ambiente escotópico sob estímulo com luz branca seguindo protocolo da ISCEV. RESULTADOS: As respostas elétricas da retina da espécie estudada para o espectro de luz aplicado mostraram-se presentes em ambos ambientes, não havendo diferença estatisticamente significativa da resposta elétrica da retina da Athene cunicularia quando estimulada com luz branca, tanto em ambiente escotópico quanto fotópico. CONCLUSÃO: Os dados nos permitem, portanto, inferir que a percepção pela Athene cunicularia da cor branca é a mesma, no claro e no escuro, o que pode ser responsável pela capacidade adaptativa da espécie no seu habitat natural.

PURPOSE: To evaluate b-wave of the electroretinogram of the burrowing owl (Athene cunicularia), differentiating the retinal electric reply in photopic and scotopic environment. METHODS: Transversal observational study was carried through, with the register of the full field electroretinogram of fourteen eyes; seven were stimulated in photopic environment and seven in scotopic environment using with white light according to the ISCEV protocol. RESULTS: The electrical responses of the retina of the species studied showed no statistically significant difference for the applied spectrum of white light in both scotopic photopic environments. CONCLUSION: The data allow us, therefore, to infer that the perception of the Athene cunicularia of the white color is the same one, in clear and dark environments, what it can be responsible for the adaptive capacity of the species in their natural habitat.

Reticulação do colágeno corneano com radiação ultravioleta e riboflavina para tratamento do ceratocone: resultados preliminares de um estudo brasileiro / Corneal collagen crosslinking with riboflavin and ultraviolet radiation for keratoconus treatment: preliminary results of a Brazilian study

OBJETIVO: Avaliar o efeito clínico e topográfico da reticulação do colágeno corneano (crosslinking) em pacientes com ceratocone pertencentes à população brasileira. MÉTODOS: Trinta e sete olhos de 37 pacientes (22 mulheres e 15 homens) com diagnóstico de ceratocone em progressão e com espessura mínima de 395 micra, foram submetidos à técnica de indução da reticulação do colágeno corneano através da aplicação durante 30 minutos de luz ultravioleta (370nm) associada à solução de riboflavina 0,1 por cento (instilada a cada 5 minutos). Foram comparados os valores ceratométricos e a melhor acuidade visual corrigida antes e após o procedimento, com intervalos de 40 e 90 dias. RESULTADOS: Houve redução do poder dióptrico médio (PDM) nos 3mm centrais em 83,8 por cento dos pacientes após três meses. O PDM reduziu em média 0,4D nos 3mm centrais (p<0,01) e 0,33D nos 5mm centrais (p<0,01). O valor ceratométrico máximo reduziu em média 0,6D (p<0,01). A acuidade visual corrigida do olho tratado evoluiu com melhora média de 6,27 letras (p<0,01) após 90 dias. CONCLUSÃO: Observamos uma melhora menos acentuada dos índices topográficos e de acuidade visual em comparação aos resultados encontrados em outras populações. São necessários mais estudos com um maior número de pacientes e maior tempo de seguimento para que esta técnica confirme seu propósito de estabilização da doença com apenas uma aplicação, e possa talvez se tornar, no futuro, o método de escolha para o tratamento do ceratocone.

PURPOSE: Assess the clinical and topographical effects of corneal collagen crosslinking in patients with keratoconus on Brazilian population. METHODS: Thirty seven eyes of 37 patients (22 female and 15 male) with diagnosis of progressive keratoconus and corneal paquimetry higher than 395 micra, were treated with riboflavin and ultraviolet A radiation, over 30 minutes, to induce corneal collagen crosslinking. Keratometric values were compared as well as the best corrected visual acuity, before and after the procedure, with ranges of 40 and 90 days. RESULTS: There was a reduction of mean dioptric power (PDM) in central 3mm in 83.8 percent of patients after three months.The PDM reduced 0.4D on average in central 3mm (p<0,01) and 0.33D in central 5mm (p<0,01). The maximum keratometric value decreased 0.6 D on average (p<0,01). The corrected visual acuity of the treated eye evolved with improvement average of 6,27 letters (p<0,01) after 90 days. CONCLUSION: We could observe a less pronounced improvement of the topographical values and visual acuity in comparison of the findings in other populations. Further studies with a larger number of patients and longer follow-up are necessary to confirm this technique's purpose of stabilizing the disease with only one application, and allow that to become the method of choice for keratoconus treatment.

[Anatomical nomenclature in ophthalmology]. / Nomenclatura anatômica em oftalmologia.

The purposes of this article are: to inform ophthalmologists about the differences between the English and Portuguese list of equivalent terms for eye structures, approved by the Federative International Committee on Anatomical Terminology; to present the anatomical terms included in the list of medical subject headings published by the United States National Library of Medicine and translated by the Regional Library of Medicine (BIREME); propose a list of Portuguese terms of common usage by ophthalmologists.

