Retinal deposits associated with type III GD
B. Obtain previous laboratory records documenting reduced glucocerebroside enzyme activity
The differential diagnosis of multiple flecklike retinal lesions includes infectious diseases (viral retinitis and bacterial or fungal chorioretinitis), inflammatory conditions (white dot syndromes), and primary hereditary retinal dystrophies (fundus albipunctatus and retinitis punctata albescens). In this patient, examining a vitreous sample for viral polymerase chain reaction (choice A) or administering an intravitreal injection of voriconazole (choice D) would not be the next recommended steps, as the patient did not have any sign of inflammation, making the diagnosis of a viral or fungal retinitis unlikely. In the absence of nyctalopia or visual field defects, an electroretinogram to rule out a hereditary retinal dystrophy was not indicated (choice C). Obtaining previous laboratory records that document reduced glucocerebroside enzyme activity (choice B) would support the diagnosis of GD, as this patient was receiving enzyme replacement therapy for more than 8 years, and current glucocerebroside enzyme activity would be normal.