Entering the era of intraocular intervention
Year: 2025
Type: article
Abstract: To the Editor: Originating from angioplasty and cardiac catheterization in the 1960s, interventional medicine experienced a significant boom with the development of percutaneous transluminal coronary angioplasty (PTCA) in the 1970s. An interventional procedure typically requires small incisions or natural body openings, accessing target areas, often with a catheter or other flexible devices under the guidance of imaging technologies. With advancements in imaging and interventional techniques, an extensive and expanding range of diseases have become amenable to interventional procedures, including but not limited to vascular, gastrointestinal, hepatobiliary, genitourinary, pulmonary, musculoskeletal, and central nervous system diseases. Guided by imaging techniques, these procedures have lower risks, less surgical trauma, and shorter recovery times compared to traditional open surgery.[1] In the field of ophthalmology, although ophthalmic artery (OA) chemotherapy has long been considered an important treatment for advanced retinoblastoma in many centers,[2] intervention therapy has not been recognized as a treatment modality. Possible explanations include that OA is a part of the central nervous system, its intervention is routinely performed by a skilled neurointerventional radiologist or neurosurgeon, and the catheter does not truly enter the eye. However, in recent years, ophthalmology has developed some new technologies that exhibit characteristics of interventional treatment. Use of imaging techniques to guide precise local treatment is a hallmark of interventional procedures. Notably, the development of intraoperative optical coherence tomography (iOCT) allows real-time visualization of retinal layers and lesions. Therefore, the safety and precision of retinal procedures can be significantly improved. For instance, in epiretinal membrane (ERM) removal surgery, iOCT helps identify the anatomical position for initiation of ERM peeling, reveal tractions to the retina during membrane peeling, and enable the surgeon to minimize collateral damage. In addition, iOCT greatly facilitates access to the subretinal space, offering an advantage over intravitreal injection for adeno-associated virus (AAV)-based gene therapy.[3] Usage of a flexible catheter or other devices (e.g., endoscope) to deliver a treatment apparatus or drug into a deep location represents another key feature of an interventional technique. For example, a British company, Gyroscope Therapeutics, developed a trans-choroidal subretinal delivery system (the OrbitTM Subretinal Delivery System [SDS]) for subretinal administration of an AAV2-based genetic treatment drug. This system uses a catheter to gain access to the suprachoroidal space, and a microneedle within the catheter for delivery of AAV vectors into the subretinal space.[4] Compared to iOCT-guided subretinal access through the vitreous cavity, the OrbitTM SDS’s suprachoroidal approach reduces vitreous disruption, mitigates risks of intraocular inflammation, and enables targeted delivery with minimal collateral tissue damage. Based on resistance sensing mechanical principle, we designed an injection device enabling precise targeting of the suprachoroidal space. This device is able to automatically control a defined injection volume [Figure 1A].[5] In the proposed design, a drug-carrying cavity is established between a distal seal and a proximal floating one at the leading end of the syringe. An elastic movement unit can be formed, comprising a flexible connection of an actuation member to the floating seal. As the puncturing process progresses, by exerting force on the pressing shaft, the distal opening of the puncturing needle with a lateral pinhole, respectively, pierces the seals before penetrating the sclera. Since the pressure at the distal opening of the syringe needle is greater than the pressure at the body opening of the syringe needle, fluid injection into the sclera is inhibited. However, once the distal opening of the syringe needle is outside the sclera and into the suprachoroidal space, there is a marked reduction in tissue resistance, facilitating the propulsion of the flowable composition from the syringe into the suprachoroidal space. As the seals achieve a pre-set mark or indicator line for volume, the distal advancement of the syringe needle is stopped. After three generations of iterative enhancements, the latest device has been optimized for the easy administration of liquid or viscoelastic substances into the suprachoroidal space of a rabbit’s eye. Building on this, we further propose a novel procedure of viscoelastic sheath protected suprachoroidal cannulation and subretinal injection [Figure 1B], which is similar to but less invasive than the OrbitTM SDS. We can use the device to inject a viscoelastic material into the suprachoroidal space to facilitate dissection of the choroid from the sclera, further expanding the suprachoroidal space. Subsequently, a lubricated flexible cannula is introduced into this expanded space and carefully navigated toward the posterior segment of the eye. Using a microneedle housed within the cannula, precised targeted delivery of a therapeutic composition into the subretinal space is achieved, avoiding retinal penetration or vitreous removal.Figure 1: The novel suprachoroidal injection device: its resistance sensing prinpiple and potential application in subretinal drug delivery. (A) The principle diagram of a novel medical penetration device and system. (B) The novel subretinal delivery system based on the suprachoroidal space injection device.With the advances of the above-mentioned techniques, we hereby propose a new treatment modality, which could be potentially named as intraocular intervention, to the field of ophthalmology. Although the current forms of the iOCT-guided procedures as well as subretinal injection using the OrbitTM SDS may not fully meet the stringent definition of “interventional therapy,” they do possess the essential features of interventional medicine. Moreover, it is conceivable that more flexible and longer catheters could be used in the iOCT-guided procedures, and imaging techniques such as iOCT could guide the advancement of subretinal microneedles when using an OrbitTM SDS-like system. By then, the improved technologies will meet the strict definition of “interventional therapy,” truly bringing ophthalmology into the era of minimally invasive intervention. Conflicts of interests None.
Source: Chinese Medical Journal
Authors: Wubi Li, Jialiang Zhao, Youxin Chen, Chan Zhao
Language: English
Topic: Retinal and Macular Surgery
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,000
OpenAlex ID: W4415605075