Nomenclatura anatômica em oftalmologia / Anatomical nomenclature in ophthalmology

Os objetivos deste estudo são: informar os oftalmologistas sobre as diferenças existentes entre as listas em língua inglesa e portuguesa de termos equivalentes para as estruturas do olho, ambas aprovadas pela Comissão Federativa Internacional de Terminologia Anatômica; apresentar os termos anatômicos incluídos na lista de descritores publicada pela Biblioteca Nacional de Medicina Norte-Americana e traduzida pela Biblioteca Regional de Medicina (BIREME); para propor uma lista em português de termos de uso comum pelos oftalmologistas.

The purposes of this article are: to inform ophthalmologists about the differences between the English and Portuguese list of equivalent terms for eye structures, approved by the Federative International Committee on Anatomical Terminology; to present the anatomical terms included in the list of medical subject headings published by the United States National Library of Medicine and translated by the Regional Library of Medicine (BIREME); propose a list of Portuguese terms of common usage by ophthalmologists.

[Leigh syndrome: case report]. / Síndrome de Leigh: relato de caso.

The authors describe for the first time in the Country a case of a 10-year-old female child, assisted at the Ophthalmology Clinic of the Hospital Universitário Clementino Fraga Filho UFRJ, with Leigh's syndrome that is part of a metabolic disease group known as mitochondrial encephalomyopathies. It is an hereditary disease transmitted by a different mode of inheritance: mitochondrial, X-linked recessive and autosomal recessive. The beginning of clinical manifestations is varied and occurs usually in the first two years of life, with progressive and insidious evolution and exacerbation periods. Diagnosis is difficult because pleomorphic presentation, based on clinical findings and complementary study related to mitochondrial production of ATP and cytochrome c oxidase deficiencies. Considering that there is no specific treatment, this is based on a palliative procedure. So, the identification of this syndrome is very important to keep it under control, since its evolution is progressive.

Síndrome de Leigh: relato de caso / Leigh syndrome: case report

Os autores descrevem pela primeira vez no país um caso de criança do sexo feminino, com 10 anos de idade, atendida no ambulatório de Oftalmologia do Hospital Universitário Clementino Fraga Filho - UFRJ, portadora da síndrome de Leigh, que faz parte de um grupo de enfermidades metabólicas conhecidas como encefalomiopatias mitocondriais. É doença hereditária transmitida por diferentes modos de herança: mitocondrial, autossômica recessiva e recessiva ligada ao X. O início das manifestações clínicas é variado, ocorrendo em geral, dentro dos primeiros dois anos de vida, com evolução insidiosa, progressiva e com períodos de exacerbações. O diagnóstico é difícil pelo pleomorfismo de sua apresentação, sendo baseado nos achados clínicos e estudos complementares relacionados à deficiência na produção mitocondrial de ATP e da citocromo C oxidase. Como não há tratamento específico, este é baseado em medidas paliativas, portanto a identificação desta síndrome é importante como diagnóstico correto permitindo condutas adequadas à melhor qualidade de vida de seus portadores.

The authors describe for the first time in the Country a case of a 10-year-old female child, assisted at the Ophthalmology Clinic of the Hospital Universitário Clementino Fraga Filho UFRJ, with Leigh's syndrome that is part of a metabolic disease group known as mitochondrial encephalomyopathies. It is an hereditary disease transmitted by a different mode of inheritance: mitochondrial, X-linked recessive and autosomal recessive. The beginning of clinical manifestations is varied and occurs usually in the first two years of life, with progressive and insidious evolution and exacerbation periods. Diagnosis is difficult because pleomorphic presentation, based on clinical findings and complementary study related to mitochondrial production of ATP and cytochrome c oxidase deficiencies. Considering that there is no specific treatment, this is based on a palliative procedure. So, the identification of this syndrome is very important to keep it under control, since its evolution is progressive.

Exame de paciente com doença neurológica: [revisão] / Patient examination with neurologic disorders: [review]

A neurologia oftalmológica e otológica tem se desenvolvido nos últimos anos até constituir uma extensa disciplina especializada. Dispomos na atualidade de importantes manuais sobre a mesma, os quais têm, ante tudo, o caráter de obras de consulta; em troca, se faz sentir, sem dúvida, a necessidade de descrições compreendidas que destaquem o mais essencial e definitivamente adquirido da bibliografia, quase inabarcável, em relação aos domínios desta especialidade; assim, temos demonstrados os repetidos desejos de alunos, solicitando a publicação de nossas conferências para pós-graduados sobre esta matéria. Fizemos uma exposição resumida da neurologia com interesse neurooftalmológico para que os estudantes desta matéria possam se interessar sobre a mesma.

