—
In unilateral blindness (no light perception), both direct and consensual pupillary light reactions are absent (amaurotic or deafferented), brought on by optic nerve or retinal damage.
Jacqueline Gattegno, a Smart Vision Behavioural Optometrist at Eyes InDesign Bondi, explains the causes and prevalence of Unilateral Vision Impairment.
Difference Between Unilateral Vision Loss And Bilateral Vision Loss
Unilateral vision loss refers to a loss of vision in one eye, while bilateral vision loss refers to a loss of vision in both eyes. The causes of these types of vision loss can vary, but they can include issues with the eyes themselves (such as cataracts or glaucoma) or issues with the brain or nerve pathways that control vision (such as a stroke or brain tumour). Treatment options will depend on the underlying cause of the vision loss.[1]
Bilateral vision loss is more common than unilateral vision loss, according to the majority of vision loss and blindness surveys. Comprehensive global epidemiological data on bilateral vision loss, but not unilateral vision loss, have been supplied by systematic reviews, such as those conducted by the Global Burden of Disease Vision Loss Expert Group and the World Health Organization.
Blindness and unilateral vision impairment both have significant negative effects on mortality, functioning, and quality of life. There is evidence that individuals with unilateral vision loss may be significantly damaged in numerous categories, even with a functional fellow eye, although there is a relatively small body of literature on the subject.
"Reduced visual-motor coordination, depth perception, and spatial orientation are the results of the loss of stereoscopic binocular vision and the shrinkage of the visual fields," explains Gattegno.
As a result, individuals with unilateral vision loss are more likely than the general population to be involved in car accidents, fall more frequently, depend on others more, and have inferior physical and mental health.
Unilateral Vision Loss In Australia
There are limited population-based statistics on unilateral vision loss in Australia. Prevalence estimates for the general population, as of today, come from 1990s sub national surveys.
These surveys included one in South Australia that reported the prevalence of unilateral blindness but not vision loss, one in New South Wales that reported prevalence based on best-corrected visual acuity (BCVA) rather than presenting visual acuity (PVA), and one in Victoria that did not report the causes of vision loss.
While the Central Australian Ocular Health Study (conducted from 2005 through 2008) reported the prevalence of unilateral blindness (5.2 per cent) in the Australian indigenous population, the 2008 National Indigenous Eye Health Survey reported prevalence of unilateral vision loss and blindness of 12.8 per cent and 2.7 per cent, respectively.
"Further research is required because modifications in population characteristics, such as population ageing and the rising incidence of diabetes, may impact the epidemiology of unilateral vision loss," explains Gattegno.
Risk Factors For Unilateral Vision Loss
From March 2015 to April 2016, a study was conducted on indigenous Australians aged 40 to 49.The study found that prevalence of unilateral vision loss more than quadrupled to 8.0 per cent; however, by the time they reached age 70 to 79, it had increased to 34.3 per cent. This rise in multi variable logistic regression was significant.
Age tripled the likelihood of unilateral vision loss in non-indigenous Australians, from 8.1 per cent in those aged 50 to 59 years old to 27.2 per cent in those aged 80 to 89 years old.
Self-reported diabetes and extremely rural habitation were both risk factors for unilateral vision loss in indigenous Australians. Not having had an eye exam during the previous two years was a substantial risk factor for non-indigenous Australians.
Main Causes of Unilateral Vision Loss
In the study mentioned above, uncorrected refractive error was the main factor in both non-indigenous and indigenous Australians developing unilateral vision loss. It was present in 23/214, or 10.7 per cent, of indigenous Australians with vision loss and 62/453, or 13.7 per cent, of non-indigenous Australians with vision loss. Cataract was the second most common cause in both groups.
Age-related macular degeneration (AMD) caused 5.7 per cent of unilateral vision loss in non-indigenous Australians, while diabetic retinopathy (DR) was to blame for 4.2 per cent of unilateral vision loss in indigenous Australians. Amblyopia caused unilateral vision loss in more than 6 per cent of non-indigenous and more than 3 per cent of indigenous Australians.
Nearly one-fifth of unilateral blindness in indigenous Australians was caused by a variety of other retinal disorders, including macular scarring, macular holes, epiretinal membranes, and retinal detachment.
The burden of unilateral blindness in this population was significantly increased by corneal pathology, cataract, DR, ocular trauma, and enucleation. Amblyopia was the main contributor of unilateral blindness in non-indigenous Australians, followed by trauma, cataract, and AMD.[2]
With integrated spectacle dispensing and cataract care, about three-quarters of unilateral vision loss in Australia might be reversed. Those with unilateral vision loss run the danger of developing bilateral vision loss due to the bilateral nature of DR, cataract, glaucoma, and AMD, which are becoming more common due to population ageing.
Conclusion
If anyone is concerned for their eye health or that of a loved one, visit a Eyes InDesign Bondi today for a Comprehensive Vision Skills Assessment. The Smart Vision Behavioural Optometrists can assist one with any queries they may have. Don't wait, act fast!
Smart Vision Optometry clinics are located in multiple suburbs in Sydney. Book a Smart Vision Comprehensive Vision Skills Assessment or Advanced Eye Health Test for any child or adult by calling the Mosman clinic (02) 9969 1600 or the Bondi clinic (02) 9365 5047, book an appointment online.
Written and syndicated by: YDMA Group
[1]
oreman, Joshua et al. “Prevalence and Causes of Unilateral Vision Impairment and Unilateral Blindness in Australia: The National Eye Health Survey.” JAMA ophthalmology vol. 136,3 (2018): 240-248. doi:10.1001/jamaophthalmol.2017.6457
[2]
Foreman, Joshua et al. “Prevalence and Causes of Unilateral Vision Impairment and Unilateral Blindness in Australia: The National Eye Health Survey.” JAMA ophthalmology vol. 136,3 (2018): 240-248. doi:10.1001/jamaophthalmol.2017.6457
Contact Info:
Name: Public Relations
Email: Send Email
Organization: Eyes InDesign Bondi
Address: 110-112 Glenayr Ave, Bondi Beach, New South Wales 2026, Australia
Phone: +61-2-9365-5047
Website: https://smartvisionoptometry.com.au/
Release ID: 89114997