PurposeTo evaluate the rate of sterile endophthalmitis (SE) following intravitreal injection of three different formulations of triamcinolone acetonide (TA) in a single physician practice and also to assess the mean diameter and concentration of particles of the two TA formulations currently available commercially in the USA. It was hypothesized that TA formulations with smaller particles and/or greater concentrations would have a higher incidence of SE.MethodsSingle-site, interventional case series in which the medical records of 392 consecutive eyes receiving intravitreal TA as Triesence®, Kenalog®-40, or preservative-free TA between September 2008 and October 2013 were retrospectively reviewed for the incidence of SE. Particle sizing of TA formulations was conducted by an independent commercial laboratory.ResultsFive cases of SE were identified. The four cases of SE following Triesence® (4.6%) represented a rate significantly higher than the one case of SE following preservative-free TA (0.6%; P=0.049) and the 0% incidence rate of SE following Kenalog®-40 (P=0.0210). Triesence® had significantly smaller particles than Kenalog®-40 (P<0.0001).ConclusionThe rate of SE was the highest with the formulation of TA that had the smallest particle size and highest particle load (number of particles injected). The lowest rate of SE was seen with Kenalog®-40, the only TA formulation that contained a benzyl alcohol preservative. The data do not support a principal causative role of benzyl alcohol in the development of TA-induced SE. Instead, the data support the particle theory of TA-induced SE; however, larger-scale, multicenter studies are needed to confirm and expand on these findings.

BackgroundOptical coherence tomography has focused mainly on central subfield thickness to quantify macular edema in central and branch retinal vein occlusion. We examined macular fields other than the central subfield to determine if they are possibly independent indicators of recurrent macular edema.MethodsSingle center, retrospective, consecutive case study of patients with recurrent macular edema secondary to either central or branch retinal vein occlusion. Thickness estimates of serial domain optical coherence tomography macular fields were obtained at the time of recurrent macular edema and analyzed retrospectively. Changes were expressed as a percentage of previous baseline levels. Change in thickness at each retreatment episode as well as average changes in thickness were calculated for each macular field for each eye. Data were analyzed via analysis of variance and Fisher’s post hoc analyses. The macular field which most frequently had the largest percent increase at the time of recurrence was also assessed using averages for each subject as well as for each retreatment episode. Individual episodes of recurrent macular edema were also examined to ascertain the frequency in which there was minimal foveal edema (<15 μm increase), but non-foveal edema was considered severe enough to warrant retreatment.Results429 episodes of recurrent macular edema in 80 eyes were examined. In addition to the central subfield, the average mean change in thickness of the most affected quadrant (central vein occlusion) or hemisphere (branch vein occlusion) of the extrafoveal 3 mm band had the largest mean changes and also most frequently had the largest increases at the time of recurrent macular edema. In approximately 20 % of both central and branch occlusions, recurrent macular edema was detected in non-central macular fields in the absence of significant edema in the central subfield.ConclusionsAnalyses of non-central macular fields as well as the central subfield may be useful in the early detection and treatment of recurrent macular edema in retinal vein occlusion.