Abstract
Purpose: :
To determine and differentiate retinal sensitivities in dry and wet age-related macular degeneration (AMD) with scanning laser ophthalmoscope imaging stabilized microperimetry (SLO-MP) with eye tracking.
Methods: :
47 eyes with dry and wet AMD and 21 age matched controls were imaged with SLO-MP (OPKO health, Miami, Fla.), using a custom microperimetry pattern to evaluate retinal sensitivity to a Goldmann III size target (108 microns on the retina) with a step-ladder algorithm to determine maximal sensitivity. Along with MP, AMD eyes had standardized protocol Spectral domain optical coherence tomography (SD-OCT), and fluorescein angiography (FA). Study eyes were categorized in three groups: Group 1: drusen, Group 2: geographic atrophy (GA), Group 3: choroidal neovascularization (CNV). We also evaluated longitudinal changes in retinal sensitivity during the course of anti-VEGF therapy of CNV.
Results: :
16 eyes with dry AMD and drusen, 12 eyes with GA, and 19 eyes with non- or pre-treated CNV were analyzed. In group 1, retinal sensitivity over drusen (mean 12.1 ± 0.47 dB) was significantly reduced compared to uninvolved adjoining retina 15.8 ± 0.32 dB (p<0.0001). In group 2 we confirmed an absolute scotoma in GA, and compared sensitivity at the border of GA to adjoining uninvolved retina; the median sensitivity at GA margins was 4.8 ± 0.72 dB versus 13.7 ± 0.7 dB (p< 0.0001). In group 3 we found a significant difference in sensitivity of retina overlying subretinal fluid (SRF) 9.55 dB, intraretinal fluid (IRF) 9.95 dB and pigment epithelium detachment (PED) 11.4 dB versus adjoining control areas 15.32 dB (each p<0.0001). In scars without photoreceptor outer line structure preservation there was an absolute scotoma similar to areas of GA. During the course of anti-VEGF therapy, retinal function improved as evidenced by increased sensitivity in the area.
Conclusions: :
SLO-MP can detect and document retinal dysfunction in all types of AMD. We found retinal sensitivity loss over drusen, possibly due to changes in overlying photoreceptors. Retina at GA margins also showed reduced sensitivity, and these areas overly SD-OCT RPE changes. In wet AMD, retinal sensitivity in areas of SRF, IRF or PED showed differences in the subtypes of CNV, and sensitivity improved during the course of anti-VEGF treatment. Our findings demonstrate that in AMD, MP is a useful diagnostic tool to predict disease progression and track treatment as it allows simultaneous retinal viewing and OCT measurements as well as microperimetry.
Keywords: macula/fovea • choroid: neovascularization • clinical (human) or epidemiologic studies: systems/equipment/techniques