Analysis of peripapillary choroidal thickness in non-arteritic anterior ischaemic optic neuropathy

Purpose To analyse peripapillary choroidal thickness (PCT) in non-arteritic ischaemic optic neuropathy (NAION). Methods 28 patients diagnosed with NAION (37 affected and 19 unaffected eyes) and 38 disease-free control individuals (38 eyes) were analysed using enhanced-depth imaging of spectral-domain optical coherence tomography. A vertical and a horizontal raster scan centred on the optic nerve were obtained per eye. PCT was measured at the superior, inferior, nasal and temporal quadrants from the posterior edge of the retinal pigment epithelium to the choroid-sclera junction at 500 mu m intervals up to 2000 mu m away from the optic nerve. Statistical analysis was used to compare average PCT and to correlate PCT with other ocular and systemic parameters. Results Mean PCT in NAION eyes and control group was 148.18+/-42.68 mu m and 182.90+/-59.81 mu m, respectively (p=0.005). Except for inferior PCT (p=0.158), superior, nasal and temporal PCT were significantly thinner in the NAION eyes than in the control group (p=0.006, 0.002 and 0.046). Thinner PCT, adjusted for refractive error, was associated with the diagnosis of NAION (p=0.048). Similarly, unaffected contralateral eyes showed a significant thinner PCT compared with the control group (p=0.024). Diagnosis of NAION was negatively associated with PCT in NAION eyes (p=0.008; OR 0.98; 95% CI 0.97 to 0.99) and in their contralateral unaffected eyes (p=0.043; OR 0.98; 95% CI 0.97 to 0.99). Conclusions Eyes affected by NAION and contralateral unaffected eyes showed significantly thinner PCT compared with disease-free control eyes after adjusting for refractive error.