COVID-19 Precautions Needed in Ophthalmology

By Lisa Rapaport

April 17, 2020

(Reuters Health) - Consensus recommendations are needed to prevent the spread of COVID-19 within the ophthalmology profession, doctors conclude in an editorial published in Ophthalmology.

"We've learnt that there are varying practice patterns worldwide in management of the COVID-19 outbreak," said coauthors Dr. Daniel Ting of Duke-NUS Medical School in Singapore and Dr. Steven Yeh of Emory Eye Center at Emory University School of Medicine in Atlanta.

For example, there are no standardized guidelines internationally in the usage of PPE among ophthalmologists, a problem that is exacerbated by a global shortage of personal protective equipment (PPE), Drs. Ting and Yeh said by email.

"During the pandemic, it will be important to gather evidence about the potential for viral infection of the eye, as well as the effectiveness of risk reduction strategies to protect the patients, public and health personnel," Drs. Ting and Yeh said.

Shedding appears to be highest in the earliest stages of infection, according to the editorial. Asymptomatic carriers of SARS-CoV-2 may confer a particular risk to ophthalmologists during examination.

Specific factors may place ophthalmologists at increased risk of infection during examination of their patients, compared to the risk experienced by clinicians in other disciplines. For instance, the face-to-face proximity of the slit lamp biomicroscopic examination may place the ophthalmologist at a high risk of aerosolized particles.

Of the healthcare workers who died from COVID-19 in Wuhan, three were Chinese ophthalmologists who worked in the same unit, including Dr. Li Wenliang, who believed he was infected while treating an asymptomatic glaucoma patient, according to the editorial.

The route of transmission in these cases is unknown, but the upper respiratory system and nasopharynx are a major site of viral infection, and likely present a higher risk to the ophthalmologist than exposure to tear film harboring SARS-CoV-2.

Recent studies have shown that viral RNA may be observed in association with the small minority of patients who display conjunctivitis. Viral RNA has not been identified in the tear film of COVID-19 patients without conjunctivitis to date, but data represent sampling performed early in disease

In most countries, ophthalmologists and patients are required to wear surgical face masks instead of N95 respirators, according to the editorial. On-site temperature screening and regular hand hygiene are broadly required for both patients and doctors.

Given the rapid surge of COVID-19 and mortality rates, China and some other countries have required ophthalmologists to wear full PPE including N95 masks for all patients.

Many practices are adopting custom designed or commercially available slit lamp breath shields to minimize respiratory droplet transmission during the ophthalmic exam. However, custom-made barriers could also become a potential source for contamination and must be carefully sterilized between patients.

Clear consensus statements with regard to operational issues such as clinic flow protocols, instrument cleaning protocols and the appropriate use of PPE under different circumstances will help in the appropriate allocation of scarce resources, the authors conclude.

"COVID-19 patients can (spread) novel coronaviruses by touching tears or eye secretions with their hands, or contaminate eye examination equipment with eye secretions, and then infect other people," said Dr. Liang Liang, of the department of ophthalmology at Yichang Central People's Hospital in China.

"The measures that ophthalmologists can take are: doctors and patients wear masks, goggles, and doctors should wear protective clothing if possible; hand hygiene is very important," Dr. Liang, who wasn't involved in the editorial, said by email. "Ophthalmic equipment needs to be disinfected after each application; (doctors) should check the throat swab, lung CT, blood analysis before surgery."

Avoidance of rubbing eyes, in addition to proper hand and respiratory hygiene, is important, said Dr. Dennis Shun Chiu Lam, chairman and chief executive of C-MER International Eye Care Group in Hong Kong.

"Furthermore, to lower the risk of cross infection, patient contact areas of general ophthalmic equipment such as slit-lamp, non-contact tonometer, autorefractor, etc. should be disinfected with 70%-75% ethanol or isopropyl alcohol immediately after each use," Dr. Lam, who wasn't involved in the editorial, said by email.

SOURCE: Ophthalmology, online March 31, 2020.