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Published Online:https://doi.org/10.3928/23258160-20140709-07Cited by:3

Abstract

BACKGROUND AND OBJECTIVE:

Accurate quantification of retinal surface area from ultra-widefield (UWF) images is challenging due to warping produced when the retina is projected onto a two-dimensional plane for analysis. By accounting for this, the authors sought to precisely montage and accurately quantify retinal surface area in square millimeters.

PATIENTS AND METHODS:

Montages were created using Optos 200Tx (Optos, Dunfermline, U.K.) images taken at different gaze angles. A transformation projected the images to their correct location on a three-dimensional model. Area was quantified with spherical trigonometry. Warping, precision, and accuracy were assessed.

RESULTS:

Uncorrected, posterior pixels represented up to 79% greater surface area than peripheral pixels. Assessing precision, a standard region was quantified across 10 montages of the same eye (RSD: 0.7%; mean: 408.97 mm2; range: 405.34–413.87 mm2). Assessing accuracy, 50 patients’ disc areas were quantified (mean: 2.21 mm2; SE: 0.06 mm2), and the results fell within the normative range.

CONCLUSION:

By accounting for warping inherent in UWF images, precise montaging and accurate quantification of retinal surface area in square millimeters were achieved.

[Ophthalmic Surg Lasers Imaging Retina. 2014;45:312-317.]

  • 1.Novotny HR, Alvis DL. A method of photographing fluorescence in circulating blood in the human retina. Circulation. 1961; 24:82–86.10.1161/01.CIR.24.1.82

    CrossrefGoogle Scholar
  • 2.Huang D, Swanson EA, Lin CP, et al.Optical coherence tomography. Science. 1991; 254(5035):1178–1181.10.1126/science.1957169

    CrossrefGoogle Scholar
  • 3.Manivannan A, Plskova J, Farrow A, Mckay S, Sharp PF, Forrester JV. Ultra-wide-field fluorescein angiography of the ocular fundus. Am J Ophthalmol. 2005; 140(3):525–527.10.1016/j.ajo.2005.02.055

    CrossrefGoogle Scholar
  • 4.Spaide RF. Peripheral areas of nonperfusion in treated central retinal vein occlusion as imaged by wide-field fluorescein angiography. Retina. 2001; 31(5):829–837.10.1097/IAE.0b013e31820c841e

    CrossrefGoogle Scholar
  • 5.Early Treatment Diabetic Retinopathy Study Research Group. Classification of diabetic retinopathy from fluorescein angiograms. Ophthalmology. 1991; 98(5 Suppl):807–822.10.1016/S0161-6420(13)38013-0

    CrossrefGoogle Scholar
  • 6.Blodi BA, Domalpally A, Scott IU, et al.Standard care vs corticoste-roid for retinal vein occlusion (SCORE) Study system for evaluation of stereoscopic color fundus photographs and fluorescein angiograms: SCORE study report 9. Arch Ophthalmol. 2010; 128(9):1140–1145.10.1001/archophthalmol.2010.193

    CrossrefGoogle Scholar
  • 7.Brown DM, Kaiser PK, Michels M, et al.Ranibizumab versus verte-porfin for neovascular age-related macular degeneration (ANCHOR). N Engl J Med. 2006; 355(14):1432–1444.10.1056/NEJMoa062655

    CrossrefGoogle Scholar
  • 8.Rosenfeld PJ, Brown DM, Heier JS, et al.Ranibizumab for neovas-cular age-related macular degeneration (MARINA). N Engl J Med. 2006; 355:1419–1431.10.1056/NEJMoa054481

    CrossrefGoogle Scholar
  • 9.Staurenghi G, Viola F, Mainster MA, et al.Scanning laser ophthalmoscopy and angiography with a wide-field contact lens system. Arch Ophthalmol. 2005; 123(2):244–252.10.1001/archopht.123.2.244

    CrossrefGoogle Scholar
  • 10.Escudero-Sanz I, Navarro R. Off-axis aberrations of a wide-angle schematic eye model. J Opt Soc Am A Opt Image Sci Vis. 1999; 16(8):1881–1891.10.1364/JOSAA.16.001881

    CrossrefGoogle Scholar
  • 11.Bugayevskiy LM, Snyder JP. Map Projections: A Reference Manual. London, UK: CRC Press; 1995.

    Google Scholar
  • 12.Donnay JDH. Spherical Trigonometry. New York, NY: Interscience Publishers; 2007.

    Google Scholar
  • 13.Samarawickrama C, Hong T, Jonas JB, et al.Measurement of normal optic nerve head parameters. Surv Ophthalmol. 2012; 57(4):317–336.10.1016/j.survophthal.2011.12.001

    CrossrefGoogle Scholar
  • 14.Patel RD, Messner LV, Teitelbaum B, et al.Characterization of ischemic index using ultra-widefield fluorescein angiography in patients with focal and diffuse recalcitrant diabetic macular edema. Am J Ophthalmol. 2013; 155(6):1038–1044.10.1016/j.ajo.2013.01.007

    CrossrefGoogle Scholar
  • 15.Tsui I, Kaines A, Havunjian MA, et al.Ischemic index and neovascularization in central retinal vein occlusion. Retina. 2011; 31:105–110.10.1097/IAE.0b013e3181e36c6d

    CrossrefGoogle Scholar

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  • Received1/23/14 12:00 AM
  • Accepted3/25/14 12:00 AM
  • Published online7/9/14 12:00 AM
  • __article__history--ppub7/1/14 12:00 AM