Long-term results of Ahmed glaucoma valve and Molteno implant in neovascular glaucoma

Abstract

Aims To evaluate the surgical success results of Ahmed glaucoma valve (AGV) and Molteno single-plate implant (MSPI) in cases of neovascular glaucoma (NVG). Methods Between May 1997 and May 2002, 38 of 38 NVG patients that underwent implantation of AGV and 27 eyes of 27 NVG patients that underwent MSPI (a total 65 eyes of 65 patients) included to the study. Results The cumulative probabilities of success were 63.2% at 1 year, 56.2% at 2 years, 43.2% at 3 years, 37.8% at 4 years, and 25.2% at 5 years in AGV group whereas the cumulative probabilities of success were 37.0% at 1 year, 29.6% at 2 years, 29.6% at 3 years, 29.6% at 4 years, and 29.6% at 5 years in MSPI group (P ¼ 0.141). Preoperative visual acuity o2/200 (P ¼ 0.003), diagnosis of diabetes mellitius (P ¼ 0.050), and preoperative IOP Z35 mmHg (P ¼ 0.038) were found to be poor prognostic factors for surgical success. Conclusions Both AGV and single plate MSPI were successful for early and intermediate-term of IOP control but in long term both implants were failed to achieve control of IOP in patients with NVG.

A Review of the Ahmed Glaucoma Valve Implant and Comparison with Other Surgical Operations

“…The existing evidence seems to suggest that AGV might have a more favorable safety profile when compared to nonvalved GDIs [20,51,52,54,55,60,61,64]. On the other hand, non-valved GDIs seem to achieve lower pressures than the AGV [54,55,[57][58][59][62][63][64].…”

“…The efficacy of the AGV and the single-plate Molteno GDI were compared in patients with NVG in a study by Yalvac et al (65 patients, 38 with AGV and 27 with Molteno GDI) [20]. Patients were matched for age, pre-operative IOP, gender and follow-up.…”

“…Indeed, a valve mechanism has been introduced in an attempt to prevent complications sometimes encountered with non-valved GDIs, such as hypotony, shallow anterior chamber, choroidal effusion and choroidal detachment [14]. Several studies have shown that AGV is safe and effective in reducing IOP in patients with primary [15][16][17], secondary [18][19][20][21][22][23][24] and refractory glaucoma [25][26][27]. However, the hypotensive efficacy of AGV in comparison with other anti-glaucoma interventions has not been completely elucidated.…”

A Surgical Technique for Difficult Glaucoma Cases: Combined Cyclectomy/Trabeculectomy

“…According to that study, the complication rate was 47% and the most common complication was obstruction of the tube (11%) (Huang et al, 1999). In a study performed specifically on NVG patients, cumulative probabilities of success were 63.2% after one year in the Ahmed Glaucoma valve group (Yalvac et al, 2007). In literature, loss of light perception in NVG was encountered as 31% and 48% after Baerveldt (Sidoti et al, 1995) and Molteno (Mermoud et al, 1993) tube implantations, respectively.…”

“…In general terms, with respect to the approaches for cases with refractory glaucoma, there are different surgical and laser techniques in the literature. Although the ideal surgical procedure is still controversial, currently, trabeculectomy with antimetabolite therapy, aqueous shunt implants (Yalvac et al, 2007), and diode laser cyclophotocoagulation (Pokroy et al, 2008) are the favored surgical treatment options. The most important cause of failure in glaucoma surgery is the fibrocellular scar tissue formation in the infiltration area.…”