Macular pigment Raman detector for clinical applications
Clinical studies of carotenoid macular pigments (MP) have been limited by the lack of noninvasive, objective instruments. We introduce a novel noninvasive optical instrument, an MP Raman detector, for...
Calculation of ocular single-pass modulation transfer function and retinal image simulation from measurements of the polarized double-pass ocular point spread function
The single-pass modulation transfer function (MTFsgl) is an important numerical parameter that can help elucidate the performance and some processes of the human visual system. In previous studies, th...
Three-dimensional computer-automated threshold Amsler grid test
J. Biomed. Opt., Vol. 9, 149 (2004);
doi:10.1117/1.1625952
Online Publication Date: 7 January 2004
ABSTRACT
REFERENCES (21)
CITING ARTICLES
Wolfgang Fink California Institute of Technology, Pasadena, California, and Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California
Alfredo A. Sadun Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California
Wedescribe a novel method for testing a visual field thatemploys a computer monitor with displays of varying contrast thatpermits unprecedented resolution and characterization of the structure of scotomasin three dimensions. Patients are placed in front of atouch-sensitive computer screen at a fixed distance. With one eyecovered, they focus on a central fixation marker and tracewith their finger the areas on an Amsler grid thatare missing from their field of vision. Increasing degrees ofcontrast of the Amsler grid are simulated by repeating thetest at different gray-scale levels. The results are recorded andthen displayed as topographical contour rings by the computer testprogram. The results can also be rendered as an immediate3-D depiction of the central hill-of-vision. Several clinical pilot studieshave been conducted at the Doheny Eye Institute and morethan 200 patients have been examined with this system sofar. Conditions such as optic neuritis, anterior ischemic optic neuropathy(AION), age-related macular degeneration (AMD), glaucoma, and ocular hypertension havebeen successfully assessed by this test. Each condition provides uniquepatterns that are most evident in 3-D. The 3-D computer-automatedthreshold Amsler grid test is an innovative and noninvasive visualfield test. It provides several advantages over state-of-the-art standard automatedperimetry, including: (1) additional information through 3-D depiction of scotomas,such as location, extent, slope, depth, and shape; (2) highangular resolution (1 deg compared with typically 6 deg); (3)a simple test setup (merely a touch-sensitive computer monitor andthe test software); (4) excellent patient compliance (spending 4 to5 min per eye). In light of its promising initialtests, the 3-D visual field test appears to have thepotential for the early detection and monitoring of various diseasesover time.