[Characteristics and frequency of cortical cataracts at an early stage (Reykjavik Eye Study in Iceland)].

BACKGROUND

The frequency and characteristics of cortical cataract localization within a dilated pupillary area were investigated in a population-based cataract epidemiological survey performed in the city of Reykjavik in Iceland.

MATERIALS AND METHODS

Among 1045 randomly selected individuals, the right eyes of 277 persons with mild cortical lens opacification (Grade I) were selected for our study. The localization of cortical cataracts was examined using retroillumination images, which were divided into 56 circular and radial sections, and calculations were made of the percentages for each opacified area. A questionnaire was used to record the number of hours spent outdoors during week days, the time of the day and whether the subjects wore spectacles, sunglasses or hats when outside.

RESULTS

The percentage of cortical opacification was significantly higher in the lower nasal quadrant than in all other quadrants (p < 0.05). Furthermore, the percentage of opacification localized in the lower nasal quadrant was higher in individuals with a longer history of outdoor activity than those without (p < 0.05). The percentage of opacification in individuals, who have had the habit of wearing sunglasses for outdoor activities lasting longer than half an hour during weekdays in their 20's and 30's was lower in all quadrants and statistically significantly lower in the upper temporal quadrant (p < 0.05) compared to those not wearing sunglasses.

CONCLUSION

This suggests that wearing sunglasses is effective in preventing the development and/or progression of cortical cataracts.