Relative afferent pupillary defect with normal vision and vertical strabismus—implications for pupillary pathway anatomy

Abstract

A pathologic RAPD with normal vision can be caused by tumour compression of the contralateral pretectal nucleus or its afferent or efferent fibres. As an implication for pupillary pathway anatomy, our case suggests that there is equal distribution between crossing and non-crossing intercalated neurons. An associated strabismus can show a non-paralytic pattern.

The pupillary light reflex pathway

“…This assumption is strengthened by several cases of a RAPD with normal visual function in lesions close to the LGN or pretectal region as well as by reports of optic tract lesions without a RAPD. 4,28,[37][38][39][40][41][42][43][44] The present findings also support the concept of cortical input into the PLR (figure 3), which may enter the PLR pathway via the area depicted in figures 1B and 2. Therefore, disturbed processing of signals along this part of the geniculostriate pathway can lead to a RAPD.…”