Hyperbaric oxygen treatment for paracentral acute middle maculopathy: a case study

A 47-year-old active-duty Navy diver with a complicated past medical history which resulted in his designation as not physically qualified (NPQ) for diving duty in 2016 presented on 07 May 2021 complaining of left-sided blurred vision. On exam by the attending undersea medical officer he was found to have a left upper inner and upper outer quadrant visual field defect along with a central scotoma. Urgent referral to ophthalmology ruled out retinal detachment but resulted in an initial diagnosis of a left branch retinal artery occlusion without embolus. Considering this a variant of central retinal artery occlusion, hyperbaric oxygen (HBO2) therapy was initiated approximately 12 hours after symptom onset, resulting in complete, though temporary, resolution of the visual field defect. He reported that after completion of his first HBO2 treatment, his visual field deficit began to return, but the deficit again resolved after initiating surface oxygen therapy between HBO2 treatments. After two days of continuous surface oxygen and daily HBO2 treatments, which kept his visual field defect minimized, his deficits changed to a persistent left lateral peripheral defect and a recurrent central nasal defect. At this time, his periodic ophthalmology evaluation revised his diagnosis to cilioretinal artery occlusion (CrAO). Further evaluation by ophthalmology revealed retinal changes consistent with a secondary diagnosis of paracentral acute middle maculopathy (PAMM), an ophthalmologic condition only recently defined in the literature (2013) [10] secondary to advances in retinal imaging technology. This case is presented to share the findings of this complicated case and to postulate a benefit from the use of HBO2 for cilioretinal artery occlusion with PAMM.