The authors studied the change according to altitude in the intraocular pressure (IOP) of rabbit models after intravitreal gas injection.

We injected C₃F₈ gas (pure gas, 0.4 cc) into the vitreous cavity in six pairs of rabbits. The six rabbits were divided into the Fast group and the Slow group. After 3 days, we measured the rabbits' IOPs at five different check points along the Young-Dong Expressway while traveling in a car.

The IOPs of the Fast and the Slow groups at each check point, respectively, were 11.83±2.14, 13.00±3.69 ( p =0.518) in Won-ju (130 m), 20.00±2.28, 21.17±2.14 ( p =0.382) in Hoeng-seong (560 m), 28.00±2.60, 24.83±1.94 ( p =0.038) in Pyeong-chang (580 m), 30.83±3.60, 26.67±1.63 ( p =0.027) in Dae-gwall-yeong (805 m) and 9.83±1.17, 10.83±2.14 ( p =0.338) in Kang-neung (70 m). We found that IOP increased with increased altitude in both groups. The IOP of the Fast group was significantly higher than that of the Slow group at the Pyeong-chang and Dae-gwall-yeong check points.

We observed that IOP increased during car travel as altitude increased. In addition, we found that the rate of ascent was a risk factor for increased IOP. Therefore, it is important to inform patients with intraocular gas to avoid fast ascents during car travel and to ascend slowly after IOP has stabilized.