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Purpose: Fungal keratitis (FK) is a serious ophthalmic disease with a potentially devastating outcome that seems to be increasing in recent years. The use of contact lenses (CLs) was evaluated as a risk factor for FK to determine possible differences in course and outcome., Methods: Data from 173 cases reported in the German FK registry until August 2019 were evaluated regarding CL behavior, other ophthalmological and general risk factors, age, sex, identified pathogens, conservative and surgical therapy, visual acuity, and findings at admission and follow-up., Results: One hundred seventy-four eyes from 173 patients between 2000 and 2019 were included [64.4% women, median age 54 (39; 72) years]; 49.7% wore CL, of which 81.3% were soft CL, and 50.3% had no history of contact lens use (NCL). CL users were significantly more often women and otherwise healthy (CL: 80.2% vs. NCL: 48.9%; P < 0.0001). The spectrum of pathogens among CL users showed a significantly higher proportion of infections with filamentous pathogens, in particular Fusarium sp. (total filament: CL 69.8% vs. NCL 27.3%; P = 0.0001; Fusarium sp.: CL 50.0% vs. NCL 14.8%; P < 0.0001). Overall, 54.6% required keratoplasty and 8.6% enucleation., Conclusions: CLS are the most important risk factor for FK in Germany. With CLs, typically, the infection is caused by molds, and patients are comparably younger and otherwise healthy. Often, extensive surgery is needed. To evaluate changes in the pathogen and resistance spectrum and to further monitor possible CL-related risk factors, a consistent collection of data remains paramount., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Significance: This study provides insight into the current recommendations, clinical behaviors, and risk assessments of eye care professionals on the topic of rigid contact lens exposure to tap water. This knowledge may motivate professional organizations to develop initiatives to educate eye care professionals on the dangers of contact lens exposure to water., Purpose: The purpose of this study was to investigate the practice patterns and risk perceptions of eye care professionals regarding gas-permeable contact lens exposure to tap water., Methods: A branched-logic survey was started by 320 clinicians, vision scientists, and industry personnel and was fully completed by 272 participants. The survey queried participants about their current practices, recommendations, and perceptions of risk regarding exposure of gas-permeable contact lenses to tap water., Results: Of those who prescribe gas-permeable contact lenses, 57.4% reported rinsing lenses with tap water, whereas only 32.7% reported engaging in this same behavior in front of patients. Of those who reported never rinsing lenses with tap water, 85.6% indicated that rinsing lenses with water increases infection risk, whereas 52.1% of those who rinse lenses with water reported the same perceived risk (P < .001). Of all participants, 60% indicated that wearing contact lenses while showering increases infection risk, and 50.2% of all participants advised patients to avoid this behavior., Conclusions: A discrepancy exists between perceptions of risk concerning exposure of contact lenses to water and both clinical practices and patient education provided by professionals., Competing Interests: Conflict of Interest Disclosure: None of the authors have reported a financial conflict of interest., (Copyright © 2021 American Academy of Optometry.)

We report a rare case of dematiaceous fungus colonization in the therapeutic bandage contact lens (BCL), in an eye with peripheral ulcerative keratitis. Bandage contact lens removal and appropriate treatment resulted in improvement of the visual acuity and prevented the spread of fungus to the underlying ocular structures. Microbiological evaluation of the BCL showed dematiaceous fungal filaments, and the fungus was identified as Bipolaris species. In patients with pigmented plaque-like lesions, with BCL in situ, dematiaceous fungus on the undersurface of the BCL should be kept in mind. Patient education regarding the importance of frequent BCL replacement, proper ocular hygiene, and timely follow-up should be emphasized.

Purpose: Contact lens (CL)-related microbial keratitis (MK) has major public health implications, with about 300 million wearers worldwide, and certain potentially modifiable risk factors. This study aimed to identify the risk factors of CL-related MK., Methods: A multicenter case-control study was conducted between 2014 and 2017. Cases presenting with CL-related MK were submitted to an anonymous 52-item questionnaire, which was also completed by healthy controls. Univariate followed by multivariate logistic regression analysis was performed. Risk factors for CL-related MK were given as odds ratio (OR) with 95% confidence interval and P-value., Results: The study included a total of 2267 patients (1198 cases and 1069 controls). The MK risk factors for the daily disposable lenses group were exceeding the lens renewal period (OR = 9.16, P = 0.008) and occasionally wearing CL when sleeping (OR = 15.83, P = 0.035). The most important risk factors in the nondaily disposable lenses group were lens cleaning solution distributed by eye care brands (OR = 3.50, P < 0.001) and failure to renew lens cases (OR = 3.39, P = 0.001). Statistically and clinically significant variables were used to establish the MK risk equation for CL wearers, allowing an individual calculation of the risk of MK under lenses., Conclusions: The MK risk equation is a valuable tool for educating patients about the risks associated with wearing CL. It allows the patient to be informed about their overall risk of infection while detailing the precipitating elements of the infectious risk with the aim of modifying risk behavior.

Significance: Scleral lenses have become an increasingly common treatment for ocular surface disease and irregular corneas. Multidose, preservative-free saline solutions are frequently used off-label to fill scleral lenses. Because the fluid resides over the ocular surface during lens wear, contaminated solutions may increase the risk of infectious complications., Purpose: We sought to assess the viability of skin microorganisms and pathogens associated with keratitis once introduced into a multidose preservative-free saline (MDPFS) solution containing the bacteriostatic agent boric acid (PuriLens Plus; The Lifestyle Co., Inc., Freehold, NJ)., Methods: Eleven bacterial and one yeast isolate were each inoculated to three lots of MDPFS as well as to sterile normal saline for comparison. Microorganism concentrations were enumerated at baseline and days 1, 3, 7, 14, 21, and 28. Persistence of microorganism viability was compared between MDPFS lots and between MDPFS and normal saline for each organism., Results: Duration of microorganism viability was ≥24 hours in MDPFS with no significant difference in the distribution of survival duration of microorganisms in MDPFS versus normal saline (P = .15). Candida albicans concentrations declined 14 days earlier in MDPFS, whereas concentrations of viable organisms in MDPFS remained within 1 log of baseline for the longest durations for Pseudomonas aeruginosa (7 days), Escherichia coli (14 days), and Achromobacter xylosoxidans (≥28 days). Gram-positive organism concentrations remained within 1 log of baseline for no more than 3 days. Mild lot-to-lot variation in organism concentrations was noted near the end points of viability. Bacteriostasis was demonstrated in that concentrations of all organisms remained at or below baseline levels throughout the 28-day period., Conclusions: After microbial contamination, persistence of organism viability was similar in PuriLens and normal saline. Environmental gram-negative organisms, many of which can contribute to infectious keratitis, can persist for weeks once introduced into saline solutions.

