The patient was a previously healthy 13-year-old girl who presented with a history of decreasing vision for one week associated with blind spots in each eye. She had no other ocular or systemic complaints. The visual acuity was 20/400 OD and count fingers at 4 feet OS. The anterior segment examination was unremarkable. The vitreous was clear, there was mild disc edema, and there were cotton-wool spots, several intraretinal hemorrhages, and cystoid edema in each macula. There was deep yellowish discoloration in the temporal mid-periphery of the left eye, as can be seen on the fundus photo. Extensive laboratory work-up included an unremarkable CT of the orbits and CBC. ANA and FTA-Abs were negative. Chemistry studies included an elevated creatinine of 2.06 (normal 0.50-1.20), normal BUN, low protein at 4.9 (normal 6.0-8.5), normal liver function tests, and normal amylase, lipase, angiotensin converting enzyme, and lysozyme. The OCTs revealed dramatic cystoid edema. The fluorescein angiogram showed extensive capillary leakage in both maculas as well as capillary nonperfusion in the posterior poles and choroidal nonperfusion in the temporal mid-periphery of the left eye. What are diagnostic considerations? What crucial piece of information has not been yet provided?