A 37-year-old man presented with sudden blurred vision in the left eye (LE). Best-corrected visual acuity (BCVA) was 20/20 in the right eye (RE) and 20/200 in the LE, and there was a left relative afferent pupillary defect (RAPD). Intraocular pressure was 16 mm Hg bilaterally. Slit-lamp examination of the RE showed no evidence of intraocular inflammation in the anterior chamber or vitreous cavity. Results of fundus examination of the RE were unremarkable. Slit-lamp examination of the LE showed a quiet anterior chamber and 1 + vitreous cells. Fundus examination of the LE revealed a localized inflammatory vitreous exudate overlying an infiltrated optic disc and peripapillary retina with associated retinal hemorrhages (Fig. 1A). There was no evidence of retinal vascular sheathing, retinal infiltrates, or any other abnormality elsewhere in the left fundus. Late-phase fundus fluorescein angiography (FFA) of the LE showed optic disc leakage and a masking effect from retinal hemorrhages (Fig. 1B). Swept-source OCT (SS-OCT) (DRI OCT Triton plus, Topcon, Tokyo, Japan) of the optic nerve head showed a “mushroom-shaped” hyperreflectivity of the PIVE seen clinically (Fig. 1C). There was an associated shallow macular serous retinal detachment (Fig. 1D). SS OCTA of the LE revealed a dark area overlying the optic disc and peripapillary retina due to blockage from the PIVE. This hypointense area was found to decrease in size while scanning deeper layers, reflecting the “mushroom-shaped” hyperreflectivity of the PIVE (Fig. 1E,F,G). There was a surrounding retinal hypervascularity with a sectoral superotemporal hyposignal area. Macular OCTA showed no obvious abnormal findings. Results of FFA, OCT, and OCTA of the RE were unremarkable.
The patient denied any prior history of specific systemic symptoms. A diagnosis of presumed toxoplasmic neuroretinitis was made based on a positive anti-toxoplasmic IgG titer and a negative laboratory work-up for other infectious and non-infectious causes of uveitis and neuroretinitis. These included cat scratch disease, rickettsial disease, tuberculosis, syphilis, sarcoidosis, and BD. The patient was treated with the association of azithromycin (500 mg the first day, and then 250 mg/day), pyrimethamine (100 mg the first day, and then 50 mg/day), folinic acid (15 mg/day), and oral prednisone (0.75 mg/kg/day). After 4 weeks of therapy, visual acuity of the LE had improved to 20/32, and the PIVE and associated optic disc and peripapillary infiltration had completely resolved (Fig. 1H).
One year after the initial presentation, the patient complained of acute vision loss in the RE. BCVA was 20/200 in the RE and 20/20 in the LE, and there was a right RAPD. Slit-lamp examination showed a quiet anterior chamber and 2 + vitreous cells in the RE. There was no evidence of intraocular inflammation in the anterior chamber or vitreous cavity in the LE. Fundus examination of the RE revealed a localized PIVE overlying an infiltrated optic disc and peripapillary retina with associated retinal hemorrhages (Fig. 2A). There was no evidence of retinal vascular sheathing, retinal infiltrates, or any other abnormality elsewhere in the right fundus. Fundus examination of the LE showed a mild temporal optic disc pallor with superotemporal bundle retinal nerve fiber layer (RNFL) defects (Fig. 3A). SS OCT of the RE showed a “mushroom-shaped” hyperreflectivity of the PIVE seen clinically and the presence of peripapillary subretinal fluid involving the fovea (Fig. 2B). An OCTA scan in the RE through the radial peripapillary capillary network showed a hypointense area overlying the optic disc and peripapillary retina due to blockage from the PIVE. There was a surrounding peripapillary retinal hypervascularity with a peripapillary vascular density (PVD) of 11.23% (Fig. 2C). OCT retinal thickness analysis of the LE showed RNFL thinning at the superotemporal region corresponding to the RNFL defects seen clinically, with an area of subclinical inferotemporal RNLF thinning (Fig. 3B and C). Results of OCT and OCTA of the LE were unremarkable.
Physical examination by an internist revealed a recent history of recurrent oral ulcers and showed the presence of genital aphthous ulcers, pseudofolliculitis, and papulopustular lesions. A final diagnosis of BD was made based on a score of 5 according to the International Criteria for diagnosis of Behçet's Disease 4. The patient was treated with oral prednisone (1 mg/kg/day, followed by gradual tapering) and azathioprine (3 mg/kg/day).
Sequential follow-up examinations showed gradual resolution of acute inflammatory changes and improvement of visual acuity in the RE. At the one- month follow-up, BCVA was 20/20 in the RE and remained unchanged at 20/32 in the LE. There were no cells in the anterior chamber or vitreous cavity in either eye. Fundus examination of the RE showed complete resolution of the PIVE and underlying optic disc and peripapillary infiltration and the development of macular hard exudates (Fig. 2D and G). SS OCTA showed the resolution of the prepapillary hyposignal area and decrease in peripapillary hypervascularity, with a PVD of 9.18% (Fig. 2F and I). Over a further 6-month follow-up period, BCVA remained stable, the macular hard exudates in the RE gradually resolved, and no inflammatory flare-ups occurred.