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K Number
K991072
Device Name
AHMED GLAUCOMA VALVE IMPLANT
Manufacturer
NEW WORLD MEDICAL, INC.
Date Cleared
1999-07-13

(104 days)

Product Code
KYF
Regulation Number
886.3920
Type
Traditional
Panel
OP
Reference & Predicate Devices
K925636,K875099
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

The Ahmed™ Glaucoma Valve is indicated for the management of refractory glaucomas, where previous surgical treatment has failed, or by experience is known not to provide satisfactory results. Such refractory glaucomas can include neovascular glaucoma, primary open angle glaucoma unresponsive to medication, congenital or infantile glaucoma, and refractory glaucomas resulting from aphakia or uveitis.

Device Description

The Ahmed™ Glaucoma Valve Bi-plate is a modification of an already approved device called the Ahmed™ Glaucoma Valve (AGV™) Ref. 510 (k) 925636 dated November 12, 1993. The Ahmed™ Glaucoma Valve (AGV™) is an ophthalmic implant for use in intractable Glaucoma. The device features a specially engineered, one way silicone membrane valve system designed to prevent collapse of the anterior chamber (AC) due to hypotony (abnormally low intraocular pressure) and to reduce excessive intraocular pressure by venting aqueous out of the anterior chamber through this control one way valve. The AGV™ implant consists of a silicone drainage tube, a polypropylene valve body to house the valve membrane, and to protect it from occlusion due to fibrosis. All materials used in the manufacturing of this device are of medical grade quality. No metallic or toxic substances are used in the manufacturing of this device. The AGV™ is terminally sterilized by gamma radiation. The AGV™ has a surface area of 184mm².

AI/ML Overview

Here's an analysis of the provided text regarding the acceptance criteria and supporting studies for the Ahmed Glaucoma Valve Bi-plate:

Disclaimer: The provided text is a 510(k) summary (K991072) for a medical device seeking substantial equivalence, not a detailed clinical study report with explicit acceptance criteria. Therefore, the "acceptance criteria" discussed below are inferred from the safety and effectiveness claims and comparisons to the predicate device. The "reported device performance" is the performance of the predicate device (Ahmed Glaucoma Valve, single plate) and the general claims made about the new device (Ahmed Glaucoma Valve Bi-plate) based on literature about double-plate implants.

Acceptance Criteria and Reported Device Performance

Given that this is a 510(k) submission for substantial equivalence, the primary "acceptance criteria" are demonstrating that the Ahmed Glaucoma Valve Bi-plate is as safe and effective as a legally marketed predicate device (Molteno Double Plate Implant, K875099, and the original Ahmed Glaucoma Valve, K925636). The performance metrics revolve around:

  • Intraocular Pressure (IOP) Reduction: The device should effectively lower IOP in refractory glaucoma patients.
  • Maintenance of IOP within normal range: After surgery, IOP should be maintained at a healthy level.
  • Prevention of Hypotony: A key feature of the Ahmed Glaucoma Valve (and claimed for the Bi-plate) is its ability to prevent abnormally low IOP.
  • Safety Profile: The device should have an acceptable complication rate.
  • Biocompatibility: The materials used should be non-toxic and biocompatible.

Since the submission specifically states, "AGV Bi-plate and Molteno Double Plate are substantially equivalent," and refers to the existing Ahmed Glaucoma Valve, the performance of these devices serves as the benchmark.

Acceptance Criteria (Inferred from goals of glaucoma shunts)Reported Device Performance (From clinical papers on AGV and Molteno)
IOP ReductionAhmed Glaucoma Valve (single plate, K925636 reference): Mean IOP reduced from 32.7 ± 0.8 mmHg before surgery to 15.9 ± 0.6 mmHg at most recent follow-up (mean 13.4 ± 0.7 months). (Huang et al., 1999)
Molteno Double Plate (literature review): Mean pre-operative pressure of 28.3mmHg reduced to 12.75mmHg (Molteno, 1981).
Reduction in Anti-glaucoma MedicationsAhmed Glaucoma Valve (single plate): Medications decreased from 2.7 ± 0.1 before surgery to 1.1 ± 0.1 after surgery. (Huang et al., 1999)
Sustained Success RateAhmed Glaucoma Valve (single plate): Cumulative probability of success was 87% at 1 year and 75% at 2 years. (Huang et al., 1999)
Visual Acuity Maintenance/ImprovementAhmed Glaucoma Valve (single plate): Visual acuity improved or within one Snellen line in 131 eyes (82%). (Huang et al., 1999)
Prevention/Reduction of HypotonyAhmed Glaucoma Valve (single plate): Transient post-operative hypotony in 13 eyes (8%).
Molteno Double Plate (literature review): Intraocular pressure was maintained at more than 5mm Hg in 11 out of 12 cases. Molteno also indicates that the use of a double plate helped in reducing post-operative hypotony.
Acceptable Complication ProfileAhmed Glaucoma Valve (single plate): Most common complication: obstruction of the tube (11%).
Molteno Double Plate (literature review): Implied acceptable, with focus on hypotony reduction.
Biocompatibility & Physical IntegrityAhmed Glaucoma Valve (single plate, K925636 reference): Sensitive in vitro biocompatibility testing demonstrated non-toxicity, non-irritation, and biocompatibility. In vitro physical testing demonstrated valve efficacy and physical integrity.

