The prevalence of pseudoexfoliation syndrome in Chinese people

Background: Pseudoexfoliation syndrome (PXS) is regarded as rare in people of Chinese ethnicity but the prevalence of this condition is not known. This epidemiology study was conducted to assess the prevalence of PXS in cataract patients and to report the clinical features present. Methods: Prospective descriptive study conducted in the period from March 1999 to May 2001 in ophthalmology departments in cluster hospitals serving a population of about 1.2 million. 500 consecutive patients aged 60 or above attending the general ophthalmic clinics with a presumed diagnosis of cataract were recruited. A detailed examination including biomicroscopy, intraocular measurement, and gonioscopy were performed on all patients. All positive PXS cases were documented photographically. Results: 500 patients were examined. They ranged from the ages of 60 to 91 years old, with a male to female ratio of 1: 2. 40% suffered from hypertension while 24% were known diabetics. Only two positive cases (0.4%) of PXS were identified in the study population. 18% of all eyes were found to have narrow angles ( defined as grade 0 to 2 by Shaffer grading). Nuclear sclerosis was the single most common type of lens opacity. Conclusion: PXS is a rare condition in Chinese people. A prevalence rate of 0.4% in patients aged 60 or above was identified in this hospital based epidemiology study. To the best of our knowledge, this was the first study conducted in a Chinese population to examine the prevalence of PXS.