Purpose: The aim of the study was to visualize and to quantify pathological foveal avascular zone (FAZ) alterations through optical coherence tomography angiography (OCT-A) in eyes with retinal vein occlusion (RVO) in comparison to the unaffected fellow eyes. Procedures: OCT-A was conducted with the Avanti® RTVue 100 XR system (Optovue Inc., Fremont, Calif., USA). The borders of the superficial vascular layer (SVL) were defined as 3 μm below the internal limiting membrane and 15 μm below the inner plexiform layer, and for the deep vascular layer (DVL) as 15 and 70 μm below the inner plexiform layer, respectively. The length of the horizontal, vertical and maximum FAZ was manually measured for the SVL and DVL in each eye. Additionally, the angle between the maximum FAZ diameter and the papillomacular plane was measured. Results: OCT-A depicted defects within the perifoveal vasculature in eyes with branch retinal vein occlusion (BRVO; n = 11) and central retinal vein occlusion (CRVO; n = 8). These resulted in an enlargement of the maximum FAZ diameter in eyes with RVO (n = 19) in comparison to the healthy fellow eyes (n = 19; 921 ± 213 vs. 724 ± 145 µm; p = 0.008). Furthermore, a significant correlation was found between best-corrected visual acuity (BCVA) and the maximum FAZ diameter in the DVL (Spearman's ρ = -0.423, p < 0.01). Lastly, in the eyes with RVO, the angle between the papillomacular plane and the maximum FAZ diameter was only in 21.05% (SVL) and 15.79% (DVL) of the cases at 0 ± 15 or 90 ± 15°, respectively. In healthy eyes, these angles (which putatively represent a regular FAZ configuration) were more prevalent (SVL 68.42 vs. 21.05%, p = 0.003; DVL 73.68 vs. 15.79%, p < 0.001). Conclusion: OCT-A shows morphological alterations of the FAZ in eyes with CRVO and BRVO. The correlation of the maximum FAZ diameter with BCVA suggests that these alterations are functionally relevant.

Keywords:
Foveal avascular zone, Optical coherence tomography, Retinal vein occlusion, Angiography
1.
Rogers S, McIntosh RL, Cheung N, Lim L, Wang JJ, Mitchell P, Kowalski JW, Nguyen H, Wong TY: The prevalence of retinal vein occlusion: pooled data from population studies from the United States, Europe, Asia, and Australia. Ophthalmology 2010;117:313-319.
2.
Klein R, Klein BE, Moss SE, Meuer SM: The epidemiology of retinal vein occlusion: the Beaver Dam Eye Study. Trans Am Ophthalmol Soc 2000;98:133-141.
3.
Mitchell P, Smith W, Chang A: Prevalence and associations of retinal vein occlusion in Australia. The Blue Mountains Eye Study. Arch Ophthalmol 1996;114:1243-1247.
4.
David R, Zangwill L, Badarna M, Yassur Y: Epidemiology of retinal vein occlusion and its association with glaucoma and increased intraocular pressure. Ophthalmologica 1988;197:69-74.
5.
Actis AG, Belli L, Dall'orto L, Penna R, Brogliatti B, Rolle T: Morphology of optic disc through heidelberg retina tomograph in retinal vein occlusions alone or in combination with primary open angle glaucoma. Open Ophthalmol J 2013;7:34-41.
6.
Karia N: Retinal vein occlusion: pathophysiology and treatment options. Clin Ophthalmol 2010;4:809-816.
7.
Beaumont PE, Kang HK: Clinical characteristics of retinal venous occlusions occurring at different sites. Br J Ophthalmol 2002;86:572-580.
8.
Parodi MB, Visintin F, Della Rupe P, Ravalico G: Foveal avascular zone in macular branch retinal vein occlusion. Int Ophthalmol 1995;19:25-28.
9.
McIntosh RL, Rogers SL, Lim L, Cheung N, Wang JJ, Mitchell P, Kowalski JW, Nguyen HP, Wong TY: Natural history of central retinal vein occlusion: an evidence-based systematic review. Ophthalmology 2010;117:1113-1123.
10.
