Differential Bacterial Colonization and Biofilm Formation on Punctal Occluders.

Dry eye is a common condition that is treated primarily by topical lubricants, immunomodulation, and a variety of punctal and canalicular plugs (occluders). Biofilm formation has been reported as an ongoing problem with the clinical use of occluders. In order to explore the role of biofilm formation on occluders, we tested the bacteria strain, Staphylococcus aureus, with three different types of occluders, DeltaR, OdysseyR, and AlphamedR. Scanning electron microscopy (SEM) of these occluders revealed a variation in surface appearance, with OdysseyR being the smoothest (but with grooves), followed by DeltaR, and AlphamedR. Exposing each type of occluder to dynamically grown bacterial cultures of S. aureus, a ~3 fold statistically significant difference in bacteria colonization between the OdysseyR and AlphamedR occluder and a ~2 fold higher trend between OdysseyR and DeltaR were detected. These quantitative results were also verified with SEM, showing extensive S. aureus colonization and biofilm formation on the surface of the OdysseyR occluder. The results also indicate that bacterial colonization readily occurs on all three types of occluders. The occluder with the smoothest but grooved surface (OdysseyR), displayed increased biofilm formation when compared to those with rougher surfaces.

Late-Onset Microsporidial Keratitis in Femtosecond Astigmatic Keratotomy After Laser-Assisted Phacoemulsification.

PURPOSE: To present a case of microsporidial keratitis in a femtosecond laser-created astigmatic keratotomy (AK) incision. METHODS: Case report. RESULTS: A 65-year-old Middle Eastern man presented 2 months after uncomplicated femtosecond laser-assisted cataract surgery (FLACS) and AK with mildly decreased vision and corneal edema in the operative eye. Shortly after treatment with topical corticosteroids, a fulminant corneal infiltrate manifested along the temporal arcuate incision. Multiple corneal scrapings sent for laboratory analysis were inconclusive. Two weeks after the initial presentation, a deep tissue sample was obtained using a 27-gauge cannula passed within the arcuate incision. The gram stain was directly observed, revealing intracellular microsporidial spores. The patient was treated with oral albendazole 400 mg once daily over 2 weeks and topical voriconazole 1% and fumagillin 3 mg/mL eye drops over 10 weeks. During this course, visual function steadily recovered as the infiltrate coalesced and ocular inflammation subsided. CONCLUSIONS: This is the first reported case of microsporidial keratitis presenting as a late-onset infection after femtosecond laser-assisted AK.

Cobalt-Chromium Metallosis With Normal Electroretinogram.

BACKGROUND: Ocular cobalt toxicity is a rare phenomenon reported with increased frequency due to the rise of cobalt-chromium metal hip implants. We report the case of a 66-year-old previously healthy man who developed decreased vision due to cobalt-chromium toxicity from a metal-on-metal hip arthroplasty. Our objective was to determine whether the origin of his visual loss was due to toxicity of the optic nerve, of the retina, or of both. METHODS: Ocular examination, 10-2 SITA-Standard Humphrey Visual Field (VF), standard full-field electroretinogram (ERG) as indicated by the International Society for Clinical Electrophysiology of Vision (ISCEV), multifocal electroretinogram (mfERG), multifocal visual evoked potentials (mfVEP), and optical coherence tomography (OCT) were conducted. RESULTS: Ocular examination revealed decreased visual acuity, poor color vision, normal funduscopy, and cecocentral scotomas on VF testing. Because his right eye was amblyopic since childhood, test results from only the left eye are shown. Electrophysiology studies revealed an ISCEV standard full-field ERG with photopic and scotopic responses within normal limits, mfERG with amplitudes and latencies within normal limits, and mfVEP with latencies within normal limits, but with decreased central amplitudes. Peripapillary and macular OCT showed retinal nerve fiber layer and retinal ganglion cell-inner plexiform layer thickness within normal limits. CONCLUSION: Because decreased color vision and cecocentral scotoma on 10-2 VF are most consistent with toxic optic neuropathy, and decreased central amplitudes on mfVEP are suggestive of neural dysfunction, we hypothesize that our patient presented with an early stage of optic nerve toxicity that was not yet apparent as a structural abnormality on OCT.

