“Diabetic third nerve palsies are the most common etiologic subset of third nerve palsy in adults. The etiology of diabetic neuropathy is hyperglycemia-induced damage to nerve cells and neuronal ischemic change. The inflammation and immune reaction may be the cause of diabetic neuropathy.”

The third cranial nerve controls the movement of four of the six eye muscles…. A complete third nerve palsy causes a completely closed eyelid and deviation of the eye outward and downward. The eye cannot move inward or up, and the pupil is typically enlarged and does not react normally to light.

“A third nerve palsy may be present at birth (congenital), and the exact cause may not be clear. Acquired third nerve palsy can be associated with head injury, infection, migraine, brain tumor, aneurysm, diabetes, or high blood pressure.”


Chou, Ping-Yin, MD; Kun-Han Wu, MD; and Povin Huang, MD, PhD. “Ptosis as the only manifestation of diabetic superior division oculomotor nerve palsy: A case report.” Medicine (Baltimore). 2017 Nov; 96(46): e8739. Published online 2017 Nov 17. doi: 10.1097/MD.0000000000008739. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5704867/ (accessed on 8/3/2020).

American Association for Pediatric Ophthalmology and Strabismus. “What Causes Third Nerve Palsy?” AAPOS (updated March 2020). https://aapos.org/glossary/third-nerve-palsy (accessed on 8/3/2020).