A strategy for averaged estimates of visual field threshold: spark.
OBJECTIVE
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. mgdelarosa@telefonica.net
Manuel Gonzalez
MG
de la Rosa
Marta
M
Gonzalez-Hernandez
D005260:Female; D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D012189:Retrospective Studies; D012684:Sensory Thresholds / Q000502:physiology*; D058609:Visual Field Tests / Q000379:methods; D014794:Visual Fields / Q000502:physiology*