Cutting Edge Glaucoma - Issue 2

48 • CUTTING EDGE - GLAUCOMA This is a compact overview of some developing and established technologies for glaucoma monitoring and treatment that fit the term ‘‘miniaturization.’’ It does not aspire to review every aspect of this new and fascinating field. This article is based on previously conducted studies and does not contain any studies with human participants or animals performed by any of the authors. Table 1 presents a summary of miniaturized devices that have been developed for glau- coma management. Diagnosing and Monitoring IOP Glaucoma is a 24-h disease, but eye care practices usually do not monitor IOP around the clock. This means that most long-term and short-term fluctuations in the IOP are not observed by tra- ditional measurement regimes. Indeed, as recently as 4 years ago, an overview of the role of pres- sure fluctuations written by a group of authors from New York and Massachusetts concluded with the following slightly pessimistic statement: ‘‘Until a reliable method is developed that allows for constant IOP monitoring, many variables will continue to hinder us from drawing adequate con- clusions regarding the significance of IOP variation’’ [18]. Aside from some other concepts that permit continuous IOP measurement, such as a contact lens that incorporates a sensor [12, 31, 41], the recently introduced and CE-certified (in Europe) Eyemate IOP sensor represents a reliable method of pressure monitoring that does not necessitate regular examinations in the office and requires only minimal patient cooperation. The Eyemate (also named the Argos) is a wireless IOP transducer that integrates pressure sensors, a temperature sensor, an identification encoder, an analog-to-digital encoder, and a telemetry unit into a single microelectromechanical system completely covered with biocompatible silicone (Implandata Ophthalmic Products GmbH, Hannover, Germany). This sensor is implanted into the sulcus (just like an intraocular lens, IOL), sometimes together with an IOL, during cataract surgery (Fig. 1). Whether implanted during cataract surgery or in a stand-alone procedure, the Eyemate is designed to stay in the patient’s eye indefinitely. The sensor does not require a battery. It derives the power it needs via electromagnetic inductive coupling to an external magnetic field generator housed in an external reader unit. The reader unit is battery powered and resembles a television Fig. 1: The Eyemate sensor implanted, visible through the iridectomy at 12 o'clock. method of pressure monitoring that does not n essit te reg lar examina ions in the offi e requi es only minimal pati t cooperation. Th Eyema e (also n med the Argos) is a wi e less IOP transduce that integrates pressure sensors, a temper ture sensor, an identification encoder, an analog-to-digital encoder, and a telemetry unit into a single microelectrome- chanical system completely covered with bio- compatible silicone (Implandata Ophthalmic Products GmbH, Hannover, Germany). This sensor is implanted into the sulcus (just like an intraocular lens, IOL), sometimes together with an IOL, during cataract surgery (Fig. 1 ). Whether implanted during cataract surgery or in a standalone procedure, the Eyemate is designed to stay in the patient’s eye indefi- nitely. The sensor does n t require a battery. It d r ves the p wer it eeds via electromagne ic nductiv coupling to an external agne ic field gen The bles desi data seq emi tran pro pres mag coo sens seco pati can dete turn tion [ 23 ] I wer The IOP- dru first enc ane smo read to b ter firm an intr Subconjunctival outflow XEN Gel (Allergan, Dublin, Ireland) Ab interno FDA appr InnFocus (Santen, Osaka, Japan) Ab externo CE marke Information in the table is accurate as of May 2018. The table is not devices sed in glaucoma management. Data on approval or investig provided by the manufacturers Fig. 1 The Eyemate sensor implanted, visible through the iridectomy at 12 o 0 clock