Frequency of Contact Lens Complications Between Contact Lens Wearers Using Multipurpose Solutions Versus Hydrogen Peroxide in the United States and Canada.

OBJECTIVES: To retrospectively compare frequency of contact lens (CL) complications in soft CL users of hydrogen peroxide (H2O2) and multipurpose solutions (MPS). METHODS: This was a multicenter, retrospective chart review of CL records from each patient's three most recent eye examinations at academic and private practices. Patients must have used the same solution type for at least 3 years. Univariate analyses were conducted using t tests, and chi-square or Fisher's exact test for categorical measures. RESULTS: There were 1,137 patients included, with 670 (59%) using MPS and 467 (41%) H2O2. In total, 706 (62%) experienced at least one complication; 409 used MPS and 297 used H2O2. There was no difference in the proportion of patients experiencing at least one complication between MPS (61%) and H2O2 (64%) (P=0.38). Multipurpose solutions users were more likely to report discomfort compared with H2O2 users (P=0.04). Presumed microbial keratitis was experienced by 16 MPS and nine H2O2 users (P=0.60). CONCLUSIONS: No significant differences were found in the frequency of CL complications between MPS and H2O2. H2O2 users were less likely to report discomfort and thus switching to a H2O2 system may be an alternative in CL users with discomfort.

Risk factors associated with contamination of orthokeratology lens cases.

PURPOSE: To evaluate the risk factors associated with contamination of lens cases in a group of orthokeratology (ortho-k) lens wearers. METHOD: Ortho-k patients attending the Contact Lens Clinic of the Hospital were required to complete a checklist about their routine daily care and handling of lens cases. Their cases were then collected for analysis. Contamination was evaluated by determining the optical density (OD) of crystal violet stained biofilm present in the cases. OD values were divided into three groups, lower, middle, and upper tertiles, and associations between risk factors were determined by multivariate analysis. RESULTS: A total of 194 subjects were recruited. Twenty-five subjects used cylindrical lens cases (CC), 98 flat cases with ridges (FCR), and 71 flat cases without ridges (FC). FCRs were the most heavily contaminated and CC showed least contamination (FCR > FC, OR 2.16, CI 1.11-4.18, p =  0.023; FCR > CC, OR 8.86, CI 2.97-26.44, p <0.001; FC > CC, OR 2.33, CI 1.35-12.45, p =  0.013). Replacing lens cases monthly significantly reduced the risk of high contamination (OR 0.013, CI 0.06-0.30, p <  0.001), compared to those used for three months. Cases that were not rinsed (OR 3.44, CI 1.50-7.86, p =  0.003) or rinsed by other methods (OR 4.07, CI 1.67-9.92, p =  0.002) had significantly more contamination, compared to those rinsed with multipurpose solution. Lens cases, which were not dried (OR 11.36, CI 2.06-62.93, p =  0.005) or air-dried (OR 8.71, CI 1.16-65.56, p =  0.036), showed more contamination compared to those wiped with tissue daily. CONCLUSION: Case design (cylindrical), monthly replacement, daily rinsing with MPS, and wiping with tissue daily can effectively reduce biofilm formation in contact lens cases.

Ocular surface response and subjective symptoms associated to lens care solutions in Palestine / Respuesta de la superficie ocular y síntomas subjetivos asociados a las soluciones para el cuidado de las lentillas en Palestina

