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1.
Neuroimage ; 233: 117966, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33744460

RESUMEN

Volitional eye closure is observed only in conscious and awake humans, and is rare in animals. It is believed that eye closure can focus one's attention inward and facilitate activities such as meditation and mental imagery. Congenital blind individuals are also required to close their eyes for these activities. Resting-state functional magnetic resonance imaging (RS-fMRI) studies have found robust differences between the eyes-closed (EC) and eyes-open (EO) conditions in some brain regions in the sighted. This study analyzed data from 21 congenital blind individuals and 21 sighted controls by using amplitude of low-frequency fluctuation (ALFF) of RS-fMRI. The blind group and the sighted group shared similar pattern of differences between the EC and EO condition: ALFF was higher in the EC condition than the EO condition in the bilateral primary sensorimotor cortex, bilateral supplementary motor area, and inferior occipital cortex, while ALFF was lower in the EC condition than the EO condition in the medial prefrontal cortex, highlighting the "nature" effect on the difference between the EC and EO conditions. The results of other matrices such as fractional ALFF (fALFF) and regional homogeneity (ReHo) showed similar patterns to that of ALFF. Moreover, no significant difference was observed between the EC-EO pattern of the two subgroups of congenital blind (i.e., with and without light perception), suggesting that the EC-EO difference is irrespective of residual light perception which reinforced the "nature" effect. We also found between-group differences, i.e., more probably "nurture effect", in the posterior insula and fusiform. Our results suggest that the acts of closing and opening the eyes are of importance for the congenital blind, and that these actions and their differences might be inherent in the nature of humans.


Asunto(s)
Ceguera/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Ojo/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Red Nerviosa/diagnóstico por imagen , Descanso , Adolescente , Adulto , Ceguera/fisiopatología , Encéfalo/fisiopatología , Ojo/fisiopatología , Párpados/diagnóstico por imagen , Párpados/fisiopatología , Femenino , Glaucoma/diagnóstico por imagen , Glaucoma/fisiopatología , Humanos , Masculino , Red Nerviosa/fisiopatología , Descanso/fisiología , Enfermedades de la Retina/diagnóstico por imagen , Enfermedades de la Retina/fisiopatología , Adulto Joven
2.
Biomed Pharmacother ; 125: 109998, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32070875

RESUMEN

Retinal ischemia reperfusion injury (IRI) is a leading cause of visual impairment or blindness, and an effective way to prevent the visual loss needs to be developed. Although decades of clinical application of Huoxue-Tongluo-Lishui-Decoction (HTLD) has demonstrated its reliable clinical efficacy against retinal IRI, no convincing randomized controlled trials were conducted in humans or animals, and the associated mechanism still needs to be explored. To confirm the protective effect of HTLD against retinal IRI and to explore its underlying mechanisms, a standard retinal IRI animal model, randomized controlled trials, objective evaluation and examination methods were adopted in this study. Flash visual evoked potentials (F-VEP) was performed 8 weeks post-reperfusion. The results showed that the medium dose of HTLD had better treatment effects than low dose of HTLD. High dose of HTLD did not further improve visual function relative to medium dose of HTLD, but had poor performance in the latency of P2 wave. The angio-optical coherence tomography (angio-OCT) examination showed that retinal nerve fiber layer (RNFL) became edematous in the early stage, then the edema subsided, and RNFL became thinning in the late stage. HTLD reduced the swelling of RNFL in the early stage and prevented the thinning of RNFL in the late stage. Similar to F-VEP, medium dose of HTLD has the best neural-protective effects against retinal IRI. In mechanisms, HTLD treatment not only enhanced autophagy at 6 h after reperfusion, but extended the enhancing effect until at least 24 h. HTLD treatment significantly reduced the cleaved Caspase-3, cleaved PARP and Caspase-3 activity at 48 h after reperfusion. HTLD inhibited neuro-toxic cytokines expression in retinal IRI by modulating Akt/NF-kB signaling. HTLD treatment enhanced the expressions of L-glutamate/L-aspartate transporter (GLAST) and glutamine synthetase (GS), and lower the concentration of free glutamate in retina after reperfusion. The phosphorylation of iNOS increased significantly in retinal IRI at 6 h, and HTLD treatment suppressed the phosphorylation of Inducible nitric oxide synthetase (iNOS). In conclusion, HTLD is visual-protective against retinal IRI, and the regulation of autophagy, apoptosis and neuro-toxic mediators may be the underlying mechanisms. These findings may provide new ideas for the clinical treatment of retinal IRI related diseases.


