Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 90
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Ophthalmic Res ; 63(3): 234-243, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31775146

RESUMO

BACKGROUND: Transcorneal electrical stimulation (TES) has been suggested as a possible treatment for retinitis pigmentosa (RP). OBJECTIVE: To expand the safety assessment of repeated applications of an electrical current from a DTL-like electrode in patients with RP. METHODS: This single-arm open label interventional safety trial included a total of 105 RP patients from 11 European centers, who received weekly TES for 6 months on 1 eye followed by observation for another 6 months without stimulation. The primary outcome measure was safety, indicated by the frequency and severity of adverse events. Secondary measures included intraocular pressure and central retinal thickness. Visual field and visual acuity were examined using the methods available at each site. RESULTS: Dry eye sensation was the most common adverse event recorded (37.5%). Serious adverse events secondary to TES were not observed. Most adverse events were mild and all resolved without sequelae. The secondary outcome measures revealed no significant or clinically relevant changes. CONCLUSION: The present results confirm the excellent safety profile of TES. Transient dry eye symptoms were the most common adverse event.


Assuntos
Terapia por Estimulação Elétrica/instrumentação , Retinose Pigmentar/terapia , Acuidade Visual , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Eletrorretinografia , Desenho de Equipamento , Feminino , Seguimentos , Humanos , Pressão Intraocular/fisiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Retinose Pigmentar/diagnóstico , Resultado do Tratamento , Adulto Jovem
2.
Graefes Arch Clin Exp Ophthalmol ; 257(6): 1207-1215, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30982101

RESUMO

PURPOSE: To assess the pupil light response (PLR) to chromatic stimulation in patients with different types of X-linked congenital stationary night blindness (CSNB). METHODS: Eight patients with CSNB due to CACNA1F and NYX mutations were exposed to blue and red light stimuli, and PLR was evaluated using infrared video pupillography. Pupil responses were compared between CSNB patients and healthy subjects (n = 34) at baseline, at maximum of constriction, for post-illumination pupil responses (PIPR) and the slope of redilation using Cohen's d. A subgroup comparison was performed descriptively between CACNA1F and NYX associated CSNB patients using the same parameters. RESULTS: In CSNB, smaller baseline pupil diameters compared to healthy subjects were measured both before blue and red light stimulation (d = 1.44-1.625). The maximum constriction to blue light stimuli was smaller for the CSNB group compared to healthy subjects (d = 1.251) but not for red light stimuli (d = 0.449). Pupil response latencies were prolonged in CSNB for both light stimuli (d = -1.53 for blue and d = -1.011 for red stimulation). No relevant differences were found between the CSNB group and healthy subjects for PIPR (d = 0.01), but the slope of redilation was smaller for CSNB patients (d = 2.12). Paradoxical pupil constriction at light offset was not seen in our patients. CONCLUSION: A reduced redilation and smaller baseline pupil diameters for patients with CSNB indicate a disinhibition of intrinsically photosensitive retinal ganglion cells due to affected post-photoreceptor transduction via bipolar cells and can explain the pupillary behavior in our patient group.


Assuntos
Adaptação à Escuridão/fisiologia , Técnicas de Diagnóstico Oftalmológico , Oftalmopatias Hereditárias/fisiopatologia , Doenças Genéticas Ligadas ao Cromossomo X/fisiopatologia , Miopia/fisiopatologia , Cegueira Noturna/fisiopatologia , Pupila/fisiologia , Reflexo Pupilar/fisiologia , Células Ganglionares da Retina/fisiologia , Oftalmopatias Hereditárias/diagnóstico , Feminino , Doenças Genéticas Ligadas ao Cromossomo X/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Miopia/diagnóstico , Cegueira Noturna/diagnóstico , Estimulação Luminosa , Opsinas de Bastonetes/metabolismo
3.
Curr Opin Ophthalmol ; 29(3): 239-247, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29528862