PURPOSE: To compare the biocompatibility and subjective symptoms of four multipurpose solutions marketed in Palestine with hydrogel contact lenses. METHODS: 50 habitual soft contact lens wearers were recruited in this interventional crossover study. Subjects were asked to attend the optometry clinic five times. A new pair of hydrogel lenses (Bioxifilcon-B) were fitted each time. This pair was soaked randomly overnight in one of the following four-multipurpose solutions (NEOPLUS(R), AvizorUnicaSensitive(R), ReNuMultiPlus(R) and COMPLETERevitaLens(R)) which contain different disinfecting agents (PHMB, Phx, PAPB, and PQ-1 + Alexidine, respectively), or non-preserved saline. At each visit, corneal staining, ocular redness and subjective symptoms were assessed. RESULTS: The percentage of corneal staining increased significantly (P ≤ 0.050) after soaking the lenses with PHMB (86%), PAPB (64%) and Phx (32%) based-solutions. However, a non-significant increase was noticed after the use of PQ-1 + Alexidine based solution (30%, P = 0.083). Ocular redness evaluation showed a significant increase (P ≤ 0.050) in limbal hyperemia after the use of all solutions, while bulbar redness was significantly increased after the use of biguanide-based solutions (P ≤ 0.050). The subjective assessment analysis showed a non-significant change in comfort, dryness, photophobia and scratchiness (P ≥ 0.050) at 2-h intervention using all solutions, except for the PHMB based solution which showed a significant change in subjective symptoms (P ≤ 0.050). Conclusion: The combination of Bioxifilcon-B hydrogel contact lenses and solution containing PHMB, PAPB and Phx-disinfectants induced a significant increase in corneal staining after 2h of CL-wear with a higher severity when the PHMB-based solution was used, while the PQ-1+Alexidine-based solution did not. Only the PHMB-based solution triggered a significant change in subjective symptoms which might which suggests that it might be related to the severity of staining rather than the induction of staining

OBJETIVO: Comparar la biocompatibilidad y los síntomas subjetivos de cuatro soluciones multiusos comercializadas en Palestina con lentillas de hidrogel. MÉTODOS: En este estudio intervencionista cruzado, reunimos a 50 usuarios habituales de lentillas blandas. Solicitamos a los sujetos que acudieran cinco veces a la clínica optométrica. Cada vez ajustamos un nuevo par de lentillas de hidrogel (Bioxifilcon-B). Dicho par se sumergió aleatoriamente por la noche en una de las siguientes soluciones multiuso (NEOPLUS(R), AvizorUnicaSensitive(R), ReNuMultiPlus(R) y COMPLETERevitaLens(R)), que contienen diferentes agentes desinfectantes (PHMB, Phx, PAPB, y PQ-1 + Alexidina, respectivamente), o solución salina sin conservantes. Durante cada visita, valoramos la coloración de la córnea, el enrojecimiento ocular y los síntomas subjetivos. RESULTADOS: El porcentaje de coloración de la córnea se incrementó significativamente (P ≤ 0,05) tras sumergir las lentillas en soluciones basadas en PHMB (86%), PAPB (64%) y Phx (32%). Sin embargo, se observó un incremento no significativo tras utilizar la solución basada en PQ-1 + Alexidina (30%, P = 0,083). La evaluación del enrojecimiento ocular reflejó un incremento significativo (P ≤ 0,05) de la hiperemia limbal tras el uso de todas las soluciones, mientras el enrojecimiento bulbar se incrementó significativamente tras utilizar soluciones basadas en biguanida (P ≤ 0,05). El análisis de valoración subjetiva reflejó un cambio no significativo en cuanto a comodidad, sequedad, fotofobia y picazón (P ≥ 0,05) durante la intervención de dos horas utilizando todas las soluciones, exceptuando la solución basada en PHMB, que reflejó un cambio significativo en cuanto a síntomas subjetivos (P ≤ 0,05). CONCLUSIÓN: La combinación de las lentillas de hidrogel Bioxifilcon-B y la solución con contenido de desinfectantes PHMB, PAPB y Phx indujo un incremento significativo de la coloración de la córnea tras 2 h de uso de lentillas, con una severidad superior al utilizarse la solución basada en PHMB, hecho que no se produjo con la solución basada en PQ-1 + Alexidina. Únicamente la solución basada en PHMB desencadenó un cambio significativo en cuanto a síntomas subjetivos, lo cual podría sugerir que podría guardar relación con la severidad de la coloración, en lugar de la inducción de la misma

Ocular surface response and subjective symptoms associated to lens care solutions in Palestine.

