Prof. John Pearn1
1Lady Cilento Children’s Hospital, South Brisbane , Australia
All members of Burns Teams are aware that thermal damage to the eye is a rare event. In a recent survey of hundreds of burns to the face, only three lesions involving conjunctival or corneal damage have been identified. The question arises, what are the mechanisms that protect the eyeball in the context of otherwise severe facial and periorbital burns? This paper explores the four mechanisms which comprise this innate protective bulwark, mechanisms produced by genetic selection through vertebrate evolution. In evolutionary terms, any vertebrate, primitive Homo included, died if they were blinded and their genes were lost to the population pool. The four protective mechanisms comprise: (a) the blink reflex, the fastest reflex in mammals; (b) the menace “reflex”, a protective blink and aversion response, present in 97% of infants by four months of age, with a reactive time of 0.25 milliseconds in young healthy adults; (c) Bell’s Phenomenon, absent during the blink reflex but the more intense with enforced involuntary eye closure during thermal threat; and (d) the insulating protection of tears due to their specific heat and specific conductance. This protective armamentarium is bypassed by shorter wavelength radiation outside the visible spectrum, resulting in thermal injury of “welders’ flash”, also known as the “Saturday Night Syndrome”.
Professor Fred Leditschke has given a professional lifetime to both the clinical care of burns patients, especially children, and influential advocacy to reduce mortality from childhood trauma, the two themes embodied in this Tribute Lecture.
Professor John Pearn is a Senior Paediatrician at the Lady Cilento Children’s Hospital; and the Paediatrician to the PEGG-Leditschke Burns Unit. A former Surgeon General of the Australian Defence Force, he has served as the Intensivist and Senior Physician on operational deployments in Papua New Guinea, Vietnam, Rwanda and Banda Aceh. He has published extensively in the research and advocacy domains of trauma management and prevention.