Blast injury: A new mechanism for central retinal vein occlusion in young men? Reporting on 2 war cases in Afghanistan

Abstract

Purpose: : The central retinal vein occlusion (CRVO) is a pathology rarely observed in young patients and necessitates thorough investigations to find an etiology.

Methods: : We report on 2 original cases of CRVO, in 2 young men without a medical history which both occurred in the same conditions: a few hours after a blast injury, induced by an improvised explosive device (IED), distant from about 20 meters. The first case is a 35-year-old French man, victim of a blast injury while he was in the turret of an armoured vehicle. Ocular signs characterized by a reduction of the visual field occurred the day after the explosion. No ENT blast was diagnosed. A secondary medical evacuation to France was carried out where a complete assessment was performed and showed no usual known cause of CRVO. The second case is about an American contractor who was 34 and victim of an IED in the same conditions. He complained of reduced vision few hours afterwards. He was first examinated at the French NATO hospital in Kaboul, then send to Germany to be checked : no cardiac and general cause of venous occlusion was found.

Results: : Explosions are part of daily life in Afghanistan. However every victim of a blast injury does not develop a vein retinal occlusion. The CRVO are particularly unusual in young men, and the coincidence between the explosion and reduced vision (12 to 24 hours) must attract our attention. While the investigations carried out gave negative, 2 specific local factors should be kept in mind. The altitude of the mission (1800m) induces a relative hypoxia with a progressive significant increase in hemoglobin and hematocrit as it has been studied by Benois et al. Increase of blood viscosity is a factor of CRVO. Despite the altitude, the sunlight is such that in the absence of regular hydration (associated with physical effort), soldiers are in relative dehydration, another factor described in the young CRVO subject. Thus the blast effect appears to be a an adjuvant, combined with the general hemodynamic effects and stress.

Conclusions: : The blast effect could be a risk factor for vascular hemodynamic alterations in predisposed patients, as it is the case of soldiers in war operations combining altitude and relative dehydration.

Keywords: vascular occlusion/vascular occlusive disease • trauma