We commend Hariprasad et al1 on their study regarding the aqueous and vitreous penetration of topically administered 0.5% moxifloxacin. We have no critiques of their study design, methods, or conclusions, but further review of their data reveals an additional interesting finding. Although their statistical analysis comparing aqueous and vitreous concentration values in phakic and pseudophakic eyes was not significant, we decided to further evaluate the potential effect of lens status on vitreous penetration by asking the questions, “Does phakic status effect the distribution of topically administered moxifloxacin from the aqueous into the vitreous?” and “What percentage of moxifloxacin entering the aqueous cavity diffuses posteriorly into the vitreous cavity, and does phakic status alter this percentage?” We feel convinced that penetration across the conjunctival, scleral, and retinochoroidal barriers into the vitreous is negligible; therefore, any topical moxifloxacin entering the vitreous cavity would do so via corneal penetration into the aqueous and from there must diffuse posteriorly around the lens.
Fuller JJ, McGwin G. Phakic Status Affects Vitreous Penetration of Topical Moxifloxacin. Arch Ophthalmol. 2006;124(5):749. doi:10.1001/archopht.124.5.749-a