59 Comparative efficacy of new contact lens care solutions against bacteria, fungi and Acanthamoeba
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Abstracts of the 2011 BCLA Annual Clinical Conference / Contact Lens & Anterior Eye 34, Supplement 1 (2011) S1–S43 S31 59 Comparative efficacy of new contact lens care solutions against bacteria, fungi and Acanthamoeba Marina Nikolic 1, *, Simon Kilvington 1 , Nancy Brady 1 , Anthony Lam 1 , James Lonnen 2 1 Abbott Medical Optics, Santa Ana, USA; 2 University of Leicester, Leicester, UK *E-mail address: [email protected] Purpose: The microbiological efficacy of multi-purpose solutions (MPS) has been subject to scrutiny following two product recalls due to Fusarium and Acanthamoeba keratitis outbreaks. Here, the biocidal efficacy of commercial MPS and a 1-step hydrogen peroxide system were compared. Method: Test solutions: MPS-1 (Biotrue: PQ1-PHMB), MPS-2 (COMPLETE RevitaLens: PQ1-alexidine) and MPS-3 (Optifree Replenish: PQ1-MAPD) and PER-1 (Clear Care: 1-step hydrogen peroxide system). ISO 14729 panel or- ganisms were: Pseudomonas aeruginosa, Serratia marcescens, Staphylococ- cus aureus, Candida albicans, Fusarium solani. A. castellanii (ATCC 50370) was also studied. Biocidal assays were performed according to ISO 14729. Acanthamoeba trophozoite and cyst viability was determined by a most probable number approach. Results: MPS-1, MPS-2 and PER-1 gave similar results with a 4–5 log kill of the bacteria and a 3–4 log kill of fungi after 4–6 hr exposure. MPS-3 showed reduced efficacy against S. aureus, S. marcescens and F. solani (2.3, 2.8 and 2.1 log kill, respectively at 6 hr). MPS-1, MPS-2 and Per-1 gave A. castellanii trophozoite log kills of >3.0 at 6 hr and 2.4 for MPS-3. For cysts, MPS-1 and MPS-3 showed a 0.2–0.5 log kill at 6 hr and 2.2 log with PER-1 compared to >3.0 log by 4 hr with MPS-2. Conclusions: Both the new MPS’s studied here showed good antimicrobial efficacy although MPS-2 had significantly greater activity against A. castel- lanii cysts. Recent product recalls have highlighted the importance of both MPS design and microbiological testing methods to meet the challenge of emerging pathogens, user noncompliance and newer, more complex, prod- uct formulations. 60 Biocidal efficacy of multipurpose contact lens disinfectant solutions and antimicrobial storage cases against Stenotrophomonas and Delftia: resistance and re-growth Simon Kilvington 1, *, Simon Cheung 1 , Anthony Lam 1 , James Lonnen 2 , Marina Nikolic 1 1 Abbott Medical Optics, Santa Ana, USA; 2 University of Leicester, Leicester, UK *E-mail address: [email protected] Purpose: Stenotrophomonas and Delftia are isolated frequently from contact lens storage cases (CLSC) of asymptomatic wearers and can cause keratitis. The biocidal efficacy of multipurpose disinfectant solutions (MPDS) and a 1- step peroxide system against these bacteria was investigated. Method: Three strains of S. maltophilia and D. acidovorans were tested. MPS studied were MPS-1 (Biotrue: PQ1PHMB), MPS-2 (COMPLETE Revi- taLens: PQ1-alexidine), MPS-3 (Optifree Replenish: PQ1-MAPD), and PER-1 (Clear Care: 3% peroxide with platinum neutralising disc). The efficacy of four silver antimicrobial CLSC was compared using bacteria inoculated in phos- phate buffered saline. The ability of the bacteria to support growth of Acan- thamoeba was studied. Results: After 6 hr, MPDS-1, MPDS-2 and PER-1 gave ≥4.0 log kill for all Stenotrophomonas and Delftia strains and no re-growth occurred up to 21 days. MPDS-3 showed ≤1.0 log kill of S. maltophilia after 6 hr and a 3 log re-growth with two strains and 0.4 log for the third by 7 days. For Delftia, MPDS 3 showed ≤1 log kill by 24 hr and re-growth (0.8–1.1 log) after 7 days. One silver CLSC reduced Stenotrophomonas and Delftia viability by 1–5 log after 24 hr and continued to be effective over 21 days (3–5 log kill). Other sil- ver CLSC showed only stasis with Stenotrophomonas or allowed re-growth of Delftia. All strains