Fourier-domain OCT provided accurate anterior eye segment measurements that agreed with those obtained with time-domain OCT.

Background:Retinal vascular diseases are one of the most common causes of blindness in the developed world. Optical Coherence Tomography Angiography (OCT-A) is a new noninvasive method that uses several algorithms to detect blood movement. This enables the creation of high-resolution vascular images with contrast depicting motionless tissue.Methods:This review presents the results of articles relevant to age-related macular degeneration (AMD), diabetic retinopathy (DR), and OCT-A. The OCT-A technique can successfully be used in the diagnosis of neovascularization, retinal vein occlusion (RVO) and retinal artery occlusion (RAO), vessel abnormalities and even anterior segment neovascularization. OCT-A can also be applied to compute data such as vessel density, and flow index in both superficial and deep plexuses.Results:Many studies have compared fluorescein angiography with OCT-A. Other studies have reported differences in vascular density in AMD patients and have compared them with people having healthy eyes. Although OCT-A offers rapid picture acquisition, high repeatability and resolution, it also has many drawbacks. The most common are: motion artifacts, projections from overlying vessels and limited field of view.An interesting new application is the possibility to assess changes during antivascular endothelial growth factor (anti-VEGF) therapy. Another function of OCT-A is the possible application in the study of choriocapillaries in many fields of ocular pathology.Conclusion:OCT-A is a new promising method that allows the visualization of the retinal vascular network and the counting of blood flow parameters. This technique provides reliable images useful in clinical routines.

N102S may also be a mutation hotspot in the Polish population, as in other previously reported populations. Corneal crystals formed a characteristic pattern on optical coherence tomography scans.

Purpose: The aim of this study was to measure and compare the retinal vascular parameters and foveal avascular zone (FAZ) in Chinese and Caucasian populations by using optical coherence tomography angiography (OCT-A). Methods: Fifty-one eyes of Han Chinese and 43 eyes of Caucasians were retrospectively included in our study. The measurements were acquired using Zeiss Cirrus 5000, with the same software version 10 in Poland and China. Results: The size of the FAZ was 0.33 AE 0.012 and 0.28 AE 0.014 mm 2 (p = 0.0289) and the diameter was 2.43 AE 0.06 and 2.18 AE 0.07 mm (p = 0.0057) for Chinese and Caucasian populations, respectively. However, no differences were observed in circularities between the populations. The full Early Treatment of Diabetic Retinopathy Study (ETDRS) vessel length density was significantly different for Chinese (17.05 AE 0.24 mm/mm 2 ) and Caucasian (16.08 AE 0.43 mm/mm 2 ) populations. In addition, the outer ETDRS vessel length density was significantly different for Chinese (16.43 AE 0.42 mm/mm 2 ) and Caucasian (17.47 AE 0.24 mm/mm 2 ) populations, but the central 7.33 AE 1.68 versus 9.32 AE 1.54 mm/mm 2 for the Caucasian and Chinese and inner 16.14 AE 0.52 for Caucasian and 16.93 AE 0.27 mm/mm 2 for Chinese subjects density was not. A significant yet weak positive correlation between FAZ and vessel density was observed (r = 0.216). Furthermore, no significant intersexual differences were observed in study parameters. Conclusion: The Chinese population had larger FAZ with higher vessel length density in the superficial layers of the retina than the Caucasian population.

Genetic mutation heterogeneity was revealed. No phenotype heterogeneity was revealed among patients with in vivo corneal morphology assessment or histological analysis.

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BackgroundThe available scientific literature contains descriptions of manual, semi-automated and automated methods for analysing angiographic images. The presented algorithms segment vessels calculating their tortuosity or number in a given area. We describe a statistical analysis of the inclination of the vessels in the fundus as related to their distance from the center of the optic disc.MethodsThe paper presents an automated method for analysing vessels which are found in angiographic images of the eye using a Matlab implemented algorithm. It performs filtration and convolution operations with suggested masks. The result is an image containing information on the location of vessels and their inclination angle in relation to the center of the optic disc. This is a new approach to the analysis of vessels whose usefulness has been confirmed in the diagnosis of hypertension.ResultsThe proposed algorithm analyzed and processed the images of the eye fundus using a classifier in the form of decision trees. It enabled the proper classification of healthy patients and those with hypertension. The result is a very good separation of healthy subjects from the hypertensive ones: sensitivity - 83%, specificity - 100%, accuracy - 96%. This confirms a practical usefulness of the proposed method.ConclusionsThis paper presents an algorithm for the automatic analysis of morphological parameters of the fundus vessels. Such an analysis is performed during fluorescein angiography of the eye. The presented algorithm automatically calculates the global statistical features connected with both tortuosity of vessels and their total area or their number.

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