[Near triad measurement--accommodative pupillometry with horizontal eye tracking and its qualitative analysis]

Recording of "near triad responses" was done by static accommodative stimulation to reveal the qualitative analysis of asthenopia.

Twelve healthy subjects in agegroups of 20, 30, and 40 years were examined before and after several hours of visual display terminal (VDT) work after informed consent. Three trials of forward <-> backward movement of focusing on a target were carried out. Response curves of horizontal eye tracking and pupillary diameter, that is, convergence with miosis and divergence with mydriasis, were recorded continuously, bilaterally and simultaneously by TriIRIS.

1) Normal patterns of vergence and pupillary responses with constant amplitudes were recorded in five subjects and were stable. 2 ) Gradual decline of the mydriatic peak was observed in two subjects, suggesting spastic accommodation. Increasing mydriatic peak or notching of mydriatic phase was seen in one eye each, suggesting tonic disaccommodation. These abnormal patterns were reversed by adequate refractive correction, and classified as an eye-fatigue group. 3) Abruption of miotic phase was observed in two cases of exophoria. 4) Low and declining amplitudes despite normal light response were observed in two subjects, suggesting debilitated accommodation, and they were classified as an eye-strain group. 5) Post-traumatic mydriatic anisocoria responded in parallel, suggesting paretic accommodation.

Coordinated dynamics of near triad responses revealed remarkable characteristics of accommodative iris movements with vergence. These objective findings revealed the different patterns of functional disorder of accommodation.