Objectives: To evaluate the risk factors, causative microorganisms, and presenting features of infection in patients with contact lens-associated microbial keratitis (CLAMK) admitted to a tertiary referral center in Turkey., Methods: A retrospective review of the medical records of 62 patients who were diagnosed as CLAMK in our clinic between 2012 and 2018 was conducted., Results: The mean age of the patients (22 men and 40 women) at the time of diagnosis was 24.5±8.3 years (range, 16-48). The mean best-corrected visual acuity (BCVA) was 0.7±0.9 log of minimal angle of resolution (logMAR) (0-3) before treatment and increased to 0.1±0.1 logMAR (0-0.4) at the end of the follow-up. All patients, except one using rigid gas-permeable CL, were frequent replacement soft CL users. Thirty-one (50%) patients declared overnight wear, and 37 (58.9%) patients declared showering or swimming in CLs regularly. Cultures of either corneal scrapings or CL materials were positive in 40 (64.5%) eyes, 12 (19.4%) of which had mixed infections. Thirteen strains of microorganisms were demonstrated, among which there were seven (53.8%) gram-negative bacteria, one (7.7%) gram-positive bacteria, four (30.7%) fungi, and Acanthamoeba (7.7%). The most common pathogen was Pseudomonas aeruginosa, followed by Serratia marcescens and Stenotrophomonas maltophilia. According to culture results, P. aeruginosa infections were associated with significantly worse BCVA. Keratitis foci were either centrally or paracentrally located in 39 (62.9%) eyes, and 16 eyes (25.8%) presented with hypopyon., Conclusion: Along with growing number of CL users, CLAMK constitutes an important problem with possibly worse visual outcomes. Thus, in addition to meticulous treatment, management of risk factors and behavioral modifications is crucial.

Purpose: To compare the infectious contact lens-related corneal ulcer (CLRU) and non-CLRU cases at Saint Louis University., Methods: Retrospective review of corneal ulcer cases identified by search of the ophthalmology and microbiology department databases between 1999 and 2016., Results: Six hundred seventy-seven cases of corneal ulcers were identified, of which 46% were CLRU. CLRU cases were seen more commonly in younger patients (P<0.001) and women (P=0.03) than non-CLRU cases. Many of the infections were vision-threatening as defined by central/paracentral location (73% CLRU and 71% non-CLRU [P=0.60]) and large size of ulcer >2 mm in 36% CLRU and 51% non-CLRU (P=0.002). Causative pathogen in cultured CLRU was predominately Pseudomonas species (44%, P<0.001 vs. the non-CLRU group), other gram-negative (6%), gram-positive (33%), fungi (13%), and Acanthamoeba (5%). Comparatively, cultured non-CLRU was predominately gram-positive (64%, P<0.001 vs. the CLRU group), gram-negative (26%), and fungi (11%). The combined oxacillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus isolates were 35% and 34%, respectively. Despite the progressive increase in the number of corneal ulcers seen, the annual trend for any one particular organism for either CLRU cases or non-CLRU cases did not change significantly., Conclusions: Most of the cases were non-CLRU. CLRU was disproportionately associated with Pseudomonas species and non-CLRU with Staphylococcal species. Fungal infections were predominately caused by filamentous organisms in both groups. Acanthamoeba keratitis was exclusively associated with CL use.

With the increasing incidence of more pathogens that can cause microbial keratitis (MK), it is necessary to periodically reassess disinfection multipurpose solutions testing requirements to ensure that relevant organisms to challenge them are being used. Current testing protocols have included common pathogens such as Pseudomonas aeruginosa, Staphylococcus aureus, Serratia marcescens, Candida albicans, and Fusarium solani but have omitted less common pathogens such as Acanthamoeba. Specifically, Acanthamoeba sp. has recently been identified as a prevalent cause of MK in certain countries. Developing an appropriate protocol for this unique organism presents a challenge, given its two distinct life stages, methods to grow the organism, encystment techniques, and many other parameters that can affect testing outcomes. Therefore, the appropriate combination of these parameters is crucial to developing a protocol that ensures consistent, accurate results. The FDA has recognized the importance of establishing a standardized testing protocol for this pathogen and embarked on research efforts to provide a recommended testing protocol for testing contact lens care products.

Objectives: The purpose of this study was to determine whether a commercial formulation of hypochlorous acid hygiene solution (0.01%), Avenova, can destroy existing biofilms formed by ocular clinical bacterial isolates, including blepharitis isolates of Staphylococcus aureus and coagulase-negative staphylococci, and a keratitis isolate of Pseudomonas aeruginosa., Methods: Biofilms grown in bacterial growth media on disposable contact lens cases were challenged with hypochlorous acid hygiene solution. At various time points, surviving bacteria were quantified by serial dilution and colony counts. Staphylococcus aureus biofilms formed on glass were challenged using a hypochlorous acid hygiene solution and imaged using vital staining and confocal laser scanning microscopy., Results: Bactericidal activity (≥3 Log10; 99.9%) was observed for all tested bacterial species after a 30-min exposure. Staphylococcus aureus biofilms had a bactericidal level of killing by 10 min (P<0.01), Staphylococcus capitis by 5 min (P<0.001), Staphylococcus epidermidis by 30 min (P<0.001), and P. aeruginosa by 10 min (P<0.01). Confocal microscopy and crystal violet staining analysis of bacterial biofilms treated with hypochlorous acid solution both demonstrated that biofilm bacteria were readily killed, but biofilm structure was largely maintained., Conclusions: Hypochlorous acid (0.01%) hygiene solution was able to achieve bactericidal levels of killing of bacteria in biofilms but did not disrupt biofilm structures. Susceptibility of tested staphylococcal blepharitis isolates varied by species, with S. capitis being the most susceptible and S. epidermidis being the least susceptible.

Objectives: Ocular infections due to Achromobacter xylosoxidans are extremely uncommon; their diagnosis is a challenge and the optimal treatment remains controversial. We present a case of A. xylosoxidans in a contact lens user and a review of the literature to facilitate diagnostic suspicion and empirical therapeutic management., Methods: Review of the literature in PubMed and MEDLINE. We also document a case diagnosed in our department in January 2016., Setting: Hospital Clínico Universitario Lozano Blesa, Zaragoza, Spain., Results: According to the literature, clinical manifestations and antibiotic sensitivity of A. xylosoxidans varied greatly. Our patient with no history of keratopathy presented three risk factors that made the diagnosis suspicious. The infection was resolved with topical moxifloxacin and fluorometholone., Conclusions: A. xylosoxidans is an uncommon cause of infection, but must be suspected in atypical keratitis, reported contact with warm or still waters, use of contact lenses, or previous corneal damage. In these cases, microbiological studies and antibiotic sensitivity testing are particularly important.

Serratia liquefaciens is a rarely encountered gram-negative organism in ophthalmology practice. The only reported ocular infections are from contamination of contact lenses. The authors report the first case of a patient who developed orbital cellulitis secondary to severe S. liquefaciens microbial keratitis.

Purpose: To understand soft contact lens (SCL) and gas-permeable (GP) lens wearers' behaviors and knowledge regarding exposure of lenses to water., Methods: The Contact Lens Risk Survey (CLRS) and health behavior questions were completed online by a convenience sample of 1056 SCL and 85 GP lens wearers aged 20 to 76 years. Participants were asked about exposing their lenses to water and their understanding of risks associated with these behaviors. Chi-square analyses examined relationships between patient behaviors and perceptions., Results: GP lens wearers were more likely than SCL wearers to ever rinse or store lenses in water (rinsing: 91% GP, 31% SCL, P < 0.001; storing: 33% GP, 15% SCL P < 0.001). Among SCL wearers, men were more likely to store (24% vs. 13%, P = 0.003) or rinse (41% vs. 29%, P = 0.012) their lenses in water. Showering while wearing lenses was more common in SCL wearers (86%) than GP lens wearers (67%) (P < 0.0001). Swimming while wearing lenses was reported by 62% of SCL wearers and 48% of GP lens wearers (P = 0.027). Wearers who rinsed (SCL; P < 0.0001, GP; P = 0.11) or stored lenses in water (SCL; P < 0.0001, GP P = 0.007) reported that this behavior had little or no effect on their infection risk, compared with those who did not. Both SCL (P < 0.0001) and GP lens wearers (P < 0.0001) perceived that distilled water was safer than tap water for storing or rinsing lenses., Conclusions: Despite previously published evidence of Acanthamoeba keratitis' association with water exposure, most SCL, and nearly all GP lens wearers, regularly expose their lenses to water, with many unaware of the risk.

