May 2008
Volume 49, Issue 13
ARVO Annual Meeting Abstract  |   May 2008
2nd Ahmed Valve Insertion in the Same-Eye
Author Affiliations & Notes
  • M. Smith
    Ophthalmology and Vision Sciences, Toronto Western Hospital, Toronto, Ontario, Canada
  • Y. M. Buys
    Ophthalmology and Vision Sciences, Toronto Western Hospital, Toronto, Ontario, Canada
  • G. E. Trope
    Ophthalmology and Vision Sciences, Toronto Western Hospital, Toronto, Ontario, Canada
  • Footnotes
    Commercial Relationships  M. Smith, None; Y.M. Buys, None; G.E. Trope, None.
  • Footnotes
    Support  None.
Investigative Ophthalmology & Visual Science May 2008, Vol.49, 1250. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      M. Smith, Y. M. Buys, G. E. Trope; 2nd Ahmed Valve Insertion in the Same-Eye. Invest. Ophthalmol. Vis. Sci. 2008;49(13):1250. doi:

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

To examine the results of same-eye second GDD insertion in eyes with refractory glaucoma despite previous Ahmed GDD insertion.


Non comparative retrospective case series.


21 patients who underwent insertion of two glaucoma drainage devices into the same eye between January 1999 and November 2007 were identified. 19 patients had follow up of at least 1 year and were included in the analysis. All surgeries involved Ahmed GDDs and were performed by a single surgeon (GT). Mean age at time of surgery was 58 years (median 60, range 37-81). Mean number of previous trabeculectomies in the operated eyes was 1.74 (median 2, range 0 to 4). The mean interval between insertion of the first and second Ahmed valves was 24.2 months (median 17, range 4-67). Mean follow up interval was 38.8 months (median 35 months, range 12-80 months).The IOP, number of glaucoma medications and LogMAR visual acuity (VA) at 12 months and at final follow-up was examined, and the results are shown in the table. P values are based on comparison with preoperative values using a Wilcoxon test, with a value of ≤0.05 considered to be statistically significant. The mean drop in IOP at 12 months and at final follow up was 8mmHg (43%) and 9.9mmHg (42%) respectively. Although the mean VA was poorer post-operatively this did not reach levels of statistical significance.16 of the 19 patients (84.2%) achieved IOP of ≥5mmHg and ≤21 mm Hg and ≥20% decrease on IOP prior to second GDD insertion with or without glaucoma drops.One patient required anterior chamber reformation on the first post-operative day and another suffered corneal decompensation which resulted in a decrease in VA from 20/70 pre-operatively to counting fingers post-operatively.


In eyes with refractory glaucoma where IOP remains uncontrolled despite an Ahmed GDD insertion of a second GDD is effective in improving IOP control.  

Keywords: intraocular pressure 

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.