(74 days)
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.
The Ahmed™ Glaucoma Valve (AGV™) is a 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 a build-up of excessive intraocular pressure, by venting aqueous humor from the eye. The AGV™ implant consists of a silicone drainage tube and polypropylene valve body to house the valve membrane and protect it from occlusion by fibrosis. All materials used in the manufacture of the device are of medical grade quality. No toxic substances are used in the manufacturing process. The AGV is terminally sterilized by gamma ray radiation.
The Acceptance Criteria and Device Performance for the Ahmed™ Glaucoma Valve Model S3 are based on a clinical study of its predicate device, the Ahmed™ Glaucoma Valve Model S2. The S3 model was deemed substantially equivalent to the S2 model.
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria (Success Definition) | Reported Device Performance (at 6 months post-operatively) |
|---|---|
| "Success": Post-operative Intraocular Pressure (IOP) of ≤ 21 mmHg and ≥ 5 mmHg, while maintaining or improving visual acuity, without the use of glaucoma medications. | Visual acuity was preserved or improved, and IOPs were reduced to 21 mmHg or less and greater than 5 mmHg in 43 out of 50 subjects (86%). The mean post-operative IOP at six months was 15.33 ± 4.5 mmHg. The document implies without medication, as a "qualified success" would delineate medication use. |
| "Qualified Success": Post-operative IOP of ≤ 21 mmHg and ≥ 5 mmHg, while maintaining or improving visual acuity, with the use of glaucoma medications. | Not explicitly reported as a separate metric; however, the "Success" rate (86%) indicates a high proportion of patients met the primary endpoint, presumably without needing additional medication in many cases. Any patients needing medication while still meeting the IOP and visual acuity criteria would fall into this category. |
| "Failure": Post-operative IOP of > 21 mmHg. | 7 out of 50 subjects (14%) were considered "failures" according to this definition. |
| No valve failures observed in non-clinical experiments (in vitro and in vivo animal studies). | "Aside from destructive testing, no valve failures were observed in any experiments." |
| Biocompatibility and non-toxicity of materials. | "Sensitive in vitro biocompatibility testing, performed by several methods, demonstrated that the valve and its components are non-toxic, non-irritating, and biocompatible." |
| Efficacy in controlling IOP in animal models. | "An in vivo, long-term and short-term animal studies using rabbits in which the AGV™ was implanted demonstrated it efficacy with regard to control of IOP, with the fellow eye used as a control, tolerance of the device, and offered further substantiation in this animal model of biocompatibility of the valve and its components." |
| Mechanism to prevent anterior chamber collapse due to hypotony and vent aqueous humor from the eye. | "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 a build-up of excessive intraocular pressure, by venting aqueous humor from the eye." "No cases of collapsed chambers were reported." |
| Immediate control of intraocular pressure upon implantation. | "In the immediate post-operative period (4-28 hours), the mean preoperative IOP decreased to 9.66 ± 7.06 mmHg." |
2. Sample Size for the Test Set and Data Provenance:
- Sample Size: 50 subjects.
- Data Provenance: Prospective clinical study conducted at six (6) institutions. The country of origin is not explicitly stated, but the submission is to the US FDA, implying it was likely conducted in the US or under US regulatory standards.
3. Number of Experts and Qualifications for Ground Truth:
- The document does not explicitly state the number of experts used to establish the ground truth for the test set or their specific qualifications. For medical device studies of this nature, clinical investigators (ophthalmologists, for this device) at the participating institutions would be responsible for patient assessments and data collection, which inherently forms the basis of the "ground truth." The study involved monitoring by medical professionals.
4. Adjudication Method:
- The document does not explicitly detail an adjudication method (e.g., 2+1, 3+1) for the test set. Clinical trials typically involve multiple investigators and a study monitor following a pre-defined protocol. The results presented are the aggregated outcomes from the participating institutions.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This study is a clinical trial evaluating the performance of a medical device (Ahmed™ Glaucoma Valve) in human subjects, not an assessment of human readers' performance with or without AI assistance.
6. Standalone (Algorithm Only) Performance Study:
- No, a standalone (algorithm only) performance study was not done. The device is a physical implant, not an AI algorithm. The studies focused on the performance of the physical device after implantation.
7. Type of Ground Truth Used:
- The ground truth was established through clinical outcomes data collected directly from patients after device implantation. This included measurements of intraocular pressure (IOP), assessment of visual acuity, and monitoring for post-operative complications, evaluated by medical professionals.
8. Sample Size for the Training Set:
- This information is not applicable. The device is a physical implant, not an AI algorithm that requires a "training set" in the computational sense. The "training" or development of the device would involve engineering, material science, and pre-clinical testing, not a data-based training set.
9. How the Ground Truth for the Training Set was Established:
- This information is not applicable for the same reason as above. The "ground truth" for the development of the physical device would be derived from physiological principles, material properties, and pre-clinical models (in vitro and animal studies) that guide its design and demonstrate its intended function.
§ 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.”