Cataract blindness in India much more prevalent in women than men, finds study

Cataract triggered blindness in India is much more prevalent in women than men but women are significantly less likely to be treated surgically for the condition than men, revealed a pooled analysis of the available data, published online in the British Journal of Ophthalmology. But women are significantly less likely to be treated surgically for the condition than men, the analysis shows.

Some 36 million people around the globe are blind--a figure that is expected to rise to over 114 million by 2050 in the absence of effective preventive measures. Blindness is more common in low- and middle-income countries. And most of those who are blind or sight impaired are aged 50 and over.

Previous studies have suggested that the prevalence of blindness is not the same in both sexes, but it’s not clear why, or exactly what the extent of this disparity might be.

To shed some light on this, a team of researchers trawled research databases for relevant studies on blindness, cataract blindness, and cataract surgery rates among people aged 50 and above in India, and published between 1990 and 2018.

They included 22 studies in their review and pooled the data from 12 of them. The average age of study participants ranged from 61 to 70. Blindness and cataract blindness were more common in women than in men, with around 4% of men being blind compared to nearly 6% of women.

What’s more, women were 35% more likely to be blind and 69% more likely to be cataract blind than men. Yet women were 27% less likely to get cataract surgery than men.

In women, around a third of the prevalence of blindness (35%) and of cataract blindness (33%) was attributable to their gender alone, the pooled data analysis shows.

The researchers highlight several possible explanations for the gender difference in the prevalence of blindness in India.

Women typically live longer than men, so are more likely to have age-related illnesses, including macular degeneration and cataract, both of which are associated with blindness. But this is unlikely to fully explain the gender difference which their analysis revealed.

“Biological predisposition to blindness and its causes can only explain a small proportion of the gender difference, and is unlikely to account for the large overall difference,” they write.

Surgical treatment for cataract is a meaningful proxy for access, they suggest, and poor access may be a contributory factor to the gender discrepancy in the prevalence of the condition.

Several factors may help to explain why women are also less likely to receive cataract surgery than men, many of which have their roots in societal expectations, suggest the researchers.

These might include cost as women in India have traditionally had low disposable income and less control over household finances; the need to travel outside the confines of their village, which they are less likely to do; and lack of education or awareness.

The researchers caution that their findings draw on a limited number of studies of varying design and methodology. But they nevertheless conclude that the findings “imply that women don’t receive cataract surgery at the same rate as men do, and closing this gender gap is a much-needed step to reducing the prevalence of cataract blindness.”

Public health experts and community eye doctors should consider targeting women specifically in an effort to curb blindness, they say. This includes stepping up efforts to find out what stops women getting the treatment they need.