Tip of the Month
Publishing date: October 2008
Tip Editors: Ann Hoste, John Salmon and John Thygesen
Tip reviewer: Roger Hitchings
The Science behind the Tip
Treatment of acute attacks of angle-closure glaucoma induced by pupillary block is based on medical therapy aiming at reducing intraocular pressure (IOP) and reopening the angle, and on peripheral irido(ec)tomy (PI) to re-establish communication between the posterior and anterior chambers (1-3).
A successful response to medical therapy with early miosis suggests a favourable prognosis after PI. In some patients however, IOP normalization may be secondary to a ciliary body shutdown, i.e. temporary inhibition of aqueous secretion due to ischemic damage to the ciliary epithelium and the medications administered to break the acute attack. It may then take several days or weeks before ciliary function recovers, thus leading to the erroneous assumption that the angle has reopened(1,2). IOP must be monitored in the months following angle-closure to detect a chronic elevation of IOP in spite of a patent PI. Dynamic gonioscopy should be performed to confirm that the angle is open, to assess the extent of peripheral anterior synechiae(4) and to exclude associated iris plateau configuration.
Patients successfully treated with PI should also be observed throughout their lifetime for the development of concurrent open-angle glaucoma(2,5).
Contributor: Michèle Detry, Brussels
Co-editors: John Thygesen and Ann Hoste
Peer reviewers: Roger Hitchings and Anders Heijl
1. Salmon JF, Kanski JJ. Glaucoma. A coloured Manual of Diagnosis and Treatment. Third Edition. Butterworth-Heinemann Eds. 2004;9:69-77.
2. Whitaker R Jr, Whitaker VB. Angle-Closure Glaucoma. In Clinical Guide to Glaucoma Management. Higginbotham EJ, Lee DA Eds. Elsevier. 2004;10:156-170.
3. Casson RJ, Salmon JF. Primary angle-closure glaucoma. Comp Ophthalmol. Update 2001;2:59-68.
4. Forbes M. Gonioscopy with corneal indentation. A method for distinguishing between appositional closure and synechial closure. Arch Ophthalmol. 1966;76:488-92.
5. Salmon JF. Long-term intraocular pressure control after Nd-YAG laser iridotomy in chronic angle-closure glaucoma. J Glaucoma. 1993;2:291-6.