dorzolamide and Diabetic-Retinopathy

Diabetic retinopathy is characterised by morphological lesions in the retina secondary to disturbances in retinal blood flow. Previous studies have shown that the carbonic anhydrase inhibitor (CAI) dorzolamide can induce immediate dilatation of retinal arterioles and a sustained increase in retinal blood flow in primary open-angle glaucoma. However, the effect of sustained treatment with CAI on retinal arterioles in normal persons and in patients with diabetic retinopathy is unknown.. The Dynamic Vessel Analyzer was used to assess the baseline diameter and the diameter response of retinal arterioles during an increase in arterial blood pressure induced by isometric exercise and during flicker stimulation before and 2 h, 24 h and 1 week after onset of topical treatment with dorzolamide. At each examination the diameter responses were studied before and during breathing in of a hypercapnic gas mixture.. Treatment with dorzolamide for 1 week significantly increased the diameter of retinal arterioles in normal persons, and breathing in of a hypercapnic gas mixture reduced this response. The pathological vasodilatation and reduced retinal autoregulation in patients with diabetic retinopathy were unaffected by dorzolamide and hypercapnia.. The study suggests a lack of relevance of CAI for the treatment of pathological vasodilatation in early diabetic retinopathy.

Topics: Administration, Ophthalmic; Adult; Arterioles; Blood Pressure; Carbonic Anhydrase Inhibitors; Diabetes Mellitus, Type 1; Diabetic Retinopathy; Female; Homeostasis; Humans; Intraocular Pressure; Male; Ophthalmic Solutions; Prospective Studies; Regional Blood Flow; Retinal Artery; Sulfonamides; Thiophenes; Vasodilation

To evaluate the efficacy of three intravitreal bevacizumab (IVB) injections versus the same combined with 2% of topical dorzolamide in the treatment of diabetic macular edema (DME).. In this randomized double-masked clinical trial, 32 eyes of 16 treatment-naive patients with bilateral DME were enrolled. The eyes were randomly assigned to receive three monthly injections of IVB (1.25 mg) plus topical dorzolamide 2% twice daily or IVB (1.25 mg) plus topical artificial tear twice daily. Best-corrected visual acuity (BCVA) was the primary outcome of the study followed by the central macular thickness (CMT) and central macular volume (CMV) as the secondary outcomes.. Mean BCVA changes were insignificant in both groups. It changed from 0.21 ± 0.08 logMAR at baseline to 0.23 ± 0.09 (. This randomized contralateral clinical trial demonstrated that adjuvant topical dorzolamide with IVB injection had no additional effects on IVB in the treatment of DME over a three-month course. This trial is registered with the Iranian Registry of Clinical Trials under the registration code IRCT20131229015975N5.

Topics: Administration, Topical; Aged; Bevacizumab; Diabetic Retinopathy; Female; Humans; Intravitreal Injections; Iran; Macular Edema; Male; Middle Aged; Sulfonamides; Thiophenes

To compare the efficacy of fixed combinations of dorzolamide-timolol (FCDT) and brimonidine-timolol (FCBT) in patients with intraocular pressure (IOP) elevations after intravitreal triamcinolone acetonide (IVTA) injections.. This was a prospective, randomized, open-label study. Patients who received IVTA injections due to diffuse diabetic macular edema and who had an IOP of 24 mm Hg or higher after IVTA treatment were included. They were randomized to receive either FCBT or FCDT twice daily. Follow-up visits were scheduled on week 4 and 12 weeks after starting the study medication. At all follow-up visits, IOP was measured with Goldmann applanation tonometry. The primary outcome measure was mean IOP, the secondary outcome was reduction in mean IOP at 4 and 12 weeks compared with postinjection values.. Sixty patients were randomized in 1:1 ratio. The FCBT and FCDT groups were similar in terms of age, sex, and preinjection IOP (P>0.05 for all). Mean postinjection IOP was 31.95±7.39 and 29.83±5.17 mm Hg in FCBT and FCDT groups, respectively (P=0.239). After 4 weeks, mean IOP was 17.05±3.61 mm Hg in FCBT and 18.93±3.30 mm Hg in FCDT groups (P=0.063). After 12 weeks, mean IOP in the FCBT and FCDT study groups was 16.35±2.70 and 18.43±2.82 mm Hg, respectively (P=0.012). Both fixed combinations significantly reduced IOP in comparison with the postinjection values (P<0.05). Mean reduction in IOP after 4 weeks were 14.90±7.28 mm Hg in FCBT and 10.90±4.83 mm Hg in FCDT groups (P=0.024); after 12 weeks, these values were 15.60±7.77 and 11.40±5.89 mm Hg in FCBT and FCDT groups, respectively (P=0.035).. Both FCBT and FCDT are effective in controlling IOP elevations after IVTA injections. The results of this study suggest that FCBT is superior to FCDT in reducing IOP and provides better IOP control after IVTA injections.

Topics: Aged; Antihypertensive Agents; Brimonidine Tartrate; Diabetic Retinopathy; Drug Combinations; Female; Glucocorticoids; Humans; Intraocular Pressure; Intravitreal Injections; Macular Edema; Male; Middle Aged; Ocular Hypertension; Prospective Studies; Quinoxalines; Sulfonamides; Thiophenes; Timolol; Tonometry, Ocular; Triamcinolone Acetonide

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