Paracentral Acute Middle Maculopathy in Pregnancy.

A 31-year-old previously healthy, pregnant woman presented with acute, unilateral, painless paracentral vision loss in the left eye. The results of neuroimaging studies were normal. Hypercoagulable workup was negative, and fundus examination showed no retinal emboli and no retinal vascular abnormalities. The patient had well-controlled blood pressure and did not have eclampsia/preeclampsia. Although a presumptive referral diagnosis of "optic neuritis" was made, optical coherence tomography (OCT) of the macula showed a hyperreflective band involving the inner nuclear layer, consistent with paracentral acute middle maculopathy (PAMM). Furthermore, OCT angiography (OCT-A) showed flow attenuation of the outer retinal capillary plexus, further supporting a diagnosis of PAMM in pregnancy. Clinicians should be aware of the benefit of OCT-A as a complement to macular OCT in the evaluation of acute monocular vision loss mimicking retrobulbar optic neuropathy, particularly when signs and findings of other retinal vasculopathy are absent. PAMM should be considered in pregnant patients with acute visual changes.