Meduri and colleagues have reported a case of a 49-year-old man with chronic and uncontrolled POAG and refractory macular edema secondary to central retinal vein occlusion who underwent deep sclerectomy combined with the implantation of an eyemate-SC suprachoroidal tonometry sensor. This device consists of a wireless transducer comprised of eight miniature pressure-sensing cells, temperature sensor, analogueto- digital encoder, and telemetry unit, all encased in silicone; it can remotely transmit IOP data (up to ten measurements per second) in real time to a handheld reader unit from a distance of two inches (5 cm). In this case, 2,382 IOP measurements were recorded over a year's time. On 13 occasions, the eye received intravitreal injections of aflibercept. During the first seven months, IOP was reduced (by ~1 mmHg) after each injection, while from month 7 onward, IOP was increased (by ~16 mmHg) after each injection. In all cases, IOP normalized within 24 hours of injection.
Our knowledge of the relationship between IOP and glaucoma progression is significantly limited by the low sampling rate of IOP in clinical practice (typically three to four times per year)
The investigators hypothesized that a microscopic bleb leak may have accounted for the early IOP reductions which, upon resolution through proposed scarring or fibrosis, led to IOP elevations with injections. This device represents one of a number of innovative devices seeking to fill the unmet need for continuous IOP monitoring in eyes with glaucoma. Our knowledge of the relationship between IOP and glaucoma progression is significantly limited by the low sampling rate of IOP in clinical practice (typically three to four times per year). The ongoing development of home tonometry, and continuous tonometry via wearable or implantable devices, will help to bridge this important knowledge gap.