Korean J Ophthalmol.  2016 Dec;30(6):416-425. 10.3341/kjo.2016.30.6.416.

Changes in Corneal Endothelial Cell after Ahmed Glaucoma Valve Implantation and Trabeculectomy: 1-Year Follow-up

• Kim MS
• Kim KN
• Kim CS

• KMID: 2373999
• DOI: http://doi.org/10.3341/kjo.2016.30.6.416

Abstract

PURPOSE
To compare changes in corneal endothelial cell density (CECD) after Ahmed glaucoma valve (AGV) implantation and trabeculectomy.
METHODS
Changes in corneal endothelium in patients that underwent AGV implantation or trabeculectomy were prospectively evaluated. Corneal specular microscopy was performed at the central cornea using a non-contact specular microscope before surgery and 6 months and 12 months after surgery. The CECD, hexagonality of the endothelial cells, and the coefficient of variation of the cell areas were compared between the two groups.
RESULTS
Forty eyes of 40 patients with AGV implantation and 28 eyes of 28 patients with trabeculectomy were studied. Intraocular pressure in the AGV implantation group was significantly higher than that in the trabeculectomy group (p < 0.001), but there was no significant difference in other clinical variables between the two groups. In the AGV implantation group, the mean CECD significantly decreased by 9.4% at 6 months and 12.3% at 12 months compared with baseline values (both, p < 0.001), while it decreased by 1.9% at 6 months and 3.2% at 12 months in the trabeculectomy group (p = 0.027 and p = 0.015, respectively). The changes at 6 months and 12 months in the AGV implantation group were significantly higher than those in the trabeculectomy group (p = 0.030 and p = 0.027, respectively). In the AGV implantation group, there was a significant decrease in the CECD between baseline and 6 months and between 6 months and 12 months (p < 0.001 and p = 0.005, respectively). However, in the trabeculectomy group, a significant decrease was observed only between baseline and 6 months (p = 0.027).
CONCLUSIONS
Both the AGV implantation group and the trabeculectomy group showed statistically significant decreases in the CECD 1 year after surgery. The decrease in CECD in the AVG implantation group was greater and persisted longer than that in the trabeculectomy group.

Keyword

Corneal endothelial cell loss; Glaucoma drainage implants; Trabeculectomy

MeSH Terms

Cell Count
Endothelium, Corneal/*pathology
Female
Follow-Up Studies
Glaucoma/diagnosis/physiopathology/*surgery
*Glaucoma Drainage Implants
Humans
*Intraocular Pressure
Male
Middle Aged
Postoperative Period
Prospective Studies
Prosthesis Implantation/*methods
Time Factors
Trabeculectomy/*methods
Treatment Outcome

Figure

• 

  Fig. 1 Postoperative percentage change following Ahmed glaucoma valve implantation or trabeculectomy. At 6 months, this change was 90.6% in the Ahmed glaucoma valve implantation group and 98.1% in the trabeculectomy group (p = 0.030, Mann-Whitney U-test). At 12 months, this change was 87.7% in the Ahmed glaucoma valve implantation group and 96.8% in the trabeculectomy group (p = 0.027). Preop = preoperative. *p < 0.05, Mann-Whitney U-test.

• 

  Fig. 2 A Kaplan-Meier survival curve showing survival of patients with a decrease in corneal endothelial cell density less than 10% from baseline. The survival was 66.9% in the Ahmed glaucoma valve (AGV) implantation group and 96.4% in the trabeculectomy (TRAB) group at 6 months and 54.0% in the AGV group and 85.7% in the TRAB group at 12 months (p = 0.005, log-rank test).

• 

  Fig. 3 Scatter plot of corneal endothelial cell density (CECD) at 12 months postoperative, according to preoperative baseline CECD. In the Ahmed glaucoma implantation group (A), the scatter plot indicates a weaker correlation between preoperative and postoperative CECD (Pearson's correlation coefficient, r = 0.770) than in the trabeculectomy group (B) (r = 0.948) (p = 0.002, Fisher's Z transformation).

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