Intravitreal Bevacizumab (Avastin) for Primary Treatment of Diabetic Macular Oedema

A. Özkirş


Eye. 2009;23(3):616-620. 

In This Article

Patients and Methods

A total of 30 eyes of 30 diabetic patients who underwent intravitreal bevacizumab injection as the primary treatment for DME were included in this study. There were 13 women and 17 men, and the mean age of the patients was 56.1±8.5 years (range, 40-73 years). All patients had macular oedema with hyperfluorescent leakage on fundus fluorescein angiography. The mean duration of DME was 7.4±3.9 months (range, 3-16 months). A detailed history of medication was obtained, and the patients were excluded from the study if they had uncontrolled systemic hypertension, thromboembolic events, severe renal dysfunction, nephrotic syndrome, and dysproteinemias or receiving vasoactive drugs or antioxidant.

Before intravitreal bevacizumab injection, some eyes had received peripheral scatter laser photocoagulation to ablate ischaemic areas or neovascularization, but no eyes received any treatment for DME. Intravitreal injection of bevacizumab (2.5 mg/0.1 ml) was offered as the first treatment of DME. All patients were fully informed about the experimental character of the treatment and informed consent was obtained from each patient. The study followed the tenets of Declaration of Helsinki. Baseline parameters were documented including best-corrected visual acuity (BCVA), oedema map values of HRT II, fundus fluorescein angiography (FFA) findings, and IOP. BCVA for each eye was ascertained using Snellen chart, which was situated 20 ft (approximately 6 m) away from the patient before intravitreal applications, and then all eyes were tested with the same correction throughout the follow-up period. The proper average VA was computed by converting the value to the LogMAR equivalent, and taking the average of the LogMAR values as described by Holladay.[21] Statistical calculations were performed using LogMAR values for VA. All intravitreal injections were performed by the same surgeon (AO) under topical anaesthesia. The drug was drawn under sterile conditions from a bevacizumab infusion bottle. The lid was prepared with povidone-iodine 5% applied directly to the eye, and bevacizumab was injected into the anterior vitreous 3.5 mm posterior to the limbus in pseudophakic eyes and 4.0 mm posterior to the limbus in phakic eyes with a tuberculin syringe and 27-gauge needle. A cotton-tipped applicator was applied at the injection site immediately after the removal of the needle to prevent reflux. Indirect ophthalmoscopy was used to confirm the central retinal artery perfusion. Topical ciprofloxacin drops were applied four times daily for 1 week.

The eyes were examined after 1 week and every 4 weeks. Response to the treatment was monitored by VA assessment, FFA, and HRT II. Potential drug- or injection-related complications were also recorded, if present. Patients received reinjections when there was a recurrence of DME, and the recurrence was considered when there was a decrease in BCVA associated with an increase of intraretinal fluid due to macular oedema on FFA and/or HRT II.

The analysis of macular oedema was performed using the HRT II Macular oedema module. Oedema map value of HRT II was used to evaluate the changes at the macula after bevacizumab injection. The HRT II is a confocal laser scanning system that requires a series of optical section images at different locations of the focal plane. Technical details of the instrument have been described elsewhere.[22] The patient's macula was focused on the monitor screen by adjusting the location of the focal plane, the best focus being directly related to subject's refractive error. The 670-nm wavelength diode laser was used to image the macula using a 15° by 15° field of view. The total scan depth was adjusted according to the thickness of the structure to be analysed from 0.50 to 4.00 mm.

Statistical Analysis

Results are presented as means±SD. Statistical evaluation of the data was performed with two-way ANOVA. The difference was considered statistically significant when P-value was lower than 0.05.