RESUMEN
PURPOSE: The purpose of this study was to correlate human retinal capillary network information derived from a prototype speckle variance optical coherence tomography (svOCT) device with histology to determine the utility of this instrument for quantitative angiography. METHODS: A retina location 3 mm superior to the optic disk was imaged with svOCT in 14 healthy human eyes. Qualitative and quantitative features of capillary networks, including capillary diameter and density, were compared with perfusion-labeled histological specimens from the same eccentricity. Twelve human donor eyes with no history of eye disease were used for histological comparisons. RESULTS: svOCT was able to clearly distinguish the morphological features of the nerve fiber layer capillary network, the retinal ganglion cell (RGC) layer capillary network, the capillary network at the border of the inner plexiform layer and superficial boundary of the inner nuclear layer, and the capillary network at the boundary of the deep inner nuclear layer and outer plexiform layer. The morphological features of these networks were highly comparable to those in previous histological studies. There were no statistical differences in mean capillary diameter between svOCT images and histology for all networks other than the RGC capillary network. Capillary density measurements were significantly greater in svOCT images, except in the RGC capillary network. CONCLUSIONS: svOCT has the capacity to provide histology-like anatomical information about human retinal capillary networks in vivo. It may have great potential as a research and diagnostic tool in the management of retinal vascular diseases. Further work is required to clarify the cause of some quantitative differences between svOCT and histology.
Asunto(s)
Capilares/diagnóstico por imagen , Retina/anatomía & histología , Vasos Retinianos/diagnóstico por imagen , Tomografía de Coherencia Óptica/métodos , Adulto , Femenino , Humanos , Masculino , Microscopía Confocal/métodos , Persona de Mediana Edad , Radiografía , Células Ganglionares de la Retina/diagnóstico por imagen , Tomografía de Coherencia Óptica/normasRESUMEN
BACKGROUND/AIMS: To evaluate optic nerve head with spectral domain optical coherence tomography (OCT) in patients with Chiari I malformation (CMI) compared to healthy controls. METHODS: Cross-sectional study. OCT of the optic nerve head of 22 patients with CMI and 22 healthy controls was quantitatively analyzed. The healthy controls were matched for age and sex with the study population. Mean retinal nerve fiber layer (RNFL) thickness was calculated for both eyes; the mean thickness value was also registered for each quadrant and for each subfield of the four quadrants. RESULTS: CMI patients showed a reduction of the RNFL thickness in both eyes. This reduction was more statistically significant (P < 0.05) for the inferior quadrant in the right eye and in each quadrant than nasal one in the left eye. CONCLUSION: A distress of the retinal nerve fibers could explain the observed reduction of the RNFL thickness in patients with CMI; in our series the reduction of the RNFL thickness seems lower when CMI is associated with syringomyelia.
Asunto(s)
Malformación de Arnold-Chiari/diagnóstico por imagen , Fibras Nerviosas/diagnóstico por imagen , Disco Óptico/diagnóstico por imagen , Tomografía de Coherencia Óptica , Adulto , Malformación de Arnold-Chiari/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fibras Nerviosas/patología , Disco Óptico/patología , Radiografía , Retina/diagnóstico por imagen , Retina/patología , Células Ganglionares de la Retina/diagnóstico por imagen , Células Ganglionares de la Retina/patologíaRESUMEN
This paper aims to explore the relationship of retinal neuron apoptosis and manganese superoxidase dismutase (MnSOD) at early phase of diabetic retinopathy. Sprague-Dawley rats were grouped into normal controls and diabetics. Data were collected after 4, 8, and 12 weeks (n = 12). The pathological changes and ultrastructure of the retina, the apoptosis rate of retinal neurons by TdT-mediated dUTP nick end label (TUNEL), mRNA expressions of MnSOD and copper-zinc superoxide dismutase (Cu-Zn SOD), and the activities of total SOD (T-SOD) and subtypes of SOD were tested. For the controls, there was no abnormal structure or apoptosis of retinal neurons at any time. There was no change of structure for rats with diabetes at 4 or 8 weeks, but there was a decrease of retinal ganglion cells (RGCs) number and thinner inner nuclear layer (INL) at 12 weeks. The apoptosis ratio of RGCs was higher than that of the controls at 8 and 12 weeks (P < 0.001). The activity and mRNA levels of MnSOD were lower in diabetics at 4, 8, and 12 weeks (P < 0.05). In summary, the apoptosis of the retinal neurons occurred at 8 weeks after the onset of diabetes. Retinal neuron apoptosis in early diabetic rats may be associated with the decreased activity and mRNA of MnSOD.
