Diagnostic accuracy of multifocal pupillographic objective perimetry in early age-related macular degeneration

Abstract

 

Purpose

 

To evaluate the diagnostic accuracy of multifocal pupillographic objective perimetry (mfPOP) in eyes with small (<63 µm), intermediate (≥63 to <125 µm) and large (>125µm) drusen using three different stimulus protocols.

 

Methods

 

Pupil responses were recorded from subjects with small (9 eyes, mean age 66.5 ± 14), intermediate (6 eyes, mean age 72.8 ± 5.2) and large (25 eyes, mean age 67.6 ± 11) drusen and compared with 20 normal controls (mean age 70.2 ± 9.88) using three 6 minute mfPOP stimulus protocols. Stimuli were presented dichoptically and both pupil responses were measured concurrently. All stimuli were yellow with a maximum luminance of 288 cd/m² and background 10 cd/m². A dart board layout having 44 independent test regions per eye extending from fixation to15° eccentricity, either using a sequence previously used in the lab with 33 ms flashes (OldStimuli), or using a new temporal sequence method was employed. Two protocols used the new temporal sequence method and on each presentation either flashed on for 33 ms (NewStimuli); or presented pedestal flicker for 266 ms at 15Hz (NewStimuliFlick). Diagnostic capacity was measured using areas under the curve (AUC) of receiver operator characteristic (ROC) plots for the two worst regions in each eye for the three mfPOP stimuli protocols.

 

Results

 

The absolute mean difference of AREDS scores between eyes was 0.48 ± 0.6 (mean ± SD). Response amplitudes for the NewStimuli achieved the best diagnostic accuracy with AUC values of 100% ± 0.0% (mean ± SE) for eyes containing small, intermediate and large drusen. In comparison NewStimuliFlick and OldStimuli were less diagnostic across all AREDS categories. In eyes containing small drusen NewStimuliFlick and OldStimuli achieved AUC values of 87.0% ± 6.8% and 92.6% ± 7.1% respectively for small drusen, 87.0% ± 8.1% and 65.8% ± 14.6% for intermediate drusen and 86.0% ± 5.3% and 82.0% ± 6.7% for large drusen. Utilizing time to peak response deviations reduced diagnostic accuracy across all stimulus protocols.

 

Conclusions

 

The new temporal sequence stimuli produced the best diagnostic accuracy for all AMD severities, in comparison to the old continuous sequence stimuli and the same stimuli containing flicker.

 

Keywords: 412 age-related macular degeneration • 667 pupil • 758 visual fields