Rogers SL, McIntosh RL, Lim L, Mitchell P, Cheung N, Kowalski JW, Nguyen HP, Wang JJ, Wong TY: Natural history of branch retinal vein occlusion: an evidence-based systematic review. Ophthalmology 2010;117:1094-1101.
11.
Wu L: Treatments for retinal vein occlusion: a review of recent developments. Retina Today 2014;4:62-63.
12.
Brown DM: Clinical implications of the BRAVO and CRUISE trials. How should physicians apply this new information in their treatment of CRVO and BRVO? Retina Today 2010;5:39-40.
13.
Parodi MB, Visintin F, Della Rupe P, Ravalico G: Foveal avascular zone in macular branch retinal vein occlusion. Int Ophthalmol 1995;19:25-28.
14.
Chui TY, Zhong Z, Song H, Burns SA: Foveal avascular zone and its relationship to foveal pit shape. Optom Vis Sci 2012;89:602-610.
15.
Tick S1, Rossant F, Ghorbel I, Gaudric A, Sahel JA, Chaumet-Riffaud P, Paques M: Foveal shape and structure in a normal population. Invest Ophthalmol Vis Sci 2011;52:5105-5110.
16.
Zhang HR: Scanning electron-microscopic study of corrosion casts on retinal and choroidal angioarchitecture in man and animals. Prog Ret Eye Res 1994;13:243-270.
17.
Henkind P, Hansen RI, Szalay J: Ocular circulation; in Records RE (ed): Physiology of the Human Eye and Visual System. New York, Harper & Row, 1979, pp 98-155.
18.
Donald J, Gass M: A Fluorescein angiographic study of macular dysfunction secondary to retinal vascular disease. Arch Ophthalmol 1968;80:606-661.
19.
Spaide RF, Klancnik JM, Cooney MJ: Retinal vascular layers imaged by fluorescein angiography and optical coherence tomography angiography. JAMA Ophthalmol 2015;1:133.
20.
Jia Y, Tan O, Tokayer J, Potsaid B, Wang Y, Liu JJ Kraus MF, Subhash H, Fujimoto JG, Hornegger J, Huang D: Split-spectrum amplitude-decorrelation angiography with optical coherence tomography. Opt Express 2012;20:4710-4725.
21.
Fang PP, Lindner M, Steinberg JS, Müller PL, Gliem M, Charbel Issa P, Krohne TU, Holz FG: Clinical applications of OCT angiography. Ophthalmologe 2016;113:14-22.
22.
Gregori NZ, Feuer W, Rosenfeld PJ: Novel method for analyzing snellen visual acuity measurements. Retina 2010;30:1046-1050.
23.
Freiberg FJ, Pfau M, Wons J, Wirth MA, Becker MD, Michels S: Optical coherence tomography angiography of the foveal avascular zone in diabetic retinopathy. Graefes Arch Clin Exp Ophthalmol 2015, Epub ahead of print.
24.
Schröder K, Brachert M, Ackermann P, Bairov S, Geerling G, Guthoff R: Quantitative und qualitative Netzhautschichtdickenanalyse bei retinalem Venenverschluss nach Resorption des initialen Makulaödems - besteht eine Korrelation zum Visus? Ophthalmologe 2014;111(suppl 1):S82.
25.
Waheed NK, De Carlo TE, Chin AT, Duker JS: OCT angiography in retinal diagnosis and treatment. A new modality for diagnostic imaging and follow-up. Retin Physician 2015;12:42-46.
26.
Fang PP, Harmening WM, Müller PL, Lindner M, Krohne TU, Holz FG: Technical principles of OCT angiography. Ophthalmologe. 2016;113:6-13.
27.
Holz FG, Krohne TU: New perspectives in retinal imaging with OCT angiography. Ophthalmologe 2016;113:4-5.
28.
Coscas F, Glacet-Bernard A, Miere A, Caillaux V, Uzzan J, Lupidi M, Coscas G, Souied EH: Optical coherence tomography angiography in retinal vein occlusion: evaluation of superficial and deep capillary plexa. Am J Ophthalmol 2016;161:160-171.
© 2016 S. Karger AG, Basel
2016
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.