title: First clinical evaluation of a new long-term subconjunctival glucose sensor.
abstract: BACKGROUND
  To evaluate the feasibility of an implantable subconjunctival glucose monitoring system (SGMS) for glucose monitoring in humans, we investigated the in vivo performance of the sensor in a clinical trial with five patients.
  
  
  METHODS
  The new SGMS consists of an implantable ocular mini implant (OMI) and a hand-held fluorescence photometer. The implantable subconjunctival glucose sensor is composed of a fluorescence resonance energy transfer system based on Concanavalin A chemistry, embedded in a nelfilcon polymer hydrogel disk. Blood glucose changes in humans were induced by oral glucose intake and insulin injections.
  
  
  RESULTS
  The in vivo response of the new SGMS was tested in a first human clinical study with five diabetes patients. The OMI was well tolerated in the eyes of the patients. The SGMS exhibited high correlation coefficients (>0.88) with blood glucose changes and a good stability of the sensor response to glucose for the study period of 2 weeks. Lag times were in the range of 5-10 min. A total of 98% of all data pairs was in the clinical acceptable ranges A and B of the consensus error grid.
  
  
  CONCLUSIONS
  For the first time, the possibility to measure glucose in vivo in the subconjunctival interstitial fluid for a period of 2 weeks was demonstrated in a human clinical trial.
authors.affiliation: Eyesense GmbH, Grossostheim, Germany. achim.mueller@eyesense.com
authors.forename: Achim Josef
authors.initials: AJ
authors.lastname: Müller
authors.forename: Monika
authors.initials: M
authors.lastname: Knuth
authors.forename: Katharina Sibylle
authors.initials: KS
authors.lastname: Nikolaus
authors.forename: Peter
authors.initials: P
authors.lastname: Herbrechtsmeier
mesh_terms: D000328:Adult; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D001786:Blood Glucose / Q000032:analysis*; D015190:Blood Glucose Self-Monitoring / Q000295:instrumentation / Q000379:methods; D002940:Circadian Rhythm / Q000502:physiology; D003208:Concanavalin A / Q000032:analysis; D003228:Conjunctiva; D003920:Diabetes Mellitus / Q000097:blood* / Q000628:therapy; D005240:Feasibility Studies; D005260:Female; D031541:Fluorescence Resonance Energy Transfer / Q000295:instrumentation; D006801:Humans; D020007:Implants, Experimental; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D010865:Pilot Projects
chemical_list: D001786:Blood Glucose; D003208:Concanavalin A