Fig 1.
Red and blue lines represent the afferent pathway, the ganglion cell axons project to the pretectal region of the midbrain; green line represents the efferent pathway, the signal transmits from preganglionic parasympathetic fiber to ciliary ganglion, finally to the constrictor muscles through the short posterior ciliary nerve.
Fig 2.
demonstration of one pupil light reflex on pupillometry.
The light onsets at the ‘0’ point; Phase 1 is a fast constriction mainly controlled by PNS; Phase 2 is a fast redilation under the control of both PNS and SNS; Phase 3 is a slow redilation phase, predominantly controlled by SNS activity.
Fig 3.
Structure of the review.
Table 1.
Search steps and results of PubMed.
Fig 4.
PRISMA flow diagram showing process for filtering search results and selecting studies for inclusion.
Table 2.
Summary of the studies comparing PLR parameters between PD patients and normal controls.
Table 3.
Summary of the studies asessesing PLR parameters in Alzheimer’s disease patients and normal controls.
Table 4.
Summary of the studies about the relationship between age and PLR parameters.
Table 5.
Summary of studies about the PLR in DM patients and normal controls.
Table 6.
Summary of the studies about the PLR in obese groups and non-obese controls.
Table 7.
Summary of the studies about the influence of schizophrenia on PLR parameters.
Table 8.
Summary of the results of the studies about the relationship between migraine patients and normal controls when comparing with PLR parameters.
Table 9.
Summary of the studies about the influence of rheumatoid arthritis on the PLR.
Table 10.
Counts of PLR constriction parameters used in all the 36 PLR+PNS studies.