supported Acanthamoeba excystment and trophozoite replication. Conclusions: S. maltophilia and D. acidivorans appear inherently resistant to MPDS-3. Bacterial replication or survival may instigate CLSC biofilm pro- duction, reduced disinfection efficacy and provide a food source and favor- able habitat for the growth of Acanthamoeba. VISION AND OPTICS 61 Comparison of spherical aberration controland visual acuity with aspheric and spherical contact lens optics Gerard Cairns*, Jeffery Schafer, Stephanie Su, Gary Mosehauer, Bill Reindel Bausch + Lomb, Rochester, USA *E-mail address: [email protected] Purpose: Aspheric optics in contact lenses are designed to reduce inherent spherical aberration in the eye. Four studies were conducted to evaluate spherical aberration and visual acuity of two marketed silicone hydrogel lenses (Test – balafilcon A with aspheric optics; Control – senofilcon A with conventional spherical optics) across a range of powers. Method: A single power was assessed in each study (+3.00D, −1.00D, −5.00D, and −9.00D). Cohorts of 22–25 subjects were dilated with 1% Tropi- camide to achieve 6mm pupils. Baseline spherical aberration readings and high contrast logMAR visual acuities using a 6mm artificial aperture were recorded and then repeated with lenses in situ. A linear mixed model was employed to analyze data across all studies and paired comparisons were conducted within each study. Results: The results showed that, over all studies, the Test lenses reduced the mean spherical aberration by 0.136um, significantly more than the Con- trol lens which reduced the spherical aberration by only 0.054um (p<0.05). On average the Test lenses were 0.07 logMAR better (p<0.05). For the −9.00D, −5.00D and +3.00D powers individually, the Test lenses provided signifi- cantly better visual acuity (0.09 logMAR, 0.07 logMAR and 0.13 logMAR, re- spectively; p<0.05 in each case) compared to the control lenses. Conclusions: Incorporating aspheric optics into contact lens designs can reduce the spherical aberration of the eyes’ optical system. These studies show that for contact lens patients, the balafilcon A lenses with aspheric optics can provide a clinically significant enhancement to vision over con- ventional spherical optics. 62 Utilizing clinical eye models to predict retinal image quality of individuals Amanda C Kingston*, Ian G Cox Bausch + Lomb, Rochester, USA *E-mail address: Amanda_C_Kingston@bausch. com Purpose: To correlate retinal image quality metrics output from custom Ze- max™ clinical eye models with visual acuity results recorded in a multifocal lens clinical study. Method: Clinical diagnostic measurements were used to create Zemax™ models of individual patient’s eyes. These clinical eye models were then used to generate a retinal image quality metric that was correlated with the visual acuity results from a multifocal lens clinical study. Three different contrast and illumination conditions were used in the clinical study: (1) normalized high contrast high illumination (NHCHI), (2) normalized low contrast high illumination (NLCHI) and (3) normalized low contrast low illumination (NL- CLI). All three conditions were correlated with the retinal image quality met- ric (weighted pattern recognition score) calculated from the Zemax™ mod- els. Results: The percent correlation was calculated for each of the three clini- cal conditions with the weighted pattern recognition score. NHCHI yielded a correlation of 76.47%, NLCHI correlated with 82.35% and NHCLI correlated with 88.25%. Normalized 20/20 Geometrical convolved E’s were also ex- ported from Zemax™ in order to give a subjective comparison of the patient’s perceived visual acuity. Conclusions: Clinical eye models can be used to predict retinal image qual- ity for a diverse population of eyes. By using this population of clinical eye models, it is now possible to model different lens design concepts to deter- mine what a patient’s visual acuity results will be with that lens.
