Causes of unilateral vision loss are mostly preventable

Hundreds of thousands of Australians have vision impairment and this can have a profound effect on a person’s life. A significant proportion of this, though an aspect that isn’t often focused on, is those who have unilateral vision impairment - that is, they are blind or have low vision in one eye but not the other. People with unilateral vision loss are more likely to be involved in car crashes, have a fall, and report lower physical and mental health outcomes compared with the general population.

In this Australian study, the researchers wanted to determine how prevalent unilateral vision impairment was and what the major causes of it were. Study candidates were identified from census data and recruited from a variety of geographical areas to ensure they reflected the diversity of the Australian population. The group contained both Indigenous and non-Indigenous Australians. Examiners, including optometrists then questioned the study participants about their eye health, medical history and socio-economic status. Each person also undertook a standard eye test. In all, 1738 Indigenous and 3098 non-Indigenous people were included in the study.

In both groups, the leading cause of unilateral vision loss was “uncorrected refractive error” - meaning common eyesight conditions (like short-sightedness or astigmatism) which weren’t treated over time and eventually led to vision loss. Cataract was also a significant cause of vision loss, while diabetic eye disease and age-related macular degeneration were additional causes.

Implications

What’s significant about these results is that many of the causes of unilateral loss of vision are preventable - including cataract and uncorrected refractive error. The study’s authors suggest that while loss of vision in one eye is less devastating than vision loss in both, those with unilateral vision loss still have poorer health outcomes than the general population and deserve more attention from national eye health care programs. Boosting the provision of eye-testing and glasses to correct vision, as well as cataract services, could go some way to decreasing the number of Australians affected by this form of vision loss in future, they say.

References

Foreman et al. (2018). Prevalence and Causes of Unilateral Vision Impairment and Unilateral Blindness in Australia. JAMA Ophthalmology doi: 10.1001/jamaophthalmol.2017.6457.