ANTIHISTAMINES REDUCE BLOOD-RETINAL BARRIER PERMEABILITY IN TYPE-I (INSULIN-DEPENDENT) DIABETIC-PATIENTS WITH NONPROLIFERATIVE RETINOPATHY - A PILOT-STUDY
Tw. Gardner et al., ANTIHISTAMINES REDUCE BLOOD-RETINAL BARRIER PERMEABILITY IN TYPE-I (INSULIN-DEPENDENT) DIABETIC-PATIENTS WITH NONPROLIFERATIVE RETINOPATHY - A PILOT-STUDY, Retina, 15(2), 1995, pp. 134-140
Purpose: To determine if histamine receptor stimulation mediates incre
ased blood-retinal barrier (BRB) permeability in patients with diabeti
c retinopathy, as it does in experimental diabetes. Methods: Fourteen
patients with type I (insulin-dependent) diabetes and mild nonprolifer
ative diabetic retinopathy were treated with combined astemizole, 20 m
g, and ranitidine, 600 mg, or an identical placebo for 6 months in a d
ouble-masked fashion, Blood-retinal barrier permeability was measured
by vitreous fluorometry at baseline and at 3 and 6 months. Results: Pe
rmeability was significantly reduced in the group treated with antihis
tamines (P < 0.05) compared with the placebo group, There were no conc
omitant significant changes in systemic arterial blood pressure or HbA
(1c) values. Conclusion: These pilot data suggest that histamine recep
tors influence permeability of the BRB in human diabetes. Further stud
ies of the effects of antihistamines on diabetic retinopathy are warra
nted.