Endogenous Endophthalmitis and Other Ocular Manifestations of Injection Drug Use

Preston M. Luong; Edmund Tsui; Nikhil N. Batra; Michael E. Zegans

Disclosures

Curr Opin Ophthalmol. 2019;30(6):506-512. 

In This Article

Embolic Retinopathy

Another known ocular consequence of injection drug use is the development of embolic pathology. Talc, a mineral composed of magnesium silicate, is a common filler of drug tablets that can be crushed and injected into systemic circulation. Larger particulates can be trapped in the pulmonary circulation but those smaller than 7 μm can bypass the lung and enter systemic circulation.[26] From the systemic circulation, talc particles can embolize to various tissues including the bone marrow, visceral organs, and lymph nodes. When such particles become trapped in the smaller retinal vessels, talc retinopathy can develop. Although most patients are asymptomatic, visual acuity may be impaired if occlusion causes severe macular ischemia, retinal neovascularization, vitreous hemorrhage, or retinal damage.[27,28] Other potential complications include foreign body granuloma within the retina and optic disc neovascularization.[29] On funduscopic exam, talc retinopathy is characterized by the presence of numerous refractile bodies lodged within retinal vessels. Fluorescein angiography may disclose areas of capillary nonperfusion, vessel occlusions, and leakage.[2] Disease course for talc retinopathy is typically static as the particles cannot be metabolized and visual acuity and clinical findings remain unchanged after months or even years.[26,27]

Endocarditis is a well known complication of injection drug use with many systemic consequences. It may lead to valve insufficiency and serve as a microbial reservoir for further hematogenous spread.[30] These microorganisms may travel through the bloodstream and seed an ocular infection through the choroid. Classic ocular findings include conjunctival hemorrhage and Roth spots, which are recognized as retinal hemorrhages with pale centers. However, these phenomena occur infrequently in cases of infectious endocarditis, present in less than 5% of patients.[31,32] This is in contrast to the highly sensitive but nonspecific findings of fever and elevated inflammatory markers, appearing in greater than half of patients. Treatment typically involves an extended course of systemic antibiotics with or without surgical valve repair.[33]

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