Background: The aim of this study was to measure the changes in the bacterial bioburden in orthokeratology (OK) lens storage cases using the DNA dot hybridization assay (DHA) after forewarning patients about their bacterial contamination severity., Methods: Thirty-one OK lens wearers were prospectively enrolled in this study. Dot hybridization assay was used for serial measurements of bacterial bioburden in OK storage cases after lenses had been soaked for approximately 6 hr. After the first assessment, the lens wearers were informed of the extent of case contamination and the possible risk of microbial keratitis (MK), and best practices for lens care and lens case hygiene were reviewed and reinforced. A second assessment by the same DHA method was performed after approximately 6 months., Results: Two universal bacterial probes confirmed a significant decrease in bacterial bioburden at the second assessment (P<0.01 and P<0.001). Genus-specific probes showed significant reductions in Acinetobacter and Klebsiella (P=0.02 and P=0.01), but not in Pseudomonas (P=0.42)., Conclusions: Making OK lens wearers aware of the bacterial bioburden in their lens cases resulted in improved quality of case care and reduced bioburden. Our results suggest that a strategy of bioburden assessment with forewarning could be a useful method to decrease the incidence of OK-related MK.

Objectives: Contact lens-acquired bacterial infections are a serious problem. Of the reported cases, inadequate cleaning of the lens case was the most common cause of lens contamination. Organoselenium has been shown to inhibit bacterial attachment to different polymer materials. This study evaluates the ability of an organoselenium monomer, incorporated into the polymer of a polypropylene contact lens case coupon, to block the formation of biofilms in a lens case., Methods: The bacteria tested were Pseudomonas aeruginosa, Staphylococcus aureus, Stenotrophomonas maltophilia, and Serratia marcescens. For this study, the bacteria were allowed to grow overnight, in trypticase soy broth media, in the presence of the selenium-containing polymer or the same polymer without organoselenium. The material was studied by both colony-forming unit determination and by confocal laser scanning microscopy., Results: The results showed that the organoselenium polymer versus the control polymer resulted in the following effect on biofilm formation: (1) a reduction in P. aeruginosa of 7.3 logs (100%); (2) a reduction in S. aureus of 7.3 logs (100%); (3) a reduction in S. maltophilia of 7.5 logs (100%); and (4) a reduction in S. marcescens reduction of 3.3 logs (99.9%). To test the stability of the organoselenium polypropylene contact lens coupon, the coupon was soaked in PBS for eight weeks at room temperature. It was found that when these soaked coupons were tested against S. aureus, complete inhibition (8.1 logs) was obtained. Because organoselenium cannot leach from the polymer, this would imply that the organoselenium polypropylene contact lens case coupon would be inhibitory toward bacterial biofilm for the life of the case., Conclusion: The organoselenium polypropylene contact lens case coupon shows the ability to inhibit biofilm formation. The use of organoselenium copolymer should play an important role in protecting against contact lens case-acquired infection.

Objective: To assess the general knowledge, behavior, and presence of potentially pathogenic amoebae in cosmetic contact lens (CCL) wearers., Methods: One hundred CCL asymptomatic wearers were randomly selected. A questionnaire regarding their lens use, and a pair of their CCL was obtained. Identification of free-living amoeba (FLA) strains was based on morphological diagnosis, enflagellation tests (for non-Acanthamoeba strains), and sequencing of the small-subunit rRNA gene fragments., Results: Most (92%) of the participants surveyed were women, and the average age of the participants was 21.5±0.2 years. The CCL wearers generally showed a moderate (47%) or good (35%) level of knowledge, and good (51%) or excellent (40%) use of CCL. Two CCL samples were positive for Acanthamoeba genotype T3 or Vahlkampfia. The Acanthamoeba-contaminated CCL was from a wearer who used saline for treating lenses, and the Vahlkampfia-contaminated CCL was from a wearer who used CCL while swimming., Conclusions: This is the first report of the presence of potentially pathogenic FLA in used CCL from asymptomatic wearers in Thailand. Although there was satisfactory knowledge and practice of lens care use, the public should be aware of CCL contaminated with potentially pathogenic FLA that can directly or indirectly cause keratitis.

Purpose: To investigate the ability of protamine, alone or in combination with other antimicrobial agents, to kill bacteria and fungi associated with contact lens-related keratitis., Methods: The International Organization for Standardization 14729:2001 procedure was used to test the antimicrobial activity of solutions of protamine (23-228 μM) with and without polyhexamethylene biguanide (PHMB) and ethylenediamine tetra-acetic acid (EDTA). The recommended ISO panel of microbes along with six clinical isolates was tested. The effect of increasing sodium chloride concentration on the antimicrobial activity was also assessed. The cytotoxicity of the final protamine/EDTA/PHMB solution was measured using ISO 10993-5 standard assays., Results: Protamine gave a dose-dependent antimicrobial effect, with the highest effect for most strains being at 228 μM (≥6 log reductions of viable bacteria and ≥1 log reduction of viable fungi). Addition of EDTA and PHMB increased the antimicrobial effect for all strains except Pseudomonas aeruginosa ATCC6538, which had optimum activity (≥6 log inhibition) even in protamine alone. The optimum antimicrobial activity of all microbes was achieved in 0.2% sodium chloride, but even in 0.8% sodium chloride, the activity met or exceeded the ISO standard (>3 log reductions for bacteria and >1 log reduction for fungi). None of the formulations was cytotoxic to mammalian cells., Conclusions: This study highlights the potential for protamine to be used for the development of effective multipurpose disinfection solutions. Further investigations such as stability, compatibility with contact lenses, and in vivo toxicity are warranted.

Purpose: To evaluate contact lens (CL) storage case contamination when used with four different CL care solutions during daily wear of three different CL materials., Methods: A parallel, prospective, bilateral, randomized clinical trial (n = 38) was conducted. Subjects were randomly assigned to use one of three CL materials (etafilcon A, senofilcon A, or galyfilcon A) on a daily wear basis. Subsequently, each subject randomly used one of four different CL care solutions (Biotrue, OPTI-FREE PureMoist, RevitaLens OcuTec, and CLEAR CARE) for 2 weeks, along with their respective storage cases. After every 2-week period, their storage cases were collected and the right and left wells of each storage case were randomized for two procedures: (1) microbial enumeration by swabbing the storage case surface and (2) evaluation of biofilm formation (multipurpose solution cases only) using a crystal violet staining assay., Results: More than 80% of storage cases were contaminated when used in conjunction with the four CL care solutions, irrespective of the CL material worn. Storage cases maintained with CLEAR CARE (mean Log colony forming units (CFU)/well ± SD, 2.0 ± 1.0) revealed significantly (p < 0.001) greater levels of contamination, compared to those maintained with Biotrue (1.3 ± 0.8) and RevitaLens OcuTec (1.2 ± 0.8). Predominantly, storage cases were contaminated with Gram-positive bacteria (≥80%). There were significant differences (p = 0.013) for the levels of Gram-negative bacteria recovered from the storage cases maintained with different CL care solutions. Storage cases maintained with OPTI-FREE PureMoist (0.526 ± 0.629) showed significantly higher biofilm formation (p = 0.028) compared to those maintained with Biotrue (0.263 ± 0.197)., Conclusions: Levels of contamination ranged from 0 to 6.4 Log CFU/storage case well, which varied significantly (p < 0.001) between different CL care solutions, and storage case contamination was not modulated by CL materials.