Asunto(s)
Apoptosis , Retinopatía Diabética/patología , Mitocondrias/diagnóstico por imagen , Estrés Oxidativo , Neuronas Retinianas/diagnóstico por imagen , Superóxido Dismutasa/metabolismo , Animales , Recuento de Células , Núcleo Celular/ultraestructura , Forma del Núcleo Celular , Tamaño del Núcleo Celular , Diabetes Mellitus Experimental/complicaciones , Retinopatía Diabética/metabolismo , Retinopatía Diabética/fisiopatología , Regulación Enzimológica de la Expresión Génica , Masculino , Mitocondrias/enzimología , Mitocondrias/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Células Ganglionares de la Retina/diagnóstico por imagen , Células Ganglionares de la Retina/enzimología , Células Ganglionares de la Retina/metabolismo , Neuronas Retinianas/enzimología , Neuronas Retinianas/metabolismo , Índice de Severidad de la Enfermedad , Superóxido Dismutasa/genética , Superóxido Dismutasa-1 , UltrasonografíaRESUMEN
PURPOSE: To describe GDxVCC retinal nerve fiber layer (RNFL) measures and associations in a predominantly white British population. METHODS: The EPIC-Norfolk Eye Study is nested within a large multicenter cohort study, the European Prospective Investigation of Cancer. RNFL measurements were taken using the GDxVCC. Generalized estimating equation models were used to assess associations of RNFL measures with age, sex, body mass index (BMI), height, blood pressure, social class, education level, alcohol intake, smoking status, axial length, intraocular pressure, and lens status. Models were linearly adjusted for typical scan score to handle scans with atypical retardation. RESULTS: There were complete data from 11,030 eyes of 6309 participants with mean age 68 years (48-90 years). Older age (-1.53 µm/decade [95% confidence interval {CI} -1.73, -1.33], P < 0.001), male sex (-0.44 µm [95% CI -0.04, -0.84], P = 0.031), shorter axial length (-0.15 µm/mm [95% CI -0.02, -0.28], P = 0.024), and pseudophakia (-0.49 µm [95% CI -0.94, -0.04], P = 0.033) were associated with thinner RNFL after adjustment for possible confounders. Higher BMI was associated with a thinner RNFL in men only (-0.30 µm/5 kg/m(2) [95% CI -0.58, -0.02], P = 0.039). CONCLUSIONS: This analysis of associations with RNFL thickness in a largely healthy population may provide insight into the determinants of glaucoma, suggesting higher risk in those who are older, in men, and in men with a higher BMI.
Asunto(s)
Glaucoma/epidemiología , Glaucoma/patología , Células Ganglionares de la Retina/patología , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Longitud Axial del Ojo/diagnóstico por imagen , Longitud Axial del Ojo/patología , Biometría , Intervalos de Confianza , Femenino , Estudios de Seguimiento , Glaucoma/fisiopatología , Humanos , Presión Intraocular , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Prospectivos , Células Ganglionares de la Retina/diagnóstico por imagen , Células Ganglionares de la Retina/fisiología , Factores Sexuales , Tomografía de Coherencia Óptica , Ultrasonografía , Reino Unido/epidemiologíaRESUMEN
PURPOSE: To evaluate the capability of optical coherence tomography (OCT), retinal nerve fiber layer (RNFL) thickness, and visual field (VF) measurements in glaucoma progression detection. METHODS: The study examined 62 eyes of 37 glaucoma patients observed over a 3-year period. All eyes underwent at least four serial RNFL measurements performed by Cirrus OCT, with the first and last measurements separated by at least 3 years. VF testing was performed by using the Swedish interactive threshold algorithm (SITA) Standard 30-2 program of the Humphrey field analyzer (HFA) on the same day as the RNFL imaging. Both serial RNFL thicknesses and VF progression were assessed by the guided progression analysis (GPA) software program. RNFL thickness progression was evaluated by event analysis. Total deviation (TD) in the superior or inferior hemifield was also examined. RESULTS: A total of 295 OCT scans and 295 VFs were analyzed. Five eyes exhibited progression by OCT only and 8 eyes exhibited progression by VF GPA only. When the analysis was based on the combined measurement findings, progression was noted in 6 eyes. The average of the progressive hemifield TD at baseline for combined RNFL and VF progression was -3.21±1.38 dB, while it was -2.17±1.14 dB for RNFL progression and -9.12±3.75 dB for VF progression. The average of the progressive hemifield TD indicated a significant advancement of VF progression as compared to RNFL progression (P=0.002). CONCLUSIONS: When a mild VF defect is present, OCT RNFL thickness measurements are important in helping discern glaucoma progression.