Asunto(s)
Medicamentos Herbarios Chinos/farmacología , Potenciales Evocados Visuales/efectos de los fármacos , Daño por Reperfusión/tratamiento farmacológico , Enfermedades de la Retina/tratamiento farmacológico , Enfermedades de la Retina/fisiopatología , Animales , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Biomarcadores , Citocinas/metabolismo , Modelos Animales de Enfermedad , Expresión Génica , Ácido Glutámico/metabolismo , FN-kappa B/metabolismo , Fármacos Neuroprotectores/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Daño por Reperfusión/diagnóstico , Daño por Reperfusión/prevención & control , Enfermedades de la Retina/etiología , Enfermedades de la Retina/prevención & control , Transducción de Señal/efectos de los fármacos , Tomografía de Coherencia Óptica
3.
Retina ; 40(10): 1988-1995, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31834130

RESUMEN

PURPOSE: To characterize dark adaptation in patients with pseudoxanthoma elasticum, a systemic disease leading to calcification of elastic tissue including the Bruch membrane. METHODS: In this prospective case-control study, dark adaptation thresholds were measured using a Goldmann-Weekers dark adaptometer. Additional assessments included best-corrected visual acuity testing, contrast sensitivity, low luminance deficit, and vision-related quality of life. RESULTS: Dark adaptation thresholds were significantly higher, and adaptation periods were prolonged in patients with pseudoxanthoma elasticum (n = 35; 33 with 2 ABCC6 mutations) compared with controls (n = 35). The time to adapt 4 log units (20.6 ± 8.6 vs. 8.0 ± 1.3 minutes) and the mean dark adaptation threshold after 15 minutes (3.5 ± 1.1 vs. 1.8 ± 0.2 log units) were significantly different between patients and controls (both P < 0.001). Low luminance deficits (12.3 ± 6.4 vs. 6.1 ± 4.3 ETDRS letters), contrast sensitivity (1.4 ± 0.3 vs. 1.9 ± 0.1), and low luminance-related quality of life (LLQ score: 1,286 ± 355 vs. 2,167 ± 68) were also significantly worse in patients with pseudoxanthoma elasticum (all, P < 0.001). Two patients were treated with high-dose vitamin A which partially reversed impaired dark adaptation. CONCLUSION: Patients with pseudoxanthoma elasticum often have impaired dark adaptation. Positive effects of vitamin A supplementation may indicate restricted retinal access of vitamin A through the Bruch membrane as one possible underlying pathogenic factor.


Asunto(s)
Lámina Basal de la Coroides/patología , Adaptación a la Oscuridad/fisiología , Seudoxantoma Elástico/fisiopatología , Enfermedades de la Retina/fisiopatología , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Sensibilidad de Contraste/fisiología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Seudoxantoma Elástico/tratamiento farmacológico , Calidad de Vida , Enfermedades de la Retina/tratamiento farmacológico , Agudeza Visual/fisiología , Vitamina A/administración & dosificación , Adulto Joven
4.
Indian J Ophthalmol ; 66(8): 1136-1140, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30038158

RESUMEN

Purpose: The purpose of this study was to evaluate the feasibility and safety of office-based vitreoretinal procedures. Methods: Patients undergoing primary elective pars plana vitrectomy were elected for surgery in an office-based setting (performed in a minor procedure room under topical anesthesia [TA] and oral anxiolysis). Rates of surgical objective achievement, surgical timing, and comfort were recorded to evaluate feasibility. Intraoperative and postoperative adverse events were assessed to evaluate safety. Results: Office-based vitrectomy surgery was performed in 34 eyes of 30 patients. The mean surgical time was 12.351 ± 8.21 min. Surgical objectives were achieved in 100% of cases. The mean best-corrected visual acuity improvement was 9.08 letters (P < 0.0001). During most parts of the procedure, no patient reported pain or discomfort. Neither intraoperative nor postoperative adverse events were reported until the final follow-up visit. Conclusion: Office-based vitreoretinal procedures under TA could be as feasible and as safe as vitreoretinal procedures under conventional anesthesia.


Asunto(s)
Procedimientos Quirúrgicos Ambulatorios/métodos , Anestesia Local/métodos , Enfermedades de la Retina/cirugía , Agudeza Visual , Vitrectomía/métodos , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Estudios Prospectivos , Enfermedades de la Retina/fisiopatología , Resultado del Tratamiento
5.
Elife ; 62017 10 24.
Artículo en Inglés | MEDLINE | ID: mdl-29063836

RESUMEN

Mutations in the human BEST1 gene lead to retinal degenerative diseases displaying progressive vision loss and even blindness. BESTROPHIN1, encoded by BEST1, is predominantly expressed in retinal pigment epithelium (RPE), but its physiological role has been a mystery for the last two decades. Using a patient-specific iPSC-based disease model and interdisciplinary approaches, we comprehensively analyzed two distinct BEST1 patient mutations, and discovered mechanistic correlations between patient clinical phenotypes, electrophysiology in their RPEs, and the structure and function of BESTROPHIN1 mutant channels. Our results revealed that the disease-causing mechanism of BEST1 mutations is centered on the indispensable role of BESTROPHIN1 in mediating the long speculated Ca2+-dependent Cl- current in RPE, and demonstrate that the pathological potential of BEST1 mutations can be evaluated and predicted with our iPSC-based 'disease-in-a-dish' approach. Moreover, we demonstrated that patient RPE is rescuable with viral gene supplementation, providing a proof-of-concept for curing BEST1-associated diseases.


