Age-related macular degeneration (AMD) and diabetic retinopathy (DR) are leading causes of blindness in the elderly worldwide. Anti-vascular endothelial growth factor (anti-VEGF) agents are injected directly into the eye (vitreous humor), have emerged as the standard of care for these diseases. More than 10,000 injections per year are performed locally in Singapore National Eye Center (SNEC). Current studies on AMD and DR suggest that the administration of intravitreal injections of anti-VEGF agents leads to good treatment outcomes. These current treatment options, while effective, are not ideal in terms of drug delivery and disease monitoring. The multiple injections are uncomfortable and difficult for patients to comply to. Moreover, the ocular and systemic safety of these repeated injections over long periods of time is unclear. Our device, termed Simultaneous ExtractoR-Injector Device (SERID), simultaneously injects therapeutic agents into the eye and extracts vitreous samples from the eye for biomarker analysis in a single puncture. This integrated design aims to reduce the number of injections to the eye, allow tailored treatments based on the patient’s current condition, and reduce unnecessary treatments and visits by patients. Preliminary ex vivo studies with porcine eyes has shown the mechanism and advantages of SERID.
We have established a functional design for SERID. The device comprises an injection port, a vacuum port, and at least one needle for selective fluid communication between the injection and vacuum port. The device is directed to having both a diagnostic and therapeutic effect capable of performing both ocular fluid biopsy (vitreous sampling) and injection of therapeutic drugs. The biopsy is done using an internal negative pressure arranged to draw in the sample. Our device is able to deliver therapeutics accurately and safely by removing a sample first to prevent an acute spike in intraocular pressure (IOP) and reducing drug reflux from the eye. It acquires biopsy samples safely as the design ensures that vitreous traction is minimised by having a shearing action for cutting through extracted vitreous humor to separate it from the eye. The injection mechanism is currently an adapted 1mL syringe. In addition, only a small amount of material is necessary for sample measurement. Measuring vitreous biomarkers may provide clinicians with the ability to treat conditions before functional damage are caused and also to move away from protocol driven treatment regimens. It paves a way for biomarker discovery in research, to allow a tailored, individualized treatment based on biomarker levels.
This will be the world’s first intravitreal diagnostic-therapeutic system specifically designed for the eye. Potential licensees of this technology include ocular syringe suppliers and ocular drug manufacturers. There are no direct competitors in the market that provide simultaneous biopsy and therapeutic injection capabilities. Current methods for obtaining a vitreous biopsy uses standard needle and syringe systems which are not purpose-built for obtaining samples and have a high risk of complications. Hence, the procedure is reserved for eye conditions where clinical need for biopsy is deemed to outweigh the risk of complications such as retinal detachment and bleeding. These biopsies are not done routinely in eyes with AMD and DR.
As the number of injections given to patients increase and the demand on our clinical workforce intensifies, safety becomes an issue. Nurses are even replacing doctors to perform the injections in large tertiary centers. The proposed solution is a device specifically designed for the eye with safety and ergonomic features. The other advantages include reduction of frequent unnecessary injections, low risk of damage to intra-ocular structures, retinal detachment and vitreal hemorrhage. The device also has the potential to deliver a wide range of drugs with the use of standard syringe fittings. Monitoring VEGF or anti-VEGF agent levels from extracted fluids as a biomarker to determine specific dosage and injection frequency enables individualized and patient-tailored therapy.