Purpose: To investigate normal flora of children with and without orthokeratology (ortho-k) treatment, and the associations between carriage of Staphylococcus aureus and Gram-negative rods with contamination of contact lenses and lens cases in ortho-k subjects and with spectacles of control subjects., Methods: Twenty-three ortho-k subjects (treatment >12 months) and 20 control myopic subjects aged 7-14 years were recruited. Samples were collected from four sites surrounding the left eye (lower conjunctiva, upper and lower eyelids, and eyelashes) for all subjects, spectacles for control subjects and contact lens accessories for ortho-k subjects. Samples were cultured, total numbers enumerated, and isolates identified using chromogenic agars., Results: Ortho-k subjects had significantly less total isolates in the conjunctiva than controls (p = 0.009). Otherwise, carriage rates in normal flora levels of the peri-orbital tissues were not significantly different between the two groups (p > 0.19). The total isolates and carriage rates of normal flora on spectacles, contact lenses, and lens cases were similar to those identified on the skin tissues. Small numbers of bacteria were identified from the multipurpose solution of two ortho-k subjects. Although the association between the carriage of S. aureus with contamination of accessories was statistically significant only in control subjects (p = 0.03), ortho-k subjects not yielding S. aureus and Gram-negative rods from samples of their peri-orbital tissues tended to be less likely to have these organisms in their accessories. No Pseudomonas was isolated from any of the sites sampled and no Acinetobacter was isolated from any of the accessories., Conclusions: Ortho-k may lower the total number of bacteria in conjunctiva due to the use of solution and lenses, but the physiologic effect of this treatment on the types of normal flora in children was minimal and should not increase the risk of microbial keratitis in children with good compliance.

Purposes: The purposes of this study were to determine whether the contact lens solution RevitaLens Ocutec (containing the antimicrobial agents alexidine and polyquaternium-1) would inhibit Fusarium organisms when heated in ReNu plastic bottles; whether alexidine would inhibit Fusarium organisms when heated in non-ReNu plastic bottles; and whether an alexidine-neutralizing compound leaches from heated ReNu bottles., Methods: RevitaLens and an alexidine solution (0.00045%), previously stored in ReNu bottles at room temperature (RT) and 56°C, were incubated with 7 different Fusarium organisms. The alexidine solution was similarly stored in seven non-ReNu plastic bottles and incubated with these same organisms. To determine if an alexidine-neutralizing compound might be leaching from heated ReNu bottles, phosphate-buffered saline (PBS) was incubated at RT and 56°C in ReNu bottles, combined with alexidine, and then tested for anti-Fusarium capability., Results: After being heated in ReNu bottles, RevitaLens retained its anti-Fusarium capability, whereas the alexidine solution did not. The alexidine solution heated in seven non-ReNu plastic bottles retained its anti-Fusarium capability. The alexidine solution retained its anti-Fusarium capability when incubated with a PBS solution that had been heated in ReNu bottles, indicating, microbiologically, that an alexidine-neutralizing compound did not leach from the heated ReNu bottle., Conclusions: Alexidine uniquely fails to inhibit Fusarium organisms when heated in a plastic ReNu bottle, but not in seven other plastic bottles, whereas the anti-Fusarium capability of RevitaLens (containing the antimicrobial agents alexidine and polyquaternium-1) is unaffected by heating in a ReNu bottle. There does not seem to be an alexidine-neutralizing compound leaching from heated ReNu bottles. An interaction between alexidine and its heated ReNu bottle may have been a critical factor in the worldwide ReNu with MoistureLoc-related Fusarium keratitis event of 2004 to 2006.

Purpose: Achromobacter xylosoxidans and Pseudomonas aeruginosa biofilms can develop in ophthalmic products and accessories such as contact lens cases, leading to the development of ocular infections. This study evaluated the efficacy of the antimicrobials polyaminopropyl biguanide (PAPB) and benzalkonium chloride (BAK) against A. xylosoxidans and P. aeruginosa biofilms., Methods: Biofilms of A. xylosoxidans and P. aeruginosa used as a comparative control were formed by incubating the bacteria on contact lens cases and on coverslips in phosphate-buffered saline. The biofilms were then exposed to PAPB and BAK for 5 minutes and 4 hours. After exposure, alginate swabs were used to remove the biofilms from the lens cases and the bacteria were plated on tryptic soy agar for determination of survivors. Also, after exposure to these disinfectants, the A. xylosoxidans and P. aeruginosa biofilms were stained with SYTO 9 and propidium iodide. Using a confocal microscope with a 488-nm laser, the number of cells with damaged cell membranes was determined., Results: After 5 minutes of exposure to BAK or PAPB, A. xylosoxidans biofilms were more resistant to the antimicrobial effects of these disinfectants than P. aeruginosa biofilms. After 4 hours, both organisms were reduced by more than 3 logs after exposure to either BAK or PAPB. Confocal microscopy studies revealed that BAK was more effective at damaging A. xylosoxidans and P. aeruginosa cell membranes than PAPB at the concentrations used in ophthalmic products., Conclusions: Biofilms of the emerging pathogen A. xylosoxidans were more resistant to the disinfectants PAPB and BAK than biofilms of P. aeruginosa. Because of the emergence of A. xylosoxidans and the demonstrated greater resistance to the common ophthalmic preservatives BAK and PAPB than the standard Gram-negative organism P. aeruginosa, A. xylosoxidans biofilms should be assessed in antimicrobial challenge tests to assure the safety of multiuse ophthalmic products.

Antimicrobial agents are being examined with the aim of developing antimicrobial contact lenses and new forms of antimicrobial lens cases. It is hoped that these developments will result in reduced contact lens-related microbial adverse events. In this review, we assess aspects of various antimicrobial strategies, such as cationic metals and peptides, selenium, quorum sensing inhibitors, and various biocidal and non-cidal agents. We highlight the historical challenges, the current scenario of this field, and recommendations for future antimicrobial strategies.

Purpose: To report a case of a fungal mass misdiagnosed as a pigmented conjunctival melanoma., Method: Case report., Result: A 38-year-old woman was referred for a pigmented conjunctival lesion that was diagnosed as a melanoma. She had a history of a scleral buckle in that eye for retinal detachment 2 years before presentation. Slit-lamp examination revealed a pigmented mass from the 11- to 2-o'clock position. This was noted to be imbricated within the invagination of a conjunctival fold from the previous surgery. The mass was removed, cultured, and confirmed to be a fungal infection from Scytalidium sp., Conclusions: Scleral buckles can cause folds in the conjunctiva, which can be foci for fungal infection.

