Dr Jennifer Acton
Research Topics and Related Projects:
My research interests involve the examination of structure to function relationships in age-related macular degeneration (AMD), which was established during my PhD and developed during my postdoctoral research fellowships abroad.
I have carried out work involving the assessment of the visual field in the healthy eye and in retinal disease, using perimetric tests such as standard perimetry, short-wavelength automated perimetry (SWAP) and microperimetry. I am also interested in imaging techniques including optical coherence tomography in association with image analysis techniques such as retinal layer segmentation. Recent studies have included multimodal imaging investigation and visual field instrumentation comparisons, involving the MP-1 microperimeter and the Humphrey Field Analyzer (HFA).
Summary of findings:
- In early AMD, thinning of the outer segment layer, measured using retinal layer segmentation of spectral-domain optical coherence tomography images, was significantly associated with reduced microperimetry sensitivity (Figure 1).
- A greater decline in visual loss due to increasing severity of AMD was found, using short-wavelength automated perimetry compared to conventional perimetry, although not all individuals with AMD are suitable for SWAP examinations.
- A Bayesian model was appropriate to model normative data collected using the MP-1 microperimeter.
- Despite similarities in stimuli and threshold procedures between microperimetry (MP-1) and conventional perimetry (HFA), there are important differences between instruments that need to be taken into account when interpreting visual field results. These include the difference in dynamic range, normative data and background luminance levels. The amount of visual loss detected, differed between instruments and this was dependent upon adaptation level and type of retinal disease.
Figure 1. Microperimetry results in early AMD.
Dr Vivienne C. Greenstein, Dept of Ophthalmology, Columbia University, Microperimetry in retinal disease