Ocular Tonometry and Sporadic Creutzfeldt - Jakob disease (sCJD): A Confirmatory Case-Control Study

Abstract

AimsTo evaluate the hypothesis that sporadic Creutzfeldt-Jakob disease (sCJD) may be transmitted through ocular tonometry.BackgroundThe infectious agent of sCJD may be present in the cornea prior to clinical symptoms. Cornea infectiousness has been documented by cornea transplants in guinea pigs and humans. sCJD is resistant to complete inactivity by conventional sterilization techniques. Thus contact tonometry equipment is not disinfected sufficiently to kill sCJD. We previously hypothesized that contact tonometry is a sCJD risk factor.Study DesignPopulation-based case-control study.Place and Duration of StudyDepartment of Neurology, School of Medicine, Loma Linda University, Loma Linda, CA, USA; 4 years.MethodologyAn 11-state case-control study of pathologically confirmed definite sCJD cases, individually matched controls, and a sample of control surrogates was conducted. Ocular tonometry histories were obtained from case-surrogates, controls, and a sample of control-surrogates.ResultsThe odds ratio (OR) for ever vs never having had an ocular tonometry test was statistically significant for matched and unmatched analyses for 15 through 3 years prior to disease onset, using both control self-responses and control surrogates: ORs were ∞ and 19.4 with 1-sided P-values <0.0001 and 0.003 and ORs=∞ and 11.1 with 1-sided P-values <0.003 and 0.02, respectively. ORs increased as the number of tonometry tests increased during this age period: trend test, 2-sided P-value < 0.0001. For ≥5 vs <5 tonometry tests, the OR was 5.8 (unmatched) and 3.7 (matched), 2-sided P-value<0.00005. Respondents generally could not specify the type of tonometry. There was no indication of increased tonometry testing among cases within 2 years of disease onset.ConclusionsThe a priori hypothesis was supported. Contact tonometry, preferred by ophthalmologists, may be capable of transmitting sCJD. Consideration should be given to using disposable instrument covers after each use. The use the disposable covers or non-contact tonometry is preferable in the absence of effective disinfectant processes at this time.

The Case For Including Neuroprotective Factors in Sporadic Creutzfeldt-Jakob Questionnaires

“…To uncover potential risk factors, researchers have investigated the link between sCJD and surgery (Hamaguchi et al, 2009;van Duijn et al, 1998;Ward et al, 2002Ward et al, , 2008, ocular tonometry (Davanipour et al, 2014b), profession (Hermann et al, n.d.), physical injuries (Kondo & Kuroiwa, 1982), living with pets (Harries-Jones et al, 1988), and dementia in relatives (Harries-Jones et al, 1988). While factors such as needing surgery or dental work are scarcely modifiable, several interesting studies have examined a possible link between sCJD and highly modifiable dietary factors.…”

Review of Hygiene and Disinfection Recommendations for Outpatient Glaucoma Care: A COVID Era Update

“…Previous studies have reported that applanation tonometry has the potential to transmit a variety of infectious agents, including adenovirus 8 and herpes simplex virus 1, and reusable tonometer prisms could, in theory, be a mode of transmission for hepatitis B, hepatitis C, human immunodeficiency virus, and Creutzfeldt-Jakob disease. [31][32][33][34][35][36][37] A systematic review of 11 studies assessing the disinfection of Goldmann tonometers concluded that there is no definitive optimal technique or agent for the disinfection of Goldmann applanation tonometer prisms. 30,33 The AAO supports the use of diluted bleach for the disinfection of reusable tonometer tips for SARS-CoV-2 and adenovirus.…”

Interventions to reduce the risk of surgically transmitted Creutzfeldt–Jakob disease: a cost-effective modelling review

“…Davanipour et al 124 postulate that ocular tonometry is a risk factor for contracting sCJD from a case-control study conducted across 11 states in the USA. Contact tonometry is used by ophthalmologists to diagnose glaucoma.…”

“…The authors conclude that disposable covers or non-contact tonometry should be used in the absence of adequate decontamination processes. 124 Tullo et al 125 document that there were three recipients of either cornea or sclera from a woman who died of biopsy-proven carcinoma of the bronchus in 1997, but was later neuropathologically identified as having sCJD. 125 At the time of publication, two recipients remained symptom-free of CJD, whereas one patient had died, aged 92 years (7 years after surgery), showing some signs of dementia that were not considered indicative of iCJD.…”