RESUMO

PURPOSE OF REVIEW: The purpose of this review is to provide an update on the efforts to restore vision through subretinal implants in patients with degenerative retinal diseases. In addition to the current technique and its latest improvements, it will focus on the surgical technique of implantation as well as explantation and reimplantation. RECENT FINDINGS: The durability of the current subretinal implant RETINA IMPLANT Alpha AMS has increased substantially compared with the predecessor model RETINA IMPLANT Alpha IMS. According to validated examinations in the laboratory, a median lifetime of 4.7 years will be reached in clinical use; in similar examinations, the previous model has reached only 8 months. Visual function has slightly increased. The surgical technique for subretinal implants is complex and demanding for ophthalmic surgeons, as it is multifaceted and combines novel surgical steps in areas, which are not commonly entered such as the suprachoroidal and the subretinal space. The surgical approach for implantation has matured considerably and has led to successful implantation in 64 patient cases. Surgical challenges are now mainly encountered with the exact subfoveal positioning of the device. The explantation procedure is relatively straight-forward because the implant can be withdrawn in a reverse direction along the already existent subretinal path. Reimplantations, however, are more challenging because some degree of scar tissue may exist along the path of the chip and around the scleral trapdoor. Nevertheless, reimplantations have now been carried out successfully in four patients. SUMMARY: The new RETINA IMPLANT Alpha AMS shows significantly improved durability compared with the predecessor model RETINA IMPLANT Alpha IMS. The subretinal implant offers excellent visual results but requires experienced surgeons. Explantation of devices is straight-forward, and reimplantations are challenging but have been successful in four patients.


Assuntos
Remoção de Dispositivo/métodos , Eletrodos Implantados , Implantação de Prótese/métodos , Retinose Pigmentar/cirurgia , Baixa Visão/cirurgia , Humanos , Retinose Pigmentar/complicações , Baixa Visão/etiologia
4.
Graefes Arch Clin Exp Ophthalmol ; 253(3): 381-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25219982

RESUMO

BACKGROUND: To restore vision in patients with retinitis pigmentosa, several types of electronic devices have been developed to stimulate neurons at different levels along the visual pathway. Subretinal stimulation of the retina with the Retina Implant Alpha IMS (Retina Implant AG, Reutlingen, Germany) has been demonstrated to provide useful vision in daily life. Here we evaluated the safety of this device. METHODS: An interventional, prospective, multi-center, single-arm study was conducted in patients with retinitis pigmentosa with the Retina Implant Alpha IMS. The results from the first nine patients of a single center regarding safety of the device are reported. Any untoward medical occurrence related or unrelated to the tested device was documented and evaluated. RESULTS: Nine adult subjects were included in the study at the Tübingen site. Seventy-five adverse events occurred in total, and 53 affected the eye and its adnexa. Thirty-one ocular adverse events had a relationship to the implant that was classified as "certain" while 19 had a probable or possible relationship; three had no relationship to the implant. Thirty-nine ocular adverse events resolved without sequelae, two resolved with sequelae, 11 remained unresolved, and in one the status was unknown. The intensity of ocular adverse events was mild in the majority of cases (n = 45), while six were of moderate and two of severe intensity. There was no non-ocular adverse event with certain relationship to the device. One subject lost light perception (without light localization) in her study eye. CONCLUSIONS: In conclusion, this prospective study, "Safety and Efficacy of Subretinal Implants for Partial Restoration of Vision in Blind Patients," shows that the Retina Implant Alpha IMS is an option for restoring vision using a subretinal stimulation device with a clinically acceptable safety profile.


Assuntos
Eletrodos Implantados/efeitos adversos , Amaurose Congênita de Leber/cirurgia , Retina/cirurgia , Retinose Pigmentar/cirurgia , Transtornos da Visão/reabilitação , Próteses Visuais/efeitos adversos , Adolescente , Adulto , Idoso , Terapia por Estimulação Elétrica/instrumentação , Angiofluoresceinografia , Humanos , Pressão Intraocular , Pessoa de Meia-Idade , Estudos Prospectivos , Método Simples-Cego , Tomografia de Coerência Óptica
5.
Graefes Arch Clin Exp Ophthalmol ; 252(1): 43-50, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24193351

RESUMO

BACKGROUND: The current study aimed to investigate retinal function during exposure to normobaric hypoxia. METHODS: Standard Ganzfeld ERG equipment (Diagnosys LLC, Cambridge, UK) using an extended ISCEV protocol was applied to explore intensity-response relationship in dark- and light- adapted conditions in 13 healthy volunteers (mean age 25 ± 3 years). Baseline examinations were performed under atmospheric air conditions at 341 meters above sea level (FIO2 of 21 %), and were compared to hypoxia (FIO2 of 13.2 %) by breathing a nitrogen-enriched gas mixture for 45 min. All subjects were monitored using infrared oximetry and blood gas analysis. RESULTS: The levels of PaCO2 changed from 38.4 ± 2.7 mmHg to 36.4 ± 3.0 mmHg, PaO2 from 95.5 ± 1.9 mmHg to 83.7 ± 4.6 mmHg, and SpO2 from 100 ± 0 % to 87 ± 4 %, from baseline to hypoxia respectively. A significant decrease (p < 0.05) was found for saturation amplitude of the dark-adapted b-wave intensity-response function (Vmax), dark-adapted a- and b-wave amplitudes of combined rod and cone responses (3 and 10 cd.s/m(2)), light-adapted b-wave amplitudes of single flash (3 and 10 cd.s/m(2)), and flicker responses (5-45 Hz) during hypoxia compared to baseline, without changes in implicit times. The a-wave slope of combined rod and cone responses (3 and 10 cd.s/m(2)) and the oscillatory potentials were significantly lower during hypoxia (p < 0.05). A isolated light-adapted ON response (250 ms flash) showed a reduction of amplitudes at hypoxia (p < 0.05), but no changes were observed for the OFF response. CONCLUSIONS: The results show significant impairment of retinal function during simulated normobaric short-term hypoxia affecting specific retinal cells of rod and cone pathways.


