Stylized eye with Ahmed valve implant emitting light

Beating Back Glaucoma: A Novel Surgical Approach

Avery Sinclair in Health & Wellness December 2025 • 4 min read.

"Combining Mitomycin C with targeted drug delivery shows promise for tough-to-treat cases, offering renewed hope for patients and preserving vision."

Glaucoma, often dubbed the "silent thief of sight," poses a significant threat to millions worldwide. This progressive disease damages the optic nerve, gradually eroding peripheral vision and, if left unchecked, leading to irreversible blindness. While various treatments exist, including eye drops, laser procedures, and traditional surgeries, some cases prove stubbornly resistant.

These refractory glaucomas—often stemming from neovascularization (abnormal blood vessel growth), uveitis (inflammation inside the eye), or previous surgical failures—demand innovative solutions. Now, a new approach is gaining traction, combining conventional surgery with precisely targeted drug delivery to improve outcomes and safeguard vision.

A recent study published in the Journal of the Korean Ophthalmological Society sheds light on this promising technique. Researchers have explored the effectiveness of Ahmed valve implant surgery, enhanced by the adjunctive use of mitomycin C (MMC) and selective injections of 5-fluorouracil (5-FU). Let's delve into the details of this combined approach and its potential to revolutionize glaucoma management.

The Triple Threat: How the Combined Approach Works

Stylized eye with Ahmed valve implant emitting light

The study, conducted at Ajou University School of Medicine in Korea, retrospectively analyzed the outcomes of 40 patients (40 eyes) with refractory glaucoma who underwent Ahmed valve implant surgery. Here’s a breakdown of the key components:

The Ahmed Valve Implant: This surgical device is designed to regulate intraocular pressure (IOP) by creating a new drainage pathway for fluid within the eye. A small tube is inserted into the anterior chamber (the space in front of the iris), allowing excess fluid to flow to a reservoir (plate) placed under the conjunctiva (the clear membrane covering the white part of the eye).

Mitomycin C (MMC): During surgery, MMC, an anti-metabolite medication, is applied to the tissues surrounding the implant. MMC helps to prevent scar tissue formation, which can obstruct the flow of fluid through the drainage pathway, leading to increased IOP and failure of the implant.
Selective 5-Fluorouracil (5-FU) Injections: Following surgery, patients receive injections of 5-FU, another anti-metabolite, into the subconjunctival space (the space beneath the conjunctiva). These injections are administered selectively based on individual patient needs and IOP levels. If the IOP starts to rise, indicating potential blockage of the drainage pathway, 5-FU injections are used to prevent scar tissue formation and maintain the flow of fluid.
Needling Procedure: In some cases, a procedure called "needling" is performed. This involves using a fine needle to break up scar tissue that may be forming around the Ahmed valve implant, further ensuring adequate drainage and IOP control.

By combining these three elements, surgeons aim to tackle glaucoma on multiple fronts: creating a new drainage pathway, preventing scar tissue formation during and after surgery, and selectively targeting areas where blockage may occur. This multi-pronged strategy offers the potential for more effective and long-lasting IOP control in patients with refractory glaucoma.

A Promising Future for Glaucoma Management

The results of the Ajou University study are encouraging. After an average follow-up period of 35.5 months, the researchers found that the combined approach of Ahmed valve implantation, MMC, and selective 5-FU injections led to a significant reduction in IOP and the number of glaucoma medications required. The cumulative probability of surgical success was 82.5% at 1 year, 79.6% at 2 years, 72.7% at 3 years, and 58.8% at 4 years. While the study identified older age as a risk factor for surgical failure, the overall outcomes suggest that this combined approach offers a valuable option for patients with refractory glaucoma.

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Everything You Need To Know

What is the primary goal of using Mitomycin C (MMC) during Ahmed valve implant surgery for glaucoma?