Asunto(s)
Bestrofinas/genética , Bestrofinas/metabolismo , Calcio/metabolismo , Cloruros/metabolismo , Mutación Missense , Enfermedades de la Retina/fisiopatología , Epitelio Pigmentado de la Retina/fisiología , Anciano , Bestrofinas/química , Células Cultivadas , Niño , Cristalografía por Rayos X , Humanos , Iones/metabolismo , Masculino , Modelos Moleculares , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Conformación Proteica , Enfermedades de la Retina/genética
6.
Int J Exp Pathol ; 98(3): 147-157, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28849621

RESUMEN

The aim of this study was to better understand the role of apoptosis in a retinal ischaemia-reperfusion injury model and to determine whether sildenafil citrate treatment can prevent retinal cell apoptosis. Thirty-six rats were divided into a control group (n = 6) and two experimentally induced ischaemia-reperfusion groups (7 and 21 days; n = 15 per group). The induced ischaemia-reperfusion groups were treated with sildenafil for 7 and 21 days (n = 10 per group), and 10 animals were treated with a placebo for the same period (n = 5 per group). Paracentesis of the anterior chamber was performed with a 30-G needle attached to a saline solution (0.9%) bag positioned at a height of 150 cm above the eye for 60 min. Intraocular pressure was measured by rebound tonometer (TonoVet® ). The eyes were analysed by histology and morphometry, and by immunohistochemistry and qRT-PCR for expression of Caspase-7, Caspase-6, Caspase-9, Tnf-r2, Fas-l, Bcl-2 and Bax. Sildenafil-treated animals showed lower levels of histopathological changes (inflammatory, cellular and tissue) than their placebo-treated counterparts at both 7 and 21 days. The retinal ganglion cell layer (RGC) was preserved in the sildenafil groups (SG), with a cell count closer to control than in the placebo groups (PG). Caspase-7 expression was significantly higher in both treated groups at 7 days compared to controls. Gene expression levels in both treatment groups differed from the controls, but in SG Bax and Caspase-6 expression levels were similar to control animals. These results suggest that the main mechanism of retinal cell death in this model is apoptosis, as there is an increase in pro-apoptotic factors and decrease in the anti-apoptotic ones. Also, sildenafil seems to protect the retinal ganglion cell layer from apoptosis. Cell survival was evident in the histological and morphometric analyses, and sildenafil treatment had a protective effect in the apoptosis pathways, with gene expression levels in SG similar to the controls.


Asunto(s)
Daño por Reperfusión/prevención & control , Enfermedades de la Retina/prevención & control , Vasos Retinianos/patología , Citrato de Sildenafil/uso terapéutico , Vasodilatadores/uso terapéutico , Animales , Apoptosis/efectos de los fármacos , Evaluación Preclínica de Medicamentos/métodos , Proteínas del Ojo/biosíntesis , Proteínas del Ojo/genética , Regulación de la Expresión Génica/efectos de los fármacos , Presión Intraocular/efectos de los fármacos , Masculino , Nervio Óptico/efectos de los fármacos , Nervio Óptico/patología , Ratas Endogámicas Lew , Daño por Reperfusión/metabolismo , Daño por Reperfusión/patología , Daño por Reperfusión/fisiopatología , Enfermedades de la Retina/metabolismo , Enfermedades de la Retina/patología , Enfermedades de la Retina/fisiopatología , Células Ganglionares de la Retina/efectos de los fármacos , Células Ganglionares de la Retina/patología
7.
BMJ Case Rep ; 20172017 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-28801333

RESUMEN

A 35-year-old pregnant Caucasian woman at 27 weeks gestation presented with sudden onset painless loss of vision and a large floater in her left eye while doing yoga. She was found to have a dense vitreous haemorrhage with a small preretinal haemorrhage. Ultrasound imaging confirmed the haemorrhage and showed no other retinal damage. She was diagnosed with valsalva haemorrhagic retinopathy and was treated conservatively. After 5 months of follow-up, this woman had had a normal delivery and her haemorrhages and vision loss had resolved.


Asunto(s)
Enfermedades de la Retina/fisiopatología , Maniobra de Valsalva , Trastornos de la Visión/fisiopatología , Cuerpo Vítreo/fisiopatología , Hemorragia Vítrea/fisiopatología , Yoga , Adulto , Femenino , Humanos , Embarazo , Recuperación de la Función , Remisión Espontánea , Enfermedades de la Retina/etiología , Trastornos de la Visión/etiología , Hemorragia Vítrea/complicaciones
8.
Graefes Arch Clin Exp Ophthalmol ; 255(7): 1349-1358, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28361176

