Effect of Dexamethasone on Reduction of Macular Thickness in Diabetic Patients, a Randomized Clinical Trial

This is a prospective, phase II, randomized, interventional, monocentric study. Data of consecutive patients with DME who volunteered to participate in the research at the department of ophthalmology of State University of Campinas (UNICAMP) - Brazil between May 2016 and December 2017 were analysed.

At the screening visit, all patients underwent complete ophthalmic evaluation, including best corrected visual acuity (BCVA), slit-lamp biomicroscopy, applanation tonometry, fundus biomicroscopy, fluorescein angiography (Visucam NM/ FA Carl Zeiss; Carl Zeiss Meditec, California, USA), SD- OCT (Spectralis; Heidelberg Engineering, Heidelberg, Germany). Central macular thickness was obtained through 7 horizontal lines ( 30° x 5° area), centered on the fovea, with 1536 A scans per line at 240 µm intervals.

At the baseline study visit, patients were randomized with a 1:1:1 allocation to receive dexamethasone solution 4 mg/ml: 0,01 ml (40 µg) ; or 0,03 ml (120 µg); or 0,05 ml (200 µg). In follow up visits (1, 3, 7, 14, 21, 28 days after) were performed BCVA, slit-lamp biomicroscopy, applanation tonometry, fundus biomicroscopy, SD- OCT.

Inclusion criteria

• age > = 18 years;
• diagnosis of DM type 2;
• pseudophakic patients
• presence of clinically significant DME according to ETDRS guidelines;
• best correct visual acuity (BCVA) between 20/400 and 20/40;
• central macular thickness (CMT) >= 300 µm measured by spectral domain optical coherence tomography ( Spectralis® Heidelberg). If both eyes of the patient met the elegibility criteria, the eye with worse BCVA at baseline was designated as the study eye.

Exclusion criteria

• any treatment of DME in the previous 4 months;
• pan retinal photocoagulation (PRP) in the previous 4 months or antecipated need of PRP for the next 6 months;
• any ophthalmologic surgery performed in the previous 4 months;
• history of pars plana vitrectomy;
• history of open-angle glaucoma or intraocular pressure elevation induced by corticosteroids that required anti-glaucomatous treatment or anti- hypertensive ocular treatment;
• intraocular pressure >= 21 mmHg;
• patients with characteristics that meet the inclusion criteria, but refused to sign the written general consent.