An Otago ophthalmologist has gone to the edge of Earth’s atmosphere for his ocular research.
Dr Francesc March, of the Department of Medicine, has spent the past two years working on an aerospace project in France into how eyes are affected by microgravity, particularly dry eye disease (DED).
“Our research is the first to investigate the disease in space-like conditions. We use parabolic flights, which create short periods of microgravity through precise flight patterns, as a precursor to orbit-based research,” he says.
DED is a “significant ocular issue” which causes eye irritation, strain and blurred vision.
“It impacts the layers of tears that cover your cornea and occurs when you either don’t have enough tears or when they evaporate too quickly,” Dr March says.
It affects about 15 per cent of the population, with a higher prevalence in women and older people, but is also related to daily activities such as eye strain from computer use.
Astronauts are particularly afflicted, with about 30 per cent of them experiencing symptoms during long-term space missions.
Dr March says the zero-gravity environment and the dry, enclosed cabin atmosphere contribute to the development of DED in space.
Several factors are likely involved in the occurrence of DED, including tear film instability and ocular surface inflammation. In microgravity, the tear film is challenged to remain stable and evenly spread due to altered fluid dynamics.
Additionally, the space environment exposes the eyes to floating dust, artificial lighting, and prolonged screen use, which present further risk of damage to the ocular surface. Fluid shifts within zero gravity cause eyelid swelling and disrupted tear drainage, likely leading to tear retention and the buildup of irritants.
