7.4 Special Precautions

7.4.1 Disinfection of Ophthalmic Instruments


General equipment

  1. Slit-lamp
  2. Non-contact tonometer
  3. Autorefractor
  • Disinfect with 70-75% ethanol or isopropyl alcohol immediately after each patient


Instruments that had direct contact with patient’s ocular surface

  1. Goldmann applanation tonometer prisms
  2. Diagnostic contact lenses
  • Disinfect by immersion in either 1:10 diluted bleach solution with sodium hypochlorite or 3% hydrogen peroxide for at least 5 minutes. 


Other surgical instruments

  • Sterilized according to standard protocols.


7.4.2 Risk with Non-contact Tonometry (NCT)

  • The air jet impacted on the tear film was reported to generate micro-aerosols. 
  • SARS-CoV-2 was reported to be present in tears and conjunctival secretions from COVID-19 confirmed patients with conjunctivitis
  • Extra caution in patients with red eyes
  • Operators should wear proper face mask or respirator
  • Alternative methods to NCT: rebound tonometry


7.4.3 Ophthalmic Operations

General cases

  • Surgical mask should be worn by all patients entering operating rooms
  • Adhesive tape could be applied across the nose bridge area to ensure complete coverage of patient’s nose and mouth
  • Require patients changing their clothes and putting on surgical caps


Suspected respiratory infection cases (urgent operations)

  • Scheduled as last case of operation
  • Thorough disinfection afterwards
  • Be cautious and vigilant against sharp needles or blades injury


High risk or confirmed cases

  • Refer to hospitals that have adequate facilities such as negative-pressure isolation rooms 

Britt JM, Clifton BC, Barnebey HS & Mills RP (1991): Microaerosol Formation in Noncontact ‘Air-Puff’ Tonometry. Archives of Ophthalmology 109: 225-228.
李纯纯, 唐媛, 陈张艳, et al. 非接触式眼压计测量产生气溶胶密度变化及其对疫情防护的意义.中华实验眼科杂志. In press.