Impact of cataract surgery on intraocular pressure after filtering operation due to primary open angle glaucoma and secondary glaucoma in pseudoexfoliation syndrome

Abstract

To analyse the impact of cataract surgery after filtering operation on the intraocular pressure (IOP) due to primary open angle glaucoma (pOAG) versus secondary open angle glaucoma in pseudoexfoliation syndrome (PEX). The regulation of IOP was evaluated on the basis of criteria of advanced glaucoma intervention study (AGIS). Retrospectively 95 eyes of 95 patients (53 x pOAG, 36 x clear cornea approach [group 1] and 17 x corneoscleral tunnel [group 2]; 42 x PEX, 30 x clear cornea approach [group 3] and 12 x corneoscleral tunnel [group 4]) were included. The IOP and antiglaucomatous eye drops were analysed before filtering operation, before cataract surgery and on average 33 months after cataract surgery. In all groups there was a significant reduction of IOP after filtering operation by 8.7 mm Hg on average and no significant difference of IOP before and after cataract surgery. At no time there was a significant difference in IOP between the four subgroups. According to criteria of the AGIS study 34 % of group 1, 29 % of group 2, 36 % of group 3 and 17 % of group 4 had an IOP lower than 14 mm Hg before cataract surgery. After cataract surgery only 31 % of group 1, 18 % of group 2, 13 % of group 3 and 8 % of group 4 met this criterion. On first glance sequential cataract surgery after filtering operation seems to have no clinically relevant impact on the IOP, neither with regard to the type of glaucoma nor in respect of the approach for cataract surgery. However, if IOP is evaluated based on the criteria of the AGIS, primary open angle glaucoma with clear cornea approach appears to yield superior results in contrast to secondary open angle glaucoma in pseudoexfoliation syndrome with corneoscleral tunnel concerning the regulation of intraocular pressure.