The primary goal of using Mitomycin C (MMC) during Ahmed valve implant surgery is to prevent scar tissue formation around the implant. Scar tissue can obstruct the flow of fluid through the drainage pathway created by the Ahmed valve, leading to increased intraocular pressure (IOP) and failure of the implant. MMC, as an anti-metabolite medication, helps to inhibit the growth of fibroblasts and reduce scarring, thus maintaining the functionality of the drainage pathway and ensuring effective IOP control. This aspect of scar tissue reduction is crucial for the long-term success of glaucoma surgery, particularly in refractory cases where scarring is a significant concern. Other drugs, such as bevacizumab, may also reduce scar tissue, however, this specific approach uses MMC.

How does the Ahmed valve implant work to lower intraocular pressure (IOP) in glaucoma patients?

The Ahmed valve implant lowers intraocular pressure (IOP) by creating a new drainage pathway for fluid within the eye. Surgically, a small tube is inserted into the anterior chamber, which is the space in front of the iris. This tube allows excess fluid, known as aqueous humor, to flow out of the eye to a reservoir, or plate, that is placed under the conjunctiva, which is the clear membrane covering the white part of the eye. This process bypasses the eye's natural drainage system, which may be blocked or compromised in glaucoma patients, effectively reducing IOP and preventing further damage to the optic nerve. If the IOP starts to rise again, selective injections of 5-Fluorouracil can be used to further aid in drainage. The valve opens when the pressure increases, and closes when the pressure decreases, ensuring consistent drainage.

What role do selective 5-Fluorouracil (5-FU) injections play in the combined surgical approach for treating refractory glaucoma?

Selective 5-Fluorouracil (5-FU) injections are administered after Ahmed valve implant surgery to prevent scar tissue formation in the subconjunctival space, which is the space beneath the conjunctiva. These injections are given selectively, based on individual patient needs and intraocular pressure (IOP) levels. If the IOP starts to rise, indicating potential blockage of the drainage pathway, 5-FU injections are used to inhibit the proliferation of fibroblasts and subsequent scar tissue formation. By preventing scar tissue, 5-FU helps maintain the flow of fluid through the Ahmed valve implant, ensuring effective IOP control and reducing the risk of surgical failure. This targeted approach allows for personalized treatment, addressing potential complications proactively and optimizing long-term outcomes. Needling is sometimes required to assist in the drainage.

What does the term 'refractory glaucoma' mean, and why is a novel surgical approach needed to treat it?

'Refractory glaucoma' refers to cases of glaucoma that are resistant to conventional treatments, such as eye drops, laser procedures, and traditional surgeries. These cases often stem from complications like neovascularization, which is abnormal blood vessel growth, uveitis, which is inflammation inside the eye, or previous surgical failures. A novel surgical approach, such as combining Ahmed valve implantation with Mitomycin C (MMC) and selective 5-Fluorouracil (5-FU) injections, is needed to address the underlying causes of treatment resistance and achieve better intraocular pressure (IOP) control. This combined approach tackles glaucoma on multiple fronts, creating a new drainage pathway, preventing scar tissue formation, and selectively targeting areas where blockage may occur, ultimately offering a more effective and long-lasting solution for patients with refractory glaucoma. The 'needling' procedure is also sometimes used in addition to the medications.

The study mentions older age as a risk factor for surgical failure in this combined approach for glaucoma. How might this affect treatment decisions for elderly patients with refractory glaucoma?

The finding that older age is a risk factor for surgical failure in the combined approach of Ahmed valve implantation, Mitomycin C (MMC), and selective 5-Fluorouracil (5-FU) injections has important implications for treatment decisions in elderly patients with refractory glaucoma. While the combined approach shows promise, surgeons need to carefully weigh the potential benefits against the increased risk of failure in older individuals. This may involve a more thorough pre-operative assessment to identify other risk factors, a more conservative surgical approach, closer post-operative monitoring, and a lower threshold for additional interventions, such as more frequent 5-FU injections or needling procedures. Additionally, surgeons may need to have a detailed discussion with elderly patients and their families about the potential risks and benefits of the surgery, as well as alternative treatment options, to ensure informed decision-making and realistic expectations. Further research is needed to explore the reasons for this age-related difference and to develop strategies to improve outcomes in older patients.