RESUMEN

PURPOSE: The purpose of this study was to assess the role of various diagnostic tests in early detection of retinal changes in ß-thalassemia major patients. METHODS: Thirty-eight visually asymptomatic ß-thalassemia major patients receiving regular blood transfusions and iron-chelation therapy with deferoxamine (group A, n = 13), deferasirox (group B, n = 11) or deferoxamine with deferiprone (group C, n = 14) and fourteen age- and sex- matched healthy individuals were included in the study. All participants underwent ophthalmoscopy, full-field electroretinography (ERG), visual evoked potentials (VEP), multifocal electroretinography (mfERG), fundus autofluorescence (FAF) imaging and optical coherence tomography (OCT) scans. RESULTS: Retinal pigment epithelium changes were present in two cases. Scotopic ERG demonstrated decreased a-wave amplitude in groups A, B and C (p = 0.03, p = 0.002 and p = 0.002, respectively) and decreased b-wave amplitude in groups B and C (p = 0.002 and p = 0.01, respectively) compared to controls. Photopic ERG showed delayed b-wave latency in groups A and C (p = 0.03 and p = 0.03, respectively) ERG maximal combined response and VEP response did not differ between groups. MfERG showed reduced retinal response density in ring 1 in groups A, B, C (p < 0.001, p < 0.001, p = 0.001, respectively) and ring 2 in group B (p = 0.02) and delayed latency in ring 5 in groups A and B (p = 0.04 and p = 0.04, respectively). Abnormal FAF images appeared in three cases and OCT abnormalities in one case, whereas no changes were observed in controls (p = 0.55 and p = 1.00, respectively). CONCLUSIONS: Full-field ERG and mfERG are more sensitive tools for detecting early retinal changes in ß-thalassemia patients compared with ophthalmoscopy, VEP, FAF imaging and OCT scans.


Asunto(s)
Diagnóstico Precoz , Electrorretinografía/métodos , Retina/fisiopatología , Enfermedades de la Retina/diagnóstico , Agudeza Visual , Talasemia beta/complicaciones , Adulto , Potenciales Evocados Visuales , Femenino , Angiografía con Fluoresceína , Fondo de Ojo , Humanos , Masculino , Persona de Mediana Edad , Oftalmoscopía , Retina/diagnóstico por imagen , Enfermedades de la Retina/etiología , Enfermedades de la Retina/fisiopatología , Tomografía de Coherencia Óptica
9.
Clin Exp Ophthalmol ; 45(7): 717-729, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28349587

RESUMEN

BACKGROUND: Retinal ischaemia is a common feature shared by numerous eye diseases. Ischaemic insult leads to retinal dysfunction and neuronal death. Lycium barbarum polysaccharides are well known for eyesight preservation. We have previously reported the effect of Lycium barbarum polysaccharides on cell death, blood ocular barrier and oxidative stress within 24 h retinal ischaemia. This study focuses on retinal function and looks for ultrastructural and cellular correlates after a relatively long period of reperfusion for 7 days. METHODS: Two-hour ischaemia was induced by intraluminal occlusion of the internal carotid artery. Either Lycium barbarum polysaccharides or phosphate-buffered saline was orally pre-administered daily for 7 days before ischaemia and continued for 1, 3 and 7 days after reperfusion. Electroretinogram was performed to evaluate visual function. Paraffin-embedded retinal sections were prepared 7 days after reperfusion and utilized for histological and immunohistochemical analyses. RESULTS: Ischaemia led to sustained inhibition of b-wave amplitude and oscillatory potentials. Lycium barbarum polysaccharide-treated mice exhibited greater b-wave and oscillatory potential responses from days 1 to 7 after reperfusion. In addition, increased number of viable cells and calretinin-positive cells, as well as enhanced immunoreactivity of protein kinase C alpha and attenuated glial fibrillary acidic protein expression, was noted in Lycium barbarum polysaccharide-treated retina. CONCLUSIONS: Daily consumption of Lycium barbarum polysaccharides effectively alleviated ischaemia-induced retinal dysfunction as well as reduced correlated neuronal death and glial activation. This prolonged effect could last at least 7 days. It suggested that Lycium barbarum polysaccharides might serve as a neuroprotective agent in ischaemic retinopathies.


Asunto(s)
Modelos Animales de Enfermedad , Medicamentos Herbarios Chinos/uso terapéutico , Isquemia/prevención & control , Retina/fisiología , Enfermedades de la Retina/prevención & control , Neuronas Retinianas/metabolismo , Vasos Retinianos/efectos de los fármacos , Administración Oral , Animales , Calbindina 2/metabolismo , Electrorretinografía , Proteína Ácida Fibrilar de la Glía/metabolismo , Isquemia/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , Fármacos Neuroprotectores/uso terapéutico , Proteína Quinasa C-alfa/metabolismo , Enfermedades de la Retina/fisiopatología , Vasos Retinianos/fisiopatología
10.
Prog Retin Eye Res ; 50: 89-107, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26404104

RESUMEN

The Argus(®) II Retinal Prosthesis System (Second Sight Medical Products) is the first prosthetic vision device to obtain regulatory approval in both Europe and the USA. As such it has entered the commercial market as a treatment for patients with profound vision loss from end-stage outer retinal disease, predominantly retinitis pigmentosa. To date, over 100 devices have been implanted worldwide, representing the largest group of patients currently treated with visual prostheses. The system works by direct stimulation of the relatively preserved inner retina via epiretinal microelectrodes, thereby replacing the function of the degenerated photoreceptors. Visual information from a glasses-mounted video camera is converted to a pixelated image by an external processor, before being transmitted to the microelectrode array at the macula. Elicited retinal responses are then relayed via the normal optic nerve to the cortex for interpretation. We reviewed the animal and human studies that led to the development of the Argus(®) II device. A sufficiently robust safety profile was demonstrated in the phase I/II clinical trial of 30 patients. Improvement of function in terms of orientation and mobility, target localisation, shape and object recognition, and reading of letters and short unrehearsed words have also been shown. There remains a wide variability in the functional outcomes amongst the patients and the factors contributing to these performance differences are still unclear. Future developments in terms of both software and hardware aimed at improving visual function have been proposed. Further experience in clinical outcomes is being acquired due to increasing implantation.