Assuntos
Hipóxia/fisiopatologia , Retina/fisiopatologia , Doença Aguda , Adulto , Gasometria , Adaptação à Escuridão/fisiologia , Eletrorretinografia , Feminino , Humanos , Masculino , Oximetria , Estimulação Luminosa , Células Fotorreceptoras de Vertebrados/fisiologia
6.
Ophthalmologie ; 121(4): 282-290, 2024 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-38459269

RESUMO

BACKGROUND: Endogenous endophthalmitis results from hematogenous spread of bacterial or fungal infection in severely diseased patients. Specific systemic and intraocular therapy is required. The basis for this treatment is causal pathogen detection in blood culture or vitreous sample. However, functional results are limited. OBJECTIVE: The current article provides practical hints for surgical therapy and pathogen detection in patients with endogenous endophthalmitis. METHODS: A retrospective analysis of anonymous data of 68 male and female patients from 2018-2023 from five ophthalmology clinics in Germany was performed. RESULTS: Mean age of affected patients was 71.4 years (31-96 years). Surgical therapy included pars plana vitrectomy (ppV) and intravitreal injection (IVOM). In 44 of 68 patients (65%), 1-3 surgeries were performed, 4-6 surgeries were required in 14/68 (21%) of patients, and 10 or more surgeries were required in 4/68 patients (6%). Pathogen detection was possible in 34% of vitreous specimens and in 11% of anterior chamber samples. Mean initial visual acuity was logMAR 1.5. After treatment and a mean follow-up of 2.5 months, mean visual acuity was logMAR 1.3. Preanalytical methods for specimen collection like the Freiburg endophthalmitis set to optimize pathogen detection are presented. CONCLUSION: Severe inflammatory intraocular reactions in endogenous endophthalmitis necessitate a combination of ppV and repeated IVOM. In addition to providing a vitreous sample, ppV also serves to remove inflammatory fibrin membranes. Early pars plana vitrectomy with specific antibiotic or antifungal therapy should be sought in addition to the focus search and systemic therapy.


Assuntos
Endoftalmite , Infecções Oculares Fúngicas , Humanos , Masculino , Feminino , Idoso , Estudos Retrospectivos , Infecções Oculares Fúngicas/diagnóstico , Endoftalmite/diagnóstico , Vitrectomia/efeitos adversos , Hospitais
7.
Int J Stroke ; : 17474930241248516, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38591748

RESUMO

RATIONALE: Meta-analyses of case series of non-arteritic central retinal artery occlusion (CRAO) indicate beneficial effects of intravenous thrombolysis when initiated early after symptom onset. Randomized data are lacking to address this question. AIMS: The REperfusion therapy with intravenous alteplase for recovery of VISION in acute central retinal artery occlusion (REVISION) investigates intravenous alteplase within 4.5 h of monocular vision loss due to acute CRAO. METHODS: This study is the randomized (1:1), double-blind, placebo-controlled, multicenter adaptive phase III trial. STUDY OUTCOMES: Primary outcome is functional recovery to normal or mildly impaired vision in the affected eye defined as best-corrected visual acuity of the Logarithm of the Minimum Angle of Resolution of 0.5 or less at 30 days (intention-to-treat analysis). Secondary efficacy outcomes include modified Rankin Score at 90 days and quality of life. Safety outcomes include symptomatic intracranial hemorrhage, major bleeding (International Society on Thrombosis and Haemostasis definition) and mortality. Exploratory analyses of optical coherence tomography/angiography, ultrasound and magnetic resonance imaging (MRI) biomarkers will be conducted. SAMPLE SIZE: Using an adaptive design with interim analysis at 120 patients, up to 422 participants (211 per arm) would be needed for 80% power (one-sided alpha = 0.025) to detect a difference of 15%, assuming functional recovery rates of 10% in the placebo arm and 25% in the alteplase arm. DISCUSSION: By enrolling patients within 4.5 h of CRAO onset, REVISION uses insights from meta-analyses of CRAO case series and randomized thrombolysis trials in acute ischemic stroke. Increased rates of early reperfusion and good neurological outcomes in stroke may translate to CRAO with its similar pathophysiology. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04965038; EU Trial Number: 2023-507388-21-00.

