dorzolamide and Retinal-Vein-Occlusion

To evaluate the efficacy of timolol-dorzolamide drops used to decrease aqueous outflow from the eye on the prolongation of the biological activity of intravitreal bevacizumab.. Thirty-eight eyes of 38 patients with macular edema (ME) following retinal vein obstruction (RVO) were enrolled. These patients were randomly assigned into 2 groups: timolol-dorzolamide drops twice daily (n = 19) or no eyedrops (control; n = 19). All patients received 1.25 mg (in 0.05 mL) of bevacizumab intravitreally and were examined before treatment, 1 week after injection, and then every 4 weeks after injection. For each patient, visual acuity (VA), intraocular pressure (IOP), and central retinal thickness (CRT) by optical coherence tomography (OCT) were recorded before injection and at each visit after injection. The mean CRT at each timepoint was considered to directly reflect the biological activities of bevacizumab at those times.. The mean CRT measured by OCT showed a significant decrease 1 week after treatment in both groups, and this difference was maintained for a total of 9 weeks (paired t-test, <0.001). The mean CRT at 1 week post-injection showed no significant between-group difference (p = 0.781). At 5 weeks post-injection, the timolol-dorzolamide group showed a significantly smaller mean CRT than the control group (p = 0.032). The difference in mean CRT between the 2 groups disappeared, however, at 9 weeks post-injection (p = 0.462). In both groups, VA improved significantly 1 week after injection, and these changes were maintained to 9 weeks post-injection in both groups. The mean VA of the 2 groups showed no difference at any time.. Timolol-dorzolamide aqueous depressant drops may delay the elimination of intravitreal bevacizumab but clinical efficacy of the eyedrops have not been proven in this study.

Topics: Administration, Topical; Adult; Aged; Aged, 80 and over; Angiogenesis Inhibitors; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antihypertensive Agents; Aqueous Humor; Bevacizumab; Diabetic Retinopathy; Drug Synergism; Drug Therapy, Combination; Female; Humans; Injections; Intraocular Pressure; Macular Edema; Male; Middle Aged; Retinal Vein Occlusion; Sulfonamides; Thiophenes; Timolol; Treatment Outcome; Visual Acuity; Vitreous Body

To study the electrophysiological consequences of experimental branch retinal vein occlusion (BRVO) in pigs and the effect of dorzolamide.. BRVO was induced in 16 pigs by diathermia. At 4 weeks animals were examined with multifocal electroretinography (mfERG) before and after dorzolamide or vehicle. The direct component P1 (outer retina) and indirect component iN1 (inner retina) were analyzed. Ophthalmoscopy, fundus photography, and fluorescence angiography were performed.. BRVO eyes displayed signs of retinal damage and ischemia on ophthalmoscopy, fundus photography, and fluorescence angiography. mfERGs were affected by surgery; amplitude ratios (BRVO/healthy) were less than one (P1 = 0.30 [0.20-0.45]; iN1 = 0.35 [0.23-0.54]), and implicit time ratios were above one (1.04 [1.03-1.06] and 1.03 [1.02-1.05)]. In healthy eyes, iN1 amplitudes after treatment normalized to baseline (after/before) were lower in dorzolamide-treated animals than in the vehicle group (P = 0.05). After dorzolamide iN1 amplitude ratios (BRVO/healthy) were significantly higher than after vehicle (P = 0.01) and were not significantly different from one (0.97 [0.74-1.26]), indicating that the iN1 amplitudes in BRVO eyes were not different from those in healthy eyes after dorzolamide.. BRVO in pig eyes examined by mfERG is a promising model for testing new treatment strategies in retinal ischemia. The local effects of BRVO are detectable on the mfERG and can be altered by dorzolamide. The decreased iN1 amplitudes caused by dorzolamide in healthy eyes were not seen in BRVO eyes possibly because of an increase in preretinal oxygen tension and improved function of the ischemic retina counteracting the effect of inner retinal acidification.

Topics: Animals; Carbonic Anhydrase Inhibitors; Electroretinography; Female; Fluorescein Angiography; Ophthalmoscopy; Photography; Reperfusion Injury; Retina; Retinal Vein Occlusion; Retinal Vessels; Sulfonamides; Swine; Thiophenes

To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs.. Experimental BRVO was induced by diathermy close to the optic disc. RPO(2) was measured with an oxygen-sensitive electrode 0.5 mm above the BRVO-affected area, which was compared to the retinal areas not affected by BRVO. In one group of five pigs, RPO(2) was measured at baseline, 1 and 3 hours after BRVO, and after intravenous injection of 500 mg dorzolamide. In a second group of five pigs, RPO(2) was measured 1 week after the BRVO, both before and after intravenous injection of 500 mg dorzolamide.. The average baseline RPO(2) was 2.64 +/- 0.09 kPa (mean +/- SD). In the BRVO-affected areas, RPO(2) decreased significantly (by 0.67 +/- 0.29 and 0.94 +/- 0.13 kPa) at 1 hour and 3 hours after BRVO induction. In the non-BRVO areas RPO(2) increased significantly (by 0.51 +/- 0.14 kPa) 1 hour after BRVO induction, but subsequently decreased and reached baseline 3 hours after BRVO induction. One week after BRVO induction, RPO(2) was 0.67 +/- 0.29 kPa lower in affected areas when compared with the non-BRVO areas. In the BRVO-affected areas, dorzolamide increased RPO(2) significantly (by 0.36 +/- 0.21 kPa at 3 to 4 hours and by 0.67 +/- 0.40 kPa) 1 week after BRVO induction.. Retinal hypoxia induced by experimental BRVO remained significant 1 week after BRVO. Dorzolamide increased retinal oxygen tension in the BRVO-affected areas both at 4 hours and 1 week after experimental BRVO in pigs.

Topics: Animals; Carbonic Anhydrase Inhibitors; Disease Models, Animal; Fluorescein Angiography; Hypoxia; Injections, Intravenous; Ion-Selective Electrodes; Ischemia; Oxygen; Oxygen Consumption; Partial Pressure; Retina; Retinal Vein Occlusion; Sulfonamides; Swine; Thiophenes