Ocular Evaluation and Disposition after Suspected Laser Exposure

INTRODUCTION

This Clinical Practice Guideline provides information and instructions for medical providers responsible for Service members following a suspected directed energy (DE) exposure involving the visual system. (Consider: There is little experience in the general medical community with DE and having a high index of suspicious for this type of injury is important. If a DE exposure is suspected – early consultation with ocular care providers is important as is having a full understanding of the physiologic and anatomic effects of this type of injury. Ocular DE injury can result in mission compromise and pose safety hazards to the individual and the unit.) These suspected exposures, presumed caused by a laser or other intense bright light source, can compromise the ability to execute mission essential functions. For the purposes of this guideline, the term laser will also include any light source, visible or invisible, capable of resulting in potential injury. The intent of this guideline is to provide a better understanding of this type of injury and its effects and to establish a care algorithm for first-line providers and follow-on care by eye care providers. This CPG is based on expert consensus because there is little available data on this type of injury. Specifically, it includes the key elements of a Service member’s history, examination, disposition, and medical record coding following potential exposures. Service and unit-specific reporting procedures for exposures and possible injuries are also included. Early recognition and treatment of potential injuries is essential to maintain optimal visual performance. In addition, timely reporting is essential to assess the operational impact of these exposures/injuries.

Clinical Scenarios

1. An aircrew making a final approach is exposed to a laser source, leading to temporary flash blindness. Spatial awareness and situational awareness is effected, compromising actions during critical operations. The symptoms resolve without functional or anatomic evidence of damage.
2. A mounted service member employs an escalation of force visible laser during operations. The beam is reflected of the turret mirror resulting in close proximity exposure. Central vision is immediately compromised. Evaluation shows decreased vision and retinal edema. This results in a central retinal scar and loss of vision

BACKGROUND

Lasers emit nonionizing radiation in the ultraviolet, visible, and infrared portions of the electromagnetic spectrum. When the eye is exposed to this energy, temporary disruption of visual function or permanent injury may occur.1 Lasers available for wide scale commercial purchase that emit at visible wavelengths (including red, green, and blue) have been increasingly reported in laser strikes on commercial aircraft. These laser strikes on commercial aircraft have been reported most frequently during takeoff and landing.2 A review of these civilian aircraft incidents found that while these laser strikes have not resulted in any documented permanent changes in visual functional or structural damage to the eyes, they have been documented to cause immediate visual effects, including flash blindness, glare, and startle that can interfere with critical functions on board the aircraft. Based on reports by civilian pilots that have been directly exposed, recovery of optimal visual function can take from seconds to minutes. However, alterations in visual function can last from several minutes to several hours.3

Potential exposures of the visual system to laser threats that are present across the spectrum of military operations are more varied. Laser technology is incorporated into multiple weapons systems from both friendly and hostile forces and presents a threat of temporary visual effects or permanent injury to the eye. Most laser systems designed for military use emit at infrared wavelengths that cannot be seen by the human eye. Visible laser systems also pose a threat to military operations. A review of data from the Defense and Veterans Eye Injury and Vision Registry (DVEIVR) from 2006-2018, found 132 service members with documentation of exposure in the medical record. Of these cases reviewed, five service members found to have permanent damage compromising visual function as a result of exposure.