The results of the implantation of the Ahmed valve drainage devices for the treatment of refractory glaucoma in the children

Purpose. To study and evaluate the safety and the effectiveness of Ahmed valve implantation for the treatment of refractory glaucoma in the children. Materials and methods. The study included 17 patients (18 eyes) at the age varying from 7 months to 15 years who had undergone the implantation of the Ahmed valve drainage devices for the treatment of uncompensated glaucoma. The FP7 and FP8 valve models were implanted into 7 eyes and 11 eyes respectively. Primary implantation was performed in 6 patients (6 eyes) and secondary implantation in 11 ones (12 eyes). The follow-up period after the implantation ranged from 1 months to 6 years (mean 17,7 ± 5,7 months). Results. All the patients presented with the severe forms of refractory glaucoma including multiply corrected (by surgical intervention) uncompensated congenital glaucoma, concomitant glaucoma, and secondary glaucoma. Terminal glaucoma occurred in 7 eyes and far-advanced glaucoma in 9 eyes. The mean intraocular pressure (IOP) before surgery was 32,2 ± 8,3 mm Hg, mean postoperative IOP 17,5 ± 6,3 mm Hg. No intraoperative complications were documented. The postoperative complications in the form of cilio-choroidal detachment developed in 4 children, posterior retraction of the drainage tube, vertical strabismus, and eyeball subatrophy in 1 patient each. The perfectly successful outcome of the operation and compensation of IOP without the additional prescription of the anti-hypertensive drugs were achieved in 12 (70,5%) patients (13 eyes); however, the number of such eyes decreased to 8 or 44,5% within 6 and more months after surgery even though IOP remained compensated due to anti-hypertensive medication. Five (29,5%) children had compensated IOP immediately after surgery as a result of the intake of anti-hypertensive preparations; in two of them IOP was normalized within 6-12 months without prescription of the anti-hypertensive medication. Visual acuity in the end of the observation period remained unaltered in 12 eyes and was improved to 0,02 in 6 eyes upon hand motion near the face due to the reduction of corneal oedema. Conclusion. Despite the small number of the patients included in the present study, the results obtained give evidence that the application of the Ahmed valve drainage devices provides an efficient tool for the reduction of IOP in the children presenting with refractory glaucoma. However, this treatment modality is associated with the risk of serious complications that can be prevented by the choice of the correct indications, the adequate surgical techniques, and the treatment modalities ensuring careful postoperative care.

refractory pediatric glaucoma, Ahmed valve implantation, intraocular pressure