Topical dexamethasone γ-cyclodextrin nanoparticle eye drops increase visual acuity and decrease macular thickness in diabetic macular oedema.

Purpose: To compare in a randomized, controlled trial topical 1.5% dexamethasone γ-cyclodextrin nanoparticle eye drops (DexNP) with posterior subtenon injection of triamcinolone acetonide in diabetic macular oedema (DME).

Methods: In this prospective, randomized, controlled trial, 22 eyes of 22 consecutive patients with DME were randomized to (i) topical treatment with DexNP ×3/day (4 weeks), ×2/day (4 weeks) and ×1/day (4 weeks) or (ii) one posterior subtenon injection of 20 mg triamcinolone acetonide. Study visits were at baseline and 4, 8, 12 and 16 weeks.

Results: The logMAR (Snellen) visual acuity (mean ± SD) improved significantly with DexNP from 0.41 ± 0.3 (Snellen 0.39) to 0.32 ± 0.25 (0.48) and 0.30 ± 0.26 (0.50) at 4 and 8 weeks, respectively. One-third of the DexNP group improved more than 0.3 logMAR units. For triamcinolone, logMAR changed significantly from 0.42 ± 0.28 (0.38) at baseline to 0.32 ± 0.29 (0.48) at 4w and 0.33 ± 0.37 (0.47) at 12w. The central macular thickness (CMT) decreased significantly with DexNP from 483 ± 141 μm to 384 ± 142 μm at 4w and 342 ± 114 μm at 8w. For triamcinolone, CMT decreased significantly at all time-points: 494 ± 94 μm, 388 ± 120, 388 ± 145, 390 ± 136 and 411 ± 104 μm at 0, 4, 8, 12 and 16 weeks, respectively. There was a modest increase in intraocular pressure (IOP) at all time-points with DexNP while no increase was seen with triamcinolone. Serum cortisol was affected by both treatments.

Conclusion: Topical DexNP significantly improve visual acuity and decrease macular thickness in patients with DME. The effect is similar to that from subtenon triamcinolone. A modest increase in IOP was seen with the nanoparticle eye drops, but IOP normalized after the discontinuation of treatment.