Ultraviolet exposure may be cataract risk factor, study shows

People who live in lower latitudes have a higher prevalence of cortical cataract than people who live in different climates, according to a multinational study. As a result, solar ultraviolet rays may be a risk factor for the development of these types of cataract, the study authors surmise.

Researchers compared characteristics of early cortical cataract localization from surveys conducted in Reykjavik, Iceland; Melbourne, Australia; and Singapore. Subjects were included in the study if their right eyes had an area of cortical opacity less than 20% of the pupil when dilated 7 mm or more. The Reykjavik study included 197 subjects, the Melbourne study comprised 231 participants, and the Singapore study included 92 people for this comparative analysis.

After opacities were located from photographs, the eyes were divided into quadrants, and the rate of opacification was then calculated for each quadrant.

The highest positive rate of opacification was observed in the lower nasal quadrant in all groups, regardless of the person’s geographic location. However, the prevalence was most pronounced in subjects living in Singapore, followed by those in Melbourne and then those in Reykjavik.

The study is published in the October issue of Investigative Ophthalmology & Visual Science.