More evidence linking pseudoexfoliation syndrome with cataract

The authors assessed the relationship between pseudoexfoliation syndrome (PXS) and the long-term incidence of cataract or cataract surgery in the Blue Mountains Eye Study cohort in Australia. The results of follow-up data of up to 10 years suggest that the presence of PXS is associated with an increased risk of nuclear cataract and cataract surgery. The authors conclude that the biological plausibility for an association between PXS and the development of cataract, together with the consistency in findings between this study and those of previous cross-sectional studies from other populations, provide further and stronger evidence to support this association.

The Blue Mountains Eye Study examined 3,654 people 49 years of age and older, 2,564 of whom were re-examined after five and/or 10 years. PXS was recorded at the baseline eye examination by an ophthalmologist. Masked graders assessed lens photographs using the Wisconsin Cataract Grading System.

Eyes with PXS had a significantly greater prevalence of cortical cataract (P= 0.02) and nuclear cataract (P < 0.0001) than eyes without PXS. The association between PXS and cortical cataract, however, did not persist after further adjustment for age, gender, smoking, diabetes, steroid use, myopia, socioeconomic status and open-angle glaucoma, whereas the association between PXS and nuclear cataract persisted after adjustment for these confounders.

In addition, significant associations were found between the presence of PXS at baseline and the 10-year incidence of either nuclear cataract (P < 0.0001) or cataract surgery (P < 0.0001), which persisted after adjustment for the same confounders. No significant cross-sectional or longitudinal associations were found between PXS and posterior subcapsular cataract.

Because PXS is a risk factor for open-angle glaucoma, glaucoma may confound the association between PXS and cataract. Nevertheless, the association found between PXS and nuclear cataract and cataract surgery remained significant after adjusting for open-angle glaucoma. The authors say this suggests that PXS may contribute to the development of cataract through a pathway different from that responsible for elevated IOP or open-angle glaucoma.