Subconjunctival reflux and need for paracentesis after intravitreal injection of 0.1 ml bevacizumab: comparison between 27-gauge and 30-gauge needle

Abstract

Purpose: Intravitreal injections may lead to a significant elevation of the intraocular pressure (IOP). A paracentesis may become necessary for acute reduction of the IOP in certain cases. The purpose of this study was to determine the frequency of paracentesis performed and the grade of reflux under the conjunctiva after injection of 0.1 ml bevacizumab (1.25 mg), depending on the thickness of the needles used.

Methods: A retrospective review was undertaken of the surgery reports of 234 consecutive intravitreal bevacizumab injections in 145 eyes of 144 patients within 14 months. In particular, the frequency of paracentesis, the thickness of the needles used (27-gauge versus 30-gauge), the lens status, and a semi-quantitative reflux grade were analysed.

Results: A paracentesis was performed in 78 cases (33%) for acute reduction of the IOP. In the 27-gauge group the frequency was 26% (25 of 96), and in the 30-gauge group 38% (53 of 138) (p = 0.05, independent estimating equation (IEE)). The medians of the semi-quantitative assessment of the reflux grade under the conjunctiva were 2.0 in the 27-gauge group (corresponding to a mild reflux) and 1.0 in the 30-gauge group (corresponding to a minimal reflux, p < 0.001, IEE).

Conclusions: When using a 30-gauge needle for intravitreal injections, the reflux under the conjunctiva was less than with a 27-gauge needle. However, the use of a 30-gauge needle appeared to be associated with a higher frequency of paracentesis.