The influence of needle gauge and infection source on vitreous aspirate cultures. Issue 4 (12th August 2015)

• Record Type: Journal Article
• Authors: Smith, Jesse M; Mathias, Marc T; Oliver, Scott C; Mandava, Naresh; Olson, Jeffrey L; Quiroz-Mercado, Hugo; Palestine, Alan G
• Is Part Of: British journal of ophthalmology. Volume 100:Issue 4(2016)
• Page Start: 453
• Page End: 455
• Publication Date: 2015-08-12
• Subjects: Infection -- Inflammation -- Microbiology -- Vitreous -- Treatment Medical; Ophthalmology -- Periodicals; 617.7
• DOI: 10.1136/bjophthalmol-2015-307081
• Languages: English
• ISSNs: 0007-1161

Abstract

Abstract : Background/aims: While the Endophthalmitis Vitrectomy Study (EVS) included only post-cataract surgery patients, the methods and data from that study are widely applied in the management of endophthalmitis of all types. We sought to examine how our experience with in-office vitreous aspiration differed from the EVS in two ways: first, by reviewing microbiological culture yields from vitreous aspirates obtained using 30-gauge needles versus 25–27-gauge needles and second, by reviewing culture yields in cases of endogenous versus non-endogenous endophthalmitis. Methods: Cases of endophthalmitis over a 14-year period were reviewed when vitreous tap was the initial diagnostic procedure. The data included infection source, needle size used to obtain a vitreous aspirate, organism cultured and rates of unsuccessful attempts at vitreous aspiration or dry taps. Results: 10 cases were endogenous endophthalmitis, while 36 cases were a mix of postoperative, post-traumatic, post-intravitreal injection and miscellaneous patients. A positive microbiological culture was obtained in 11/36 (31%) of vitreous taps using a 25–27-gauge needle and in 8/10 (80%) taps using a 30-gauge needle (p<0.01). A positive vitreous culture was obtained in 18/36 (50%) of all non-endogenous cases, while a positive result was obtained in 0/10 (0%) cases of endogenous endophthalmitis (p<0.01). Conclusions: The use of a smaller needle in obtaining vitreous samples in endophthalmitis did not lower the microbiological yield. A positive microbiological yield was significantly less likely in cases of endogenous endophthalmitis compared with non-endogenous cases. Vitreous tap as a method for identifying the causative organism in endogenous endophthalmitis was of limited utility.