8.
Proc Biol Sci ; 280(1757): 20130077, 2013 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-23427175

RESUMO

This study aims at substituting the essential functions of photoreceptors in patients who are blind owing to untreatable forms of hereditary retinal degenerations. A microelectronic neuroprosthetic device, powered via transdermal inductive transmission, carrying 1500 independent microphotodiode-amplifier-electrode elements on a 9 mm(2) chip, was subretinally implanted in nine blind patients. Light perception (8/9), light localization (7/9), motion detection (5/9, angular speed up to 35 deg s(-1)), grating acuity measurement (6/9, up to 3.3 cycles per degree) and visual acuity measurement with Landolt C-rings (2/9) up to Snellen visual acuity of 20/546 (corresponding to decimal 0.037° or corresponding to 1.43 logMAR (minimum angle of resolution)) were restored via the subretinal implant. Additionally, the identification, localization and discrimination of objects improved significantly (n = 8; p < 0.05 for each subtest) in repeated tests over a nine-month period. Three subjects were able to read letters spontaneously and one subject was able to read letters after training in an alternative-force choice test. Five subjects reported implant-mediated visual perceptions in daily life within a field of 15° of visual angle. Control tests were performed each time with the implant's power source switched off. These data show that subretinal implants can restore visual functions that are useful for daily life.


Assuntos
Cegueira/cirurgia , Implantes Experimentais , Próteses Neurais , Percepção Visual , Próteses Visuais , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa , Células Fotorreceptoras de Vertebrados/fisiologia , Desenho de Prótese , Acuidade Visual
9.
Mol Vis ; 19: 1350-5, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23805042

RESUMO

PURPOSE: Progressive rod-cone degeneration (PRCD) is a canine form of autosomal recessive photoreceptor degeneration and serves as an animal model for human retinitis pigmentosa (RP). To date, only two RP-causing mutations of the PRCD gene have been reported in humans. We found a novel mutation in PRCD (c.52C>T, p.R18X) in three siblings affected by RP and present detailed morphologic and functional parameters. METHODS: A complete ophthalmological examination was performed including psychophysical tests (best-corrected visual acuity, Lanthony Panel D-15 color vision test, and visual field) and electrophysiology (ganzfeld and multifocal electroretinogram). Additionally, color and infrared fundus photography, autofluorescence, and spectral domain optical coherence tomography recordings were performed. Genomic DNA of the three affected individuals was analyzed with high-throughput sequencing for all RP-related genes in a diagnostic set-up. RESULTS: We identified a novel homozygous mutation in PRCD (c.52C>T, p.R18X) with diagnostic high-throughput panel sequencing. All three patients showed an advanced stage of retinitis pigmentosa with reduced visual acuity (mean: 20/80), small residual visual fields (mean for target III4e: 1134.35 deg²), and non-detectable electrophysiological responses. Myopia, posterior subcapsular cataract, bone spicule-like pigmentation, and attenuated arterioles were typical findings. Interestingly, bull's eye maculopathy due to patchy retinal pigment epithelium atrophy was also present in all patients. The mean central retinal thickness observed in optical coherence tomography was 148 µm. CONCLUSIONS: The identification of a third mutation in PRCD confirms its role in the pathogenesis of RP. Clinical findings were in line with the morphological changes observed in previous studies. Bull's eye maculopathy seems to be a hallmark of RP due to mutations in the PRCD gene.


