hydroxychloroquine (Plaquenil) Toxicity - Taiwanese 56 year old female (Asian)

56 year old female on 400 mg plaquenil for 22 years presents with vision loss. VA 20/50 both eyes. Plaquenil was stopped. The vision in the left eye continued to deteriorate to 3/200. 5'2" 127 lb (6.6 mg/kg body weight)