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Comparisons of Two Microperimeters: The Clinical Value of an Extended Stimulus Range

Arango, Tiffany, MA1,2*; Morse, Alan R., PhD2; Seiple, William, PhD2,3,4,5

doi: 10.1097/OPX.0000000000001258
Original Investigations

SIGNIFICANCE Fundus-guided perimetry is a common clinical tool used to measure visual field sensitivities. Comparisons between perimeters are often made despite relative differences in hardware parameters. We directly compared two perimeters using Weber contrast, which allowed us to assess the clinical gain associated with the extended stimulus range of the macular integrity assessment (MAIA).

PURPOSE The purpose of this study was to directly compare sensitivity thresholds for two microperimeters, the MAIA and Optos optical coherence tomography/scanning laser ophthalmoscope, using Weber contrast values. We also examined the clinical utility of the extended stimulus range of the MAIA.

METHODS Six normally sighted adults with no visual field loss and 16 adults with low vision were recruited. Thresholds were measured on the MAIA and Optos using the same threshold algorithm and test points. To compare equivalent units, decibel thresholds were converted to light increments in apostilbs and then to delta increment intensities relative to each instrument's background luminance. Repeatability was assessed for normally sighted adults by testing both instruments on 3 separate days.

RESULTS For normally sighted observers, mean thresholds were similar on both instruments, and repeatability within microperimeters was high. The MAIA has a 0.3-log lower contrast range and 1.37 higher contrast range. The lower contrast values did not result in lower thresholds for the normally sighted observers on the MAIA. There was a 25% increase in the number of measurable thresholds owing to the higher contrast values in low-vision observers.

CONCLUSIONS The higher contrast range in the MAIA yielded only a small increase in detectable thresholds for participants with visual field loss.

1Department of Psychology, Northeastern University, Boston, Massachusetts

2Lighthouse Guild, New York, New York

3Department of Ophthalmology, NYU School of Medicine, New York, New York

4Institut de la Vision, Aging in Vision and Action Lab, Paris, France

5Jesse Brown VA Medical Center, Chicago, Illinois *

Submitted: August 24, 2017

Accepted: May 22, 2018

Funding/Support: US Department of Veterans Affairs.

Conflict of Interest Disclosure: None of the authors have reported a conflict of interest.

Author Contributions: Conceptualization: TA, WS; Formal Analysis: TA, WS; Investigation: TA, WS; Methodology: TA, WS; Project Administration: TA, WS; Resources: ARM; Software: WS; Visualization: WS; Writing – Original Draft: TA, WS; Writing – Review & Editing: TA, ARM, WS.

© 2018 American Academy of Optometry