Topical apraclonidine testing discloses pupillary sympathetic denervation in diabetic patients

Autonomic denervation is common in diabetes mellitus (DM). Pupillary sympathetic denervation (PSD) has been found in Horner syndrome following instillation of apraclonidine 0.5%. We have applied this technique to investigate the prevalence of PSD in DM.

Apraclonidine 0.5% was instilled in the eyes of 50 patients with DM and 30 age-matched and gender-matched subjects without DM (control subjects). Pupil diameters (PD) were measured before and 60 minutes after instillation. The duration of DM and the degree of diabetic retinopathy (DR) were recorded for each patient.

Apraclonidine instillation caused an average of 0.9 mm of mydriasis (range 0 to 4.5 mm) in DM and -0.1 mm miosis (range 0.5 to -1 mm) in control subjects (P < 0.001). Mydriasis of at least 1 mm was observed in 42% of DM patients. The change in PD was highly correlated with the duration of DM (r = 0.368, P = 0.008) and the presence of DR (r = 0.532, P < 0.001).

Apraclonidine testing, which is easy to perform and not distressing to the patient, identified PSD in nearly half of DM patients, the degree of mydriasis being correlated to the duration of DM and the presence of DR.