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Transcript of 59 Comparative efficacy of new contact lens care solutions against bacteria, fungi and Acanthamoeba
Abstracts of the 2011 BCLA Annual Clinical Conference / Contact Lens & Anterior Eye 34, Supplement 1 (2011) S1–S43 S31
59
Comparative efficacy of new contact lens care solutions against bacteria,fungi and Acanthamoeba
Marina Nikolic1,*, Simon Kilvington1, Nancy Brady1, Anthony Lam1, JamesLonnen2
1Abbott Medical Optics, Santa Ana, USA; 2University of Leicester, Leicester, UK
*E-mail address:[email protected]
Purpose: The microbiological efficacy of multi-purpose solutions (MPS) hasbeen subject to scrutiny following two product recalls due to Fusarium andAcanthamoeba keratitis outbreaks. Here, the biocidal efficacy of commercialMPS and a 1-step hydrogen peroxide system were compared.
Method: Test solutions: MPS-1 (Biotrue: PQ1-PHMB), MPS-2 (COMPLETERevitaLens: PQ1-alexidine) and MPS-3 (Optifree Replenish: PQ1-MAPD) andPER-1 (Clear Care: 1-step hydrogen peroxide system). ISO 14729 panel or-ganisms were: Pseudomonas aeruginosa, Serratia marcescens, Staphylococ-cus aureus, Candida albicans, Fusarium solani. A. castellanii (ATCC 50370)was also studied. Biocidal assays were performed according to ISO 14729.Acanthamoeba trophozoite and cyst viability was determined by a mostprobable number approach.
Results:MPS-1,MPS-2 and PER-1 gave similar resultswith a 4–5 log kill ofthe bacteria and a 3–4 log kill of fungi after 4–6 hr exposure. MPS-3 showedreduced efficacy against S. aureus, S. marcescens and F. solani (2.3, 2.8 and2.1 log kill, respectively at 6 hr). MPS-1, MPS-2 and Per-1 gave A. castellaniitrophozoite log kills of >3.0 at 6 hr and 2.4 for MPS-3. For cysts, MPS-1 andMPS-3 showed a 0.2–0.5 log kill at 6 hr and 2.2 log with PER-1 compared to>3.0 log by 4 hr with MPS-2.
Conclusions: Both the newMPS’s studied here showed good antimicrobialefficacy although MPS-2 had significantly greater activity against A. castel-lanii cysts. Recent product recalls have highlighted the importance of bothMPS design and microbiological testing methods to meet the challenge ofemerging pathogens, user noncompliance and newer, more complex, prod-uct formulations.
60
Biocidal efficacy of multipurpose contact lens disinfectant solutions andantimicrobial storage cases against Stenotrophomonas and Delftia:resistance and re-growth
Simon Kilvington1,*, Simon Cheung1, Anthony Lam1, James Lonnen2,Marina Nikolic1
1Abbott Medical Optics, Santa Ana, USA; 2University of Leicester, Leicester, UK
*E-mail address: [email protected]
Purpose: Stenotrophomonas and Delftia are isolated frequently from contactlens storage cases (CLSC) of asymptomatic wearers and can cause keratitis.The biocidal efficacy of multipurpose disinfectant solutions (MPDS) and a 1-step peroxide system against these bacteria was investigated.
Method: Three strains of S. maltophilia and D. acidovorans were tested.MPS studied were MPS-1 (Biotrue: PQ1PHMB), MPS-2 (COMPLETE Revi-taLens: PQ1-alexidine), MPS-3 (Optifree Replenish: PQ1-MAPD), and PER-1(Clear Care: 3% peroxidewith platinum neutralising disc). The efficacy of foursilver antimicrobial CLSC was compared using bacteria inoculated in phos-phate buffered saline. The ability of the bacteria to support growth of Acan-thamoeba was studied.
