Lowering of IOP by Echothiophate Iodide in Pseudophakic Eyes with Glaucoma

Abstract

Purpose: We retrospectively investigated the intraocular pressure (IOP)-lowering effects of echothiophate iodide (EI) as adjunctive treatment for pseudophakic glaucoma patients who were receiving maximal medical therapy (MMT), including the newer class of medications, i.e., prostaglandin analogs, alpha-2 agonists, and topical carbonic anhydrase inhibitors.

Methods: The medical records of all pseudophakic glaucoma patients (24 eyes) under MMT who received supplementary EI 0.125% between January 2002 and December 2003 were reviewed. IOP data and number of medications before, during and after EI treatment were collected.

Results: Adding EI to MMT further reduced IOP in 23 of 24 eyes. Three eyes (12.5%) showed some lowering of IOP, but not enough to be considered controlled (IOP above the target pressure). The mean baseline IOP of 30.4 ± 8.2 mmHg (median 29 mmHg) dropped at final follow-up (11.2 ± 3.9 months) to 16.6 ± 4.2 mmHg (median 17 mmHg, p < 0.0001) in all eyes that had showed effective pressure reduction upon the addition of EI. Their IOP rose to 27.7 ± 8.0 mmHg (median 28 mmHg, p < 0.001) when EI was discontinued because of commercial non-availability. IOP reduction was ≥20% in 18 (75%) eyes and ≥30% (a mean decrease of 16.7 ± 8.3mmHg) in 15 eyes (63%). Four eyes (16.6%) required a trabeculectomy despite EI supplement. Five eyes were re-challenged with EI when a small amount was released for sale: their IOP of 26.6 ± 7.1 mmHg after the first EI discontinuation had dropped to 16.4 ± 4.3 mmHg (p < 0.0001) and rose to 29.6 ± 7.1 mmHg when EI was again discontinued. The recorded EI-associated side effects were increased miosis in all eyes and headache (8/24 patients), neither of which were reasons for discontinuation of the drug in any patient.

Conclusion: EI substantially decreased the IOPs in pseudophakic glaucoma eyes receiving maximal medical therapy, including the newer class of medications. This drug may be the last resort for post-cataract advanced glaucoma patients and may obviate the need for filtering surgery among the very elderly.

KEYWORDS::

• Adjunctive therapy
• Echothiophate iodide
• Glaucoma
• Intraocular pressure
• Pseudophakia

ACKNOWLEDGMENT

The authors with to thank Esther Eshkol for editorial assistance.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.