Purpose: To investigate the utility of additional microbial analyses to detect the causative microorganism of microbial keratitis and to determine the strength of association between clinical variables., Methods: This retrospective study included 125 eyes of 123 people presenting with presumed infectious keratitis associated with contact lens wear, and examined between January 2001 and November 2011., Results: Sixty-three male and 60 female patients with a mean age of 24.14 ( ±6.7) and 26.7 (±10.0) years, respectively, were included in the study. Among the samples tested, 38 (40%) corneal cultures, 85 (92%) contact lens cultures, and 49 (80%) contact lens case cultures yielded positive results. In the samples for which all microbial investigations were performed and corneal culture was positive, cultures of contact lenses and corneas yielded the same microbes in 94% of cases, and for contact lens case and corneal cultures 77% of cases yielded the same microbes. Importantly, these were monocultures of the same microbe isolated from the cornea in the contact lens and lens case cultures. The odds of having a positive corneal culture was 37 times higher (p = 0.008) when patients presented to the clinic 2 weeks after the onset of symptoms. Pseudomonas aeruginosa was the predominant organism isolated, and most isolates were susceptible to commonly used antimicrobials., Conclusions: Contact lens culture might be an effective test to perform to detect and determine the causative microorganism when corneal cultures are unavailable or yield no microorganisms upon culture. A longer duration of symptoms before presenting to the clinic was significantly associated with obtaining a positive corneal culture.

Objective: Contact lens safety is an important topic in clinical studies. Corneal infections usually occur because of the use of bacteria-carrying contact lenses. The current study investigated the impact of plasma surface modification on bacterial adherence to rigid contact lenses made of fluorosilicone acrylate materials., Methods: Boston XO and XO2 contact lenses were modified using plasma technology (XO-P and XO2-P groups). Untreated lenses were used as controls. Plasma-treated and control lenses were incubated in solutions containing Staphylococcus aureus or Pseudomonas aeruginosa. MTT colorimetry, colony-forming unit counting method, and scanning electron microscopy were used to measure bacterial adhesion., Results: MTT colorimetry measurements showed that the optical density (OD) values of XO-P and XO2-P were significantly lower than those of XO and XO2, respectively, after incubation with S. aureus (P < 0.01). The OD value of XO-P was also much lower than that of XO after incubation with P. aeruginosa (P < 0.01). Colony-forming unit counting revealed that a significantly lower number of bacterial colonies attached to the XO-P versus XO lenses and to the XO2-P versus XO2 lenses incubated with S. aureus (P < 0.01). Fewer bacterial colonies attached to the XO-P versus XO lenses incubated with P. aeruginosa (P < 0.01). Further, scanning electron microscopy suggested different bacterial adhesion morphology on plasma-treated versus control lenses., Conclusion: Plasma surface modification can significantly decrease bacterial adhesion to fluorosilicone acrylate contact lenses. This study provides important evidence of a unique benefit of plasma technology in contact lens surface modification.

Purpose: To measure adhesion forces of Pseudomonas aeruginosa, Staphylococcus aureus, and Serratia marcescens to a rigid contact lens (CL), standard polypropylene, and Ag-impregnated lens cases using atomic force microscopy and determine bacterial transmission from lens case to CL., Methods: Adhesion forces of bacterial strains to Ag-impregnated and polypropylene lens cases and a rigid CL were measured using atomic force microscopy. Adhesion forces were used to calculate Weibull distributions, from which transmission probabilities from lens case to CL were derived. Transmission probabilities were compared with actual transmission of viable bacteria from a lens case to the CL in 0.9% NaCl and in an antimicrobial lens care solution., Results: Bacterial transmission probabilities from polypropylene lens cases based on force analysis coincided well for all strains with actual transmission in 0.9% NaCl. Bacterial adhesion forces on Ag-impregnated lens cases were much smaller than that on polypropylene and CLs, yielding a high probability of transmission. Comparison with actual bacterial transmission indicated bacterial killing due to Ag ions during colony-forming unit transmission from an Ag-impregnated lens case, especially for P. aeruginosa. Transmission of viable bacteria from Ag-impregnated lens cases could be further decreased by use of an antimicrobial lens care solution instead of 0.9% NaCl., Conclusions: Bacterial transmission probabilities are higher from Ag-impregnated lens cases than from polypropylene lens cases because of small adhesion forces, but this is compensated for by enhanced bacterial killing due to Ag impregnation, especially when in combination with an antimicrobial lens care solution. This calls for a balanced combination of antimicrobial lens care solutions and surface properties of a lens case and CL.

Objectives: To describe surveillance cultures of bandage contact lenses (BCL) in patients with a history of Boston type 1 keratoprosthesis (KPro) surgery., Methods: An institutional review board-approved retrospective review of patients with a history of Boston type 1 KPro surgery and BCL cultures between July 2008 and June 2010. Data on demographics, preoperative diagnosis, topical corticosteroid and antibiotic use, duration of BCL wear, clinical diagnosis of microbial keratitis or endophthalmitis, and culture results were recorded., Results: There were 14 patients (15 eyes) who underwent Boston type 1 KPro between July 2008 and June 2010 with BCL culture data. Ten eyes showed positive growth and one eye developed an infection. Thirty-four cultures were performed and 12 were positive. The most common organism cultured was coagulase-negative staphylococcus (CoNS). Positive cultures, colonization by non-CoNS pathogens, and infection occurred more frequently in patients with an ocular history of autoimmune disease or chemical burn. The growth of 15 or more CoNS colonies occurred only in patients not on vancomycin. An antibiotic was added to the regimen in response to positive cultures for three patients., Conclusions: Contact lens surveillance cultures may provide valuable information on the characteristics of microbial colonization, particularly in highlighting inflammatory disease and disuse of vancomycin as possible risk factors. Bandage contact lenses cultures also have the potential to be useful adjuncts in the clinical management of antibiotic therapy.

Objective: To report an unusual case of keratitis in a cosmetic contact lens wearer caused by two rare organisms., Method: Case report., Results: A 14-year-old cosmetic contact lens user presented with a paracentral corneal ulcer in her right eye. The cosmetic lenses were bought online. The cultures from corneal scrapings and contact lenses demonstrated heavy growth of Chryseobacterium meningosepticum and Delftia acidovorans. The treatment with topical ciprofloxacin and fortified gentamicin was effective, and the infection resolved with corneal scar after 5 weeks., Conclusion: Use of cosmetic contact lenses and buying them online is a fairly common practice among teenagers. This can lead to serious eye infection as in this case. To our knowledge, this is the first report of contact lens-related keratitis simultaneously involving these two rare organisms.

Purpose: To examine the effectiveness of heating contact lens cases after disinfection on reducing microbial contamination., Methods: One strain each of Pseudomonas aeruginosa (071) and Staphylococcus aureus (31) were used to set up robust biofilms in polypropylene contact lens cases. The effect of dilutions (from 1:10 to 1:1000) of trypticase soy broth (TSB) in phosphate-buffered saline and incubation time (24 to 48h) on the ability of strains to from biofilms with high levels of bacteria were first examined. Then the effect of increasing the temperature of incubation (from 14°C to 60°C) of biofilms during drying was examined. In the final set of experiments, biofilms of strains were subjected to heating in a warming device set to deliver 60°C for 3 hours, and the effect of this temperature after disinfection with a multipurpose disinfecting solution (MPDS; containing polyquat and Aldox) was examined by culturing the number of viable bacterial cells remaining., Results: A dilution of 1:100 TSB for S. aureus 31 and 1:1000 TSB for P. aeruginosa 071 together with an incubation time of 24 hours gave high numbers of viable cells of these 2 strains adhered to the contact lens cases. Having established the biofilms of bacteria, heating these to 60°C for 3 hours resulted in significant reductions in the number of viable cells that could be cultured (1 log reduction for S. aureus 31, P=0.0003; 3.5 log reduction for P. aeruginosa 071, P=0.002). Exposing the biofilms of cells to a disinfection cycle (6h at ambient temperature) in the presence of the MPDS and air drying at ambient temperature resulted in 2441±1237 colony-forming units/lens well for S. aureus 31 and 7401±4374 colony-forming units/lens well for P. aeruginosa 071. Increasing the drying temperature to 60°C resulted in zero viable cells (i.e., ≥4log reduction) for either bacterial type., Conclusions: Using a warming device for contact lens cases after a disinfection cycle with an MPDS during drying for 3 hours results in substantial kill of biofilms of P. aeruginosa and S. aureus that have been formed in the wells of the cases.

