Dexamethasone/Netilmicin Eye Drops and Eye Gel for the Treatment of Ocular Inflammation After Micro-Incisional Vitreoretinal Surgery

Abstract

Purpose: To evaluate the effect of dexamethasone/netilmicin (dexa/net) fixed combination in the treatment of ocular inflammation after sutureless micro-incisional vitreoretinal surgery (MIVS).

Patients and methods: This multicenter, open, randomized, active-controlled, parallel-group, clinical trial was run in 6 sites in Italy. Treatment started the day of surgery and continued 4 times daily for 14 days. Patients were 1:1 randomized to dexa/net (eyedrops solution and eye gel) or dexamethasone/tobramycin (dexa/tobra) eyedrops suspension and ointment. Viscous formulations (gel or ointment) were used alone during the early post-operative phase; afterwards, a combination of eye drops during daytime and viscous formulations at bedtime was adopted. The primary efficacy parameter evaluated was bulbar conjunctival hyperemia. Additional efficacy and safety parameters (palpebral conjunctival hyperemia, anterior chamber flare and cells, symptoms of ocular discomfort and ocular tolerance, adverse events and intraocular pressure) were also evaluated. Control visits were performed at day 1, day 4 and day 14 after surgery; the endpoint of the study was set at 14±2 days after surgery.

Results: A complete resolution of bulbar conjunctiva hyperaemia at the study end point was reached in 92.9% of patients treated with dexa/net and 75.0% of those treated with dexa/tobra (p=0.02, Fisher's exact test). No differences were observed between treatments for other efficacy parameters. Statistically significant differences in favour of dexa/net (p< 0.0001, ANOVA) were observed for most of subjective tolerance variables examined (blurred vision, foreign body sensation, stickiness, burning) starting day 1 after surgery when only the viscous formulations were used. No increase in intraocular pressure or adverse events was observed during the study.

Conclusion: The combination dexa/net is safe and effective in the treatment of post-operative inflammation following sutureless MIVS. In particular, the use of eye gel formulation is characterized by a great tolerability.

Keywords: fixed combination; tolerability; vitreoretinal surgery; xanthan gum.

Figure 1

Patients disposition.

Figure 2

Effects of treatment on hyperemia of the conjunctiva. Percentage of patients with a complete resolution of conjunctival hyperemia (score=0) at the end of the study (day 14 after surgery). A Fisher Exact Test was performed between the two groups of treatment.