Assuntos
Proteínas do Olho/genética , Genes Recessivos/genética , Mutação/genética , Retinose Pigmentar/genética , Adulto , Sequência de Aminoácidos , Animais , Sequência de Bases , Criança , Cães , Proteínas do Olho/química , Família , Feminino , Predisposição Genética para Doença , Homozigoto , Humanos , Masculino , Dados de Sequência Molecular , Linhagem , Retinose Pigmentar/fisiopatologia , Turquia , Adulto Jovem
11.
Retin Cases Brief Rep ; 17(2): 189-190, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33731602

RESUMO

PURPOSE: To describe a technique of using subretinal air to create and stabilize a neurosensory detachment performed during placement of a subretinal implant. METHODS: A case report of an experiment in a live porcine model. RESULTS: Creation of a neurosensory detachment may be facilitated by instillation of subretinal air. We use a small-gauge cannula to infuse approximately 0.1 mL of subretinal air to create a neurosensory detachment. We then expand the bleb using an additional 0.1 cc to 0.2 cc of subretinal air followed by balanced salt solution and stabilize it further with installation of viscoelastic. The small-gauge retinotomy should be created on the anterior and superior aspect of the bleb so that the air can tamponade the retinotomy both during surgery and postoperatively. CONCLUSION: This technique may be useful for some newer procedures, such as subretinal implants and perhaps administration of subretinal gene therapy or cell therapy, that require access to the subretinal space.


Assuntos
Descolamento Retiniano , Animais , Cânula , Retina/cirurgia , Descolamento Retiniano/cirurgia , Suínos , Vitrectomia
12.
Transl Vis Sci Technol ; 12(2): 29, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36809335

RESUMO

Purpose: To assess whether transcorneal electrical stimulation (TcES) current-dependently slows progressive loss of visual field area (VFA) in retinitis pigmentosa (RP). Methods: Data from 51 patients with RP who received monocular TcES treatment once weekly over 1 year in an interventional, randomized study have been analyzed a posteriori. Current amplitudes were 0.1 to 1.0 mA in the TcES-treated group (n = 31) and 0.0 mA in the sham group (n = 20). VFA was assessed in both eyes (semiautomatic kinetic perimetry, Goldmann targets V4e, III4e). Annual decline rate (ADR) of exponential loss and model-independent percentage reduction of VFA at treatment cessation were correlated to current amplitude. Results: For V4e, mean ADR was -4.1% in TcES-treated eyes, -6.4% in untreated fellow eyes, and -7.2% in placebo-treated eyes; mean VFA reduction in TcES-treated eyes was 64% less than in untreated fellow eyes (P = 0.013) and 72% less than in placebo-treated eyes (P = 0.103). Individual VFA reductions correlated with current amplitude (P = 0.043) and tended toward zero in patients who received 0.8 to 1.0 mA. For III4e, there was a marginally significant current-dependency of interocular difference in reduction (P = 0.11). ADR and VFA reduction did not significantly correlate with baseline VFA. Conclusions: Loss of VFA (V4e) in patients with RP was significantly reduced in treated eyes compared to untreated eyes by regular use of TcES in a dose-dependent manner. No dependence of effects on the initial extent of VFA loss was found. Translational Relevance: TcES provides potential for preservation of visual field in patients with RP.


Assuntos
Retinose Pigmentar , Testes de Campo Visual , Humanos , Campos Visuais , Transtornos da Visão , Retina , Estimulação Elétrica
13.
Pathologie (Heidelb) ; 44(Suppl 3): 150-154, 2023 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-37947807

RESUMO

Primary vitreoretinal lymphoma (PVRL) represents a subtype of intraocular lymphomas, which are a subgroup of malignant lymphomas of the eye. PVRL is considered a special form of primary diffuse large cell lymphoma (DLBCL) of the CNS (central nervous system) (PCNSL) and arises primary or secondary to PCNSL. According to the cell of origin (COO) classification of DLBCL, PVRL largely belongs to the activated B­cell (ABC) type of DLBCL. Based on a recently established genetic-biological classification of DLBCL, PCNSL and thus also PVRL belong to a group of DLBCL of the MYD88/CD79B-mutated (MCD) or cluster 5 subtype, which often shows extranodal manifestations and MYD88 and CD79A mutations as well as CDKN2A deletions.PVRL diagnostics is often complicated as it represents a classic masquerade syndrome. Due to the usually limited material with often large numbers of reactive lymphocytes and/or degenerative changes in the cells, the results of diagnostic tests are difficult to interpret. Classic diagnostic tests include cytology on vitreous aspirates, immunocytochemistry, and clonality analysis.New insights into the spectrum of genetic alterations of vitreoretinal lymphomas (VRL) confirm the close relationship to PCNSL and could significantly improve pathological diagnosis. Next-generation sequencing panel-based diagnostics allow VRL diagnosis confirmation with little DNA in almost 100% of patients in cases with insufficient cytological evidence or lack of clonality detection. PVRL, as well as secondary vitreoretinal lymphomas after PCNSL or extracerebral DLBCL, have high mutation frequencies in characteristically mutated genes in PCNSL or MCD/cluster 5 type DLBCL. Supporting diagnostics, mutation detection can also be performed on cell-free DNA from the vitreous supernatant.


