Foveal RPE autofluorescence as a prognostic factor for anti-VEGF therapy in exudative AMD.
BACKGROUND
Autofluorescence (AF) of the retinal pigment epithelium (RPE) are thought to reflect metabolic activity of the RPE cells, which in turn is largely driven by photoreceptor outer segment renewal. In exudative AMD, choroidal new vessels (CNV) may be confined to Bruch's membrane, or transgress the RPE, with consequence loss of photoreceptor cells. It has been suggested that they may be distinguished with autofluorescence imaging. The aim of our study was to analyze the prognostic value of RPE autofluorescence in relationship to the therapeutic outcome of anti-VEGF (vascular endothelial growth factor) therapy in exudative AMD.


METHODS
AF images (Heidelberg Retina Angiograph) were obtained from 95 eyes (95 patients, mean age 77.64 years, 39 male and 56 female) with exudative macular lesions and associated drusen before therapy with intravitreal Bevacizumab (Avastin). Increased, normal, or decreased AF of a central area with diameters of 500 and 1,000 microm around the foveola were distinguished, and compared with the outcome of central vision. As a measure of data reproducibility (inter- and intraobserver variability), the kappa statistics (K > 0.6 "good", K > 0.8 "excellent") and exact agreement in % were calculated.


RESULTS
Analysis of AF showed a significant difference in outcome of visual acuity in eyes with changes in AF of the central 500 and 1000 microm (Mann-Whitney test, p500 mum < 0.001, p1,000 microm = 0.02). Comparison of eyes with increased AF to the other eyes also resulted a significant difference in visual acuity at follow-up (p (incr) < 0.001); those with decreased AF had no significant difference to the eyes with normal or increased AF (p (decr) = 0.1733).


CONCLUSIONS
The RPE-AF of exudative AMD lesions varies greatly. The AF differences probably represent different kinds of metabolism disorders in the RPE. Furthermore, they apparently have a great influence on the chances of anti- vascular endothelial growth factor (VEGF) therapy success; in particular the development of visual acuity is less favorable in eyes with initially increased central AF.
Department of Ophthalmology, St. Franziskus Hospital, Hohenzollernring 74, 48145 Münster, Germany. heimesb@web.de
Britta
B
Heimes
Albrecht
A
Lommatzsch
Meike
M
Zeimer
Matthias
M
Gutfleisch
Georg
G
Spital
Alan C
AC
Bird
Daniel
D
Pauleikhoff
D000368:Aged; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab; D005122:Exudates and Transudates; D005260:Female; D005453:Fluorescence; D005584:Fovea Centralis / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008062:Lipofuscin / Q000378:metabolism; D008268:Macular Degeneration / Q000175:diagnosis* / Q000188:drug therapy*; D008297:Male; D015588:Observer Variation; D010857:Pigment Epithelium of Eye / Q000378:metabolism / Q000473:pathology*; D011379:Prognosis; D011726:Pyridinium Compounds / Q000378:metabolism; D012176:Retinoids / Q000378:metabolism; D012189:Retrospective Studies; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors*; D014792:Visual Acuity
C112040:A2-E (N-retinylidene-N-retinylethanolamine); D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D008062:Lipofuscin; D011726:Pyridinium Compounds; D012176:Retinoids; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab