Abstract
Purpose: :
Increased fundus autofluorescence (AF) has been reported to occur in the new foveal location following 360° full macular translocation (FMT) surgery. The aim of this study is to investigate whether these findings correlate to morphological changes on SD-OCT and functional outcomes.
Methods: :
We retrospectively evaluated a series of 34 eyes of 34 patients who underwent 360° FMT between September 2003 and July 2009. All the eyes were affected by subfoveal choroidal neovascularization secondary to high myopia (5/34 eyes) or age-related macular degeneration (29/34 eyes). All of them revealed new areas of hyper-AF after surgery as determined with a Heidelberg HRA scanning laser ophthalmoscope (wavelength of 488nm). Patients were recalled for further examination with SD-OCT (Heidelberg HRA Spectralis) and fundus microperimetry (Nidek MP-1). Qualitative analysis through hyper-AF areas was made for presence or absence of external limiting membrane (ELM), inner/outer segment interface (IS/OS) and retinal pigment epithelium (RPE). Outer nuclear layer (ONL) thickness was measured inside the hyper-AF area and in the adjacent retina with normal-AF; retinal sensitivity scores were collected.
Results: :
Mean pre-operative BCVA was 0.18±0.09. After surgery mean BCVA was 0.37±0.28. OCT scanning through hyper-AF areas showed abnormal outer retinal layers: the ELM was present in 13% of the cases, discontinuous in 19%, or absent in 68%. IS/OS interface was either absent (77%) or discontinuous (23%); RPE was normal (61%) or irregular (39%). Mean ONL thickness in hyper-AF areas was 32.40 µm, whereas it was 57.10 µm in the adjacent normal-AF areas. Median retinal sensitivity was 8 dB and 13 dB respectively. Retinal sensitivity was significantly lower when IS/OS was absent (ANOVA p<0.01) and hyper-AF was present (ANOVA p<0.0001).
Conclusions: :
hyper-AF after FMT360 seems to be due to absence or rarefaction of photoreceptors outer segments of translocated neuroretinal layer instead of accumulation of lipofuscin inside RPE cells. ONL is reduced and retinal sensitivity is lower but present in these areas.
Keywords: vitreoretinal surgery • age-related macular degeneration • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)