Asunto(s)
Ceguera/rehabilitación , Terapia por Estimulación Eléctrica/instrumentación , Electrodos Implantados , Enfermedades de la Retina/cirugía , Prótesis Visuales , Animales , Ceguera/fisiopatología , Terapia por Estimulación Eléctrica/métodos , Humanos , Neuroestimuladores Implantables , Diseño de Prótesis , Enfermedades de la Retina/fisiopatología , Agudeza Visual , Percepción Visual/fisiología
11.
Adv Exp Med Biol ; 854: 437-41, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26427443

RESUMEN

Evidence is growing that exposure of tissue to low energy photon irradiation in the far-red (FR) to near-infrared (NIR) range of the spectrum, collectively termed "photobiomodulation" (PBM) can restore the function of damaged mitochondria, upregulate the production of cytoprotective factors and prevent apoptotic cell death. PBM has been applied clinically in the treatment of soft tissue injuries and acceleration of wound healing for more than 40 years. Recent studies have demonstrated that FR/NIR photons penetrate diseased tissues including the retina. The therapeutic effects of PBM have been hypothesized to result from intracellular signaling pathways triggered when FR/NIR photons are absorbed by the mitochondrial photoacceptor molecule, cytochrome c oxidase, culminating in improved mitochondrial energy metabolism, increased cytoprotective factor production and cell survival. Investigations in rodent models of methanol-induced ocular toxicity, light damage, retinitis pigmentosa and age-related macular degeneration have demonstrated the PBM attenuates photoreceptor cell death, protects retinal function and exerts anti-inflammatory actions.


Asunto(s)
Rayos Infrarrojos , Fototerapia/métodos , Retina/efectos de la radiación , Enfermedades de la Retina/terapia , Animales , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Modelos Animales de Enfermedad , Complejo IV de Transporte de Electrones/metabolismo , Electrorretinografía , Metabolismo Energético/efectos de los fármacos , Metabolismo Energético/efectos de la radiación , Humanos , Metanol/toxicidad , Ratones , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/efectos de la radiación , Fotones , Células Fotorreceptoras de Vertebrados/efectos de los fármacos , Células Fotorreceptoras de Vertebrados/efectos de la radiación , Ratas , Retina/efectos de los fármacos , Retina/patología , Enfermedades de la Retina/inducido químicamente , Enfermedades de la Retina/fisiopatología
12.
Graefes Arch Clin Exp Ophthalmol ; 253(6): 935-9, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25863672

RESUMEN

PURPOSE: The purpose was to measure the retinal venous pressure (RVP) in both eyes of primary open-angle glaucoma (POAG) patients before and 3 weeks after treatment with low-dosed Nifedipine. METHODS: This retrospective study included 20 POAG patients who were treated with Nifedipine (5 mg daily) and 20 untreated control POAG patients. In both the treated and untreated control group, a distinction was made between those patients who had the Flammer-Syndrome (FS) and those who did not. The RVP was measured in all patients bilaterally at baseline and 3 weeks later by means of contact lens ophthalmodynamometry and the RVP measurements of the treated POAG patients were compared to the RVPs of the untreated POAG controls. Ophthalmodynamometry is done by applying an increasing force on the eye via a contact lens. The minimum force required to induce a venous pulsation is called the ophthalmodynamometric force (ODF). The RVP is defined and calculated as the sum of ODF and intraocular pressure (IOP) [RVP = ODF + IOP]. RESULTS: The RVP decreased significantly after 3 weeks in both eyes of patients treated with low-dosed Nifedipine compared to the untreated group (mean decrease of 12.5 mmHg (SD 12.5), P < 0.001). A larger response to therapy was found in patients with the FS compared to patients lacking the FS (mean decrease of 16.07 vs. 7.28 mmHg, confidence Interval (CI): 5.2 to 9.3 vs. 12.3 to 19.7; P < 0.001). No significant differences were accounted for in the IOP's of the patients after treatment. In the untreated control group, no significant differences were accounted for either in the RVP or the IOP after 3 weeks. CONCLUSIONS: Treatment with low-dosed Nifedipine decreases RVP in both eyes of glaucoma patients, particularly in those with the Flammer-Syndrome. This effect may be due to the partial inhibition of Endothelin-1 (ET-1) by Nifedipine.


