All authors are employees of Alcon Research, Ltd.

Data supporting the concept that microbial biofilms are a major cause of non-healing ulcers remain limited. A porcine model was established where delayed healing resulted from methicillin-resistant Staphylococcus aureus (MRSA) infection in full-thickness wounds. At the end of one study a wound remaining open was sampled and a MRSA strain was isolated. This pig-passaged strain was used as the inoculating strain in several subsequent studies. The resulting MRSA wound infections exhibited a greater, more stable tissue bioburden than seen in studies using the parent strain. Furthermore, wounds infected with the passaged strain experienced a greater delay in healing. To understand whether these changes corresponded to an increased biofilm character of the wound infection, wound biopsy samples from studies using either the parent or passaged MRSA strains were examined microscopically. Evidence of biofilm was observed for both strains, as most samples at a minimum had multiple isolated, dense microcolonies of bacteria. However, the passaged MRSA resulted in bacterial colonies of greater frequency and size that occurred more often in concatenated fashion to generate extended sections of biofilm. These results provide a model case in which increasing biofilm character of a wound infection corresponded with a greater delay in wound healing.

PurposeTo compare the resolution and optical quality of the ReSTOR® +3.0 D and ReSTOR +2.5 D multifocal intraocular lenses (IOLs) with the AT LISA® tri and FineVision® trifocal IOLs.MethodsResolution, image quality, and photic phenomena were evaluated in the AcrySof® IQ ReSTOR +3.0 D and +2.5 D multifocal IOLs and compared with the AT LISA tri 839MP and FineVision Micro F12 trifocal IOLs, using a Badal optometer and a Snellen visual acuity chart. Simulated headlight images were obtained using a modulation transfer function (MTF) bench and a 50 μm pinhole target. MTF values, using vertical and horizontal slits, were determined at far, intermediate, and near distances.ResultsResolution at 20/40 Snellen visual acuity equivalence was attainable over nearly the entire viewing distance range with the AT LISA tri and FineVision IOLs, but background shadows were more prominent with the AT LISA tri and FineVision IOLs than with the ReSTOR IOLs. Distance MTF peaks at 20/20 Snellen–equivalent spatial frequency were greatest for ReSTOR +2.5 D and ReSTOR +3.0 D IOLs. The near MTF peak occurred at 53 cm with ReSTOR +2.5 D and had a 20/20 Snellen–equivalent value that was lower than the near peaks of the other models but higher than the intermediate foci of the trifocal IOLs.ConclusionAT LISA tri and FineVision trifocal IOLs achieved a useful third focus for intermediate vision but were associated with increased background halos and reduced distance visual quality compared with ReSTOR +2.5 D and +3.0 D multifocal IOLs.

A wound biofilm model was created by adapting a superficial infection model. Partial-thickness murine wounds were inoculated with methicillin-resistant Staphylococcus aureus (MRSA). Dense biofilm communities developed at the wound surface after 24 h as demonstrated by microscopy and quantitative microbiology. Common topical antimicrobial agents had reduced efficacy when treatment was initiated 24 h after inoculation compared to 4 h after inoculation. This model provides a rapid in vivo test for new agents to treat wound biofilm infections.

The data demonstrate that wound pH in a model of contaminated pig wounds is alkaline during the first 10 days of healing. As healing progresses, pH decreases with no significant change in the level of bacterial bioburden. C collagenase exhibited robust activity in the pH range found in this contaminated pig wound model, suggesting it can effectively debride necrotic tissue in the environment found in most chronic wounds in humans.