Retinal changes in various altitude illnesses

This study aimed to evaluate the retinal changes associated with altitude illness in young soldiers. A total of 50 young soldiers with altitude illness, who were referred to a tertiary care hospital between October 2003 and January 2006, were included in the study. All the soldiers were male. The mean age of the subjects was 30.3 (range 20-44) years. Nine (18 percent) soldiers had acute mountain sickness (AMS), nine (18 percent) had high-altitude pulmonary oedema (HAPE) and 20 (40 percent) had high-altitude cerebral oedema (HACE). Retinal haemorrhages were observed in 29 soldiers (58 percent). Among these 29 cases, two also had symptoms of AMS, five had symptoms of HAPE and twelve had symptoms of HACE. High-altitude retinal haemorrhage alone as a sign of altitude illness was seen in ten cases. Severe grades of high-altitude retinopathy were found mostly in soldiers who suffered from HAPE and HACE. Visual recovery was complete in 22 (76 percent) soldiers. High-altitude retinal haemorrhage was associated with partial visual impairment in five (17 percent) soldiers and permanent visual loss in two (seven percent) soldiers. Retinal haemorrhages were noticed in 58 percent of soldiers with altitude illness. The association of severe grades of high-altitude retinopathy with HAPE and HACE was statistically significant. Branch retinal vein occlusion with macular oedema is an additional finding in our study, which has not been previously reported.