Purpose: The aim of this study was to simulate the biofilm formation in contact lens (CL) case under poor hygiene behaviors; antimicrobial efficacies of multipurpose solutions (MPSs) against biofilm on the lens case were evaluated., Methods: Five MPSs (Epica Cold, Complete 10 min, ReNu MultiPlus, SoftOne Mois, and OPTI-FREE Plus) were tested. Lens cases containing ACUVUE2 were inoculated with 1×10, 10, or 10 colony-forming units (CFUs) of Staphylococcus epidermidis (SE). Each lens case was treated with 1 MPS for 4 hrs followed by the estimation of the number of SE by the CFU method. Disinfection efficacies of MPSs against SE biofilm were evaluated by biomicroscopy with safranin staining and scanning electron microscopy., Results: Lens cases, inoculated with 1×10 CFU, were disinfected by all MPSs. Epica Cold, Complete 10 min, ReNu MultiPlus, and OPTI-FREE showed almost a 2-log reduction of the CFU, whereas SoftOne Mois effect was almost a 1 log reduction, significantly lower than other MPSs (P<0.05). No biofilm formations were observed in Epica Cold, Complete 10 min, ReNu MultiPlus, and OPTI-FREE Plus-treated groups unlike significant biofilm formation in the SoftOne Mois-treated group (P<0.01)., Conclusions: Greater efforts to educate patients regarding compliant lens care behavior are needed to reduce the incidence of CL-associated microbial keratitis.

Purpose: To compare the rates of bacterial contamination in cylindrical and flat contact lens cases of orthokeratology (ortho-k) users and to investigate their preference of lens case design based on ease of use and handling., Methods: Twenty-four children receiving ortho-k treatment were recruited. Each subject was given one cylindrical and one flat lens case, of which one side (50% right, 50% left) was sealed to prevent usage. Subjects were instructed to either rinse the case with water and air dry or rinse with multipurpose solution (MPS) and refill with MPS for storage after lens removal. After 1 month, cases were collected for culture, which was performed on the screw top, inner surface of cases, and also the holder for cylindrical cases. Each subject/parent completed a questionnaire about preference of case design., Results: No significant differences in rates of surfaces contaminated were found between cleaning methods. Overall, 30% of both inner surfaces and screw tops of the cases yielded potentially pathogenic organisms, with significantly higher numbers present on both the inner surfaces (p = 0.003) and the screw tops of the flat cases (p = 0.001). Contamination of the inner surfaces with only normal flora occurred exclusively in the flat cases, but the screw tops of both case types frequently yielded only normal flora. Cylindrical case holder contamination was similar to the inner surface. There was a strong preference (75%) for the cylindrical cases, with subjects/parents citing ease of use and cleaning, good appearance and transparency, and reduced amount of MPS used., Conclusions: Although correct lens case care remains the most important factor in reducing contamination of the case, use of the cylindrical case design, preferred by the majority of subjects/parents, significantly reduced contamination in ortho-k subjects. The method used for cleaning the lens case had no effect on the rates of contamination in this study.

Objective: ReNu with MoistureLoc (ReNuML), containing the antimicrobial agent alexidine 0.00045%, was associated with the Fusarium keratitis epidemic of 2004 to 2006. Although a single-point source contamination was ruled out, only Fusarium organisms were reported during the outbreak. This study investigated whether the reported loss of antimicrobial effectiveness toward Fusarium of ReNuML after exposure to heat in high-density polyethylene (HDPE) plastic containers could also be demonstrated with other common fungal and bacterial agents of keratitis., Methods: A buffered solution of alexidine 0.00045% was incubated in glass and ReNu HDPE plastic containers at room temperature (RT) and 56°C for 4 weeks, serially diluted, and tested for its ability to inhibit the growth of 20 bacterial isolates, 12 non-Fusarium fungal isolates, and 7 Fusarium isolates originally involved in the keratitis epidemic., Results: A statistically significant loss of antimicrobial capability was seen with all fungi, all gram-positive bacteria, and all isolates of Klebsiella when alexidine 0.00045% was incubated at 56°C in ReNu HDPE containers compared with RT or glass incubation (P≤0.0001)., Conclusions: Heating of an alexidine solution in ReNu HDPE plastic (but not glass) containers results in the same loss of anti-Fusarium activity as reported when testing the original ReNuML solution. This loss of inhibitory activity is not specific to Fusarium and occurs with other fungi and bacteria that cause keratitis. The reasons for the lack of reports of bacterial and/or non-Fusarium fungal keratitis during the original Fusarium keratitis epidemic remain unclear at this time.

Purpose: This study investigated contamination of saline and daily disposable contact lens (DDCL) stored overnight after use in the original blister pack and the practices of a group of DDCL users., Methods: Twenty DDCL wearers placed their lenses after 1 day's use back into the blister pack saline (BPS) and left them overnight before transferring both lens and BPS to a new CL case. The lens and BPS were cultured the following day, and total number of organisms, Staphylococci, and gram negative organisms enumerated. Each subject submitted five pairs of lenses over a 1 month period., Results: Ninety-five percent of subjects had at least one pair of contaminated lenses, and the BPS yielded similar results to the contaminated lenses, with staphylococcal contamination being predominant. Three subjects admitted to not washing their hands before handling their lenses and six to habitual reuse of their lenses with storage in the BPS. There was a higher risk of contamination in male subjects., Conclusions: Reuse of lenses poses an important risk for DDCL users because they are unlikely to have received proper training in cleaning and disinfection of lenses and do not use a lens case or disinfecting solutions. Overnight storage in BPS results in contaminated lenses which if reused increases the infection risk especially with Staphylococci. It is important that practitioners carefully educate their patients in correct use of DDCL and, as cost of lenses is a major factor in willingness to reuse, ensure that DDCL is the most suitable choice when prescribing.

Background: Alcaligenes xylosoxidans can result in opportunistic infections in patients who are immunocompromised. Alcaligenes xylosoxidans keratitis is a rare infection, almost always occurring in a compromised cornea. Few reported cases have occurred as contact lens-induced keratitis. The purposes of this report are to report a case of A. xylosoxidans keratitis in an immunocompetent contact lens wearer (2-week disposable) and to review the related literature., Methods: A 30-year-old man developed acute keratitis in the right eye. He was a 2-week disposable contact lens wearer. He did not report any ocular or systemic illness. Corneal scraping, contact lens, and conjunctiva cultures were performed., Results: 0.5% moxifloxacin eye drops were started hourly with quick recovery and healing of the ulcer and epithelial defect noted within a few days. Culture of the contact lens was positive for A. xylosoxidans. The organism was sensitive to penicillins, third-generation cephalosporins, and fluoroquinolones but resistant to aminoglycosides., Conclusions: Alcaligenes xylosoxidans is a potential pathogen in compromised corneas. It has high susceptibility to extended-spectrum penicillins and current generations of fluoroquinolones but rarely responds to aminoglycosides. Alcaligenes xylosoxidans should be considered in the differential diagnosis of contact lens-induced keratitis.