Results: After 6 hr, MPDS-1, MPDS-2 and PER-1 gave ≥4.0 log kill for allStenotrophomonas and Delftia strains and no re-growth occurred up to 21days. MPDS-3 showed ≤1.0 log kill of S. maltophilia after 6 hr and a 3 logre-growth with two strains and 0.4 log for the third by 7 days. For Delftia,MPDS 3 showed≤1 log kill by 24 hr and re-growth (0.8–1.1 log) after 7 days.One silver CLSC reduced Stenotrophomonas and Delftia viability by 1–5 logafter 24 hr and continued to be effective over 21 days (3–5 log kill). Other sil-ver CLSC showed only stasis with Stenotrophomonas or allowed re-growthof Delftia. All strains supported Acanthamoeba excystment and trophozoitereplication.
Conclusions: S. maltophilia and D. acidivorans appear inherently resistantto MPDS-3. Bacterial replication or survival may instigate CLSC biofilm pro-duction, reduced disinfection efficacy and provide a food source and favor-able habitat for the growth of Acanthamoeba.
VISION AND OPTICS
61
Comparison of spherical aberration controland visual acuity withaspheric and spherical contact lens optics
Gerard Cairns*, Jeffery Schafer, Stephanie Su, Gary Mosehauer, Bill Reindel
Bausch + Lomb, Rochester, USA
*E-mail address: [email protected]
Purpose: Aspheric optics in contact lenses are designed to reduce inherentspherical aberration in the eye. Four studies were conducted to evaluatespherical aberration and visual acuity of two marketed silicone hydrogellenses (Test – balafilcon A with aspheric optics; Control – senofilcon A withconventional spherical optics) across a range of powers.
Method: A single power was assessed in each study (+3.00D, −1.00D,−5.00D, and −9.00D). Cohorts of 22–25 subjects were dilated with 1% Tropi-camide to achieve 6mm pupils. Baseline spherical aberration readings andhigh contrast logMAR visual acuities using a 6mm artificial aperture wererecorded and then repeated with lenses in situ. A linear mixed model wasemployed to analyze data across all studies and paired comparisons wereconducted within each study.
Results: The results showed that, over all studies, the Test lenses reducedthe mean spherical aberration by 0.136um, significantly more than the Con-trol lens which reduced the spherical aberration by only 0.054um (p<0.05).On average the Test lenses were 0.07 logMAR better (p<0.05). For the −9.00D,−5.00D and +3.00D powers individually, the Test lenses provided signifi-cantly better visual acuity (0.09 logMAR, 0.07 logMAR and 0.13 logMAR, re-spectively; p<0.05 in each case) compared to the control lenses.
Conclusions: Incorporating aspheric optics into contact lens designs canreduce the spherical aberration of the eyes’ optical system. These studiesshow that for contact lens patients, the balafilcon A lenses with asphericoptics can provide a clinically significant enhancement to vision over con-ventional spherical optics.
62
Utilizing clinical eye models to predict retinal image quality ofindividuals
Amanda C Kingston*, Ian G Cox
Bausch + Lomb, Rochester, USA
*E-mail address: Amanda_C_Kingston@bausch. com
Purpose: To correlate retinal image quality metrics output from custom Ze-max™ clinical eye models with visual acuity results recorded in a multifocallens clinical study.
Method: Clinical diagnostic measurements were used to create Zemax™models of individual patient’s eyes. These clinical eyemodels were then usedto generate a retinal image quality metric that was correlatedwith the visualacuity results from a multifocal lens clinical study. Three different contrastand illumination conditions were used in the clinical study: (1) normalizedhigh contrast high illumination (NHCHI), (2) normalized low contrast highillumination (NLCHI) and (3) normalized low contrast low illumination (NL-CLI). All three conditions were correlated with the retinal image quality met-ric (weighted pattern recognition score) calculated from the Zemax™ mod-els.
Results: The percent correlation was calculated for each of the three clini-cal conditions with the weighted pattern recognition score. NHCHI yielded acorrelation of 76.47%, NLCHI correlated with 82.35% and NHCLI correlatedwith 88.25%. Normalized 20/20 Geometrical convolved E’s were also ex-ported fromZemax™ in order to give a subjective comparison of the patient’sperceived visual acuity.
Conclusions: Clinical eyemodels can be used to predict retinal image qual-ity for a diverse population of eyes. By using this population of clinical eyemodels, it is now possible to model different lens design concepts to deter-mine what a patient’s visual acuity results will be with that lens.
