Progression to photocoagulation treatment for CSME was associated with higher retinal vascular leakage at baseline, whereas baseline retinal vessel diameters and retinal thickness were comparable in progressing and nonprogressing eyes. Baseline leakage was the strongest predictor of progression from non-CSME to photocoagulation for CSME.

Glycerol is used as a peroral treatment of increased intraocular and intracranial pressure due to its osmotic effect despite the potential increase in blood pressure and blood glucose. We examined the effects of peroral glycerol in diabetic patients and healthy individuals on blood pressure, capillary glucose, and plasma osmolarity. On two separate days, 15 diabetic patients ingested glycerol in doses of 855 and 1710 mg ⁄ kg body weight in a randomised, unmasked sequence. Five healthy individuals ingested a dose of 1710 mg ⁄ kg body weight. Mean arterial blood pressure (MAP), capillary glucose (CG) and plasma osmolarity (pOSM) were monitored for 180 min. At baseline, the MAP was comparable between the groups of healthy individuals and diabetic patients (p = 0.55), CG was marginal different (p = 0.06), and pOSM values were significantly different (p = 0.007). Following glycerol ingestion, a transient, non-significant increase occurred in blood pressure. Maximal DCG was approximately 1 mM irrespective of the dose and presence of diabetes (p > 0.1). The pOSM response was analysed with a kinetic model and found independent of the presence of diabetes (p = 0.6). The maximal fitted DpOSM was 12.7 and 25.3 mOsm ⁄ l in the group of diabetic patients after the low and high dose, respectively, reflecting a dose-response relationship. Nausea, fatigue and headache were common side effects. In conclusion, peroral glycerol had similar effects on blood glucose, MAP and pOSM in the diabetic patients and healthy individuals. Specific precautions should not be implemented when treating diabetic patients with a single dose up to 1.7 g ⁄ kg body weight. A peak increase of 8% in the pOSM within 1 hr can be expected from this dose.Glycerol is an osmotic agent, which is primarily used for therapeutic purposes to lower severely increased intraocular or intracranial pressure [1][2][3][4][5][6][7][8]. Alternatively, some athletes drink glycerol solutions for hyperhydration during longlasting physical challenges [9].Although glycerol treatments are widely used, few studies on the drug's pharmacokinetic effects have been published [1]. Our pharmacodynamic knowledge mainly arises from even older studies, often on animals, concentrating on glycerol's pressurelowering effect on either the brain or the eyes [3,6,7,[10][11][12][13][14].Documentation of how much glycerol affects the blood pressure is scarce [3], and controversy exists on the effect on blood glucose in both healthy and diabetic patients [2,7,[15][16][17]. Furthermore, descriptions of glycerol's other side effects are mostly based on scattered information and casuistic reports [2,5,13,14,18,19]. We therefore investigated whether the changes in plasma osmolarity (pOSM), blood pressure, blood glucose and general side effects are similar in diabetic patients and in healthy individuals after peroral administration of glycerol. Two doses of glycerol were used to test any difference in dose response. MethodsFifteen diabetic patients from our outpatient ward and five healthy in...

The maximum reduction in MV was doubled in the healthy group compared with the diabetic group, whereas the glycerol permeability was 12 times higher in the diabetic participants. These findings confirm the paradigm of BRB breakdown in DME, but also suggest a novel procedure for the determination of retinal permeability to various agents, which is independent of the vitreous condition (ClinicalTrials.gov number, NCT00333671).