Patient demographics
| Number of patients | 13 |
| Male:female | 7:6 |
| Number of eyes | 19 |
| Age at insertion of Ahmed valve (months) | |
| Mean | 96 |
| Range | 9–189 |
| Reduction in IOP (mm Hg) | |
| Mean | 17.9 |
| Range | 8–26 |
| Previous surgical procedures | 9 |
| Trabeculectomy alone | 1 |
| Cycloablation alone | 3 |
| Trabeculectomy + cycloablation | 5 |
| Length of follow up (months) | |
| Mean | 32 |
| Range | 3–84 |