Role of Flight Duration and Altitude in Ocular Health of Military Pilots.

BACKGROUND At great heights, reduced oxygen levels and barometric pressure can cause retinal damage, leading to high-altitude retinopathy. Military pilots additionally experience gravitational forces from rapid changes in speed and direction, which can impair vision due to short-term retinal ischemia. This study evaluated the association between flight duration and altitude with retinal and choroidal changes on optical coherence tomography (OCT) in 44 Polish military pilots. MATERIAL AND METHODS This study enrolled 88 adult men - 44 pilots from military bases in Poland and 44 controls recruited from among male ground staff in these bases. Data regarding the pilots' individual work experience was obtained from their official records on site. The average age of the pilots was 39.7 years (SD=6.9; range: 27-50), while the average age of the comparison group was 41.2 years (SD=6.3; range: 28-53). RESULTS Retinal thickness in the foveal and parafoveal region, along with the mean retinal nerve fibers layer (RNFL) thickness and total ganglion cells complex (GCC) thickness, did not differ significantly between study groups. There was also no statistically significant difference in terms of choroidal thickness between the military pilots and controls. However, after splitting the pilots into groups based on their overall hours spent flying, a very significant correlation was revealed in reduction of subfoveal choroidal thickness (SCT) (P=0.0010) proportionally to total flight time. CONCLUSIONS The results of our study suggest that retinal parameters remain stable in military pilots, but the cumulative changes are expressed in choroidal thinning.