References might be helpful. It is to be read as one mixes the antibiotics. It is better to have this manuscript published here than in a handbook of therapeutics or to revise it as suggested and publish it in a hardcopy journal. With internet becoming widely accessable, the publication of the manuscipt on the internet increases the chance it will be available to the vitreoretinal surgeon when needed. An area free of contaminants should always be sought.
Pharmacies often prepare ophthalmic solutions with a laminar flow hood.
If the author is suggesting that his method is equally acceptable, data should be provided on actual cases to relieve the reader of this concern. One must weigh the theoretical risk of mixing outside a laminar flow hood against the risk of delaying injection of the antibiotics while waiting for antibiotics to arrive from a distant site because it was insisted that a laminar flow hood be used. Thus, the author describes a method to avoid backflush in the first section of this paragraph. It is intimated that this could over dilute the concentration of antibiotic solutions in the syringe to which you are adding water. This could be a problem, too.