Choroidal thickness in nonarteritic anterior ischemic optic neuropathy.

PURPOSE

To examine choroidal thickness in nonarteritic anterior ischemic optic neuropathy (AION).

DESIGN

Retrospective case control study.

METHODS

In the eye clinic of the University Medical Center in Mannheim, Germany, we studied a group that consisted of patients with nonarteritic AION and a control group that consisted of individuals with normal fundus. Choroidal thickness was measured by the enhanced-depth imaging of spectral-domain optical coherence tomography. The main outcome measure was choroidal thickness.

RESULTS

The study group consisted of 20 patients: 11 patients with acute nonarteritic AION and an unaffected contralateral eye and 9 patients with acute unilateral nonarteritic AION and previously nonarteritic AION in the contralateral eye. The control group consisted of 58 patients (58 eyes). In multivariate analysis, thinner subfoveal choroidal thickness was associated with the diagnosis of nonarteritic AION (P = 0.001; regression coefficient B, -55.1), after adjusting for age (P < 0.001) and refractive error (P = 0.20). Similarly, unaffected eyes contralateral to eyes with acute nonarteritic AION as compared to control eyes showed thinner subfoveal choroidal thickness (P = 0.037) after adjusting for age (P = 0.001) and refractive error (P = 0.06). In a reverse manner, nonarteritic AION was associated with thinner subfoveal choroidal thickness (P = 0.007) after adjusting for age, optic disc diameter, gender, and refractive error.

CONCLUSIONS

Eyes affected by nonarteritic AION and unaffected contralateral eyes showed significantly thinner macular choroids than eyes of a control group after adjusting ocular and systemic parameters. A thin choroid may be added to the diagnostic features of nonarteritic AION. Future studies may examine the pathophysiologic meaning of the finding.