Quantification of Rising the Osmotic Pressure in Diabetic Intraretinal Fluid Accumulation (Diabetic Macular Oedema)
Status:
Completed
Trial end date:
2007-04-01
Target enrollment:
Participant gender:
Summary
Diabetic macular oedema is characterized by fluid accumulation in the retinal tissue from
leaking retinal vessels, the capillaries. This state can lead to severe visual loss and
blindness. According to basic physiologic rules several factors influence the fluid transport
between the capillaries and the surrounding tissue. One of these factors is the balance
between the large molecules within the vessel lumen and the retinal tissue. Some drugs change
this balance, the osmotic balance, by moving the fluid from the tissue to the vessel lumen.
In relation to diabetic macular oedema, treatment with such a drug potentially would reduce
the retinal thickness because it extracts fluid from the retinal tissue. Glycerol has this
potential. If reduction of the thickness with glycerol is confirmed, then it proves the
significance of the osmotic balance in the basic nature of diabetic macular oedema.
In this study we therefore examine the time dependent change in retinal thickness after
glycerol intake by an instrument called optical coherence tomography (OCT). The participants
drink glycerol and the thickness of the retina is then monitored closely by OCT during the
following three hours. Since diabetic changes in the retina are focal pr. definition, the
secondary purpose of the study is to find any regional differences in the response. The
examinations are repeated at a second visit where the patient drink another dose of glycerol,
because we also want to analyse for a dose dependent response. Which dose is given at each
visit is randomised on beforehand. In addition to measuring the retinal thickness a variety
of examinations are performed both before and during the study, e.g. blood samples and
systemic blood pressure measurements.