Asunto(s)
Bloqueadores de los Canales de Calcio/uso terapéutico , Glaucoma de Ángulo Abierto/tratamiento farmacológico , Nifedipino/uso terapéutico , Enfermedades de la Retina/fisiopatología , Vena Retiniana/fisiopatología , Administración Oral , Anciano , Velocidad del Flujo Sanguíneo/fisiología , Presión Sanguínea/fisiología , Endotelina-1/antagonistas & inhibidores , Femenino , Glaucoma de Ángulo Abierto/fisiopatología , Humanos , Presión Intraocular/fisiología , Masculino , Persona de Mediana Edad , Oftalmodinamometría , Flujo Sanguíneo Regional , Estudios Retrospectivos , Tonometría Ocular , Presión Venosa/fisiología
13.
Br J Ophthalmol ; 99(9): 1220-3, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25777817

RESUMEN

PURPOSE: To assess the frequency and significance of optic disk cupping after methanol poisoning. METHODS: We retrospectively reviewed the medical records of 50 consecutive patients with methanol poisoning, including visual acuity, pupillary reaction, and optic disk features such as the presence and degree of cupping. All patients were examined in the chronic phase after optic nerve damage. RESULTS: Optic disk cupping ≥0.8 c/d was present in at least one eye of 22 of these 50 patients (43/100 eyes). Severity of cupping was statistically symmetric in the two eyes, and increasing severity of cupping was correlated with worse visual acuity (p=0.007) and increasing visual field loss. Degree of cupping was significantly correlated with increasing patient age but not with putaminal necrosis. CONCLUSIONS: Optic disk cupping after methanol poisoning may be more common than previously recognised. Cupping in this setting may reflect toxicity of methanol metabolites to axons and glial cells in the prelaminar, laminar and retrolaminar regions, and seems to be important as a marker for worse optic nerve damage.


Asunto(s)
Metanol/envenenamiento , Disco Óptico/efectos de los fármacos , Enfermedades de la Retina/inducido químicamente , Solventes/envenenamiento , Adolescente , Adulto , Factores de Edad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Disco Óptico/patología , Enfermedades de la Retina/fisiopatología , Estudios Retrospectivos , Trastornos de la Visión/inducido químicamente , Trastornos de la Visión/fisiopatología , Agudeza Visual/fisiología , Campos Visuales/fisiología , Adulto Joven
14.
Br J Ophthalmol ; 99(3): 350-3, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25342274

RESUMEN

INTRODUCTION: The incidence of spontaneous resolution of vitreomacular traction (VMT) is low in studies of Ocriplasmin that have had a limited follow-up. Previous studies did not look for morphological parameters in the natural history using spectral-domain ocular coherence tomography (SD-OCT) imaging. The purpose of this study was to investigate how often and when spontaneous VMT resolution occurs in candidates for Ocriplasmin therapy. METHODS: The study is a retrospective chart review of patients who would have high chances of a benefit by an Ocriplasmin injection, without epiretinal membrane or vitreomacular adhesion of 1500 µm or more on SD-OCT. Main outcome measures were the frequency of complete VMT resolution and the best corrected visual acuity seen in the natural history. RESULTS: Out of the 46 patients that were included after screening 889 SD-OCT images, 20 were found to exhibit spontaneous resolution during the follow-up period (median: 594 days, 95% CI 567 to 719 days), the majority after 6-12 months of observation (95% CI 266 to 617 days). The group with spontaneous VMT resolution and a mean improvement of one line in best corrected visual acuity included a few patients losing vision by macular hole formation. In the absence of resolution, patients lost on average one early treatment diabetic retinopathy study letter per year. Younger age was found to increase the chance of spontaneous resolution. CONCLUSIONS: A shorter follow-up might underestimate the incidence of spontaneous VMT resolution as the functional outcome of watchful waiting. The likelihood of resolution does not seem to decrease after 12 months.


Asunto(s)
Fibrinolisina/uso terapéutico , Fibrinolíticos/uso terapéutico , Fragmentos de Péptidos/uso terapéutico , Enfermedades de la Retina/fisiopatología , Desprendimiento del Vítreo/fisiopatología , Espera Vigilante/métodos , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Remisión Espontánea , Enfermedades de la Retina/tratamiento farmacológico , Estudios Retrospectivos , Factores de Tiempo , Adherencias Tisulares , Tomografía de Coherencia Óptica , Agudeza Visual/fisiología , Cuerpo Vítreo/patología , Desprendimiento del Vítreo/tratamiento farmacológico
15.
JAMA Ophthalmol ; 132(12): 1453-60, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25275721

