Dichoptic Multifocal Pupillography Reveals Afferent Visual Field Defects in Early Type 2 Diabetes

Abstract

Reasonable diagnostic power was obtained, especially for the 16 eyes that had had T2D for more than 10 years, inferring that even in the near absence of visible diabetic retinopathy, some retinal damage had been sustained. This result, if confirmed in a wider group, suggests the that the method may be clinically useful in screening for early damage to the retina in T2D diabetes.

Stimulus Parameters for Multifocal Pupillographic Objective Perimetry

“…The method has been shown to reduce the effects owing to changes in mean pupil size associated with age. [23][24][25] We examined the main effects defining the difference in responses obtained for the 10 protocols using multivariate regression models. The AmpStd data were first transformed to decibels, which stabilized the variance and allowed multiplicative effects to be fitted.…”

“…The ROC analysis was based upon deviations from the median data of the normal subjects computed for each visual field location. 23,25 The medians were computed at each visual field location across eyes and pupils. The resulting decibel deviations from that normative data are like the total deviations of a perimeter.…”

“…Detailed explanation of this method has been given. 25 Figure 2A shows the median peak amplitudes for each stimulus protocol, computed across eyes, direct and consensual responses, visual field locations and subjects. The responses to the infrequent stimuli (OnDI, OnI, F15I) were particularly large; however, their variances were also large (as evidenced by the large SE).…”

“…All the mean fields were quite similar having the largest responses in the temporal field as reported previously for different multifocal stimuli. [21][22][23]25 Two of the stimuli that had lower presentation rates, OnI, and F15I had responses that were consistently large across the field. Given the differences across the field seen for the other stimuli, the combination of larger responses and flatter fields might indicate saturation of the responses to these stimuli.…”

“…Those methods have been demonstrated to have diagnostic value in glaucoma and early stage diabetic retinopathy. [23][24][25] In addition dichoptic stimulation permits independent information about afferent and efferent pupil defects to be obtained at every visual field region. 25,26 To elucidate the optimum stimulus conditions for glaucoma diagnosis, the present study examines the diagnostic performance of 10 mfPOP stimulus variants.…”