title: Blood glucose self-monitoring with a long-term subconjunctival glucose sensor.
abstract: BACKGROUND
  To evaluate the feasibility of an implantable subconjunctival glucose monitoring system (SGMS) for long-term glucose monitoring, we investigated the in vivo performance of the system.
  
  
  METHODS
  The SGMS consists of an implantable ocular mini implant (OMI) and a handheld fluorescence photometer.        A clinical study was performed on 47 diabetes patients split into two cohorts. Two different types of OMI were used, with and without a biocompatible surface coating. Duration of the study was 1 year. Correlation between capillary blood glucose and SGMS-derived interstitial fluid glucose was investigated during the first 6 months of the study.
  
  
  RESULTS
  Both OMI types were tolerated well in the eyes of the patients. At the beginning of the study, the SGMS of both cohorts revealed a high accuracy with mean absolute relative difference (MARD) values of 7-12%.        The performance of the uncoated OMIs deteriorated within 3 months of wearing time, exhibiting a MARD value of 20%. The performance of the surface-coated OMIs was preserved longer. Glucose correlation measurement with reasonable results (MARD of 14%) could be performed for up to 6 months of wear.
  
  
  CONCLUSIONS
  The biocompatible surface coating on the OMIs enabled a longer duration of action of up to 6 months compared with 3 months for uncoated implants in a clinical trial.
authors: Eyesense GmbH, Grossostheim, Germany. achim.mueller@eyesense.com
authors: Achim Josef
authors: AJ
authors: Müller
authors: Monika
authors: M
authors: Knuth
authors: Katharina Sibylle
authors: KS
authors: Nikolaus
authors: Roland
authors: R
authors: Krivánek
authors: Frank
authors: F
authors: Küster
authors: Christoph
authors: C
authors: Hasslacher
authors: Gerd Uwe
authors: GU
authors: Auffarth
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D001786:Blood Glucose / Q000032:analysis*; D015190:Blood Glucose Self-Monitoring / Q000295:instrumentation* / Q000379:methods; D003228:Conjunctiva / Q000601:surgery*; D003920:Diabetes Mellitus / Q000097:blood*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D013997:Time Factors
chemical_list: D001786:Blood Glucose