Assuntos
Neoplasias do Sistema Nervoso Central , Neoplasias Oculares , Linfoma Difuso de Grandes Células B , Neoplasias da Retina , Humanos , Neoplasias da Retina/diagnóstico , Fator 88 de Diferenciação Mieloide/genética , Patologia Molecular , Corpo Vítreo/metabolismo , Neoplasias Oculares/diagnóstico , Linfoma Difuso de Grandes Células B/diagnóstico , Neoplasias do Sistema Nervoso Central/metabolismo
14.
Doc Ophthalmol ; 124(1): 27-39, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22179598

RESUMO

To refine methods of electroretinographical (ERG) recording for the analysis of low retinal potentials under scotopic conditions in advanced retinal degenerative diseases. Standard Ganzfeld ERG equipment (Diagnosys LLC, Cambridge, UK) was used in 27 healthy volunteers (mean age 28 ± SD 8.5 years) to define the stimulation protocol. The protocol was then applied in clinical routine and 992 recordings were obtained from patients (mean age 40.6 ± 18.3 years) over a period of 5 years. A blue stimulus with a flicker frequency of 9 Hz was specified under scotopic conditions to preferentially record rod-driven responses. A range of stimulus strengths (0.0000012-6.32 scot. cd s/m² and 6-14 ms flash duration) was tested for maximal amplitudes and interference between rods and cones. Analysis of results was done by standard Fourier Transformation and assessment of signal-to-noise ratio. Optimized stimulus parameters were found to be a time-integrated luminance of 0.012 scot. cd s/m² using a blue (470 nm) flash of 10 ms duration at a repetition frequency of 9 Hz. Characteristic stimulus strength versus amplitude curves and tests with stimuli of red or green wavelength suggest a predominant rod-system response. The 9 Hz response was found statistically distinguishable from noise in 38% of patients with otherwise non-recordable rod responses according to International Society for Clinical Electrophysiology of Vision standards. Thus, we believe this protocol can be used to record ERG potentials in patients with advanced retinal diseases and in the evaluation of potential treatments for these patients. The ease of implementation in clinical routine and of statistical evaluation providing an observer-independent evaluation may further facilitate its employment.


Assuntos
Adaptação à Escuridão/fisiologia , Eletrorretinografia/métodos , Estimulação Luminosa/métodos , Células Fotorreceptoras Retinianas Cones/fisiologia , Doenças Retinianas/diagnóstico , Células Fotorreceptoras Retinianas Bastonetes/fisiologia , Adulto , Seguimentos , Humanos , Projetos Piloto , Doenças Retinianas/fisiopatologia
15.
Doc Ophthalmol ; 124(3): 225-36, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22457045

RESUMO

To evaluate changes in electroretinographic (ERG) findings after panretinal photocoagulation (PRP) compared to PRP plus intravitreal injection of ranibizumab (IVR) in eyes with high-risk proliferative diabetic retinopathy (PDR). Patients with high-risk PDR and no prior laser treatment were assigned randomly to receive PRP (PRP group; n = 9) or PRP plus IVR (PRPplus group; n = 11). PRP was administered in two sessions (weeks 0 and 2), and IVR was administered at the end of the first laser session (week 0) in the PRPplus group. Standardized ophthalmic evaluations including (ETDRS) best-corrected visual acuity (BCVA), and fluorescein angiography to measure area of fluorescein leakage (FLA), were performed at baseline and at weeks 16 (±2), 32 (±2) and 48 (±2). ERG was measured according to ISCEV standards at baseline and at week 48 (±2). At 48 weeks, 2,400-3,000 laser spots had been placed in eyes in the PRP group, while only 1,400-1,800 spots had been placed in the PRPplus group. Compared to baseline, there was a statistically significant (P < 0.05) FLA reduction observed at all study visits in both groups, with the reduction observed in the PRPplus group significantly larger than that in the PRP group at week 48. ROD b-wave amplitude was significantly reduced to 46 ± 5% (P < 0.05) of baseline in the PRP group and 64 ± 6% (P < 0.05) in the PRPplus group. This reduction was significantly larger in the PRP group than in the PRPplus group (P = 0.024; t Test). Similar results were observed for the dark-adapted Combined Response (CR) b-wave amplitude, with a reduction at 48 weeks compared to baseline of 45 ± 4% in the PRP group and 62 ± 5% in the PRPplus group; the reduction in CR b-wave amplitude was significantly larger in the PRP group than in the PRPplus group (P = 0.0094). CR a-wave, oscillatory potentials, cone single flash, and 30 Hz flicker responses showed statistically significant within-group reductions, but no differences in between-group analyses. These results suggest that treating high-risk PDR with PRP plus IVR is effective for PDR control, and permits the use of less extensive PRP which, in turn, induces less retinal functional loss, in particular for rod-driven post-receptoral responses, than treatment with PRP alone.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Retinopatia Diabética/fisiopatologia , Retinopatia Diabética/terapia , Eletrorretinografia , Fotocoagulação a Laser , Células Fotorreceptoras Retinianas Bastonetes/fisiologia , Terapia Combinada , Adaptação à Escuridão , Retinopatia Diabética/tratamento farmacológico , Retinopatia Diabética/cirurgia , Feminino , Angiofluoresceinografia , Humanos , Injeções Intravítreas , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa , Ranibizumab , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Acuidade Visual/fisiologia
16.
Graefes Arch Clin Exp Ophthalmol ; 250(11): 1597-606, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22460632

