Exfoliation syndrome as a risk factor for cataract development: five-year follow-up of lens opacities in exfoliation syndrome.

PURPOSE: To ascertain whether the exfoliation syndrome (EXS) is a risk factor for cataract development.
SETTING: Helsinki University Eye Hospital, Helsinki, Finland.
METHODS: This prospective study examined the development of lens opacities using the Lens Opacity Meter. Visual acuity and refraction were measured in both eyes of 63 nonglaucomatous patients with clinically unilateral EXS. After 5 years, 46 patients were available for follow-up. Case histories of 14 patients were recorded.
RESULTS: During the 5 year study, the rate of conversion to bilateral disease was 22% and to exfoliative glaucoma, 30%. At the beginning of the study, the mean lens opacity was 23.5 opacity units (OU) +/- 6.7 (SD) in EXS eyes and 22.9 +/- 7.2 OU in fellow, initially nonexfoliative (NE) eyes; the difference was not significant. After 5 years, the mean opacity was 30.0 +/- 8.8 OU in EXS eyes and 26.9 +/- 8.3 OU in NE eyes (P <.001). In patients who remained unilaterally affected, the EXS eye had a higher opacity value than the NE eyes at the start of the study (23.6 +/- 7.3 OU and 22.7 +/- 7.2 OU, respectively) (P <.05) and after 5 years (29.9 +/- 9.0 OU and 27.0 +/- 8.5 OU) (P <.01). There was a significant myopic change in refraction over time in both groups. The mean refraction in EXS eyes was +1.02 +/- 2.48 diopters (D) at the start and + 0.11 +/- 3.06 D after 5 years (P =.0001) and in NE eyes, +0.99 +/- 2.25 D and +0.43 +/- 2.55 D, respectively (P <.01). At the start of the study, the mean difference in refraction between fellow eyes (refraction in NE eye - refraction in EXS eye) was -0.27 +/- 1.00 D. After 5 years, it was +0.32 +/- 1.44 D (P =.016), showing a greater myopic change in EXS eyes.
CONCLUSION: The results show that EXS is a risk factor for lens opacification.