A 40-year-old Japanese woman complained of bilateral metamorphopsia. She had bilateral retinochoroiditis with unknown origin and was referred to the Japanese Red Cross Medical Center, Department of Ophthalmology, Tokyo, Japan in December 2016. She had a history of proteinuria at age 8 and was diagnosed with MPGN type III by renal biopsy in 2011. The laboratory tests showed proteinuria (urinary protein 0.60 g/gCre) and hematuria. Urinalysis showed RBC count of 10-19/high power field (HPF) and WBC count of 1-4/HPF. Hemoglobin (13.4 g/dL), total protein (7.2 g/dL) and albumin (4.2 g/dL) were in normal ranges. Hepatitis B surface antigen and hepatitis C virus antibodies were negative. Immunoglobulin levels were in normal ranges (IgG 1290 mg/dL, IgA 367 mg/dL, IgM 129 mg/dL). Anti-nuclear antibody and anti-neutrophil cytoplasmic antibody were negative. Renal function was normal (blood urea nitrogen 20.0 mg/dL, serum creatinine 0.67 mg/dL, estimated glomerular filtration rate 80.1 mL/min). C3 levels (53 mg/dL) was low, and CH50 (44 U/m) and C4 (22.2 mg/dL) were normal. Renal biopsy showed a lobular appearance of the glomerular tuft with increased glomerular cellularity on hematoxylin and eosin (H&E) staining (Fig. 1a). Periodic acid methenamine silver (PAM) staining showed the double loop sign representing interposition of mesangial cell elements with new glomerular basement membrane synthesis (Fig. 1b and c, white arrow) and has a bubbling appearance (Fig. 1c black arrow). Fluorescence immunostaining showed strong granular C3 staining in both mesangium and capillary loops (Fig. 1d). Electron microscopy showed proliferation of mesangial cells, mesangial expansion (Fig. 1e, star) and subepithelial immune deposits (Fig. 1f, black arrow). She received oral prednisolone 30 mg/day and was gradually tapered between January 2012 and February 2013. She had no family history or history of smoking.
In December 2016, her visual acuities were 20/20 OD and 20/16 OS. The intraocular pressures were 15 mmHg OD and 18 mmHg OS. Slit-lamp biomicroscopic exam revealed no abnormal findings in the anterior segment. No inflammatory cells were observed in the anterior chamber and vitreous cavity in both eyes. Fundus exam revealed numerous yellow-white granular patches at the central macula in both eyes (Fig. 2a and b). Fibrin tissue and a small hemorrhage was noted at the lower part of the central fovea of the right eye (Fig. 2a, white arrow). Fundus auto fluorescence (TRC-DX50, TOPCON, Fig. 2c and d) showed numerous granular hypofluorescence surrounded by a ring shaped hyperfluorescence in both eyes. Fluorescein angiography showed granular hyperfluorescence at the posterior pole of both eyes without fluorescein leakage in the late phase (Fig. 3a and b). Fluorescein leakage from CNV was noted at the inferior parafovea of the right eye (fig. 3a and c, white arrow). There was no leakage at the area of the ring shaped hyperfluorescences in the late phase of the left eye (Fig. 3d). Optical coherence tomography (OCT, CIRRUS HD-OCT model 4000, Carl Zeiss Meditec, Dublin, CA) showed various shaped protrusions of retinal pigment epithelium (RPE) in both eyes (Fig. 4a and b). Apical and basal borders of the RPE showed higher reflection than normal and granular hyperreflective substances were noted at the basal side of the RPE. There was low reflection between the basal side of RPE and Bruch’s membrane at the protruded lesion of RPE. Vertical scan imaging showed CNV and subretinal fluid in the right eye (Fig. 4c, arrow head) and fibrin tissue was noted above the CNV. Full field electroretinogram (ERG, TOMEY LE-2000, TOMEY, Nagaya, Japan) showed normal responses in both eyes.
Serous retinal detachment (SRD) in the right eye disappeared at 11 months after the initial visit and CNV in the right eye disappeared spontaneously with resolution of subretinal fluid at 12 months after the initial visit. (Fig. 5a and c). However, multiple dome-shaped elevations of RPE remained in both eyes (Fig. 5a-d). At 12 months after the initial visit, visual acuities were 20/16 OD and 20/16 OS and there was no recurrence of CNV with SRD.