A new method of image analysis of fluorescein angiography applied to age-related macular degeneration

Quantitative analysis of retinal and choroidal abnormalities using current photographic techniques is complex and laborious. Digital image analysis techniques using the scanning laser ophthalmoscope overcome many of the problems with present techniques and allow reliable quantitation. A prerequisite of quantitation is accurate image acquisition and registration. The authors describe a reliable method of image analysis and apply it to the quantitation of hyperfluorescence in scanning laser fluorescein angiograms of different forms of age-related macular degeneration. Retrospective analysis of scanning laser fluorescein angiograms obtained using a standardised technique was undertaken. Eighty-six angiograms from patients with age-related macular degeneration were analysed and categorised as dry maculopathy, geographic atrophy of the retinal pigment epithelium, retinal pigment epithelial detachment (PED) or subretinal neovascularisation (SRNV). Fluorescein characteristics of both SRNV and PED showed a characteristic pattern of fluorescence. The advantages and disadvantages of the technique are discussed.

[1]  Paul Wintz,et al.  Digital image processing (2nd ed.) , 1987 .

[2]  J Noack,et al.  An algorithm for the fast registration of image sequences obtained with a scanning laser ophthalmoscope. , 1994, Physics in medicine and biology.

[3]  P. Nagin,et al.  Measurement of fluorescein angiograms of the optic disc and retina using computerized image analysis. , 1985, Ophthalmology.

[4]  Robert H. Webb,et al.  Fundus tracking with the scanning laser ophthalmoscope. , 1987, Applied optics.

[5]  A. Bird,et al.  Evolution of age-related macular degeneration with choroidal perfusion abnormality. , 1992, American journal of ophthalmology.

[6]  T. Dawber,et al.  The Framingham Eye Study monograph: An ophthalmological and epidemiological study of cataract, glaucoma, diabetic retinopathy, macular degeneration, and visual acuity in a general population of 2631 adults, 1973-1975. , 1980, Survey of ophthalmology.

[7]  T Bantel,et al.  Global tracking of the ocular fundus pattern imaged by scanning laser ophthalmoscopy. , 1991, International journal of bio-medical computing.

[8]  Fluorescence characteristics of indocyanine green in the normal choroid and in subretinal neovascular membranes. , 1992, German journal of ophthalmology.

[9]  J. A. Parker,et al.  Measurement of Torsion from Multitemporal Images of the Eye Using Digital Signal Processing Techniques , 1985, IEEE Transactions on Biomedical Engineering.

[10]  C. Puliafito,et al.  Indocyanine green videoangiography of choroidal neovascularization. , 1989, Ophthalmology.

[11]  W H Woon,et al.  The Scanning Laser Ophthalmoscope: Basic Principles and Applications , 1990 .

[12]  R. Webb,et al.  Flying spot TV ophthalmoscope. , 1980, Applied optics.

[13]  W. Freeman.  Practical atlas of retinal disease and therapy , 1993 .

[14]  A. Sorsby.  Department of Health and Social Security. Reports on Public Health and Medical Subjects. No. 128. The incidence and causes of blindness in England and Wales 1963-68. With an appendix on services available for incipient blindness. , 1972, Reports on public health and medical subjects.

[15]  H. A. Kahn,et al.  Statistics on Blindness in the Model Reporting Area 1969-1970. , 1973 .

[16]  P F Sharp,et al.  Digital fundus imaging using a scanning laser ophthalmoscope. , 1993, Physiological measurement.

[17]  G J Klein,et al.  An image processing approach to characterizing choroidal blood flow. , 1990, Investigative ophthalmology & visual science.

[18]  A. Scheider,et al.  Fluorescence characteristics of drusen during indocyanine-green angiography and their possible correlation with choroidal perfusion. , 1992, German journal of ophthalmology.

[19]  R Eckmiller,et al.  A general numerical method evaluating three‐dimensional eye rotations by scanning laser ophthalmoscopy , 1990, Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians.

[20]  R. Webb,et al.  Confocal scanning laser ophthalmoscope. , 1987, Applied optics.