1 Abnormal Pupil Condition

Adies tonic pupil

Adies tonic pupil is a neurological condition of unknown origin with an unusual, asymmetric presentation known as anisocoria, an inequality in the size of the pupils of the eye.

A result of damage to the nerve innervating a muscle of the eye known as the ciliary body. Alternately, the problem may be located at the ciliary ganglion, a kind of nerve junction structure from which the nerve to the ciliary body runs.

Accommodation, or the adjustment of the eye for distance, is affected, as well as pupillary dilation and contraction, the ability of the eye's iris to open. Accommodation, or the adjustment of the eye for distance, is affected, as well as pupillary dilation and contraction, the ability of the eye's iris to open or close in response to ambient light.

Activation of the near response in this situation produces a better near reaction than light reaction (light-near dissociation of the pupils), and the reaction is tonic.

It is caused by damage to the postganglionic fibers of the parasympathetic innervation of the eye, usually by a viral or bacterial infection which causes inflammation, and characterized by a tonically dilated pupil.






References

Adie's tonic pupil: Definition from Answers.com
http://www.answers.com/topic/adie-s-pupil
Adies Tonic Pupil: General Health - Australian Lifestyle Message Boards
http://www.au.messages.yahoo.com/lifestyle/general-health/30?p=3
Tonic Pupil: Up to date for patients
http://www.uptodate.com/patients/content/topic.do?topicKey=~4xxNsYPaPiTR1r

Measuring Pupil Size

Pupillary Pathway

When light shines on the left eye, the temporal nerve fibres of the left eye will be transmitted to its pretectal nucleus, and then to ipsilateral Edinger Westphal Nucleus. It then passes to its ipsilateral ciliary ganglion via its parasympathetic nerve. Then, the information goes on to the left sphincter through the short ciliary nerve. This marks the direct papillary pathway.

At the same time when information is passed from the temporal nerve fibres to its ipsilateral pretectal nucleus, nasal nerve fibres are also passed to contralateral pretectal nucleus. From the contralateral pretectal nucleus, it branches its information out to ipsilateral and contralateral Edinger Westphal Nucleus. From the ipsilateral Edinger Westphal Nucleus, information is also passed on to ipsilateral ciliary ganglion via the parasympathetic nerve. Information is then passed to the sphincter of right eye via short ciliary nerve to also constrict. This marks the consensual papillary pathway.