Abstract
Purpose :
Drusen in age-related macular degeneration (AMD) are known to be associated with disruptions to retinal pigment epithelium (RPE) cells, which in turn lead to structural and functional deficits of photoreceptors. Here we investigated quantitatively the impact of CSF drusen on VA and SDH.
Methods :
Twenty patients (mean age±SD 73.4±8.2 yrs) with early to intermediate AMD were reviewed retrospectively. The study eye had drusen in the CSF of ETDRS macular grid with VA 0.30 logMAR (20/40) or better (mean 0.12±0.11 logMAR), and had SD-OCT volume scans including CSF. Twenty normal subjects served as controls (69.8±7.8 yrs; VA 0.02±0.08 logMAR). OCT volume scans were first segmented automatically using Spectralis software (ver. 1.9.10), then were manually corrected, if needed, to obtain average CSF thickness (CSFT) and CSF RPE/drusen thickness. The SDH was obtained using myVisionTrack® app (Vital Art & Science) on a mobile device (Wang, et al. IOVS 2013 54:5497-505). A linear regression model was employed to assess the relationship between OCT thickness and visual function measurements.
Results :
There was no significant difference in CSFT between the AMD group (288.4±21.3SD μm) and the control group (287.4±19.6 μm, p>0.87). In comparison, the mean CSF RPE thickness of the AMD group (36.1±9.0 μm) was higher than that of the control group (22.8±1.5 μm, p<0.0001). Both VA and SDH of the AMD group were significantly worse than the control group (p<0.0022 for VA, p<0.0001 for SDH). Linear regression analyses revealed that, while both VA and SDH of AMD eyes were correlated with CSF RPE thickness, SDH showed higher correlation coefficient (r=0.79, p<0.05) compared to VA (r=0.41). In addition, the slope of the regression line between SDH and CSF RPE thickness was twice that between VA and CSF RPE thickness (p<0.05). Neither VA nor SDH was significantly correlated with CSFT.
Conclusions :
These results support the hypothesis that drusen lead to photoreceptor dysfunction and deficits in visual function. The results also suggest that the displacement of photoreceptor outer segment due to drusen impacts the veridical perception of local position and orientation cues required for optimal performance of SDH (Wang & Hess, Vis Res 2005), hence rendering a greater loss of hyperacuity than VA. SDH may be a more effective functional marker than VA to predict disease progression of AMD.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.