Cataract frequency and light scattering profiles in retired members of light protected communities ‐ The Irish Nun Eye Study (INES)

Abstract

Abstract Purpose Investigation of cataract frequencies, yellow discoloration and light scattering profiles in the lenses of a subset of nuns from the Irish Nun Eye Study (INES) correlated to age and outdoor activity. Methods After obtaining informed consent, the anterior eye segment of 144 retired nuns from contemplative and missionary convents in Northern Ireland and the Republic of Ireland were monitored with a Scheimpflug camera (Pentacam HR®, Oculus, Wetzlar, Germany). Images of the cornea and lens were recorded automatically in 25 meridians in mydriasis, using the recording algorithm of the camera. In addition retro‐images of the lenses were recorded using the Neitz Cataract screener and lens discoloration was recorded using a manual slitlamp and the LOCS III grading system. Image analysis was performed using special analytical software (BIOM®) and cataract classification was done using the Bonn cataract classification system. Results Age‐related light scattering increase is most pronounced in the anterior deep cortex and the anterior nuclear shell of the lenses and is generally lowest in the posterior nuclear shell. Cortical cataracts were the most frequent type in this study, the highest frequency found in the lower nasal quadrant followed by the lower temporal quadrant. Pure subcapsular cataracts have not been found in this study. The increase in yellow discoloration correlated to the increase in nuclear light scattering. Nuns with cortical cataracts had less discoloration, but were also younger. Conclusion The frequency of nuclear cataracts was lower in the INES cohort was lower, but the amount of cortical cataracts was similar to other studies like Beaver Dam Eye Study. The increases in nuclear light scattering and discoloration correlated with age and exposure index. The data from the INES study support the hypothesis that light protection has a positive effect on the frequencies of nuclear and subcapsular cataracts as well as on lens discoloration. The Pentacam HR® provided better documentation of lens transmission characteristics than the Neitz cataract scanner.