Vascular changes in diabetic retinopathy-a longitudinal study in the Nile rat.

Diabetic retinopathy is the most common microvascular complication of diabetes and is a major cause of blindness, but an understanding of the pathogenesis of the disease has been hampered by a lack of accurate animal models. Here, we explore the dynamics of retinal cellular changes in the Nile rat (Arvicanthis niloticus), a carbohydrate-sensitive model for type 2 diabetes. The early retinal changes in diabetic Nile rats included increased acellular capillaries and loss of pericytes that correlated linearly with the duration of diabetes. These vascular changes occurred in the presence of microglial infiltration but in the absence of retinal ganglion cell loss. After a prolonged duration of diabetes, the Nile rat also exhibits a spectrum of retinal lesions commonly seen in the human condition including vascular leakage, capillary non-perfusion, and neovascularization. Our longitudinal study documents a range and progression of retinal lesions in the diabetic Nile rat remarkably similar to those observed in human diabetic retinopathy, and suggests that this model will be valuable in identifying new therapeutic strategies

Evaluation of optical coherence tomography findings in age-related macular degeneration: a reproducibility study of two independent reading centres

International audienceBackground/aims : To determine the reproducibility among readers of two independent certified centers, the Vienna Reading Center (VRC) and the University of Wisconsin-Madison Reading Center (UW-FPRC) for OCT images in age-related macular degeneration (AMD). Methods : Fast macular thickness scans and 6 mm cross hair scans were obtained from 100 eyes with all subtypes of AMD using Stratus OCT. Consensus readings were performed by two certified OCT readers of each Reading Center using their grading protocol. Common variables of both grading protocols, such as presence of cystoid spaces, subretinal fluid, vitreomacular traction and retinal pigment epithelial detachment were compared using kappa statistics. In addition, the intraclass correlation coefficient (ICC) was calculated for center point thickness (CPT) of values remeasured manually in the presence of alignment errors. Results : The reproducibility was dependent on the variable measured with a kappa value of 0.81 for the presence of cystoid spaces, 0.78 for the presence of subretinal fluid and 0.795 for the presence of vitreomacular traction. The lowest reproducibility was found for the presence of retinal pigment epithelial detachment with a kappa value of 0.51. The CPT was remeasured in 29 out of 100 scans at both sites with an ICC of the remeasured thicknesses of 0.92. Conclusion : OCT scan data are crucial in monitoring treatment efficacy in AMD clinical trials. For comparison of results obtained by different Reading Centers, the inter-Reading Center reproducibility is essential. Although the reproducibility is generally high, the reliability depends on the selected morphological parameters

Vascular changes in diabetic retinopathy-a longitudinal study in the Nile rat

Diabetic retinopathy is the most common microvascular complication of diabetes and is a major cause of blindness, but an understanding of the pathogenesis of the disease has been hampered by a lack of accurate animal models. Here, we explore the dynamics of retinal cellular changes in the Nile rat (Arvicanthis niloticus), a carbohydrate-sensitive model for type 2 diabetes. The early retinal changes in diabetic Nile rats included increased acellular capillaries and loss of pericytes that correlated linearly with the duration of diabetes. These vascular changes occurred in the presence of microglial infiltration but in the absence of retinal ganglion cell loss. After a prolonged duration of diabetes, the Nile rat also exhibits a spectrum of retinal lesions commonly seen in the human condition including vascular leakage, capillary non-perfusion, and neovascularization. Our longitudinal study documents a range and progression of retinal lesions in the diabetic Nile rat remarkably similar to those observed in human diabetic retinopathy, and suggests that this model will be valuable in identifying new therapeutic strategies

Baseline Predictors of Visual Acuity and Retinal Thickness Outcomes in Patients with Retinal Vein Occlusion. SCORE Study Report 10

To investigate baseline factors significantly associated with visual acuity and central retinal thickness outcomes in patients with macular edema secondary to retinal vein occlusion in the Standard Care versus COrticosteroid for REtinal Vein Occlusion (SCORE) Study