Purpose: To evaluate the clinical and microbiological profiles of pediatric patients with ocular surface infections requiring corneal or conjunctival scraping for diagnosis., Methods: The medical records of 138 consecutive patients aged 18 years or younger who had undergone corneal or conjunctival scraping over a 5-year-period in a tertiary ophthalmic center were reviewed. Demographics, clinical features, risk factors, microbiological results, and treatment were recorded., Results: Ocular surface infections were classified into 4 groups: infectious keratitis (group 1); blepharokeratoconjunctivitis (group 2); conjunctivitis (group 3); and congenital nasolacrimal duct obstruction or dacryocystitis (group 4). The groups had different mean ages of presentation, with group 4 presenting the youngest at 2 years and group 1 presenting the oldest at 14 years. Contact lens wear and blepharitis were the major risk factors. The positive culture rate was 60.9%, of which 65.5% were Gram-positive organisms. Coagulase-negative staphylococci were the most common organisms (23.2%), followed by Pseudomonas aeruginosa (9.4%) and Staphylococcus aureus (8.0%). Microbial yield was highest in group 1 (86%) and lowest in group 3 (38.6%). There were 9 orthokeratology-related infectious keratitis cases (18%) and 9 chlamydial ophthalmia neonatorum cases isolated., Conclusions: With increasing contact lens wear in the pediatric and adolescent populations and the common occurrence of blepharokeratoconjunctivitis and staphylococcal ocular surface infections, parents and children should be highly vigilant with eyelid hygiene and contact lens practice.

Purpose: To report trends in fungal keratitis from a single institution between 1999 and 2008., Methods: Retrospective chart review of the patients presenting to the cornea service with fungal keratitis from April 1999 to December 2008., Results: Seventy-eight eyes of 76 patients were identified. The most common predisposing factors included contact lens use (35.9%), trauma (21.8%), and history of penetrating keratoplasty (15.4%). There was a significant increase in the rate of contact lens-related Fusarium infections over time, which peaked in 2005 and 2006 (P = 0.021). Almost 40% of fungal keratitis cases [11 of 28 eyes (39.3%)] were soft contact lens-related Fusarium infections in 2005 and 2006, and this decreased to less than 10% [2 of 25 eyes (8%)] in 2007 and 2008. The odds of having a contact lens-related Fusarium infection in 2005-2006 compared with 2007-2008 was 4.40 (95% confidence interval of 0.60-32.50) (P = 0.178). Despite the decrease in contact lens-related Fusarium infections, the number of fungal infections remained elevated in 2007 (10 eyes) and 2008 (14 eyes), including contact lens-related infections (3 in 2007 and 6 in 2008)., Conclusions: A definite increase in the number of fungal keratitis cases began in 2004 and continued through 2006 during the Fusarium outbreak associated with ReNu with MoistureLoc. Despite the decrease in contact lens-related Fusarium infections, the overall number of fungal keratitis cases remained high through 2008. Fungal keratitis was more often associated with contact lens use than with trauma in this time.

Objectives: To estimate the rate of corneal erosion coupled with gram-negative bacterial contamination of contact lenses and compare this with the rate of microbial keratitis (MK) with contact lenses., Methods: The rate of corneal erosion and contact lens contamination by gram-negative bacteria were calculated from several prospective trials. These rates were used to calculate the theoretical rate of corneal erosion happening at the same time as wearing a contact lens contaminated with gram-negative bacteria. This theoretical rate was then compared with the rates of MK reported in various epidemiological and clinical trials., Results: Corneal erosions were more frequent during extended wear (0.6-2.6% of visits) compared with daily wear (0.01-0.05% of visits). No corneal erosions were observed for lenses worn on a daily disposable basis. Contamination rates for lenses worn on a daily disposable basis were the lowest (2.4%), whereas they were the highest for low Dk lenses worn on an extended wear basis (7.1%). The estimated rate of corneal erosions occurring at the same time as wearing lenses contaminated with gram-negative bacteria was the lowest during daily wear of low Dk lenses (1.56/10,000 [95% CI: 0.23-10.57]) and the highest during extended wear of high Dk lenses (38.55/10,000 [95% CI: 24.77-60.04]). These rates were similar in magnitude to the rates reported for MK of different hydrogel lenses worn on differing wear schedules., Conclusion: The coincidence of corneal erosions during lens wear with gram-negative bacterial contamination of lenses may account for the relative incidence of MK during lens wear with different lens materials and modes of use.

Objectives: To examine seven cases of contact lens-related Fusarium keratitis that resulted in therapeutic penetrating keratoplasty, to investigate which factors were associated with favorable versus poor graft outcome in this population., Methods: Seven patients who underwent corneal transplant after contact lens-related, culture-proven Fusarium keratitis were identified through a retrospective chart review. The cases occurred between September 2005 and January 2006 at the University of Medicine and Dentistry of New Jersey and Wills Eye Hospital. All seven patients had used Bausch and Lomb's ReNu with MoistureLoc. The outcomes studied were graft status, infection recurrence, and 6-month postoperative visual acuity., Results: The rejection rate was 57.1% and the recurrence rate was 28.6% in this study. No eyes were lost to fungal endophthalmitis. In this population, larger ulcer size and a greater total number of medical agents used before and after penetrating keratoplasty were significantly associated with poor outcomes, namely graft rejection and poor visual acuity. In addition, it was noted that the patients who suffered recurrence of infection had both a larger median graft size and a longer median duration of postoperative antifungal use although these results did not reach statistical significance., Conclusions: Larger ulcer size, larger graft size, a greater number of medical agents used, and a longer duration of postoperative antifungal therapy may be useful parameters in predicting surgical outcomes in patients with fungal keratitis. Further research is needed to validate our results and to elucidate the mechanisms behind graft rejection in the setting of fungal keratitis.

Purpose: The aim of this study is to evaluate the role of real-time polymerase chain reaction (PCR) and conventional bacterial culture methods in the detection of Pseudomonas aeruginosa in contact lens-induced severe, partially treated corneal ulcers referred to a tertiary center., Methods: The study duration was 6 months. All patients with contact lens-related corneal ulcer, requiring admission during the study period were recruited. Samples from corneal scrapings were simultaneously sent at the time of admission for PCR and culture testing. An in-house real-time PCR was developed to detect the P. aeruginosa lasA gene. The results of PCR and culture were compared using McNemar's chi2 test., Results: Ten patients were recruited. The mean age was 33 years (20-45 years). All the patients had contact lens-related keratitis (>4 mm) of which eight (80%) were found positive for P. aeruginosa by PCR or culture. There was no significant difference between PCR and culture in detecting P. aeruginosa (P<0.05)., Conclusions: PCR is, at least, as good as conventional cultures in detecting P. aeruginosa. It is a rapid assay as compared with culture, and early detection enables prompt treatment thus reducing the destructive effect of the organism on the cornea.

