Objective: To describe a series of patients with combined pigment dispersion syndrome (PDS) and exfoliation syndrome (XFS) and to introduce a concept, the overlap syndrome, to aid in assessing multiple risk factors for glaucomatous damage.
Design: Clinic-based, cross-sectional study.
Setting: New York Eye and Ear Infirmary.
Participants: Twenty-six patients identified from the glaucoma database as having combined pigment dispersion syndrome-glaucoma and exfoliation syndrome-glaucoma.
Main outcome measures: Quantification of patients with both pigment dispersion syndrome-glaucoma (PDS/PG) and exfoliation syndrome-glaucoma (XFS/XFG) and its clinical implications.
Results: Among the 26 patients (all white) having both XFS/XFG and PDS/PG, the average age was 64.3 +/- 9.8 years and 19 of 26 were men. All patients had bilateral PDS/PG. Bilateral XFS/XFG was present in 9 of 26 patients and, of the 17 patients with unilateral involvement, the left eye was affected in 13.
Conclusions: Both XFS and PDS are common. Middle-aged patients with known PDS/PG should be suspected of having the onset of XFS if one eye escapes intraocular pressure control. Patients with unilateral XFG at presentation may also have signs of PDS/PG, often remitted. We define the term overlap syndrome to describe the sequential appearance over time of two or more risk factors for glaucomatous damage. The appearance of a new risk factor in a patient whose condition has been stable can alter the course and prognosis of the disease. This concept should prove useful in dealing with secondary and normal-tension glaucomas.