title: Safety and accuracy of a new long-term subconjunctival glucose sensor.
abstract: BACKGROUND
  A new biosensor has been developed by EyeSense (Großostheim, Germany) that is placed into the conjunctiva of one eye to measure the glucose concentration of the surrounding tissue in a non-invasive manner. In the present study we investigated the correlation between glucose concentrations measured by the EyeSense implant and those determined by finger prick testing, as well as the tolerability and safety of the implant over a 16-week period.
  
  
  METHODS
  The study was performed in 28 diabetic patients. The biosensor was inserted under local anesthesia and sterile conditions. Correlations between capillary glucose measured by laboratory methods and interstitial glucose determined by the biosensor were investigated by inducing increases and decreases in glucose values between 60 and 300 mg/dL.
  
  
  RESULTS
  Most patients experienced a mild subconjunctival hemorrhage postoperatively. Except for the minor sensation of the presence of foreign body, the implants were well tolerated. Three patients lost the ocular mini insert spontaneously, whereas there was a function failure of the insert in four patients. Error grid analysis showed that the percentage of data pairs in the acceptable ranges (zone A and B) was very high (>96%). However, there was a shift from zone A to zone B during observation. This was due primarily to an increase in the lag time between capillary and interstitial measured glucose.
  
  
  CONCLUSIONS
  he present study demonstrates good tolerability and measurement performance of the biosensor. The reasons for an increase in the lag time are still unknown; local reactions may be involved.
authors.affiliation: Diabetes Institute Heidelberg University Eye Clinic, Heidelberg EyeSense, Großostheim, Germany. c.hasslacher@diabetesinstitut-hd.de
authors.forename: Christoph
authors.initials: C
authors.lastname: Hasslacher
authors.forename: Gerd
authors.initials: G
authors.lastname: Auffarth
authors.forename: Isabell
authors.initials: I
authors.lastname: Platten
authors.forename: Tanja
authors.initials: T
authors.lastname: Rabsilber
authors.forename: Beate
authors.initials: B
authors.lastname: Smith
authors.forename: Felix
authors.initials: F
authors.lastname: Kulozik
authors.forename: Monika
authors.initials: M
authors.lastname: Knuth
authors.forename: Katharina
authors.initials: K
authors.lastname: Nikolaus
authors.forename: Achim
authors.initials: A
authors.lastname: Müller
mesh_terms: D000328:Adult; D015374:Biosensing Techniques / Q000295:instrumentation*; D001786:Blood Glucose / Q000032:analysis*; D015190:Blood Glucose Self-Monitoring / Q000295:instrumentation*; D003228:Conjunctiva / Q000601:surgery; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000175:diagnosis; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000175:diagnosis; D004869:Equipment Safety; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation; D011183:Postoperative Complications / Q000209:etiology; D019736:Prostheses and Implants / Q000009:adverse effects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D001786:Blood Glucose