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A Strategy for Averaged Estimates of Visual Field Threshold: Spark

de la Rosa, Manuel Gonzalez PhD; Gonzalez-Hernandez, Marta PhD

doi: 10.1097/IJG.0b013e318239c1a3
Original Studies

Purpose: The purpose of this work is to design a rapid perimetric strategy to provide averaged results.

Methods: We designed a simulation examination model using the distribution frequency of local deviations or defects, based on a retrospective study of 90,335 examinations performed in a glaucoma department.

Results: Threshold deviation from normal age-adjusted values of 6 points representative of the main areas of glaucomatous visual field allowed estimating the real mean deviation (MD) with a correlation coefficient r=0.995 (SE=0.71 dB) when original values were used, and r=0.984 (SE=1.26 dB) when values from a rapid simulated test model were used. SE of the local deviations (average=3.06 dB) was close to usual mean threshold fluctuation in patients with different degrees of defect. In patients with early glaucoma (MD<6 dB) the SE of the estimated MD was <0.9 dB and the SE in estimating the local point-to-point deviations was 1.8 dB. We included 3 additional phases to obtain 3 additional results and a final averaged result. For the average and median of the 4 phases, the SE of MD ranged from 0.4 to 0.5 dB for the whole sample and from 0.3 to 0.4 in early glaucoma. Local deviation SE was close to 2 dB in the whole sample and between 1.2 and 1.5 dB in early glaucoma.

Conclusions: Bearing in mind threshold fluctuation, the strategy allows for several possible outcomes, and provides averaged and theoretically more stable results.

Hospital Universitario de Canarias, University of La Laguna, Santa Cruz de Tenerife, Spain

Disclosure: Both authors have proprietary interest in the Spark patent.

Reprints: Manuel Gonzalez de la Rosa, PhD, Facultad de Medicina, Universidad de La Laguna. 38071 La Laguna, Santa Cruz de Tenerife, Spain (e-mail:

Received May 8, 2011

Accepted September 19, 2011

© 2013 Lippincott Williams & Wilkins, Inc.