RESUMO

PURPOSE: Indocyanine green (ICG) has been widely used as a vital dye for macular surgery. However, ICG can be toxic to retinal cells. Here we evaluate whether tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl), a free radical scavenger, can protect against ICG-induced retinal damage in rats. METHODS: Brown Norway rats received intravitreal injections of ICG 0.5 % or BSS as controls. Tempol (20 mg/kg BW) or PBS as a control was administered intraperitoneally 24 h and 30 min before ICG and once daily for 7 consecutive days. Tempol was detected in the retina using electron paramagnetic resonance (EPR) spectroscopy. One week after ICG injections, the effects of tempol on retinal toxicity were assessed by retinal ganglion cell (RGC) back-labeling and by light microscopy. Electroretinography (ERG) was performed after 1 and 2 weeks. RESULTS: ICG administration reduced RGC numbers by 17 % (1,943 ± 45 vs. 2,342 ± 31 RGCs/mm(2)). Tempol treatment rescued RGCs in a significant manner (2,258 ± 36, p < 0.01) and diminished morphological changes detected by light microscopy. ICG-injected eyes showed a significant reduction of ERG potentials only in PBS-treated animals (V(max) 530 ± 145 µV vs. 779 ± 179 µV, p = 0.0052), but not in the tempol-treated group. CONCLUSIONS: Tempol significantly attenuates ICG-induced toxicity in rat retinas and may therefore be considered for further evaluation as accompanying treatment in ICG-assisted chromovitrectomy.


Assuntos
Corantes/toxicidade , Óxidos N-Cíclicos/farmacologia , Sequestradores de Radicais Livres/farmacologia , Verde de Indocianina/toxicidade , Fármacos Neuroprotetores/farmacologia , Doenças Retinianas/prevenção & controle , Células Ganglionares da Retina/efeitos dos fármacos , Animais , Contagem de Células , Sobrevivência Celular , Adaptação à Escuridão , Espectroscopia de Ressonância de Spin Eletrônica , Eletrorretinografia , Feminino , Injeções Intravítreas , Estimulação Luminosa , Ratos , Ratos Endogâmicos BN , Células Fotorreceptoras Retinianas Cones/fisiologia , Doenças Retinianas/induzido quimicamente , Doenças Retinianas/patologia , Células Ganglionares da Retina/patologia , Marcadores de Spin
18.
Clin Ophthalmol ; 16: 223-229, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35125864

RESUMO

PURPOSE: To evaluate retinal sensitivity using chromatic full-field stimulus thresholds (FST) in patients with treatment naive exudative age-related macular degeneration (e-ARMD) before and during the first intravitreal anti-vascular endothelial growth factor (anti-VEGF) treatment. PATIENTS AND METHODS: After general ophthalmological examinations to diagnose patients with e-ARMD the FST, the central foveal thickness (FCt) and the visual acuity were assessed in 20 eyes of 20 patients during this prospective study. Examinations were performed before and during the first treatment series with three intravitreal anti-VEGF injections. Normal values for FST were assessed in 19 eyes of 19 healthy subjects. Results were analyzed using Student's two-tailed t-test and Pearson's correlation coefficients between all functional parameters. RESULTS: At baseline and before the 1st intravitreal anti-VEGF treatment, a moderately significant negative correlation between VA and FCt was found in the e-ARMD group (p = 0.02, r = -0.45 and p = 0.03, r = -0.45), respectively. After the 2nd intravitreal anti-VEGF injection, no significant correlation between VA and FCt was found (p = 0.12). However, a significant correlation between FCt and blue FST was evident (p = 0.04, r = 0.4). After the 3rd intravitreal anti-VEGF treatment, there was no correlation evident between VA and FCt (p = 0.31) but a high significant correlation between FCt and FST using red (p = 0.01, r = 0.53), green (p = 0.002, r = 0.6) and blue light (p = 0.007, r = 0.66). CONCLUSION: During anti-VEGF treatment in patients with e-ARMD, the FST test showed higher significant correlations with the morphology measured by FCt, as it is the case for VA. These findings support that the FST test might serve as a valuable diagnostic tool for monitoring patients with e-ARMD and enhance functional assessment of retinal function under treatment with anti-VEGF.

