Short wavelength fundus autofluorescence versus near-infrared fundus autofluorescence, with microperimetric correspondence, in patients with geographic atrophy due to age-related macular degeneration.
OBJECTIVE
To compare standard short-wavelength fundus autofluorescence (SW-FAF) and near infrared-wavelength fundus autofluorescence (NIR-FAF) in detecting geographic atrophy (GA) secondary to age-related macular degeneration, and its retinal sensitivity impairment.


METHODS
Twenty-five consecutive patients (36 eyes) affected by GA were studied by means of fundus autofluorescence imaging, using both SW-FAF (excitation: 488 nm, emission >500 nm) and NIR-FAF (excitation: 787 nm, emission >800 nm). All patients underwent microperimetry to assess fixation characteristics and retinal sensitivity.


RESULTS
In the extrafoveal region, the total hypoautofluorescent (hypo-FAF) area was significantly wider with NIR-FAF than with SW-FAF (8.03±6.68 mm(2) vs 7.37±6.34 mm(2) respectively; p=0.005). In the foveal area, the total hypo-FAF area was smaller with NIR-FAF than with SW-FAF (0.19±0.03 mm(2) versus 0.42±0.12 mm(2) respectively; p=0.008). Foveal sparing was larger at NIR-FAF compared with SW-FAF (p=0.021). In nine cases (25%) the site of fixation was hypoautofluorescent on SW-FAF, but normal on NIR-FAF with preserved retinal sensitivity.


CONCLUSIONS
Standard SW-FAF may overestimate GA in the foveal area, correctly detected by NIR-FAF. In the extrafoveal area, SW-FAF may underestimate GA. Standard SW-FAF should be integrated with NIR FAF when detecting and following GA to avoid inconsistent results and misinterpretation, from both a morphological and functional perspective. Microperimetry helps to quantify retinal sensitivity in GA.
Pilotto
Elisabetta
E
Department of Ophthalmology, University of Padua, via Giustiniani 2, Padua 35128, Italy. elisabetta.pilotto@unipd.it
Vujosevic
Stela
S
Melis
Riccardo
R
Convento
Enrica
E
Sportiello
Patrik
P
Alemany-Rubio
Ernesto
E
Segalina
Sara
S
Midena
Edoardo
E
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005453:Fluorescence; D005584:Fovea Centralis / Q000378:metabolism / Q000473:pathology; D057092:Geographic Atrophy / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007259:Infrared Rays; D008268:Macular Degeneration / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009887:Ophthalmoscopy / Q000379:methods* / Q000592:standards*; D015203:Reproducibility of Results; D012684:Sensory Thresholds; D014792:Visual Acuity; D058609:Visual Field Tests / Q000379:methods* / Q000592:standards*; D014794:Visual Fields