PURPOSE: To compare the biocompatibility and subjective symptoms of four multipurpose solutions marketed in Palestine with hydrogel contact lenses. METHODS: 50 habitual soft contact lens wearers were recruited in this interventional crossover study. Subjects were asked to attend the optometry clinic five times. A new pair of hydrogel lenses (Bioxifilcon-B) were fitted each time. This pair was soaked randomly overnight in one of the following four-multipurpose solutions (NEOPLUS®, AvizorUnicaSensitive®, ReNuMultiPlus® and COMPLETERevitaLens®) which contain different disinfecting agents (PHMB, Phx, PAPB, and PQ-1+Alexidine, respectively), or non-preserved saline. At each visit, corneal staining, ocular redness and subjective symptoms were assessed. RESULTS: The percentage of corneal staining increased significantly (P≤0.050) after soaking the lenses with PHMB (86%), PAPB (64%) and Phx (32%) based-solutions. However, a non-significant increase was noticed after the use of PQ-1+Alexidine based solution (30%, P=0.083). Ocular redness evaluation showed a significant increase (P≤0.050) in limbal hyperemia after the use of all solutions, while bulbar redness was significantly increased after the use of biguanide-based solutions (P≤0.050). The subjective assessment analysis showed a non-significant change in comfort, dryness, photophobia and scratchiness (P≥0.050) at 2-h intervention using all solutions, except for the PHMB based solution which showed a significant change in subjective symptoms (P≤0.050). CONCLUSION: The combination of Bioxifilcon-B hydrogel contact lenses and solution containing PHMB, PAPB and Phx-disinfectants induced a significant increase in corneal staining after 2h of CL-wear with a higher severity when the PHMB-based solution was used, while the PQ-1+Alexidine-based solution did not. Only the PHMB-based solution triggered a significant change in subjective symptoms which might which suggests that it might be related to the severity of staining rather than the induction of staining.

Effect of 2, 6-Dichlorobenzonitrile on Amoebicidal Activity of Multipurpose Contact Lens Disinfecting Solutions.

Multipurpose contact lens disinfecting solutions (MPDS) are widely used to cleanse and disinfect microorganisms. However, disinfection efficacy of these MPDS against Acanthamoeba cyst remain insufficient. 2, 6-dichlorobenzonitrile (DCB), a cellulose synthesis inhibitor, is capable of increasing the amoebical effect against Acanthamoeba by inhibiting its encystation. In this study, we investigated the possibility of DCB as a disinfecting agent to improve the amoebicidal activity of MPDS against Acanthamoeba cyst. Eight commercial MPDS (from a to h) were assessed, all of which displayed insufficient amoebicidal activity against the mature cysts. Solution e, f, and h showed strong amoebicidal effect on the immature cysts. Amoebicidal efficacy against mature cysts remained inadequate even when the 8 MPDS were combined with 100 µM DCB. However, 4 kinds of MPDS (solution d, e, f, and h) including 100 µM DCB demonstrated strong amoebicidal activity against the immature cysts. The amoebicidal activity of solution d was increased by addition of DCB. Cytotoxicity was absent in human corneal epithelial cells treated with either DCB or mixture of DCB with MPDS. These results suggested that DCB can enhance the amoebicical activity of MPDS against Acanthamoeba immature cyst in vitro.

Identification of free-living amoebae isolated from tap water in Istanbul, Turkey.

Free-living amoebae (FLA) are widely spread in the environment and also known to cause rare but often serious infections. The present work focuses on a local survey on FLA. It is essential to know the prevalence and distribution of these microorganisms in order to get infections caused by them under control. In this study, FLA isolated from domestic tap water samples from homes of contact lens wearers were identified by morphology and by 18S rRNA gene sequence analysis. Morphological analysis and partial sequencing of the 18S rDNA revealed the presence of Acanthamoeba genotype T4 and Vermamoeba vermiformis in the investigated tap water samples. Naegleria fowleri, Balamuthia mandrillaris, and Sappinia spp. were not detected during this study. It was shown that species of FLA known to cause eye infections in humans are widely distributed in tap water in Istanbul, Turkey. Contact lens wearers should be aware of the risk of contamination from tap water and strictly apply stringent contact lens hygiene. With this study, we established Acanthamoeba genotype T4 and Vermamoeba vermiformis as contaminants of tap water in Istanbul.

