Bacterial contamination of intravitreal needles by the ocular surface microbiome.

PURPOSE: The ocular surface microbiota are recognised as one of causative microorganisms in post-procedural endophthalmitis but in many cases the vitreous tap is culture negative. This study investigated bacterial contamination of intravitreal (IVT) needles using multiple approaches covering culturing, 16S rRNA gene sequencing, fluorescent in situ hybridisation (FISH) and scanning electron microscopy (SEM). METHODS: IVT needles were obtained immediately after injection from patients undergoing treatment for predominantly age-related macular degeneration. Eighteen needles were analysed by culturing on chocolate blood agar. In addition, 40 needles were analysed by extracting DNA and paired-end sequencing of the 16S rRNA gene. Sequences were quality filtered (USEARCH), taxonomically classified (SILVA) and contaminant filtered (DECONTAM). Nine needles were analysed by either FISH using the bacterial probe EUB338 or SEM. RESULTS: Using culturing, three bacteria were identified from 5 of 18 needles (28%) - Kocuria kristinae, Staphylococcus hominis and Sphingomonas paucimobilis. The negative control needles showed no growth. Following rigorous data filtering, bacterial community analysis using 16S rRNA gene sequencing showed the presence of predominantly Corynebacterium but also Pseudomonas, Acinetobacter, Sphingomonas, Staphylococcus and Bacillus on the needles. Cocci-shaped cells in a tetrad formation were observed using FISH, while SEM images showed cocci-shaped bacteria in pairs and irregular tetrads. CONCLUSIONS: The study showed evidence for a large diversity of bacteria on IVT needles and visually confirmed their adherence. The diversity was similar to that found on the ocular surface and in conjunctival tissue. This suggests the risk of exogenous endophthalmitis remains even with sterilization of the conjunctival surface.

Seeing the difference-Painless progressive vision loss in a vasculopath.

A 78-year-old Caucasian man with significant vascular disease reported sudden onset of worsened vision during a routine wound-care appointment for nonhealing necrotic leg ulcers. He described painless blurring of vision with grey scotomas in his right eye, his only well-seeing eye, after trauma to the left eye as a child. He presented with retinal ischemia, a cotton wool spot, and optic nerve swelling. Temporal artery biopsy showed myxoid degeneration and extensive calcium deposition, which also was present on imaging throughout his carotid and vertebral arterial system-the clinical picture of calciphylaxis.

Phenotypic variation in enhanced S-cone syndrome.

PURPOSE: To characterize the clinical, psychophysical, and electrophysiological phenotype of 19 patients with enhanced S-cone syndrome (ESCS) and relate the phenotype to the underlying genetic mutation. METHODS: Patients underwent ophthalmic examination and functional testing including pattern ERG, full-field ERG, and long-duration and short-wavelength stimulation. Further tests were performed in some patients, including color contrast sensitivity (CCS), multifocal ERG, fundus autofluorescence imaging (FAI), optical coherence tomography (OCT), and fundus fluorescein angiography (FFA). Mutational screening of NR2E3 was undertaken in 13 patients. RESULTS: The fundus appearance was variable, from normal to typical nummular pigment clumping at the level of the retinal pigment epithelium in older patients. Nine patients had foveal schisis, and one had peripheral schisis. Pattern ERG was abnormal in all patients. In all patients, ISCEV Standard photopic and scotopic responses had a similar waveform, the rod-specific-ERG was undetectable and the 30-Hz flicker ERG was markedly delayed with an amplitude lower than the photopic a-wave. Most ERG responses arose from short-wavelength-sensitive mechanisms, and a majority of patients showed possible OFF-related activity. Multifocal ERG showed relative preservation of central function, but reduced responses with increased eccentricity. Mutations were identified in NR2E3 in 12 of 13 patients including four novel variants. CONCLUSIONS: The phenotype in ESCS is variable, both in fundus appearance and in the severity of the electrophysiological abnormalities. The ERGs are dominated by short-wavelength-sensitive mechanisms. The presence, in most of the patients, of possible OFF-related ERG activity is a finding not usually associated with S-cones.