Ischemic ophthalmoplegia in diabetic mellitus

Abstract

Purpose : To analyze the natural course of ischemic diabetic palsies of the 3 rd , 4 th , and 6 th cranial nerves and their correlations with the status of diabetic control and retinopathy. Materials and methods : Twenty-nine patients with diabetic ophthalmoplegia, treated in Kaohsiung Medical University Hospital during the period 1996-1999, were included in the study. Data on clinical characteristics of the patients were obtained by chart review and the natural course of the cranial nerve palsies was analyzed. Laboratory studies, neuroimaging, and fundus studies were also performed. Results : Thirty-six episodes of ischemic ophthalmoplegia were recorded in 29 patients. Seventeen episodes of ophthalmoplgia occurred in patients with poor diabetic status. Third cranial nerve involvement occurred in 21 episodes, six of which (28.6%) had pupil involvement. Four patients had 4 th cranial nerve palsy and 11 episodes in nine patients involved 6 th cranial nerve palsy. Four patients had recurrent or alternate cranial nerve involvement, and three had simultaneous multiple cranial nerve involvement.The mean duration of paralysis was 2.8 ± 1.5 months with a significant difference ( p = 0.009) between the complete and incomplete palsy groups. Most of the cases had either no diabetic retinopathy ( No-DR )(55.2%) or only background diabetic retinopathy ( BDR )(34.5%). Except for average age, no significant difference was found between No-DR , BDR , and proliferative diabetic retinopathy ( PDR ) groups with respect to the duration of the palsies and fasting blood sugar levels. Age was significantly higher in the less severe diabetic retinopathy group (especially in the No-DR group). Conclusion : Cranial neuropathy with ophthalmoplegia is benign and self-limited. The oculomotor nerve was the most frequently involved in our group. Recovery time was dependent on ophthalmoplegia severity.The status of diabetic retinopathy and blood sugar level was not significantly related to the prognosis. Older diabetics (age > 63 years) had less severe retinopathy during attacks of ophthalmoplegia (p < 0.05). There might also be other risk factors, such as arteriosclerosis, inflammation, or anatomic variation, intervening in the pathogenesis of diabetic ophthalmoplegia.