RESUMEN

IMPORTANCE: Hydroxychloroquine sulfate is widely used for the long-term treatment of autoimmune conditions but can cause irreversible toxic retinopathy. Prior estimations of risk were low but were based largely on short-term users or severe retinal toxicity (bull's eye maculopathy). The risk may be much higher because retinopathy can be detected earlier when using more sensitive screening techniques. OBJECTIVES: To reassess the prevalence of and risk factors for hydroxychloroquine retinal toxicity and to determine dosage levels that facilitate safe use of the drug. DESIGN, SETTING, AND PARTICIPANTS: Retrospective case-control study in an integrated health organization of approximately 3.4 million members among 2361 patients who had used hydroxychloroquine continuously for at least 5 years according to pharmacy records and who were evaluated with visual field testing or spectral-domain optical coherence tomography. EXPOSURE: Hydroxychloroquine use for at least 5 years. MAIN OUTCOMES AND MEASURES: Retinal toxicity as determined by characteristic visual field loss or retinal thinning and photoreceptor damage, as well as statistical measures of risk factors and prevalence. RESULTS: Real body weight predicted risk better than ideal body weight and was used for all calculations. The overall prevalence of hydroxychloroquine retinopathy was 7.5% but varied with daily consumption (odds ratio, 5.67; 95% CI, 4.14-7.79 for >5.0 mg/kg) and with duration of use (odds ratio, 3.22; 95% CI, 2.20-4.70 for >10 years). For daily consumption of 4.0 to 5.0 mg/kg, the prevalence of retinal toxicity remained less than 2% within the first 10 years of use but rose to almost 20% after 20 years of use. Other major risk factors include kidney disease (odds ratio, 2.08; 95% CI, 1.44-3.01) and concurrent tamoxifen citrate therapy (odds ratio, 4.59; 95% CI, 2.05-10.27). CONCLUSIONS AND RELEVANCE: These data suggest that hydroxychloroquine retinopathy is more common than previously recognized, especially at high dosages and long duration of use. While no completely safe dosage is identified from this study, daily consumption of 5.0 mg/kg of real body weight or less is associated with a low risk for up to 10 years. Knowledge of these data and risk factors should help physicians prescribe hydroxychloroquine in a manner that will minimize the likelihood of vision loss.


Asunto(s)
Antirreumáticos/efectos adversos , Hidroxicloroquina/efectos adversos , Retina/efectos de los fármacos , Enfermedades de la Retina/inducido químicamente , Adulto , Anciano , Peso Corporal , Estudios de Casos y Controles , Electrorretinografía , Femenino , Angiografía con Fluoresceína , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Curva ROC , Retina/patología , Retina/fisiopatología , Enfermedades de la Retina/diagnóstico , Enfermedades de la Retina/fisiopatología , Estudios Retrospectivos , Factores de Riesgo , Tomografía de Coherencia Óptica , Pruebas del Campo Visual , Campos Visuales
16.
Clin Interv Aging ; 9: 637-52, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24748782

RESUMEN

BACKGROUND: Oxidative stress (OS) and its biomarkers are the biochemical end point of the imbalance between reactive oxygen species (ROS) production and the ability of the antioxidant (AOX) biological systems to fight against oxidative injury. OBJECTIVE: We reviewed the role of OS and its downstream signaling in aging eyes. METHODS: A search of the literature and current knowledge on the physiological and pathological mechanisms of OS were revisited in relation to the eyes and the aging process. Most prevalent ocular diseases have been analyzed herein in relation to OS and nutraceutic supplements, such as dry-eye disorders, glaucoma, age-related macular degeneration, and diabetic retinopathy. RESULTS: Clinical, biochemical, and molecular data from anterior and posterior eye segment diseases point to OS as the common pathogenic mechanism in the majority of these ocular disorders, many of which are pathologies causing visual impairment, blindness, and subsequent loss of life quality. Studies with nutraceutic supplements in aging eye-related pathologies have also been reviewed. CONCLUSION: OS, nutritional status, and nutraceutic supplements have to be considered within the standards of care of older ophthalmologic patients. OS biomarkers and surrogate end points may help in managing the aging population with ocular diseases.


Asunto(s)
Envejecimiento/metabolismo , Ojo/metabolismo , Estrés Oxidativo/fisiología , Anciano , Envejecimiento/fisiología , Suplementos Dietéticos , Síndromes de Ojo Seco/metabolismo , Síndromes de Ojo Seco/fisiopatología , Glaucoma/metabolismo , Glaucoma/fisiopatología , Humanos , Fenómenos Fisiológicos Oculares , Enfermedades de la Retina/metabolismo , Enfermedades de la Retina/fisiopatología
17.
Can J Ophthalmol ; 48(5): 438-42, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24093193

RESUMEN

OBJECTIVE: To evaluate the efficacy of the MP-1 microperimeter (Nidek Technologies Srl, Padova, Italy) and Visual Pathfinder (LACE Inc) in improving visual function of patients with myopic maculopathy. DESIGN: Prospective, nonrandomized, interventional case series. PARTICIPANTS: Seventeen patients (34 eyes) between 36 and 58 years of age with myopic maculopathy and central retinal scotomas. METHODS: After a complete eye examination, all patients underwent 10 training sessions with MP-1 biofeedback (7 minutes) and Visual Pathfinder (3 minutes) for each eye once a week. Statistical analysis was performed with Student t test. The p values less than 0.05 were considered statistically significant. RESULTS: The mean best corrected visual acuity increased from 0.64 ± 0.22 to 0.38 ± 0.20 logMAR at the end of follow-up (p = 0.03); visual-evoked potential P100 amplitude increased from 3.54 ± 1.90 to 6.64 ± 2.91 µV at the end of follow-up (p = 0.04); average retinal sensitivity, calculated in the 12 degrees of the central retina, increased from 6.6 ± 2.6 to 14.6 ± 3.6 dB (p = 0.03). Fixation behaviour in the 2 degrees of the central retina increased from 45% ± 17% to 75% ± 23% (p = 0.04). The bivariate contour ellipse area (95%) increased from 10.34 ± 3.11 to 7.64 ± 2.71 square degrees (p = 0.04). CONCLUSIONS: The combination of acoustic biofeedback training with MP-1 and Visual Pathfinder offers a reasonable improvement of visual function in patients with myopic maculopathy. This method might be considered as a rehabilitative strategy as a "therapeutic option" in these patients for whom most treatments usually do not work.


