Late last year, rescue defenders assigned to the 943d Security Forces Squadron demonstrated proper usage of Mission Oriented Protective Posture gear during a training exercise at Davis-Monthan Air Force Base in Arizona. MOPP gear protects service members from toxic exposures during wartime operations, such as in chemical, biological, radiological, or nuclear warfare environments. Photo by Master Sgt. Luke Johnson.
OMAHA, NE — As chemical agent exposure remains a threat to military servicemembers, it’s important to consider that each chemical agent affects the eye differently and requires appropriate treatment, according to a recent review article.
Published in Frontiers in Toxicology, the article reviewed the literature on the ophthalmic manifestations and treatment considerations for a range of emerging chemical threats, including vesicants (mustards, lewisite), nerve agents (sarin, VX), knockdown gasses (hydrogen cyanide) and caustics (hydrofluoric acid).1
Chemical agents “have been used in warfare for centuries, and during armed conflict, these agents pose a threat to the health of civilians and military personnel,” according to the authors. In addition to “temporarily disarming opposing forces or causing fatality at high concentrations, many chemical agents have significant long-term effects,” the review article reported. “Chemical agent exposure remains a threat despite treaties and regulations against the use of these agents.”
“Many of these chemical agents have both acute and chronic ocular complications, and measures to understand their effects and countermeasures for systemic and organ-specific health are needed,” the authors suggested.
For this report, ophthalmologists from the University of Nebraska Medical Center in Omaha, NE, partnered with colleagues from the Walter Reed National Military Medical Center in Bethesda, MD, and other collaborators to consider the broad issues of emerging chemical threats.
“Each agent affects the eye differently, needing special care, which is dependent on the chemical exposure,” Steven Yeh, M.D., professor and Stanley Truhlsen Jr. Chair in Ophthalmology at University of Nebraska Medical Center in Omaha told U.S. Medicine. “For instance, sulfur mustard can result in corneal edema (swelling), in addition to uveitis (inflammation within the eye), while other agents such as sarin or VX can lead to pupillary constriction, in addition to other systemic effects.”
“The treatments vary depending on the specific area of the eye affected,” Yeh said. “One of the most critical interventions is ocular rinsing with tap water, normal saline or lactated Ringer’s solution to flush the chemical from the eye’s surface and normalize the ocular pH. The systemic therapy varies depending on the inciting chemical agent.”
If alteration of the ocular pH is observed, “acute interventions include normalization of pH to 7.2 to 7.4,” according to the review article. “Besides vigorously flushing the eye, acute therapies may also include topical corticosteroids and non-steroid anti-inflammatory therapies,” the article reported.
The authors explored this topic because they saw a need for an article “that synthesized existing and up-to-date information on the ocular management of emerging chemical threats,” Yeh advised.
Eye Manifestations
“This is particularly notable, as chemical agents have been used in recent conflicts,” Yeh said. “In some situations, eye manifestations can be an early sign of chemical exposure (e.g., pupillary construction and lacrimation, or tearing with nerve agents).”
When a patient is suspected of being exposed to any chemical agent, “it’s critical that healthcare professionals also wear proper personal protective equipment to prevent self-contamination,” he suggested. This can include “fluid impervious gowns, aprons, protective footwear, gloves, chemical resistant glasses or shields and respirators. Proper donning and doffing techniques are essential in these potentially challenging situations,” he explained.
“An important immediate consideration includes ocular rinsing to flush the chemical from the ocular surface,” Yeh said. “An ophthalmology consultation is a consideration for immediate evaluation, treatment recommendations and ongoing care of sequelae of a chemical exposure, which may involve care beyond the acute event.”
“Besides the management of the acute event, ongoing ophthalmic care—both medical and surgical—may be needed, depending on the type of chemical treat, amount of exposure and mechanism of action. Awareness of known chemical agents and their effects, as well as general preparedness, are important for broader management of suspected chemical incidents,” he added.
This literature review provides a “compendium of emerging chemical threats, and we hope that this will continue to raise awareness and improve operational readiness for ophthalmologists and the multidisciplinary care team in the event of a chemical incident or suspected chemical threat exposure,” Yeh wrote in an email.
Unfortunately, “chemical warfare agents continue to remain a threat for military personnel and civilians, especially in areas with political and civil unrest,” the researchers pointed out. Future studies are needed “to better understand the acute and chronic complications of these chemical agents and the appropriate local ophthalmologic and systemic management,” the study authors suggested.
“The ocular effects of these chemical agents aren’t well-known, and in the event of any chemical exposure, early onset of ophthalmic symptoms requires an assessment of ocular structures,” according to the authors, adding that early recognition of dangerous toxins is crucial to “prevent acute and long-term disabling complications and ocular consequences.”
Having a better understanding of these agents “will improve the ability to identify and treat both civilians and military personnel in the event of a chemical incident,” the researchers concluded.
- Menke BA, Ryu C, Justin GA, Chundury RV, Hayek BR, Debiec MR, Yeh S. Ophthalmic manifestations and management considerations for emerging chemical threats. Front Toxicol. 2023 Oct 18;5:1281041. doi: 10.3389/ftox.2023.1281041. PMID: 37941806; PMCID: PMC10629503.