Molecular Bioburden of the Lens Storage Case for Contact Lens-Related Keratitis.

PURPOSE: To elucidate the bioburden of a lens care system in patients with contact lens (CL)-related keratitis. METHODS: In this prospective case-control study, the CL storage case was used as the target of bioburden assessment. Participants were CL wearers with (n = 26) or without (n = 24) keratitis in southern Taiwan. The case fluid sample was consecutively collected and assessed using a dot hybridization assay (DHA) for bioburden assessment. The DHA was composed of 3 universal bacterial probes for detecting all bacteria, genus-specific probes for Pseudomonas and Acinetobacter, and 1 probe for Acanthamoeba. The receiver operating characteristic curve was used to analyze the differentiating performance of a probe. RESULTS: The storage case bioburden was significantly higher in those with CL-related keratitis than in control subjects; patients with CL-related keratitis had stronger standardized signals in all universal bacterial probes. Moreover, in the cases of these patients, the bioburden was significantly heavier in confirmed infectious keratitis than in presumed noninfectious keratitis. Receiver operating characteristic analysis showed that stronger signals in all 3 universal bacterial probes and the Pseudomonas probe might suggest that the wearers have infectious keratitis. Only the storage case of the Acanthamoeba keratitis case showed positive detection by the Acanthamoeba probe. CONCLUSIONS: A heavier bioburden in the lens storage case was associated with a higher risk of CL-related keratitis and infectious keratitis. Inappropriate maintenance of the CL will lead to microbial contamination and transfer the pathogen onto the ocular surface causing keratitis accordingly. The DHA assessment for the lens storage case might provide an alternative way to differentiate infectious from noninfectious CL-related keratitis.

Contact Lens Solutions and Contact Lens Discomfort: Examining the Correlations Between Solution Components, Keratitis, and Contact Lens Discomfort.

OBJECTIVES: This article will examine the current literature, as it relates to contact lens discomfort (CLD) secondary to contact lens solutions. The reader will better understand the characteristics of contact lenses, as they uniquely interact with each type of contact lens solution and also gain a better comprehension of the components of contact lens solution such as preservatives, surfactants, and chelating agents, which may contribute to discomfort. By investigating corneal staining theory and the mechanisms that contribute to its presence, the reader will gain insight into this clinical finding, which relates to selection of contact lens solutions. The FDA standards for testing solutions and how this relates to contact lens keratitis will also be appraised in regards to current ISO recommendations. Finally, better selection of multipurpose contact lens solution (MPS) and hydrogen peroxide-based solutions for patients should be accessible to the clinician based on this review and preexisting clinical findings or diagnoses. METHODS: A review of current published literature from peer reviewed journals and online journals was conducted to gain an understanding of contact lens solution's impact on contact lens discomfort. CONCLUSIONS: Many studies have been conducted comparing comfort between various types of contact lens solutions. It is challenging to decipher this information and apply it clinically when selecting solutions for patients. By comparing solution components, how contact lens solutions interact with different types of lenses, keratitis related to contact lenses, and preexisting ocular conditions, this review will improve a clinician's ability to eliminate CLD.

Acanthamoeba keratitis: An emerging disease among microbial keratitis in the Cap Bon region of Tunisia.