The 24-2 Visual Field Test Misses Central Macular Damage Confirmed by the 10-2 Visual Field Test and Optical Coherence Tomography.

PURPOSE: To determine the extent to which the 24-2 visual field (VF) misses macular damage confirmed with both 10-2 VF and optical coherence tomography (OCT) tests and to evaluate the patterns of damage missed. METHODS: One hundred forty-one eyes of 141 glaucoma patients or suspects underwent 24-2 VF (mean deviation [MD] better than -6 dB), 10-2 VF, and OCT testing. Retinal nerve fiber layer (RNFL) and retinal ganglion cell plus inner plexiform (RGC+) probability plots were combined with 10-2 VF probability plots. Eyes were classified as "abnormal macula" if abnormal regions on both the 10-2 VF and OCT plots agreed. The number of abnormal eyes missed (i.e., false negatives) was determined for the following 24-2 VF metrics: MD; pattern standard deviation (PSD); glaucoma hemifield test (GHT); cluster criteria (CC); and abnormal points within ± 10°. Eyes that were missed on one or more of the 24-2 metrics were classified by damage type based upon circumpapillary RNFL thickness plots. RESULTS: Fifty-nine (41.8%) eyes were classified as "abnormal macula," and comprised the reference standard. Of the 59, 31 (52.5%) were missed by one or more of the 24-2 metrics. The individual 24-2 metrics missed between 7 (CC) and 20 (MD) eyes. The eyes missed had widespread macular damage, as well as both shallow and deep local defects. CONCLUSIONS: Eyes with macular glaucomatous damage may be classified as normal based on the 24-2 VF alone. TRANSLATIONAL RELEVANCE: To detect macular damage with perimetry, the 10-2 VF test (or a modified 24-2 VF test) is essential.

A Region-of-Interest Approach for Detecting Progression of Glaucomatous Damage With Optical Coherence Tomography.

IMPORTANCE: Detecting progression of glaucomatous damage is often challenging. OBJECTIVE: To test the feasibility of using frequency-domain optical coherence tomography (FD-OCT) and a region-of-interest (ROI) approach to measure progressive changes in glaucomatous damage. DESIGN, SETTING, AND PARTICIPANTS: Among a group of patients in an institutional glaucoma practice who were likely to show glaucoma progression, eyes with a history of an optic disc hemorrhage (DH) confirmed by stereophotography were followed up with FD-OCT cube scans of the optic disc. All patients underwent FD-OCT scans on at least 2 occasions separated by at least 1 year (mean, 3.45 years; range, 1.42-6.39 years). Because we were not studying the effects of an optic DH, no constraint was placed on the time between the documentation of an optic DH and the first scan used in the analysis. MAIN OUTCOMES AND MEASURES: After en face images of the FD-OCT scan were aligned based on the blood vessels, circumpapillary images were derived for an annulus 100 µm in width, and the retinal nerve fiber layer (RNFL) thickness profiles were plotted for the first and last visits. The ROI width associated with the optic DH was defined as the region of the RNFL profile below the 1% CI based on healthy norms. The change in the ROI width was compared with the change in the global RNFL thickness, which was obtained by averaging the circumpapillary RNFL thickness. RESULTS: The change in the ROI width (mean [SD], 8.0° [6.4°]; 95% CI, 4.9° to 11.1°; range, -0.7° to 19.3°) was significant (P < .001, 2-tailed t test) while the change in the global thickness (mean [SD], 2.40 [5.87] µm; 95% CI, -0.48 to 5.28 µm) was not significant (P > .12, 2-tailed t test). Although 15 of the 16 ROIs increased in width between visits, only 11 showed a decrease in the global RNFL thickness. CONCLUSIONS AND RELEVANCE: For detecting progression of local RNFL damage in patients with glaucoma, an OCT ROI approach appears superior to the OCT global RNFL thickness measure typically used.