Effectiveness of remote screening for diabetic retinopathy among patients referred to Mozambican Diabetes Association (AMODIA): a retrospective observational study.

AIMS: Diabetes represents a growing public health problem in sub-Saharan Africa, where diabetic retinopathy (DR) is a major cause of permanent visual loss. We reported the results of a remote screening of DR among urbanized Mozambican people with diabetes. METHODS: We retrospectively collected retinal images and clinical characteristics from 536 patients screened for DR in Maputo (Mozambique), over a period of 2 years (2018-2019). Retinal photographs were captured, digitally stored, and scored locally and by an expert ophthalmologist in Italy remotely. RESULTS: The overall prevalence of DR was 29% with sight-threatening forms accounting for 8.1% of that number. Inter-reader agreement between the local and the Italian ophthalmologists was poor (k < 0.2). Patients with DR were older, had a longer duration of disease, worse glycaemic control, and a higher prevalence of comorbidities. In the multivariate logistic regression analysis, HbA1c, diabetes duration, and coronary heart disease (CHD) were associated with DR. CONCLUSION: Prevalence of DR among urbanized Mozambican patients was similar to that observed in Western countries. Telediagnosis might partially overcome the paucity of local ophthalmologists with experience in DR.

Bilateral optic neuropathy and intraretinal deposits after pars plana vitrectomy in amyloidosis.

Pathological examination of material from a nonextensive pars plana vitrectomy (PPV) in the right eye provided a diagnosis of nonfamilial amyloidosis in a 68-year-old woman, who presented with bilateral glass wool-like vitreous opacities. Genetic testing revealed a Tyr114Cys mutation in the transthyretin gene. Six months after PPV, perimetry showed intense constriction with a temporal island and central scotoma in the right eye. An extensive PPV was performed in the left eye. Spectral domain optical coherence tomography evidenced bilateral epimacular amyloid deposits and unreported reflective spots within the inner retina. One year later, visual acuity had decreased to 20/400 in the left eye, with mild vitreous opacity, pale cupped optic disc and inferior altitudinal field defect. Bilateral diurnal intraocular pressure, transiently increased after PPV, never exceeded 16 mmHg with medication. Our patient presented optic nerve blood supply impairment, due to amyloidosis, which caused optic atrophy. Epiretinal and intraretinal deposit detection could aid in diagnosing patients with suspected amyloidosis.

Exploratory data analysis for robot perception of room environments by means of an in-air sonar scanner.

In this paper, the authors have developed a new method for reconstructing the boundary walls of a room environment by using a mechatronic device consisting of four ultrasonic sensors rotated by a servo modular actuator. This scanning system allows to measure the times of flight in each motor position so as to explore the surrounding space detecting reflections from the boundary walls and from other static obstacles. In addition to undesired reflections, due to non-target obstacles interposed between the sensors and the target surfaces, several spurious times are observed at the corners because of multiple reflections. The Fuzzy C-Means (FCM) algorithm is used for partitioning the obtained dataset in five clusters and some considerations on the output signal energy permit to select the two subsets concerned with multipath echoes. Each remaining cluster is associated to a set of three-dimensional points by considering the directivity of the wide beam propagated. In order to discard the observations that are numerically distant from the confidence data, the three sets are filtered by means of an ellipsoid defined by the Principal Component Analysis (PCA). The best-fit planes are obtained by testing the eigenvalues and relating eigenvectors of the covariance matrix of each filtered set. Several tests are shown and discussed for appreciating the effectiveness of the described approach and they are aimed at making a robot aware of its environment.

Fundus autofluorescence and microperimetry in progressing geographic atrophy secondary to age-related macular degeneration.

PURPOSE: To prospectively analyse microperimetry, standard short-wavelength fundus autofluorescent (SW-FAF) and near infrared-wavelength FAF (NIR-FAF) changes in eyes with geographic atrophy (GA) secondary to age-related macular degeneration. METHODS: Twenty consecutive eyes (14 patients) affected by GA were enrolled. Repeated microperimetric examinations and FAF images were obtained over a mean follow-up period of 12.3±4.5 months. RESULTS: GA area was always wider on NIR-FAF versus SW-FAF images (5.05±2.40 mm(2) vs 4.45±2.41 mm(2), p=0.005 baseline; 5.78±2.87 mm(2) vs 5.21±2.77 mm(2), p<0.0001 follow-up). Mean retinal sensitivity significantly decreased during follow-up from 7.68±3.92 dB to 6.71±4.37 dB (p=0.0013). 47.3% of the relative dense scotomas (≤5 dB) progressed to dense scotoma (0 dB). Retinal areas showing relative dense scotoma and characterised by hypo-SW-FAF or hyper-NIR-FAF at baseline had a higher risk of evolving to dense scotoma compared with normo-FAF and hyper-FAF on SW-FAF (OR=2.62 and 2.77, respectively), or normo-FAF at NIR-FAF (OR=2.96). CONCLUSIONS: SW-FAF, compared with NIR-FAF, underestimates GA area at baseline and at follow-up. The enlargement rate of progression based on NIR-FAF is not greater than on SW-FAF. Different SW-FAF and NIR-FAF patterns show different relative risk of progression from relative to dense scotoma. Microperimetry, SW-FAF and NIR-FAF should be combined to obtain adequate morphological and functional prospective information.