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Optic disc swelling occurs when there is an obstruction to axonal transport at the level of the lamina cribrosa. This may result from compression, ischemia, inflammation, or metabolic and toxic etiologies. Some of these etiologies may be life threatening and others may be self-limited. Thus, differentiating the different etiologies is important, albeit often difficult. We present a case of a 25-yr-old high-performance fighter aviator who presented with unilateral optic disc swelling 2 d after an F-16 flight, in which decompression was suspected. Visual acuity of the affected eye was decreased to 20/25, with enlarged blind spot and shallow arcuate scotomata on visual field testing. Pupil function, brightness intensity, and color vision were normal. Marked swelling of the entire optic disc, retinal flame-shaped hemorrhages, and engorgement of the retinal veins were seen. Since decompression sickness with nitrogen bubbles obstructing the optic nerve head vasculature was suspected, he was treated with hyperbaric oxygen. He rapidly improved, recovering full vision function within 6 d. No concurrent disease was found on extensive investigation. He returned to high-performance aviation 3 mo after onset of symptoms. No recurrence was seen during 3 yr of follow-up.

Introduction: Asthma is considered relatively incompatible with aviation. Firstly, due to the risk of sudden incapacitation, and secondly, due to cold and dry air and other asthmogenic factors characteristic of the aviation environment. The medical requirements for flying fitness of asthmatic aviators are inconsistent between different air services, and many flight surgeons are unfamiliar with the recent developments in asthma management. This study aims to describe our experience with asthmatic aviators and to discuss the medical standards required for flying fitness in chronic asthma., Methods: The records of all aviators diagnosed with asthma between January 1988 and September 2005 were reviewed. Pulmonary function tests and examination by a pulmonary disease specialist and flight surgeon were performed at least annually., Results: Nineteen Israeli Air Force aviators with asthma were studied. Most were treated with inhaled long-acting beta agonists and corticosteroids. Disease control was satisfactory in more then 90%, with significant worsening in only one case. We had no cases of sudden incapacitation or any other safety breach. One aviator was grounded 23 yr after diagnosis due to deterioration in the severity of the disease, and another aviator was permanently grounded 1 yr after diagnosis., Conclusions: Adequate asthma control is readily feasible, even in the aviation environment. Long-term inhaled corticosteroids are effective and have few side effects in aviators. Our management approach to aviators with asthma appears to be safe and effective.

There is little in the literature on dental restoration breakage in the aviation environment since reports of problems in combat aviators in War World II. We report two cases of dental fractures during acute exposure to a hypobaric environment. Case 1 was a young officer who suffered an amalgam restoration breakage during a 25,000-ft decompression chamber simulation. Case 2 occurred in an experienced aviator who had a tooth cusp fracture in a molar with a defective amalgam restoration during an unpressurized helicopter flight to 18,000 ft. In both cases, after removing the defective fillings, deep secondary caries were found; both teeth were successfully restored. Because hard-tissue tooth fracture during a high-altitude flight is a rare event, few flight surgeons or dentists are familiar with this phenomenon. We recommend regular dental examinations with careful assessment of previous dental restorations in aircrew subject to decompression.

Apical hypertrophic cardiomyopathy (ApHCM), a subtype of hypertrophic cardiomyopathy, may be found incidentally in healthy young adults. Arrhythmias are poor prognostic signs, and are the most frequent cause of sudden cardiac death. We present two cases of military aviators with ApHCM. One was a high-performance jet weapon system operator, who had asymptomatic non-sustained ventricular tachycardia (NSVT) and subsequently a symptomatic episode of paroxysmal atrial fibrillation. The second was a helicopter pilot, who had asymptomatic NSVT. Both aviators continue their aviation duties without exposure to +Gz under a regime of regular thorough cardiac assessment.

Syncope is defined as a sudden temporary loss of consciousness and postural tone that is associated with spontaneous recovery. Vasovagal or neurocardiogenic syncope is a common and usually benign cause of syncope. The mechanism may be cardioinhibitory, vasodepressor, or both. Diagnosis is usually made by a typical patient history with a definite trigger. Although vasovagal syncope is considered a benign condition, its occurrence in an aviator is worrisome, especially if recurrent and without a definite trigger. The head-up tilt test (HUTT) is used as a vasovagal syncope challenge test. A drop in BP and asystole during HUTT suggest a tendency to recurrent vasovagal syncope. We describe two military aviators with recurrent episodes of vasovagal syncope, one with definite triggers and one without. Both had positive HUTTs. The aviator with trigger-defined vasovagal syncope was disqualified from high-performance platforms due to his positive HUTT. The second case was disqualified from all platforms, irrespective of his HUTT result, because a definite trigger was not definable for all his syncopal episodes.

Introduction: Running gasoline engines in a confined space causes heat stress and carbon monoxide (CO) buildup. Loading the C-130 aircraft by driving the vehicles onto the platform may expose the C-130 cabin crew to these environmental hazards. This study was aimed at investigating heat stress and CO exposure in the C-130 cabin during vehicle airlift., Methods: There were four summer flights (two two-vehicle, two three-vehicle; 2 d, 2 nights) studied. The cabin heat stress index (wet bulb globe temperature, WBGT) and CO levels before vehicle loading (control) were compared with those after vehicle loading. Furthermore, two- and three-vehicle transportations, as well as day and night transportations, were compared., Results: Ground temperature ranged from 18.2 to 33.4 degrees C. Mean heat stress index was higher in vehicle transportation than control flights, the greatest difference being 5.9 degrees C (p < 0.001). The WBGT levels exceeded the recommended exposure limit in 28 of 38 measurements during day flights. The cabin heat stress increased sharply with vehicle loading, and continued to increase for a range of 60-140 min after loading. Elevated cabin CO levels were found in three-vehicle flights as compared with two, and in night flights as compared with day., Conclusions: In hot climates, C-130 vehicle transportation may exacerbate heat stress. The in-flight heat stress can be predicted by the ambient temperature, duration of the vehicle transportation, and number of transported vehicles. The cabin CO level is related to the number of transported vehicles. We recommend the use of effective environmental control systems during C-130 vehicle transportation in hot climates.