Multimodal Views of the Human Retina
A. Terry Bahill *
Systems Engineering, University of Arizona,1622 W. Montenegro, Tucson AZ USA, 85704-1822, USA
Patrick J. Barry
Envision Eye Care Center, Tucson Arizona, USA
*Author to whom correspondence should be addressed.
Abstract
Aims:To show the relationships among subject-reported measures of vision, the view through an ophthalmoscope, the view through a slit lamp, the view through a clinician’s eye, optical coherence tomography (OCT) images, fundus photos, visual field diagrams and Optomap images.
Methodology: Over 1000 clinical ocular measures (taken on one subject over a six-year period of time) were collected, analyzed and summarized. These measures were reduced to 50 images and tables: they were then categorized and filtered, and the essence resulted in the figures contained in this paper.
Results: This paper shows that the retina literature is full of contradictory nomenclature. For example, clinicians use the term fovea to name the 1° diameter disk at the very center of the retina and they use the term macula to name the 5° diameter ring that surrounds it. Whereas, anatomists use the term fovea to name the 5° diameter disk at the center of the retina and they use the term macula to name the 20° diameter ring that surrounds it. This paper demonstrates how the same information appears in the subject’s reports of vision, a facial photograph, an optical coherence tomography image, a fundus photo and a visual field diagram. Finally, it shows how to map information between these views.
Conclusions: The retina-viewing techniques analyzed in this paper can be compared qualitatively, but differences in the techniques preclude precise superposition of the images. A perfect mapping is impossible: because (among other reasons) the algorithms for transforming three-dimensional (3D) shapes into two-dimensional (2D) images are nonlinear and are different for different techniques.
Keywords: Retina imaging, OCT, fundus photograph