A medicine called OGT 918 has been shown to slow the production of the lipid that builds up in Gaucher disease. It also has been shown to enter the brain. It is hoped that taking OGT 918 will reduce the storage of glycolipids in cells and improve the neurological symptoms of the disease. This clinical trial seeks to evaluate OGT 918 as a treatment for neuronopathic Gaucher disease by assessing changes in eye movement velocity. A secondary goal is to assess the clinical safety and tolerability of OGT 918 therapy.