Lately, the ophthalmologic and otological neurology has been developed into a broad and specialized subject. Currently, we have important manuals on this issue, which above all have the purpose of a work for research. However, undoubtedly one can feel the necessity for comprehended descriptions that will highlight what is most essential and definitely taken from the biography, almost inaccessible, regarding the realm of such specialty; thus, the repeated wishes of the students asking for the publication of our lectures for the post-graduates on this matter have been demonstrated. We have included a summary of the neurology with neuro-ophthalmologic interest aiming at drawing the students' attention on this subject.

[Comparative study between diurnal intraocular pressure curve and the association of ambulatory intraocular pressure curve with the water-drinking test in open angle glaucoma, normal tension glaucoma and normal eyes]. / Estudo comparativo entre a curva diária de pressão intra-ocular e a associação da curva ambulatorial com o teste de sobrecarga hídrica no glaucoma primário de ângulo aberto, glaucoma de pressão normal e olhos normais.

PURPOSE: To evaluate and correlate the peaks and the fluctuation of intraocular pressure seen in the association of the ambulatory intraocular pressure curve with the water-drinking test versus the peaks and the fluctuation seen in the daily intraocular pressure curve. METHODS: The sample was as follows: 77 eyes belonging to 77 patients who were divided into three groups composed of 31 eyes belonging to 31 patients with primary open-angle glaucoma, 26 eyes belonging to 26 patients with normal tension glaucoma and 20 normal eyes belonging to 20 individuals. RESULTS: A significant correlation could be observed between the pressure peaks collected from the daily intraocular pressure curve and the pressure peaks seen in the ambulatory intraocular pressure curve, on the water-drinking test, as well as in the association of the ambulatory intraocular pressure curve with the water-drinking test. The procedure which showed the highest rate of correlation between the pressure peaks and the peaks of the daily intraocular pressure curve was the ambulatory intraocular pressure curve (r2= 0.81). However, no statistically significant difference was found between the pressure peaks and the correlation coefficients observed in the other methods. The correlation between the fluctuation of intraocular pressure obtained in the association of the ambulatory intraocular pressure curve with the water-drinking test and the fluctuation of the pressure seen in the daily intraocular pressure curve showed a slight association (r2= 0.21). CONCLUSIONS: The association between ambulatory intraocular pressure curve and water-drinking test was not efficient to estimate peaks and the fluctuation of daily intraocular pressure curve. The ambulatory intraocular pressure curve and the water-drinking test must be analyzed separately. When predicting the peak and the fluctuation of the daily intraocular pressure curve, the ambulatory intraocular pressure curve was the most efficient procedure.

Estudo comparativo entre a curva diária de pressão intra-ocular e a associação da curva ambulatorial com o teste de sobrecarga hídrica no glaucoma primário de ângulo aberto, glaucoma de pressão normal e olhos normais / Comparative study between diurnal intraocular pressure curve and the association of ambulatory intraocular pressure curve with the water-drinking test in open angle glaucoma, normal tension glaucoma and normal eyes

OBJETIVO: Avaliar e correlacionar os picos e a flutuação da pressão intra-ocular verificados na associação da curva ambulatorial com o teste de sobrecarga hídrica com os picos e a flutuação verificados na curva diária de pressão intra-ocular. MÉTODOS: A amostra foi constituída de 77 olhos de 77 pacientes divididos em três grupos compostos por 31 olhos de 31 pacientes portadores de glaucoma primário de ângulo aberto, 26 olhos de 26 pacientes com glaucoma de pressão normal e 20 olhos normais de 20 indivíduos. RESULTADOS: Houve correlação significativa entre os picos de pressão obtidos na curva diária de pressão intra-ocular e os picos de pressão verificados na curva ambulatorial, no teste de sobrecarga hídrica e na associação da curva ambulatorial com o teste de sobrecarga hídrica. O procedimento em que os picos de pressão apresentaram maior correlação com os picos da curva diária de pressão intra-ocular foi a curva ambulatorial (r²= 0,81), embora não tenha havido diferença estatisticamente significativa com os coeficientes de correlação verificados nos outros métodos. A correlação entre a flutuação da pressão intra-ocular obtida na associação da curva ambulatorial com o teste de sobrecarga hídrica e a flutuação da pressão verificada na curva diária de pressão intra-ocular apresentou uma fraca associação (r²= 0,21). CONCLUSÃO: A associação da curva ambulatorial com o teste de sobrecarga hídrica não se mostrou eficaz para predizer os picos e a flutuação da curva diária de pressão intra-ocular. A curva ambulatorial e o teste de sobrecarga hídrica, devem ser analisados separadamente. O procedimento mais eficaz em prever o pico e a flutuação da pressão da curva diária de pressão intra-ocular foi a curva ambulatorial.

