ISSUES: Use of crack cocaine and associated medical complications persists globally. Some reports in medical literature describe a sight-threatening condition commonly referred to as 'crack eye' or 'crack eye syndrome'. The purpose of this review is to describe what is known about crack eye from case reports in peer-reviewed literature.
APPROACH: A structured search was completed in MEDLINE, TOXLINE, EMBASE, PsychInfo, Scopus and Biomed Central, to collect case reports and case series on corneal complications attributed to crack cocaine smoking.
KEY FINDINGS: Of 111 articles screened, 11 contained case reports or series. Thirty individual cases of 'crack eye' were reported. The majority (63%) of cases had bilateral involvement; 83% of all cases with microbial culture results had corneal infections. Aggressive treatment caused an improvement in 95% of all cases and 23% of all cases were lost to follow up. Of those who received treatment for corneal complications associated with crack cocaine, 22% remained with significant visual impairment (hand motions only) in the affected eye.
IMPLICATIONS: Clinicians should consider crack cocaine involvement in patients presenting with corneal disease without known predisposing factors, and elicit comprehensive drug histories to prevent a reduction in visual acuity.
CONCLUSION: Corneal complications of crack cocaine smoking are caused by a number of synergistic factors, including direct toxicity of crack cocaine vapours to surface cells, impairment of neurogenic support to corneal epithelial integrity, desiccation of the eye surface due to diminished blinking reflex, low level chemical burns and mechanical denudement of surface cells through eye rubbing.