@article{2997735,
    title = "A pilot optical coherence tomography angiography study on superficial and deep capillary plexus foveal avascular zone in patients with beta-thalassemia major",
    author = "Georgalas, I. and Makris, G. and Papaconstantinou, D. and Petrou, P. and Chalkiadaki, E. and Droutsas, K. and Andreanos, K. and Kanakis, M.",
    journal = "Investigative Ophthalmology and Visual Science",
    year = "2019",
    volume = "60",
    number = "12",
    pages = "3887-3896",
    publisher = "Association for Research in Vision and Ophthalmology Inc.",
    doi = "10.1167/iovs.19-27291",
    keywords = "adult;  area to perimeter ratio;  Article;  capillary;  circularity;  clinical article;  contour temperature;  controlled study;  female;  foveal avascular zone;  foveal avascular zone convex hull;  foveal avascular zone diameter;  foveal avascular zone perimeter;  human;  human tissue;  image segmentation;  imaging algorithm;  iron load;  liver biopsy;  male;  maximum inscribed circle diameter;  metabolic parameters;  minimum feret diameter;  nuclear magnetic resonance imaging;  optical coherence tomography angiography;  physical parameters;  priority journal;  retina fovea;  solidity;  thalassemia major;  thermodynamics;  visual system parameters;  beta thalassemia;  blood;  capillary;  comparative study;  diagnostic imaging;  fluorescence angiography;  middle aged;  normal human;  optical coherence tomography;  pathology;  pilot study;  procedures;  retina blood vessel;  retina fovea;  vascularization, deferoxamine;  ferritin;  siderophore, Adult;  beta-Thalassemia;  Capillaries;  Deferoxamine;  Female;  Ferritins;  Fluorescein Angiography;  Fovea Centralis;  Healthy Volunteers;  Humans;  Male;  Middle Aged;  Pilot Projects;  Retinal Vessels;  Siderophores;  Tomography, Optical Coherence",
    abstract = "PURPOSE. To investigate foveal avascular zone (FAZ) changes in the superficial (SCP) and deep (DCP) capillary plexuses in beta-thalassemia major (BTM) patients, as shown in optical coherence tomography angiography. METHODS. Nonrandomized, comparative case series of 54 eyes of 27 BTM patients and 46 eyes of 23 healthy controls, utilizing an automated FAZ detection algorithm. Measurements included FAZ area and FAZ shape descriptors (convexity, circularity, and contour temperature). Results were compared between the two groups, and correlated to iron load and chelation therapy parameters. RESULTS. SCP and DCP FAZ area were not significantly different between the control and BTM groups (P = 0.778 and P = 0.408, respectively). The same was true regarding SCP FAZ convexity (P = 0.946), circularity (P = 0.838), and contour temperature (P = 0.907). In contrast, a statistically significant difference was detected between controls and BTM group regarding DCP FAZ convexity (P = 0.013), circularity (P = 0.010), and contour temperature (P = 0.014). Desferrioxamine dosage was strongly correlated to the DCP area (r = 0.650, P = 0.05) and liver magnetic resonance imaging/T2-star to DCP circularity (r = -0.492, P = 0.038). Correlations were also revealed between urine Fe excretion and DCP convexity (r = 0.531, P = 0.019), circularity (r = 0.661, P = 0.002), and contour temperature (r = -0.591, P = 0.008). CONCLUSIONS. Retinal capillary plexuses and especially DCP seem to present unique morphologic changes in BTM patients, not in the FAZ area, but in specific shape descriptors, indicating minor but detectable FAZ changes. These changes correlate well with iron load and chelation therapy parameters. Their clinical importance and pathophysiologic implications remain to be elucidated through further studies. © 2019 The Authors."
}