19.
Blood Adv ; 6(5): 1598-1607, 2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-34448823

RESUMO

Vitreoretinal lymphoma (VRL) is a rare subtype of diffuse large B-cell lymphoma (DLBCL) considered a variant of primary central nervous system lymphoma (PCNSL). The diagnosis of VRL requires examination of vitreous fluid, but cytologic differentiation from uveitis remains difficult. Because of its rarity and the difficulty in obtaining diagnostic material, little is known about the genetic profile of VRL. The purpose of our study was to investigate the mutational profile of a large series of primary and secondary VRL. Targeted next-generation sequencing using a custom panel containing the most frequent mutations in PCNSL was performed on 34 vitrectomy samples from 31 patients with VRL and negative controls with uveitis. In a subset of cases, genome-wide copy number alterations (CNAs) were assessed using the OncoScan platform. Mutations in MYD88 (74%), PIM1 (71%), CD79B (55%), IGLL5 (52%), TBL1XR1 (48%), ETV6 (45%), and 9p21/CDKN2A deletions (75%) were the most common alterations, with similar frequencies in primary (n = 16), synchronous (n = 3), or secondary (n = 12) VRL. This mutational spectrum is similar to MYD88mut/CD79Bmut (MCD or cluster 5) DLBCL with activation of Toll-like and B-cell receptor pathways and CDKN2A loss, confirming their close relationship. OncoScan analysis demonstrated a high number of CNAs (mean 18.6 per case). Negative controls lacked mutations or CNAs. Using cell-free DNA of vitreous fluid supernatant, mutations present in cellular DNA were reliably detected in all cases examined. Mutational analysis is a highly sensitive and specific tool for the diagnosis of VRL and can also be applied successfully to cell-free DNA derived from the vitreous.


Assuntos
Ácidos Nucleicos Livres , Neoplasias do Sistema Nervoso Central , Linfoma Difuso de Grandes Células B , Linfoma não Hodgkin , Neoplasias da Retina , Uveíte , Ácidos Nucleicos Livres/metabolismo , Neoplasias do Sistema Nervoso Central/metabolismo , Humanos , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma não Hodgkin/patologia , Neoplasias da Retina/diagnóstico , Neoplasias da Retina/genética , Neoplasias da Retina/patologia , Uveíte/metabolismo , Uveíte/patologia , Corpo Vítreo/metabolismo , Corpo Vítreo/patologia
20.
Proc Biol Sci ; 278(1711): 1489-97, 2011 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-21047851

RESUMO

A light-sensitive, externally powered microchip was surgically implanted subretinally near the macular region of volunteers blind from hereditary retinal dystrophy. The implant contains an array of 1500 active microphotodiodes ('chip'), each with its own amplifier and local stimulation electrode. At the implant's tip, another array of 16 wire-connected electrodes allows light-independent direct stimulation and testing of the neuron-electrode interface. Visual scenes are projected naturally through the eye's lens onto the chip under the transparent retina. The chip generates a corresponding pattern of 38 × 40 pixels, each releasing light-intensity-dependent electric stimulation pulses. Subsequently, three previously blind persons could locate bright objects on a dark table, two of whom could discern grating patterns. One of these patients was able to correctly describe and name objects like a fork or knife on a table, geometric patterns, different kinds of fruit and discern shades of grey with only 15 per cent contrast. Without a training period, the regained visual functions enabled him to localize and approach persons in a room freely and to read large letters as complete words after several years of blindness. These results demonstrate for the first time that subretinal micro-electrode arrays with 1500 photodiodes can create detailed meaningful visual perception in previously blind individuals.


Assuntos
Eletrodos Implantados , Implantes Experimentais , Leitura , Retina/cirurgia , Distrofias Retinianas/cirurgia , Auxiliares Sensoriais , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Luz , Masculino
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA