Ophthalmic surgery and Creutzfeldt-Jakob disease

Although the evidence does not suggest that contaminated ophthalmic instruments represent a risk of onward transmission of sporadic CJD, this conclusion should be treated with caution The occurrence of variant Creutzfeldt-Jakob disease (vCJD) and the probable causal link with bovine spongiform encephalopathy (BSE) in cattle have increased interest in the search for possible environmental sources of sporadic CJD (sCJD). Presumed iatrogenic CJD is rare. Up to the year 2000 there had been 267 cases reported worldwide: three cases secondary to human corneal grafting (one confirmed, one probable, and one possible case), 114 related to human dura mater grafts, 139 related to human growth hormone treatment, four related to human pituitary gonadotrophin therapy, and seven linked to neurosurgical procedures or stereotactic EEG electrodes.1 Because of the marked resistance of the infectious agent of CJD to conventional sterilisation techniques, there is concern about the possibility of transmission of infection via surgical instruments in contact with infected tissue, especially in neurosurgery or ophthalmic surgery. The presence of infection in the eye in sCJD was first demonstrated following the intracerbral inoculation of pooled sCJD eye tissue in non-human primates.2 Recently the infectious form of prion protein (PrPSc) has been identified in the neural retina, optic nerve, and in retinal pigmented epithelium in variant and sporadic CJD using immunohistochemistry or western blot,3,4 with comparable levels to those found in brain. PrPSc was not detected in other ocular tissues. Although this suggests that there may be a greater risk of contaminating surgical instruments in procedures involving the posterior segment of the eye, infectivity has been demonstrated in animal and human cornea,5 and circumstantial evidence has implicated corneal transplantation as a mechanism of transmission of iatrogenic CJD.6 Experimental infection has been achieved following conjunctival installation of scrapie infectivity in …