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Published February 2009 | public
Journal Article

Quantitative analysis of central visual field defects in macular edema using three-dimensional computer-automated threshold Amsler grid testing

Abstract

Purpose; To evaluate the central visual field (CVF) with specialized Amsler grid testing methods that include contrast sensitivity evaluation, in an attempt to detect abnormalities not identified with standard methods and to define new patterns of CVF deficits in two different diseases. Methods: 3D computer-automated threshold Amsler grid testing (3D-CTAG) was performed at five levels of contrast in one eye of 37 patients with diabetic macular edema (DME, n = 16) and exudative age-related macular degeneration (AMD, n = 21). Results: 3D-CTAG abnormalities were detected in six patients (16%) who had no abnormalities with conventional Amsler grid testing. DME patients had more foci of CVF deficits (3.56 ± 2.92 defects/eye), than AMD patients (1.24 ± 0.89 defects/eye; P  < 0.0002). The shape of the 3D-CTAG abnormality in DME was an inverted cone, while the deficits in AMD were always cylindrical. All eyes showed significant increases in CVF deficit surface area at minimum contrast levels when compared to maximum contrast (295% greater with DME, P < 0.02 and 150% greater with AMD, P < 0.03). Conclusion: 3D-CTAG detected CVF abnormalities not identified with conventional Amsler grid testing in 16% of subjects. Low-contrast conditions elicited a larger defect in both DME (3-fold) and AMD (1.5-fold). DME and AMD have unique 3D-CTAG profiles, enabling diagnostic discrimination. Measuring CVF defects with 3D-CTAG can quantitatively index disease severity and may be useful in longitudinal studies of the natural history of disease, as well as providing a quantitative outcome measure of the response to therapy.

Additional Information

© 2009 Springer. Received: 12 May 2008. Revised: 26 September 2008. Accepted: 6 October 2008. Published online: 29 October 2008. This research was supported by funding from the VMR Institute, Huntington Beach, California. The results of this study have been presented in part at the Western Retina Study Club meeting in Pasadena, CA, USA, March 2007 and at the Association for Research in Vision and Ophthalmology (ARVO) meeting in Fort Lauderdale, FL, USA, May 2007. The principal investigator, JS, had full access to all the data in the study, and takes responsibility for the integrity of the data and accuracy of the data analysis. All authors agree to allow Graefe's Archive for Clinical and Experimental Ophthalmology to review their data if requested. All human studies have been reviewed by the appropriate ethics committee and have therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki. Competing interests: Authors AAS and WF may have proprietary interest in the 3D computer-automated threshold Amsler grid test described in the study as patents on the technology are issued.

Additional details

Created:
August 22, 2023
Modified:
October 17, 2023