Endothelial effect of Ahmed valve versus ExPRESS mini shunt

Session Details

Session Title: Glaucoma II

Session Date/Time: Monday 15/09/2014 | 08:00-10:30

Paper Time: 08:50

Venue: Boulevard F (Level 1)

First Author: : A.Aref EGYPT

Co Author(s): :    M. Hassan   T. El Beltagy   H. Khalil   T. Shaarawy     

Abstract Details

Purpose:

The main aim of this study was to investigate the impact of the Ahmed glaucoma valve versus Ex-Press minishunt on the corneal endothelium.

Setting:

Geneva , Switzerland, in the :Hopitaux Universitaires de Geneve.

Methods:

Prospective, comparative, randomized study. 40 Patients suffering refractory glaucoma that did not respond to maximal medical treatment, transcleral diode cyclophotocoagulation, and/or previous filtering procedures were assigned randomly into 2 groups; A, 20 eyes were operated for Ahmed Valve implantation and B, 20 were operated for Ex-Press minishunt implantation. In the preoperative examinationn, data collection included demographic information, type of glaucoma, and number of antiglaucoma medications. All the patients were completely examined preoperatively including: Best corrected visual acuity (BCVA),Slit-lamp examination,IOP assessment,Fundus examination,Endothelial cell count using the HRT II confocal microscopy. Postoperative follow-up examinations were performed on the first day post- operatively, at week 1, at months 1, 2, 3, 6 and 12.At one preoperative visit and the follow-up visits of, 6 and 12 months, all patients will undergo in vivo confocal microscopy using HRT II of the cornea in the study eye and AS-OCT at month 6.

Results:

In group A the mean age of our patients was 73.2±15.5 years, There were 36.3 % males and 63.6 % females, 14 patients (70%) suffered POAG, 2 (10 %) patients had uveitic glaucoma, 2 (10%) had PEX glaucoma and 2 (10%) suffered neovascular glaucoma. In group B mean age was 68.27± 12.36 years, 45.45 % males and 54.54 % females in group 16 patients (80%) suffered POAG, 2 (10 %) had PEX glaucoma and 2 (10%) suffered neovascular glaucoma. In group A, at 6 and 12 month respectively, the median percentage of the endothelial cell loss was 9 % and 18 % respectively. For both time periods, this cell loss was statistically significant P < 0.0001. In group B, at 6 and 12 month respectively, the median percentage of the endothelial cell loss was 4 % and 7 % respectively. For both time periods, this cell loss was statistically significant (P < 0.0001). In group A the IOP decreased by 38% at 6 and 12 month and in group B IOP decreased by 36.9 %. No significant correlation could be found between central corneal endothelial cell loss and the Tube–Cornea and Tube–Iris distances or the Intra Cameral Lens

Conclusions:

Comparison between the two study groups revealed that there was a statistically significant difference between the two groups at six and twelve months (P < 0.0001) postoperatively. The Ex-Press Minishunt group showed statistically significant lower endothelial cell loss compared to the Ahmed valve group at all points denoting that the Ex-Press Minishunt caused less damage to the endothelium in comparison to the Ahmed valve. The values of EC loss in the Ahmed valve group in our study are almost comparable to the values of EC loss in the studies investigating endothelial effect of glaucoma draining devices. In our study, in the Ahmed valve group the IOP decreased from 24.8± 9 preoperatively to 13.2 ± 6 and 13.3 ± 6.3 at 6 and 12 months postoperatively respectively, yielding a percentage reduction of 38 % at both time points. The number of antiglaucoma eye drops decreased from 3.36 ± 1.3 preoperatively to 0.9 ±1 at 6 months postoperatively but increased to 1 ± 1.3 at 12 months postoperatively. This result was comparable do the result of other studies on intermediate term results of Ahmed valve implantation. In the Ex-Press minishunt group IOP decreased from 26 ± 6.5 preoperatively to 12 ± 6 and 12 ± 7.3 at 6 and 12 month postoperatively, respectively, yielding a percentage reduction of 36.9 %. Number of antiglaucoma eye drops decreased from 3.36 ± 1.2 preoperatively to 0.09±0.2 at 6 months postoperatively but increased to 0.18±0.3 at 12 months postoperatively. This % IOP reduction was similar to that found in the literature for the studies comparing Ex-Press minishunt to trabeculectomy. AS-OCT and the in vivo confocal microscopy using HRT II of the cornea proved to be useful tools in visualizing in vivo the anatomic relationships between the drainage tube and the AC structures

Financial Interest:

NONE