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    Haptic Length in Intrascleral Haptic Fixation

    In reference to “Intrascleral Haptic Fixation as an Alternative to Sutures” (Clinical Update, May), I’d like to add that the causes of IOL tilt after flanged IOL fixation are asymmetric needle penetration and length mismatch between cornea diameter and haptic.

    To prevent the former issue, I created an instrument to keep the needle penetration angle constant so that any sur­geon who is unfamiliar with flanged IOL fixation can fix the IOL without tilt. (The tool is currently sold in Japan and is expected to be available in other countries within the year.)

    When surgeons feel that the haptics are long, they should cut the haptics by 1-2 mm. In the glue technique, the haptics are externalized about 3 mm outside the eye. In the flanged technique, since the length of the haptics to be externalized is shorter, the scenario is the same as it would be when using the glue technique on haptics that had been cut slightly.

    Shin Yamane, MD
    Urafune-cho Minami-ku, Yokohama, Japan

    Reusing Tonometers Increases Risk of Illness

    How to Disinfect and Calibrate Your Goldmann Applana­tion Tonometer” (Clinical Update, May) brings an important subject to the attention of eye care professionals. However, there are some inadvertent oversights in the article. The statement “no case of Creutzfeldt-Jakob disease has been linked to GAT” may not be entirely accurate.1

    Additionally, the potential risk of transmission of hepa­titis C via tonometry was not given enough attention. In the cohort of adults born between 1950 and 1960, the prevalence of hepatitis C infection is estimated to be 5%, and a majority of those infected are in a chronic carrier state without any disease manifestation.2 The hepatitis C virus (HCV) is pres­ent in tears of infected individuals and can be infectious.3 HCV is now the leading cause of death from infectious disease in the United States, and its associated mortality rate is expected to increase.4

    The presence of HCV and other infectious agents in the tears of carriers is a public health issue and a potential occu­pational health hazard. As carriers manifest no symptoms of infection, any individual is potentially infectious. The only way to prevent transmission via tonometry is through the use of disposables.

    We must protect the health of our patients and the public.

    Francis Y. Falck Jr., MD, PhD, MS
    Mystic, Conn.

    ___________________________

    1 Davanipour Z et al. Br J Med Med Res. 2014;4(12):2322-2333.

    2 HCV epidemiology in the United States. Hepatitis C Online. https://www.hepatitisc.uw.edu/pdf/screening-diagnosis/epidemiology-us/core-concept/all;HCV.

    3 Feucht H et al. J Clin Microbiol. 1995;33(8):2202-2203.

    4 The Clinical Advisor. 2016;(6):6. https://issuu.com/clinicaladvisor/docs/ca0616_digital-edition.

    A Response

    We thank Dr. Falck for his interest in the article and agree with him that this subject is important.

    Dr. Falck voices concern that the risk of prion disease transmission, such as Creutzfeldt-Jakob disease (CJD), is misrepresented in the article. In support, he quotes Davanipour et al.,1 who establish that eye care providers may perform tonometry on asymptomatic carriers of CJD. However, the incidence of prion disease is low in the United States (approximately 1 case per million per year).2-4 The risk of prion transmission by applanation tonometry is considered low to none by experts in the field,5 who advise that instruments contam­inated with high-risk tissue (i.e., brain, spinal cord, retina) from patients with known or suspected CJD require special precautions.2 To date (June 18, 2018), there are no reports of prion disease transmission by tonometry. We agree with Dr. Falck that absolute elimination of prion transmission will require the use of disposable instruments.

    Similarly, there are no reports of HCV transmission via tonometry to date (June 18, 2018). The prevalence of hepatitis C may be on the rise, but the virus is readily eliminated by 10% dilute bleach (hypochlorite), as are the human immunodeficiency virus, herpes simplex virus 1 and 2, and adenoviruses, with adenovirus being the greatest threat for nosocomial infection in the eye care setting.6

    Philip P. Chen, MD, Seattle
    Teresa C. Chen, MD, Boston
    Anna K. Junk, MD, Miami
    Shan C. Lin, MD, San Francisco
    Kouros Nouri-Mahdavi, MD, Los Angeles
    Sunita Radhakrishnan, MD, San Mateo, Calif.
    Kuldev Singh, MD, MPH, Palo Alto, Calif.

    ___________________________

    1 Davanipour Z et al. Br J Med Med Res. 2014;4(12):2322-2333.

    2 Rutala WA, Weber DJ. Clin Infect Dis. 2001;32(9):1348-1356.

    3 CDC. Creutzfeldt-Jakob Disease, classic (CJD). Occurrence and transmis­sion. https://www.cdc.gov/prions/cjd/occurrence-transmission.html.

    4 CDC. Variant Creutzfeldt-Jakob disease (vCJD). vCJD cases reported in the US. https://www.cdc.gov/prions/vcjd/vcjd-reported.html.

    5 Rutala WA, Weber DJ, Healthcare Infection Control Practices Advisory Committee. Guideline for disinfection and sterilization in healthcare facilities, 2008. Atlanta: CDC; 2008. https://www.cdc.gov/infectioncontrol/guidelines/disinfection/.

    6 Junk AK et al. Ophthalmology. 2017;124(12):1867-1875.