Spatial statistical modelling of capillary non-perfusion in the retina

Manual grading of lesions in retinal images is relevant to clinical management and clinical trials, but it is time-consuming and expensive. Furthermore, it collects only limited information - such as lesion size or frequency. The spatial distribution of lesions is ignored, even though it may contribute to the overall clinical assessment of disease severity, and correspond to microvascular and physiological topography. Capillary non-perfusion (CNP) lesions are central to the pathogenesis of major causes of vision loss. Here we propose a novel method to analyse CNP using spatial statistical modelling. This quantifies the percentage of CNP-pixels in each of 48 sectors and then characterises the spatial distribution with goniometric functions. We applied our spatial approach to a set of images from patients with malarial retinopathy, and found it compares favourably with the raw percentage of CNP-pixels and also with manual grading. Furthermore, we were able to quantify a biological characteristic of macular CNP in malaria that had previously only been described subjectively: clustering at the temporal raphe. Microvascular location is likely to be biologically relevant to many diseases, and so our spatial approach may be applicable to a diverse range of pathological features in the retina and other organs

Activities of daily living independence in Iranian blind war survivors: a cross sectional study, 2008

Aim: Assessment of activities of daily living (ADL) can be helpful for designing individualized rehabilitation programs for disabled individuals. Measuring and comparing the basic ADL (BADL) and instrumental ADL (IADL) independence between middle aged and senior Iranian blind war survivors (IBWS) was the aim of this study. Methods: This cross-sectional study assessed BADL and IADL of 312 blind war survivors, using the Barthel Index and the Lawton-Bordy scale. Data collection was carried out in a recreational event for the blind war survivors in Mashhad, Iran, 2008. Results: The majority of the participants were male (99%), and more than 80% had multiple injuries. None of them were independent in all BADL and IADL. Older groups were more dependent in IADL such as telephone use, drug management, financial management, and BADL such as walking on uneven surfaces, bed/chair transfer and using stairs. The functional status and activities' level differences between those aged younger than 50 years and those aged older than 50 years were significant (

OCT Signs of Early Atrophy in Age-Related Macular Degeneration: Interreader Agreement: Classification of Atrophy Meetings Report 6.

PURPOSE: To determine the interreader agreement for incomplete retinal pigment epithelium (RPE) and outer retinal atrophy (iRORA) and complete RPE and outer retinal atrophy (cRORA) and their related features in age-related macular degeneration (AMD). DESIGN: Interreader agreement study. PARTICIPANTS: Twelve readers from 6 reading centers. METHODS: After formal training, readers qualitatively assessed 60 OCT B-scans from 60 eyes with AMD for 9 individual features associated with early atrophy and performed 7 different annotations to quantify the spatial extent of OCT features within regions of interest. The qualitative and quantitative features were used to derive the presence of iRORA and cRORA and also in an exploratory analysis to examine if agreement could be improved using different combinations of features to define OCT atrophy. MAIN OUTCOME MEASURES: Interreader agreement based on Gwet's first-order agreement coefficient (AC1) for qualitatively graded OCT features and classification of iRORA and cRORA, and smallest real difference (SRD) for quantitatively graded OCT features. RESULTS: Substantial or better interreader agreement was observed for all qualitatively graded OCT features associated with atrophy (AC1 = 0.63-0.87), except for RPE attenuation (AC1 = 0.46) and disruption (AC1 = 0.26). The lowest SRD for the quantitatively graded horizontal features was observed for the zone of choroidal hypertransmission (± 190.8 μm). Moderate agreement was found for a 3-category classification of no atrophy, iRORA, and cRORA (AC1 = 0.53). Exploratory analyses suggested a significantly higher level of agreement for a 3-category classification using (1) no atrophy; (2) presence of inner nuclear layer and outer plexiform layer subsidence, or a hyporeflective wedge-shaped band, as a less severe atrophic grade; and (3) the latter plus an additional requirement of choroidal hypertransmission of 250 μm or more for a more severe atrophic grade (AC1 = 0.68; P = 0.013). CONCLUSIONS: Assessment of iRORA and cRORA, and most of their associated features, can be performed relatively consistently and robustly. A refined combination of features to define early atrophy could further improve interreader agreement

Evaluating the role of human papillomaviruses in conjunctival neoplasia

Mucosal, cutaneous and Epidermodysplasia verruciformis (EV)-related human papillomaviruses (HPVs) were searched by broad-spectrum PCR in 86 conjunctival neoplasia biopsies and 63 conjunctival non-neoplastic control tissue from Ugandan subjects. Seven different EV-related HPV types, including a putative new HPV, and two mucosal HPVs were detected in 25% (14 out of 56) of HIV-positive, in 10% (three out of 30) of HIV-negative conjunctival neoplasia samples, and rarely (0–1.6%) in control subjects. The absence of high-risk HPVs and the low detection frequency of EV-related HPV types in more advanced tumour stages (10%) raise doubts about their role in conjunctival carcinomas