Study Details Proving Acceptance Criteria

The document refers to several studies and prior 510(k) submissions rather than presenting a single, new clinical trial for the Ahmed Glaucoma Valve Bi-plate. The main approach is through demonstrating substantial equivalence to existing devices, supported by:

  1. Prior Approval of the Single-Plate Ahmed Glaucoma Valve (K925636): This forms the foundation of the device's safety and effectiveness.
  2. Literature Review of Double-Plate Implants (especially Molteno Double Plate): This supports the safety and effectiveness of increasing surface area.
  3. Comparisons of Technological Characteristics: Demonstrating similarity in materials, design, and function between the AGV Bi-plate and the predicate Molteno Double Plate.

Here's a breakdown based on the provided text:

  1. Sample sizes used for the test set and the data provenance:

    • Ahmed Glaucoma Valve (single plate) - Huang et al. (1999):
      • Sample Size: 159 eyes (144 patients).
      • Data Provenance: Multi-center, retrospective clinical follow-up. Country of origin not specified, but the journal "Am J Ophthal." is a US-based publication.
    • Ahmed Glaucoma Valve (single plate) - K925636 Clinical Testing (50 patients):
      • Sample Size: 50 patients.
      • Data Provenance: Clinical study performed at five centers for six months. Retrospective or prospective not explicitly stated for this particular summary, but prior 510(k)s often involve prospective data collection. This data would be from the US, as it's a US FDA submission.
    • Molteno Double Plate - Molteno (1981) paper:
      • Sample Size: 12 patients for the double plate group.
      • Data Provenance: Clinical study. Country of origin not specified, but Molteno is associated with New Zealand.

  2. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

    • This information is not provided directly within the 510(k) summary. For the studies cited (Huang et al., Molteno 1981, and the initial 50-patient study), the "ground truth" (e.g., IOP measurements, complication assessments) would have been established by the clinicians participating in those studies (presumably ophthalmologists or glaucoma specialists), but their specific number or qualifications are not detailed here. For 510(k) submissions of this nature, the "ground truth" often comes from standard clinical practice and validated measurement techniques rather than an independent expert panel for the submission itself.

  3. Adjudication method (e.g., 2+1, 3+1, none) for the test set:

    • This information is not provided in the 510(k) summary for any of the cited clinical studies. Clinical studies typically have internal review processes, but formal adjudication methods like "2+1" or "3+1" are not mentioned.

  4. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:

    • No, an MRMC comparative effectiveness study was not done. This device is a physical implant, not an AI or imaging diagnostic tool. Therefore, the concept of "human readers improve with AI vs without AI assistance" is not applicable.

  5. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

    • Not applicable. This is a physical medical device. The "standalone performance" would relate to its physical function (e.g., fluid flow, pressure regulation), which was assessed via in vitro and in vivo animal studies.

  6. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

    • Clinical Outcomes Data: This is the primary type of ground truth used. It includes:
      • Intraocular Pressure (IOP) measurements.
      • Number of anti-glaucoma medications.
      • Visual acuity.
      • Incidence and type of complications (e.g., hypotony, tube obstruction, iritis).
      • Success rates (based on predefined clinical criteria like target IOP without severe complications).
    • In vitro and In vivo (animal) studies: For biocompatibility and physical function.

  7. The sample size for the training set:

    • This term "training set" is typically used in the context of machine learning or AI models. It is not applicable here as the device is a physical implant. The development of the original Ahmed Glaucoma Valve would have involved iterative design and testing, but not in the framework of training sets.

  8. How the ground truth for the training set was established:

    • Not applicable, as there is no "training set" in the AI/ML sense. The "ground truth" for the device's performance claims comes from clinical data and scientific literature on similar devices, as described above.

§ 886.3920 Aqueous shunt.

(a)
Identification. An aqueous shunt is an implantable device intended to reduce intraocular pressure in the anterior chamber of the eye in patients with neovascular glaucoma or with glaucoma when medical and conventional surgical treatments have failed.(b)
Classification. Class II. The special controls for this device are FDA's:(1) “Use of International Standard ISO 10993 ‘Biological Evaluation of Medical Devices—Part I: Evaluation and Testing,’ ”
(2) “510(k) Sterility Review Guidance of 2/12/90 (K90-1),” and
(3) “Aqueous Shunts—510(k) Submissions.”