Age-related macular degeneration (AMD) is one of the main causes of loss of sight and hypovision in people over working age. Results of optical coherence tomography (OCT) are essential for diagnostics of the disease. Developing the recommendation system to analyze OCT images will reduce the time to process visual data and decrease the probability of errors while working as a doctor. The purpose of the study was to develop an algorithm of segmentation to analyze the results of macular OCT in patients with AMD. It allows to provide a correct prediction of an AMD stage based on the form of discovered pathologies. A program has been developed in the Python programming language using the Pytorch and TensorFlow libraries. Its quality was estimated using OCT macular images of 51 patients with early, intermediate, late AMD. A segmentation algorithm of OCT images was developed based on convolutional neural network. UNet network was selected as architecture of high-accuracy neural net. The neural net is trained on macular OCT images of 125 patients (197 eyes). The author algorithm displayed 98.1% of properly segmented areas on OCT images, which are the most essential for diagnostics and determination of an AMD stage. Weighted sensitivity and specificity of AMD stage classifier amounted to 83.8% and 84.9% respectively. The developed algorithm is promising as a recommendation system that implements the AMD classification based on data that promote taking decisions regarding the treatment strategy.
Purpose. Analysis of electron microscopic changes in rabbit eyes with intravitreal tamponade of perfluorocarbon liquids (PFCL) (perfluoro-1,3-dimethylcyclohexane and perfluorodecalin).Material and Methods. The study was performed on Chinchilla breed rabbits. 25G vitrectomy with PFCL intravitreal tamponade was performed on 12 eyes of 6 rabbits (perfluorodecalin (Bausch+Lomb «Dk-line», USA) and perfluoro-1,3-dimethylcyclohexane (ZAO “Optimedservis”, Russia). Standard three-port vitrectomy technique was used. After removal of the vitreous body 2.5 ml of PFCL were injected in vitreous cavity. Research studies were performed in 5, 14 and 30 days after surgery by electron microscopy. Eyes were enucleated in 20 minutes after animal was killed by air embolization. Intact eyes were used as a control. All samples were prepared in same conditions. The damage of the retina architectonics and the presence of intracellular inclusions were evaluated.Results. Tamponade of the vitreous cavity by both types of PFCL in 5, 14 and 30 day caused following similar electron microscopic changes at date: swelling ganglion layer and dystrophy of inner and outer nuclear layer. Electron microscopic changes in outer nuclear layer appeared at 30 days. The photoreceptor neurons were characterized by single ultrastructural changes. Retina pigment epithelium cells had a typical ultrastructure.Conclusion. Intravitreal perfluoro-1,3-dimethylcyclohexane tamponade caused similar electron microscopic changes as well as perfluorodecalin in the experiment and it was relatively harmless to rabbit retina for up to 14 days. Irreversible changes in the retinal ultrastructure were not observed.
Purpose: to evaluate the efficiency of vitreous floaters removal using the Nd: YAG-laser DIXION LPULSA SYL-9000 with a coaxial light splitter. Patients and Methods. The study involved 24 patients (24 eyes) with Weiss ring-type floating vitreous opacities. All patients underwent laser vitreolysis on a Nd: YAG-laser DIXION LPULSA SYL-9000 with a coaxial light splitter. Laser procedures were performed at OPTIMED Laser Recovery Center. The age of the patients was from 47 to 81 years (average 58.3 ± 8.9 years). Among the patients 15 (62.5 %) were women and 9 (37.5 %) — men. Before procedure, a complete ophthalmological examination including registration of best corrected visual acuity (BCVA), autorefractometry, pneumotonometry, biomicroscopy, fundus examination, ultrasonic biometry, ultrasound B-scan was performed. Statistical processing was performed using Statistica v.10.0.0 (StatSoft®, Inc.) and Excel (Microsoft Office Professional 2016) software. The patients were observed for three months before the procedure. Follow-up examination was performed one day after the procedure. Results. After laser vitreolysis procedure all patients had a subjective vision quality improvement. In 18 (75 %) patients, floating “flies” completely disappeared. The remaining patients noted the disappearance of a large floating spot. Conclusion. The laser vitreolysis on the Nd: YAG-laser with a coaxial light splitter allows to improve the quality and visual acuity in patients with vitreous floater. The obtained results demonstrated that Nd: YAG-laser DIXION LPULSA SYL-9000 is effective and could be recommended for treatment of symptomatic vitreous floaters.
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