Prolongation of activity of single intravitreal bevacizumab by adjuvant topical aqueous depressant (Timolol-Dorzolamide).
BACKGROUND
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Byeon
Suk Ho
SH
Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, 134 Shinchon-Dong, Seodaemun-Gu, Seoul 120-752, Korea. shbyeon@yuhs.ac
Kwon
Oh W
OW
Song
Ji Hun
JH
Kim
Sung Eun
SE
Park
Yong Sik
YS
D000287:Administration, Topical; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage / Q000009:adverse effects; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000009:adverse effects; D061067:Antibodies, Monoclonal, Humanized; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000009:adverse effects; D001082:Aqueous Humor / Q000502:physiology; D000068258:Bevacizumab; D003930:Diabetic Retinopathy / Q000150:complications / Q000188:drug therapy / Q000473:pathology; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007267:Injections; D007429:Intraocular Pressure / Q000187:drug effects; D008269:Macular Edema / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012170:Retinal Vein Occlusion / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D013449:Sulfonamides / Q000008:administration & dosage* / Q000009:adverse effects; D013876:Thiophenes / Q000008:administration & dosage* / Q000009:adverse effects; D013999:Timolol / Q000008:administration & dosage* / Q000009:adverse effects; D016896:Treatment Outcome; D014792:Visual Acuity / Q000187:drug effects; D014822:Vitreous Body
D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000959:Antihypertensive Agents; D013449:Sulfonamides; D013876:Thiophenes; D000068258:Bevacizumab; D013999:Timolol; C062765:dorzolamide