To compare peripapillary choroidal thickness, macular thickness, and peripapillary retinal nerve fiber layer (RNFL) thickness between the affected eyes of patients with non-arteritic anterior ischemic optic neuropathy (NAION) and their unaffected eyes and the eyes of normal control participants.

Thirty eyes with NAION, 30 unaffected fellow eyes, and 25 normal control participants who met the inclusion criteria were included in this prospective comparative study at a single academic institution. The optic disc area, macular thickness, and RNFL thickness were evaluated in the last follow-up session using spectral-domain optical coherence tomography (OCT). Enhanced depth imaging OCT was obtained to evaluate peripapillary choroidal thickness (PCT).

The mean follow-up time was 4.9 ±0.9 months and all data was collected from the last follow-up session. The mean optic disc area in the NAION eyes and their unaffected fellow eyes was significantly smaller than normal control participants (P<0.001). The mean PCT in the NAION eyes, unaffected fellow eyes, and the control group was 201.6±42.4, 212.1±45.1, and 166.9±49.9 µm, respectively (ANOVA, P=0.01). All regional PCT values were significantly greater in the NAION eyes and unaffected fellow eyes than the control eyes. In all participants, the optic disc area was correlated with the average PCT (r = ?0.33, P = 0.002). In addition, RNFL thickness and macular thickness values were significantly lower in the NAION eyes versus the unaffected fellow eyes and control eyes.

PCT is thicker in NAION eyes and unaffected fellow eyes than control eyes. Thick peripapillary choroid might contribute to the development of NAION.