Asunto(s)
Glaucoma/diagnóstico , Presión Intraocular , Fibras Nerviosas/patología , Células Ganglionares de la Retina/patología , Tomografía de Coherencia Óptica/métodos , Campos Visuales/fisiología , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Glaucoma/fisiopatología , Humanos , Masculino , Microscopía Acústica , Persona de Mediana Edad , Fibras Nerviosas/diagnóstico por imagen , Células Ganglionares de la Retina/diagnóstico por imagen , Estudios Retrospectivos , Factores de Tiempo , Pruebas del Campo VisualRESUMEN
The adverse biological effects of continuous exposure to cobalt and chromium have been well defined. In the past, this toxicity was largely an industrial issue concerning workers exposed in occupational setting. Nevertheless, recent reports have described a specific toxicity mediated by the high levels of cobalt and chromium released by metallic prostheses, particularly in patients who had received hip implants. Clinical symptoms, including blindness, deafness and peripheral neuropathy, suggest a specific neurotropism. However, little is known about the neuropathological basis of this process, and experimental evidence is still lacking. We have investigated this issue in an experimental setting using New Zealand White rabbits treated with repeated intravenous injections of cobalt and chromium, alone or in combination. No evident clinical or pathological alterations were associated after chromium administration alone, despite its high levels in blood and tissue while cobalt-chromium and cobalt-treated rabbits showed clinical signs indicative of auditory and optic system toxicity. On histopathological examination, the animals showed severe retinal and cochlear ganglion cell depletion along with optic nerve damage and loss of sensory cochlear hair cells. Interestingly, the severity of the alterations was related to dosages and time of exposure. These data confirmed our previous observation of severe auditory and optic nerve toxicity in patients exposed to an abnormal release of cobalt and chromium from damaged hip prostheses. Moreover, we have identified the major element mediating neurotoxicity to be cobalt, although the molecular mechanisms mediating this toxicity still have to be defined.
Asunto(s)
Cobalto/toxicidad , Pérdida Auditiva Central/inducido químicamente , Intoxicación del Sistema Nervioso por Metales Pesados/etiología , Nervio Óptico/efectos de los fármacos , Animales , Cloruros/farmacocinética , Cloruros/toxicidad , Compuestos de Cromo/farmacocinética , Compuestos de Cromo/toxicidad , Cobalto/farmacocinética , Cóclea/diagnóstico por imagen , Cóclea/efectos de los fármacos , Cóclea/inervación , Cóclea/metabolismo , Relación Dosis-Respuesta a Droga , Femenino , Células Ciliadas Auditivas/efectos de los fármacos , Células Ciliadas Auditivas/metabolismo , Células Ciliadas Auditivas/ultraestructura , Pérdida Auditiva Central/metabolismo , Pérdida Auditiva Central/patología , Intoxicación del Sistema Nervioso por Metales Pesados/metabolismo , Intoxicación del Sistema Nervioso por Metales Pesados/patología , Masculino , Microscopía Electrónica , Nervio Óptico/diagnóstico por imagen , Nervio Óptico/metabolismo , Conejos , Retina/diagnóstico por imagen , Retina/efectos de los fármacos , Retina/metabolismo , Células Ganglionares de la Retina/diagnóstico por imagen , Células Ganglionares de la Retina/efectos de los fármacos , Células Ganglionares de la Retina/metabolismo , Nervio Ciático/diagnóstico por imagen , Nervio Ciático/efectos de los fármacos , Nervio Ciático/metabolismo , Distribución Tisular , UltrasonografíaRESUMEN
BACKGROUND: Glaucoma is associated with a progressive loss of retinal ganglion cell axons and the evaluation of the thickness of the retinal nerve fibre layer (RNFL) is important for early diagnosis and follow-up. Results of RNFL thickness measurements may vary according to the devices used. Therefore, the present study has analysed and compared the reproducibility of data obtained with three different instruments. METHODS: RNFL thickness was determined using a circular identification line around the optic nerve head by optical coherence tomography (OCT), a Heidelberg Retina Tomograph (HRT) and a Nerve Fiber Analyser (NFA). Each eye was tested six times. The values for RNFL thickness were calculated for the superior, inferior, nasal and temporal areas. A one-way analysis of variance with random effects was chosen to estimate the variance components. The intraclass correlation coefficient (ICC) as a measure of reliability and the coefficient of variation (CV%) as a measure of precision were determined to estimate the reproducibility of RNFL thickness measurements. RESULTS: With all three instruments, the reproducibility of measurements between the superior, inferior, temporal and nasal areas did not differ significantly suggesting that reproducibility does not depend on the thickness of the RNFL. Data obtained by NFA showed the highest ICC values (0.9) and lowest CV% values (7.0), followed by those obtained by HRT (reliability ICC 0.8; precision CV% 12). A markedly lower degree of reproducibility was found for the OCT compared to NFA and HRT (reliability ICC 0.5; precision CV% 15). CONCLUSION: The comparison of RNFL thickness measurements with OCT, NFA, and HRT showed that the NFA yielded the most reliable results followed by HRT.