Comparison of macular optical coherence tomography findings between postacute retinal artery occlusion and nonacute optic neuropathy.

PURPOSE: The purpose of this study was to report differentiating optical coherence tomography (OCT) findings between postacute retinal arterial occlusion (PARAO) and nonacute optic neuropathy (NAON). METHODS: A retrospective observational comparative study included 17 eyes with postacute permanent retinal arterial occlusion and 32 eyes with NAON whose assessment included a fast macular Status OCT. The macular OCT changes in the postacute phase of central retinal arterial occlusion and branch retinal arterial occlusion were, respectively, compared with those in diffuse and segmental NAON in an effort to establish differentiating features. The findings were used in the workup of four additional consecutive cases referred with suspected NAON. RESULTS: Three main features differentiating PARAO from NAON were identified on macular OCT. Complete inner retinal atrophy with loss of the normal stratification of the inner retinal layers, loss of the normal foveal depression, and marked thinning of the involved retina were characteristic findings of PARAO and were absent even in the most severe cases of NAON. The involved retina was significantly thinner in PARAO compared with that in NAON (P < 0.05). These OCT features helped establish the diagnosis of PARAO in four additional consecutive cases referred with the misdiagnosis of NAON. CONCLUSION: The extent and pattern of inner retinal atrophy differentiate PARAO from NAON and help guide the systemic workup.