Unilateral exfoliation syndrome: Conversion to bilateral exfoliation and to glaucoma: A prospective 10-year follow-up study

Purpose: This prospective 10-year follow-up study was conducted to examine conversion of nonglaucomatous eyes with unilateral exfoliation syndrome (EXS) to bilateral EXS and to glaucoma. Risk factors for conversion to a bilateral condition and to glaucoma were studied. Patients: Sixty-three nonglaucomatous subjects (mean age, 68.6 +/- 6.2 years) with unilateral EXS were enrolled. Of these patients, 56 were followed-up (89%). The effects of age, initial intraocular pressure (IOP), IOP difference between the fellow eyes, angle pigmentation, amount of exfoliation material, pupillary dilatation, optic disc topography, and phenylephrine-induced pigmentary dispersion on occasional conversion to the bilateral form and to glaucoma were studied by multivariate survival analysis. Results: In 10 years, 38% had converted to bilateral EXS. Conversion to exfoliation glaucoma (EG) was 32% in the initially exfoliative eyes and 38% in the initially nonexfoliative (non-EXS) fellow eyes. Primary open-angle glaucoma developed in 3.5% of the non-EXS eyes. In the initially EXS eyes, a significant association was found between the initial IOP and conversion to EG (relative risk = 1.471, P = 0.0001). When initial IOP was removed from the model, the pupillary dilatation values (relative risk = 0.488, P = 0.035) and the differences in IOP between the fellow eyes (relative risk = 1.224, P = 0.0181) were associated with conversion to EG. None of the factors studied was associated with conversion to the bilateral form. Conclusion: In unilateral EXS, factors associated with conversion to EG were initial IOP, pupillary dilatation value, and difference in IOP between the fellow eyes. No risk factors for conversion to bilateral EXS were found.