Purpose: This study was designed to assess whether hydrogel contact lens (CL) surface hydrophobicity and roughness affect Staphylococcus epidermidis adhesion., Methods: Bacterial adhesion experiments were performed on two unworn silicone hydrogel and three unworn conventional hydrogel CLs using the S.epidermidis strain CECT 4184. Microbial colonization was assessed by conducting counts expressed as colony-forming units. CL hydrophobicity was determined through water contact angle measurements and the roughness parameters such as mean surface roughness (Ra), kurtosis (Rku), and skewness (Rsk) were determined through atomic force microscopy in Tapping Mode., Results: The conventional CLs showed similar water contact angles (p > 0.05) and were classified as hydrophilic. The silicone hydrogel CLs yielded hydrophobic contact angles with no significant differences between them (p > 0.05). The lenses with the highest (nelfilcon A and ocufilcon B) or lowest (comfilcon A and omafilcon A) Ra values displayed a lesser or greater extent of spikiness of their surfaces, respectively. All lenses showed a predominance of peaks (Rsk > 0) over troughs. S. epidermidis adhered more to the hydrophobic CLs (p < 0.05). Omafilcon A and comfilcon A, which showed the lowest Ra values among the hydrophilic and hydrophobic lenses, respectively, returned the lowest bacterial adhesion scores (p < 0.05)., Conclusions: Our results suggest that more hydrophobic CLs are more prone to S. epidermidis adhesion. Although the Ra appears to be related to S. epidermidis adhesion, the influence of Rku and Rsk on this variable remains unclear.

Sight-threatening microbial keratitis associated with contact lens wear remains a serious concern for patients, eye-care practitioners, and the contact lens industry. Several decades of research and some major advances in lens and solution technology have not resulted in a decline in disease incidence. Here, we offer a perspective on the complex pathogenesis of microbial keratitis, the factors that have prevented a better understanding of this disease, and new approaches being used to tackle this important clinical problem.

Purpose: To evaluate the frequency level and profile of contact lens storage case contamination in asymptomatic contact lens wearers and to examine whether different areas of the same lens case may show a different rate and profile of contamination. The relationship between lens storage case contamination and the age of the lens storage case was also examined., Methods: Sixty-four lens cases and case age information were collected from asymptomatic contact lens wearers. Lens cases were sampled at two locations, the upper rim and the lower base. The samples underwent microbiological investigation for recovery of bacteria and fungi. Contamination rate between the two sampling locations and the relationship between the contamination levels and the age of the lens case were analyzed., Results: Contamination occurred in 58% (37 of 64) of lens cases. The most frequently recovered microorganisms were coagulase-negative Staphylococci (51%, 19 of 37), Bacillus spp. (43%,16 of 37), and fungi (27%,10 of 37). For flat-well lens cases, higher numbers of microorganisms were recovered from the upper rim than that from the lower base (p = 0.02), and a greater variety of Gram-negative bacteria were recovered from the upper rim. A higher recovery rate of Micrococcus spp. (p = 0.02; in flat cases) and coagulase-negative Staphylococci (p = 0.01; for both flat and basket type cases) was found from the base of the case well compared with the upper rim. For stand-up cases, higher numbers of microorganisms were recovered from the lens basket compared to the upper hinge (p = 0.047). Lens cases that were <9 months of age had lower levels of contamination (p = 0.013) than older cases., Conclusions: Frequent replacement of lens cases may reduce microbial contamination. Future studies should specify the areas swabbed in the lens case. Better lens storage case design and additional hygiene attention need to be introduced to reduce contamination in these "risky" areas.

Purpose: A contact lens (CL) can act as a vector for microorganisms to adhere to and transfer to the ocular surface. Commensal microorganisms that uneventfully cohabitate on lid margins and conjunctivae and potential pathogens that are found transiently on the ocular surface can inoculate CLs in vivo. In the presence of reduced tissue resistance, these resident microorganisms or transient pathogens can invade and colonize the cornea or conjunctiva to produce inflammation or infection., Methods: The literature was reviewed and used to summarize the findings over the last 30 years on the identification, enumeration, and classification of microorganisms adherent to CLs and their accessories during the course of normal wear and to hypothesize the role that these microorganisms play in CL infection and inflammation., Results: Lens handling greatly increases the incidence of lens contamination, and the ocular surface has a tremendous ability to destroy organisms. However, even when removed aseptically from the eye, more than half of lenses are found to harbor microorganisms, almost exclusively bacteria. Coagulase-negative Staphylococci are most commonly cultured from worn lenses; however, approximately 10% of lenses harbor Gram-negative and highly pathogenic species, even in asymptomatic subjects. In storage cases, the incidence of positive microbial bioburden is also typically greater than 50%. All types of care solutions can become contaminated, including up to 30% of preserved products., Conclusions: The process of CL-related microbial keratitis and inflammation is thought to be preceded by the presence or transfer or both of microorganisms from the lens to the ocular surface. Thus, this detailed understanding of lens-related bioburden is important in the understanding of factors associated with infectious and inflammatory complications. Promising mechanisms to prevent bacterial colonization on lenses and lens cases are forthcoming, which may decrease the incidence of microbially driven CL complications.

Purpose: To determine the rates of microbial contamination of solutions and lens accessories of existing ortho-k lens wearers and the effect on contamination rates of monthly replacement and warnings. To investigate self-reported levels of compliance with care of the lenses and lens accessories and correlation of these levels with the rates of microbial contamination., Methods: Asymptomatic ortho-k lens wearers with at least 6-month successful use were requested to bring their lenses, solutions, and accessories to their next aftercare visit. All items, except the lenses, were replaced at each data collection visit. Samples collected from the lens surface, solution, and accessories were cultured for pathogens. These procedures were repeated twice at 1-month intervals. At the first visit, each subject and/or parent was interviewed about the care/use of the lens and accessories., Results: Thirty-eight subjects completed the study. Initial contamination rates of the lenses, lens cases, and tweezers were 29, 34, and 46%, respectively. Rates of contamination dropped for lenses, suction holders, and tweezers during the three-visit intervention. Contact lens solutions, except lens cleaner were contaminated on all occasions with the most contaminated product being artificial tears [33% (n = 18)]. There was no improvement in the contamination rate of the lens cases. The most common pathogens isolated were Staphylococcus aureus and Serratia marcescens. Compliance was lowest for care of lens cases and highest for care of lenses. However, correlation between reported compliance and presence of pathogens failed to reach significance., Conclusions: Subjects' awareness of the importance of lens cleanliness is high and can be improved by regular reinforcements. However, attitudes toward cleaning of accessories was far less satisfactory and while replacement and warnings resulted in significant improvements of contamination rates of tweezers and suction holders, more emphasis should be placed on educating patients on correct care of lens accessories.

Purpose: To report a case of daily wear soft contact lens-associated keratitis caused by Alcaligenes xylosoxidans in a portable toilet sanitation worker., Methods: A previously healthy 30-year-old man presented with bilateral decreased vision, redness, and irritation, beginning 1 week earlier. The patient had been treated with moxifloxocin for 1 week before presentation without improvement. Bacterial staining cultures were performed from corneal scrapings, contact lenses, contact lens case, and solution. Preliminary culture results and antibiotic sensitivities were generated using an automated identification system. Positive results from the contact lens, case, and solution were confirmed using polymerase chain reaction (PCR)., Results: The contact lenses, contact lens case, and solution cultures revealed heavy growth of A. xylosoxidans. These findings were confirmed by PCR. The organism was found to be resistant to aminoglycosides, fluoroquinolones, and cephalosporins. The patient was started on polymyxin B or trimethoprim. After 21 days of treatment, the infection completely resolved with a final spectacle-corrected visual acuity of 20/25., Conclusions: To our knowledge, this is the first case report of a corneal infection caused by A. xylosoxidans, which was isolated and identified from a contact lens, case, and solution using culture and PCR technique as well the first description of ocular surface disease resolution after the treatment with topical polymyxin B or trimethoprim. A. xylosoxidans should be considered as uncommon but potential pathogen capable of infectious spread through contaminated contact lens solution.