Clinical Study
Eye (2009) 23, 1836–1844; doi:10.1038/eye.2008.321; published online 24 October 2008
Coupling of HRT II and AS-OCT to evaluate corneal endothelial cell loss and in vivo visualization of the Ahmed glaucoma valve implant
This study was presented in part at the 6th International Glaucoma Symposium-IGS, 28–31 March 2007, Athens, Greece and at the World Glaucoma Congress, 18–21 July 2007, Singapore
E Mendrinos1, A Dosso1, J Sommerhalder1 and T Shaarawy1
1Department of Ophthalmology, Geneva University Hospitals, Geneva, Switzerland
Correspondence: T Shaarawy, Department of Ophthalmology, 22 rue Alcide Jentzer, 1211 Geneva 14, Switzerland Tel: +0041 22 38 28 400; Fax: +0041 22 382 83 82; E-mail: tarek.shaarawy@ hcuge.ch
Received 21 May 2008; Revised 23 September 2008; Accepted 23 September 2008; Published online 24 October 2008.
Abstract
Aims
To report corneal endothelial cell loss and in vivo visualization of the Ahmed glaucoma valve implant in eyes with refractory glaucoma.
Methods
Ten eyes underwent Ahmed valve implant surgery and were followed-up for 12 months. Data collected included intraocular pressure (IOP), number of antiglaucoma medications and surgery-related complications. At 6 and 12 months postoperatively, the intracameral length of the drainage tube (ICL) and the distance between the tube and the cornea (T–C distance), and the iris (T–I distance) were assessed using anterior segment optical coherence tomography (AS-OCT). Heidelberg cornea tomograph II (HRT II) was used to measure the corneal endothelial cell density.
Results
Mean (
SEM) preoperative IOP was 29.54 mmHg. Mean postoperative IOP was 11.62 at 12 months (P<0.01). Over a 6-month period, mean corneal endothelial loss was 7.9%2.5 in the central and 7.5%2.4 in the peripheral cornea (P<0.01). There was no correlation between central or peripheral corneal endothelial cell loss and the T–C, T–I distance or the ICL of the tube.
Conclusions
Corneal endothelial cell loss occurs following Ahmed valve implant surgery, this appears to be multifactorial. AS-OCT and HRT II are promising methods for the follow-up of patients with a glaucoma drainage device.
Keywords:
Ahmed valve, corneal endothelial cell loss, anterior segment OCT, in vivo confocal microscopy
