Improved predictive diagnosis of diabetic macular edema based on hybrid models: An observational study.

Diabetic Macular Edema (DME) is the most common sight-threatening complication of type 2 diabetes. Optical Coherence Tomography (OCT) is the most useful imaging technique to diagnose, follow up, and evaluate treatments for DME. However, OCT exam and devices are expensive and unavailable in all clinics in low- and middle-income countries. Our primary goal was therefore to develop an alternative method to OCT for DME diagnosis by introducing spectral information derived from spontaneous electroretinogram (ERG) signals as a single input or combined with fundus that is much more widespread. Baseline ERGs were recorded in 233 patients and transformed into scalograms and spectrograms via Wavelet and Fourier transforms, respectively. Using transfer learning, distinct Convolutional Neural Networks (CNN) were trained as classifiers for DME using OCT, scalogram, spectrogram, and eye fundus images. Input data were randomly split into training and test sets with a proportion of 80 %-20 %, respectively. The top performers for each input type were selected, OpticNet-71 for OCT, DenseNet-201 for eye fundus, and non-evoked ERG-derived scalograms, to generate a combined model by assigning different weights for each of the selected models. Model validation was performed using a dataset alien to the training phase of the models. None of the models powered by mock ERG-derived input performed well. In contrast, hybrid models showed better results, in particular, the model powered by eye fundus combined with mock ERG-derived information with a 91 % AUC and 86 % F1-score, and the model powered by OCT and mock ERG-derived scalogram images with a 93 % AUC and 89 % F1-score. These data show that the spontaneous ERG-derived input adds predictive value to the fundus- and OCT-based models to diagnose DME, except for the sensitivity of the OCT model which remains the same. The inclusion of mock ERG signals, which have recently been shown to take only 5 min to record in daylight conditions, therefore represents a potential improvement over existing OCT-based models, as well as a reliable and cost-effective alternative when combined with the fundus, especially in underserved areas, to predict DME.

Vitreous amyloidosis as primary manifestation of disease: case report. / Amiloidosis vítrea como manifestación primaria de enfermedad: reporte de caso.

A 35-year-old woman with progressive decrease of vision in both eyes and with no other associated symptoms, manifested as the only antecedent, the death of her brother due to amyloidosis. The visual acuity was counting fingers at 30 centimetres in the right eye and 20/70 in the left eye. In ophthalmoscopy of the right eye, a white, homogeneous vitreous, that was difficult to assess in detail, was observed, and in the left eye a whitish vitreous with band-like opacities in the cortical region. Vitrectomy was performed in the right eye, and a study with specific stains showed positive for amyloid material. A case is reported of amyloidosis diagnosed with specific stains in a vitreous sample for which the initial and only manifestation was the presence of vitreous opacities. The processing of these samples should be considered in patients with family history, early vitreous opacities, negative results of systemic biopsy, or atypical course of the disease.