Lens Extraction for Angle-Closure Glaucoma
Angle-closure glaucoma (ACG) is a growing problem and represents a significant proportion of glaucomas in Inuit, Chinese, and other Asian populations. Accurate and timely diagnosis of ACG is essential to its successful management. While clinical examination remains a critical linchpin to proper recognition and diagnosis, adjunctive imaging is also of great utility. This chapter reviews the classification and mechanism of the disease as well as a focus on the treatment of lens-mediated angle closure. Unique considerations for lens extraction in the angle-closure eye are reviewed including stabilization of the anterior chamber, pupil management, zonular laxity strategies, and lens disassembly techniques, and IOL choices are addressed as well as adjunctive procedures which may be performed to address differing mechanisms and severity of ACG. Finally, as these eyes are more prone to malignant glaucoma, the surgical management of this condition is also addressed.
KeywordsAnterior Chamber Trabecular Meshwork Angle Closure Anterior Chamber Depth Anterior Segment Optical Coherence Tomography
Non-compression gonioscopic view of peripheral anterior synechiae (Video courtesy of Ike K. Ahmed, MD) (MPG 3844 kb)
In this video, it can be seen that after a small amount of dispersive OVD is injected into the anterior chamber, further deepening is unable to be achieved, even with a high-viscosity OVD, which when injected is pushed immediately back out of the eye. In order to create sufficient space in the anterior chamber to safely perform lens extraction, a pars plana tap is performed 4 mm posterior to the limbus. After the pars plana tap, the anterior chamber is comfortably deepened with a high-viscosity viscoadaptive OVD and, in this case, mini-sphincterotomies performed to assist in pupil management (Video courtesy of Ike K. Ahmed, MD) (MPG 123006 kb)
In this angle-closure patient who underwent concurrent lens extraction, focal areas of atonicity were noted which were closed with 10-0 polypropylene pupilloplasty sutures. The nasal area is closed with an intraocular microtying technique with microinstrumentation in the anterior chamber, and the temporal iris is sutured using the McCannel technique (MOV 907932 kb)
In this angle-closure patient who also underwent concurrent lens extraction, a 3-clock-hour atonic area was noted and closed with a partial iris cerclage suture using 10-0 polypropylene suture again. This is tied with a modified McCannel technique using a microtying forceps to bring one end of the suture intraocularly to eliminate the need to bring iris to the corneal incision. This results in less iris pulling and manipulation (MOV 588788 kb)
This video illustrates a case of spherophakia-induced angle-closure glaucoma. This patient underwent lens extraction with capsular tension ring implantation. The CTR was injected early on to achieve equatorial expansion and prevent collapse during phacoemulsification. When a CTR is injected early, it is imperative that definitive and careful viscodissection occur between the capsule and the cortex to avoid the CTR entrapping cortical material. In this case, the patient undergoes concurrent ECP and GSL. The CTR can be seen endoscopically (Video courtesy of Ike K. Ahmed, MD) (MPG 152571 kb)
This video illustrates the injection of a CTR with a CTS being held in position by an inverted iris hook (Video courtesy of Ike K. Ahmed, MD) (MOV 166226 kb)
This video illustrates endoscopic cycloplasty, the technique by which ablation of the ciliary processes is performed beginning with the tail of the process causing a downward rotation or shrinking of the ciliary processes thereby allowing the iris to fall posteriorly and open the angle (AVI 3949 kb)
This video illustrates goniosynechialysis under visualization with a gonio mirror performed with anterior segment microinstrumentation (Video courtesy of Ike K. Ahmed, MD) (MPG 35928 kb)
In this patient who had a penetrating keratoplasty previously, the gonio mirror prevented adequate view of the angle. As a result, GSL was performed with the assistance of an endoscopic probe (Video courtesy of Ike K. Ahmed, MD) (MPG 33393 kb)
A vitrectomy-hyaloidotomy-iridectomy (VHI) is performed using an automated vitreous cutter in the anterior chamber through the previous LPI this patient had. With the assistance of anterior segment microforceps to grasp the iris, the vitrector can be placed as peripheral as possible to avoid making an excessively large iridectomy. The vitrector is then placed further posteriorly to cut through the zonules and hyaloid face and into the vitreous cavity. This procedure can also be performed from the pars plana cutting the vitreous first, then the hyaloid face, and the zonules and finally emerging through the peripheral iris into the anterior chamber (MOV 417549 kb)
- 35.Gazzard G, Foster PJ, Friedman DS, et al. Light to dark physiological variation in iridotrabecular angle width. Br J Ophthalmol. 2004. Available at: http://bjo.bmj.com/cgi/content/full/88/11/DC1/1. Accessed 20 Apr 2013.
- 76.Podbielski DW, Varma DK, Tam DY, Ahmed IIK. Endocycloplasty: a new technique for managing angle-closure glaucoma secondary to plateau iris syndrome. Glaucoma Today. Oct 2010.Google Scholar
- 81.Fakhrale G, Vahedian Z, Moghimi S, et al. Phacoemulsification and goniosynechialysis for the management of refractory acute angle closure. Eur J Ophthalmol. 2012;22:714–8.Google Scholar