Cutting Edge Glaucoma - Issue 2

MINIATURIZATION IN GLAUCOMA MONITORING AND TREATMENT: A REVIEW OF NEW TECHNOLOGIES THAT REQUIRE... • 47  In the industrialized world, treating glaucoma and monitoring glaucoma patients is a main- stay of daily ophthalmological practice. POAG particularly affects the elderly, as the risk of suffer- ing from glaucoma increases with age. In Americans aged 40 years or older, glaucoma prevalence is about 2.1% according to the National Health and Nutrition Examination Survey (NHANES). That study also confirmed a fact that is well known to every practitioner in eye care: that many people suffering from glaucoma are completely unaware of having the disease; in the NHANES, half of the glaucoma cases were previously undiagnosed [10]. In an elderly German population of 822 individuals aged 68–96 years, glaucoma was prev- alent in 9% of the study participants—a proportion surpassed by only two other eye diseases, cataract (36%) and dry eyes (15%) [38]. Since most societies are undergoing demographic aging, the number of people suffering from glaucoma who are in need of glaucoma therapy and robust monitoring of their symptoms (particularly their intraocular pressure, IOP) is set to increase in the foreseeable future. In the United States, for instance, it is projected that the number of glau- coma patients will increase by 28% per decade [43]. The Challenge of Monitoring and Treating IOP in the Real World In recent years, considerable progress has been made in the detection, diagnosis, and treatment of glaucoma. Innovative imaging techniques, for instance, can highlight the early signs of glaucoma- tous damage and allow meticulous monitoring of the morphological changes that occur during the course of the disease and its progression. Our understanding of the pathomechanism of glau- coma has deepened, and the impact of factors such as oxidative stress and irregularities in retinal blood flow has been thoroughly investigated [7, 25, 26]. IOP is widely considered the only modifi- able risk factor for glaucoma. Therefore, the disease is generally managed by lowering the pressure to slow the progression of a disease that cannot be cured but can—with the optimal approach—be controlled. Both monitoring the IOP and lowering it for therapeutic purposes entail a number of challenges in daily eye care practice, i.e., in the real world [20]. To get a clear picture of a patient’s IOP, it is necessary to monitor diurnal and nocturnal variations (‘‘dips and peaks’’), which would require measurements far beyond those currently performed by most eye care providers on their patients, as such measurements are generally only carried out during visits to the doctor every 3 months. A one-off IOP measurement of this kind—probably taken at the same time of day at every visit, such as in the morning or after the office’s lunch break—is nothing but a snapshot that provides hardly any information on what the pressure could be like 10 or 12 h later, during sleep, or when waking up in the morning. In all three fields that comprise glaucoma management (diagnosis and long-term control based on reliable IOP measurements, the application of antiglaucomatous drugs, and surgical intervention), there have been some recent developments that seem to point to a future in which glaucoma monitoring and treatment will differ from the approaches used in the past and from what is considered routine or the ‘‘gold standard’’ today. These new devices and procedures have two things in common: they are part of the trend in medicine towards miniaturization—towards employing ever-smaller contraptions. And they are all (at least initially) handled by an ophthalmic surgeon—even the concept of ‘‘conservative’’ therapy described henceforth.