TOKYO — The prevalence of glaucoma-related and diabetic retinopathy-related blindness has shown a decrease over the past 20 years, but there are reasons to be cautious about drawing overly optimistic conclusions, according to a global public health expert.
“First of all, we must take into account that surveys on diabetic retinopathy- and glaucoma-related vision impairment are based on central [visual acuity] and are not taking into consideration visual field defect. Also, in epidemiological studies, the attribution of cause of blindness is, by rule, to the most curable cause,” Serge Resnikoff, MD, PhD, said at the World Ophthalmology Congress. “If there are two conditions, for example, some level of cataract and glaucoma, the actual cause of blindness will be coded as being cataract. By nature, these studies tend to overestimate cataract and uncorrected refractive error and underestimate vision loss related to DR and glaucoma.”
The absolute number of people who are blind and visually impaired from these conditions is high, with a total of 4.5 million for DR and 6.3 million for glaucoma. In addition, age-standardized prevalence of moderate to severe vision impairment has increased over the past 20 years for both conditions.
An alarming increase in the prevalence of DR is expected as a consequence of the exponential increase of diabetes mellitus worldwide.
“In 1995, the WHO projected that the number of people affected globally would be in the order of 366 million in 2030, but a number of revisions of this projection show that it will be more in the order of 600 million,” Resnikoff said.
Disclosure: Resnikoff has no relevant financial disclosures.