The typical patient is an intravenous drug abuser who injects a liquid prepared from an oral tablet. This was initially described with oral methadone tablets..
Risk factors for talc retinopathy:
(1) repeated injections (Murphy et al report injection of 9,000 tablets or more)
(2) failure to completely solubilize the medicine and to filter the liquid
(3) some sort of right-to-left shunt
The material is often inert and insoluble (why it was chosen as a pharmaceutical filler) so can persist for years after the abuse has stopped.
Examination of the fundus will show deposits that are irregularly shaped and refractile.
If a deposit can be retrieved then it can be submitted for analysis if the specialized resources are available.
A patient with talc retinopathy is also at risk for:
(1) pulmonary talcosis (with interstitial fibrosis)
(2) microembolization to the brain, kidney, heart and/or digits
Differential diagnosis:
(1) bacterial endocarditis
