EURORAD ESR

Case 15372

Giant reservoir formation as a complication of an Ahmed glaucoma valve device

Author(s)
Hernan Nova-Escobar 1, Vanessa Bornacelli-Barreneche 2, Carolina Diaz-Angulo 3

1: Radiology Resident, PGY 3, Universidad del Norte.
2: Radiology Resident, PGY 2, Universidad del Norte.
3: Radiologist, Barranquilla, Colombia.

Email:hernannova@gmail.com
 
Patient
male, 32 year(s)
 
 
  • Figure 1
    Ahmed glaucoma valves
     

    Different models of Ahmed glaucoma valves. All are made of silicone, an elastomer membrane and medical-grade polypropylene. Models shown from left to right: FP7 (most commonly used), FP8, S2 and S3.

     
    Area of Interest: Eyes; Imaging Technique: Neural networks; Procedure: Decision analysis; Special Focus: Foreign bodies;

    Normal globe demonstrating correct positioning of the AGV in the superotemporal aspect.

     
    Area of Interest: Eyes; Imaging Technique: Image manipulation / Reconstruction; Procedure: Decision analysis; Special Focus: Foreign bodies;

    Direction of aqueous humour flow through the Ahmed valve device FP7.

     
    Area of Interest: Eyes; Imaging Technique: Image manipulation / Reconstruction; Procedure: Decision analysis; Special Focus: Foreign bodies;
     
     
  • Figure 2
    MRI coronal view
     

    Coronal T1WI. Well-defined, ovoid, hypointense lesion in the superotemporal quadrant of the left orbit.

     
    Area of Interest: Eyes; Imaging Technique: MR; Procedure: Decision analysis; Special Focus: Cysts;

    Coronal T2WI. Hyperintense lesion with a low signal linear band (yellow arrow) at its centre representing silicone within the Ahmed glaucoma valve.

     
    Area of Interest: Eyes; Imaging Technique: MR; Procedure: Decision analysis; Special Focus: Cysts;
     
     
  • Figure 3
    MRI axial view
     

    Axial T1WI. Thin-walled reservoir in the Ahmed device at the superotemporal aspect of the left globe.

     
    Area of Interest: Eyes; Imaging Technique: MR; Procedure: Decision analysis; Special Focus: Cysts;

    Axial T2WI Giant reservoir with fluid signal intensity the Ahmed device. Note the low signal band (yellow arrow) at its centre representing silicone within the valve.

     
    Area of Interest: Eyes; Imaging Technique: MR; Procedure: Decision analysis; Special Focus: Cysts;

    Axial 3D FIESTA. Better appreciation of the cyst-like reservoir formed inside the Ahmed valve device with its silicone band (yellow arrow).

     
    Area of Interest: Eyes; Imaging Technique: MR; Procedure: Decision analysis; Special Focus: Cysts;
     
     
  • Figure 4
    Contrast-enhanced MRI
     

    Coronal T1 FS + Gd. No enhancement is present in the ovoid lesion at the superotemporal aspect of the left orbit, nor in surrounding soft tissues.

     
    Area of Interest: Eyes; Imaging Technique: MR; Procedure: Decision analysis; Special Focus: Cysts;

    Axial T1 FS + Gd. Note the lack of contrast enhancement in the left orbit.

     
    Area of Interest: Eyes; Imaging Technique: MR; Procedure: Decision analysis; Special Focus: Cysts;
     
     
  • Figure 5
    Comparison with a normal Ahmed device
     

    Coronal T2WI. The left-hand image demonstrates a normal Ahmed device (blue arrow), whilst the right shows a non-functional device with reservoir formation (white arrow).

     
    Area of Interest: Eyes; Imaging Technique: MR; Procedure: Decision analysis; Special Focus: Cysts;

    Axial T2WI. The left-hand image shows a normal Ahmed device (blue arrow) and on the right is a non-functional device with reservoir formation (white arrow).

     
    Area of Interest: Eyes; Imaging Technique: MR; Procedure: Decision analysis; Special Focus: Cysts;
     
     
Different models of Ahmed glaucoma valves. All are made of silicone, an elastomer membrane and medical-grade polypropylene. Models shown from left to right: FP7 (most commonly used), FP8, S2 and S3.
 
Normal globe demonstrating correct positioning of the AGV in the superotemporal aspect.
 
Direction of aqueous humour flow through the Ahmed valve device FP7.
 
Coronal T1WI. Well-defined, ovoid, hypointense lesion in the superotemporal quadrant of the left orbit.
 
Coronal T2WI. Hyperintense lesion with a low signal linear band (yellow arrow) at its centre representing silicone within the Ahmed glaucoma valve.
 
Axial T1WI. Thin-walled reservoir in the Ahmed device at the superotemporal aspect of the left globe.
 
Axial T2WI Giant reservoir with fluid signal intensity the Ahmed device. Note the low signal band (yellow arrow) at its centre representing silicone within the valve.
 
Axial 3D FIESTA. Better appreciation of the cyst-like reservoir formed inside the Ahmed valve device with its silicone band (yellow arrow).
 
Coronal T1 FS + Gd. No enhancement is present in the ovoid lesion at the superotemporal aspect of the left orbit, nor in surrounding soft tissues.
 
Axial T1 FS + Gd. Note the lack of contrast enhancement in the left orbit.
 
Coronal T2WI. The left-hand image demonstrates a normal Ahmed device (blue arrow), whilst the right shows a non-functional device with reservoir formation (white arrow).
 
Axial T2WI. The left-hand image shows a normal Ahmed device (blue arrow) and on the right is a non-functional device with reservoir formation (white arrow).
 
 
 
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