Asunto(s)
Biorretroalimentación Psicológica/métodos , Potenciales Evocados Visuales/fisiología , Miopía Degenerativa/rehabilitación , Enfermedades de la Retina/rehabilitación , Escotoma/rehabilitación , Agudeza Visual/fisiología , Pruebas del Campo Visual/métodos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Miopía Degenerativa/complicaciones , Miopía Degenerativa/fisiopatología , Estudios Prospectivos , Lectura , Retina/fisiopatología , Enfermedades de la Retina/etiología , Enfermedades de la Retina/fisiopatología , Escotoma/etiología , Escotoma/fisiopatología , Resultado del Tratamiento
19.
J AAPOS ; 17(2): 129-34, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23522948

RESUMEN

PURPOSE: To describe visual function and associated characteristics at the 6-year examination in children enrolled in the Early Treatment for Retinopathy of Prematurity Study who had unfavorable visual outcomes despite favorable structural outcomes in one or both eyes. METHODS: The clinical examination records of children completing the 6-year follow-up examination were retrospectively reviewed. Eligible subjects were those with visual acuity of ≤20/200 in each eye (where recordable) and a normal fundus or straightening of the temporal retinal vessels with or without macular ectopia in at least one eye. Data regarding visual function, retinal structure, presence of nystagmus, optic atrophy, optic disk cupping, seizures/shunts, and Functional Independence Measure for Children (ie, WeeFIM: pediatric functional independence measure) developmental test scores were reviewed. RESULTS: Of 342 participants who completed the 6-year examination, 39 (11%) met inclusion criteria. Of these, 29 (74%) had normal retinal structure, 18 (46%) had optic atrophy, and 3 (8%) had increased cupping of the optic disk in at least one eye. Latent and/or manifest nystagmus occurred in 30 children (77%). The presence of nystagmus was not related to the presence of optic atrophy. Of the 39 children, 28 (72%) had a below-normal WeeFIM score. CONCLUSIONS: In 25 participants (7%) completing the 6-year examination, cortical visual impairment was considered the primary cause of visual loss. The remainder likely had components of both anterior and posterior visual pathway disease. Clinical synthesis of ocular anatomy and visual and neurologic function is required to determine the etiology of poor vision in these children.


Asunto(s)
Enfermedades de la Retina/fisiopatología , Retinopatía de la Prematuridad/fisiopatología , Agudeza Visual/fisiología , Niño , Estudios de Cohortes , Femenino , Fondo de Ojo , Humanos , Recién Nacido , Masculino , Enfermedades de la Retina/etiología , Enfermedades de la Retina/patología , Vasos Retinianos/patología , Retinopatía de la Prematuridad/complicaciones
20.
J Glaucoma ; 22(4): 269-77, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23221900

RESUMEN

AIM: Dietary deficiencies in ω-3 polyunsaturated fatty acids are known to effect retinal function including retinal ganglion cell (RGC) activity, which may have implications for glaucoma. In this study we consider retinal function after dietary manipulation and intraocular pressure (IOP) stress designed to compromise RGCs. METHODS: Sprague-Dawley dams were fed either ω-3 sufficient (ω-3, n=15) or deficient (ω-3, n=16) diets 5 weeks before conception with pups subsequently weaned onto their mothers diets. At 20 weeks of age, acute IOP elevation was induced repeatedly through anterior chamber cannulation to 70 mm Hg for 1 hour on 3 separate occasions separated by 1 week. Electroretinograms were recorded 1 week after each IOP elevation to assay the photoreceptors (PIII), ON-bipolar cells (PII), and ganglion/amacrine cells (STR). RESULTS: Repeat IOP insult results in a specific RGC dysfunction (pSTR -14.5%, P<0.035) as does ω-3 deficiency (-26.4%, P<0.01). However, the combination of both causes an even larger RGC functional loss (-40.1%, P<0.001) than does either diet or IOP insult in isolation (P<0.001). CONCLUSIONS: Both ω-3 deficiency and repeat acute IOP insult cause RGC dysfunction and the combination of these factors results in a cumulative effect. Our data indicate that sufficient dietary ω-3 improves RGC function making it less susceptible to IOP insult.


Asunto(s)
Grasas Insaturadas en la Dieta/efectos adversos , Ácidos Grasos Omega-3/fisiología , Presión Intraocular , Hipertensión Ocular/complicaciones , Enfermedades de la Retina/etiología , Células Ganglionares de la Retina/patología , Células Amacrinas/patología , Animales , Presión Sanguínea , Modelos Animales de Enfermedad , Electrorretinografía , Lípidos/deficiencia , Células Fotorreceptoras de Vertebrados/patología , Ratas , Ratas Sprague-Dawley , Células Bipolares de la Retina/patología , Enfermedades de la Retina/fisiopatología , Factores de Riesgo
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