PURPOSE: To evaluate and correlate the peaks and the fluctuation of intraocular pressure seen in the association of the ambulatory intraocular pressure curve with the water-drinking test versus the peaks and the fluctuation seen in the daily intraocular pressure curve. METHODS: The sample was as follows: 77 eyes belonging to 77 patients who were divided into three groups composed of 31 eyes belonging to 31 patients with primary open-angle glaucoma, 26 eyes belonging to 26 patients with normal tension glaucoma and 20 normal eyes belonging to 20 individuals. RESULTS: A significant correlation could be observed between the pressure peaks collected from the daily intraocular pressure curve and the pressure peaks seen in the ambulatory intraocular pressure curve, on the water-drinking test, as well as in the association of the ambulatory intraocular pressure curve with the water-drinking test. The procedure which showed the highest rate of correlation between the pressure peaks and the peaks of the daily intraocular pressure curve was the ambulatory intraocular pressure curve (r²= 0.81). However, no statistically significant difference was found between the pressure peaks and the correlation coefficients observed in the other methods. The correlation between the fluctuation of intraocular pressure obtained in the association of the ambulatory intraocular pressure curve with the water-drinking test and the fluctuation of the pressure seen in the daily intraocular pressure curve showed a slight association (r²= 0.21). CONCLUSIONS: The association between ambulatory intraocular pressure curve and water-drinking test was not efficient to estimate peaks and the fluctuation of daily intraocular pressure curve. The ambulatory intraocular pressure curve and the water-drinking test must be analyzed separately. When predicting the peak and the fluctuation of the daily intraocular pressure curve, the ambulatory intraocular pressure curve was the most...

Estudo eletrorretinográfico de visão cromática / Electroretinographic study of chromatic vision

OBJETIVO: O objetivo deste estudo é descrever o traçado eletrorretinográfico no gambá sul-americano (Didelphis aurita) obtido com estímulo cromático de comprimento de onda seletivo. O eletrorretinograma é o registro das variações de voltagem nas células retinianas, desencadeadas por estímulo luminoso. O eletrorretinograma representa a atividade elétrica combinada de diferentes células, e sofre variações dependendo da fisiologia retiniana e do método de exame. MÉTODOS: Foram registrados os eletrorretinogramas de seis animais em adaptação ao escuro utilizando filtros cromáticos Kodak Wratten®, e registrada a sensibilidade espectral para comprimentos de onda específicos nas faixas de cores do azul, verde, amarelo, laranja e vermelho. RESULTADOS: Os resultados eletrorretinográficos mais consistentes foram obtidos quando o animal foi estimulado por faixas espectrais seletivas, ao invés de luz branca; e são consistentes com a curva de absorbância das opsinas descritas em fotorreceptores de marsupiais. Estudos prévios sugeriram a tricromacia dos marsupiais por microespectrofotometria de opsinas e imuno-histoquímica de retina. Esse fundamento morfológico não tinha demonstração fisiológica eletrorretinográfica, até este estudo. CONCLUSÃO: O gambá sul-americano tem se mostrado interessante como animal experimental no estudo comparativo da fisiologia visual em mamíferos, especialmente no estudo filogenético da visão cromática. Os marsupiais apresentam um modelo retiniano que superpõe os sistemas fotópico e escotópico; e o gênero Didelphis conserva características encontradas em fósseis do período pleoceno. Portanto, o sistema visual de um marsupial resgata características dos primórdios da evolução dos mamíferos, até o desenvolvimento dos padrões retinianos modernos.

PURPOSE: To describe the electroretinogram of the South-American opossum (Didelphis aurita) obtained by chromatic stimulus of specific wavelengths. The electroretinogram records voltage variations of retinal cells triggered by light stimulation. The electroretinogram represents the combination of electric activity of many different cells and varies according to retinal physiology and examination methods. METHODS: We recorded the electroretinogram of six animals in dark adaptation using chromatic Kodak Wratten® filters, and recorded the spectral sensitivity to specific wavelengths in the spectrum of blue, green, yellow, orange and red light bands. RESULTS: The most consistent electrorretinographic results were obtained when the animals were stimulated by selective spectral bands instead of white light. These results are consistent with the absorbance curve of the opsins described in marsupial photoreceptors. Previous studies using microspectrophotometry of opsins and retinal immunohistochemistry suggested marsupial trichromacy. This morphologic knowledge has not before been physiologically demonstrated by electroretinographic methods. CONCLUSION: The South-American opossum has proven to be an interesting experimental animal for comparative visual physiology studies among other mammals, especially studies on phylogenetic of chromatic vision. The opossum represents a retinal model that superimposes both the photopic and scotopic systems; and the Didelphis genus shows few changes when compared to the fossils of the Pleocene period. Therefore the marsupial's visual system retrieves characteristics from ancient mammal evolution to the retinal patterns found in modern mammals.