INTRODUCTION: The aim of this study was to describe the prevalence of AK among microbial keratitis as well as their clinical features and to compare their risk factors to those of other infectious keratitis, over the last five years in a referral center in the region of Cap Bon, Tunisia, North Africa. METHODS: A retrospective review of the charts of 230 patients (230 eyes) diagnosed with presumed infectious keratitis between January 2011 and December 2016 at the department of ophthalmology of the university hospital of Nabeul in Tunisia. After a detailed ocular examination using standard technique, corneal scrapes were performed under aseptic conditions from each ulcer. Plates were incubated at 30 °C and screened daily for Amoeba. The treatment was adjusted according to the results of microbiological findings and the response of initial treatment. The mean follow up was 11.4 months (1 month-26 months). RESULTS: A total of 230 corneas were scraped. The prevalence of Acanthamoeba keratitis was 6% (14 cases of 230). All cases of Acanthamoeba keratitis with a history of contact lenses were diagnosed thanks to the test of Contact lenses, their cases or their storage solution, while their corneal scrapings were negative. The corneal scraping was positive for Acanthamoeba only in 4 cases of 14. Acanthamoeba was identified more in young patients (92.8%). Significantly, more patients (54 of 74; 73%) with fungal keratitis and Acanthamoeba keratitis (11 of14; 78.6%) were rural population The most cases of Acanthamoeba keratitis (10 of 14; 71.4%) used contact lenses. Ocular injury was identified in 4 cases of 14 AK (28,5%). Coexistent ocular disease was seen in seven cases of 14 (50%). Of the 230 microbial keratitis, an early diagnosis (≤30 days) was done in 200 cases (86.95%), while a late diagnosis (≥30 days) was made in 30 cases (13%). In AK, most cases (11 of 14; 78,5%) were diagnosed with a delay of more than 30 days. Slit-lamp examination showed stromal infiltrate in 12 cases (85,7%), hypopion in 2 cases (14,3%), immunitary ring in 2 cases (14,3%) and radial keratoneuritis in one case (7,1%). CONCLUSION: Contact lenses were identified as the main risk factor of Acanthamoeba keratitis in our study. The diagnosis of AK should be considered in case of atypical keratitis especially among CL wearers in the rural regions of CapBon where the rules of hygiene are not respected.

Clinical Outcomes and Contact Lens Case Contamination Using a Povidone-Iodine Disinfection System.

OBJECTIVE: To assess the incidence of adverse events during the use of a povidone-iodine disinfecting solution (cleadew) and the microbial contamination in contact lens cases. METHODS: A prospective, single-center, open-label, controlled study evaluating the use of cleadew cleaning and disinfecting system in existing daily wear soft contact lens wearers over a 3-month period was conducted. Ocular signs and symptoms during lens wear were assessed at baseline and after 1 and 3 months of using cleadew. Contact lens cases were assessed for the frequency of microbial contamination and the types of microbes, using traditional microbial culture, followed by identification of bacteria using 16S rRNA sequencing. RESULTS: Use of cleadew was well tolerated. There was reduction in corneal staining (0.5±0.5 at 3 months of use) compared with the participant's habitual multipurpose disinfecting system (1.1±1.0); all other clinical signs were not significantly different. There were no cases of solution-induced corneal staining. There was a low adverse event rate of 0.8% per 100 participant-months. Contact lens case contamination was low, with 30% of cases having no culturable microbes. Comparison with previously published data showed that use of cleadew resulted in low frequencies of Gram-positive (49%) and fungal (8%) contamination and a low, but higher than some other disinfecting solutions, level of Gram-negative bacteria. CONCLUSIONS: Cleadew cleaning and disinfecting system was associated with low levels of adverse events during use. Contact lens cases were significantly less frequently contaminated than for some other types of disinfecting solutions.

Hydrogen-peroxide and silicone-hydrogel contact lenses: Worsening of external eye condition and tear film instability.

PURPOSE: The aim is discussing the origins of worsening of external eye condition (EEC) and of tear film (TF) instability after wear of silicone-hydrogel contact lenses (CLs) with hydrogen-peroxide (H2O2) care system. METHODS: EEC and TF stability were evaluated before and after 15days of wear combined with different care systems: (1) H2O2, (2) detergent solution and H2O2, (3) multipurpose solution (MPS), (4) H2O2 and artificial tears. In-vitro cell mortality tests were performed after 24h cell incubation with CLs treated with H2O2. Photon correlation spectroscopy (PCS) was carried out on tears of non-wearers and CL wearers who used MPS or H2O2 solution. RESULTS: Worsening of EEC was observed only for the group using H2O2 (group 1). In-vitro, cell mortality was found higher for worn CL than for unworn CLs. Worsening of TF stability was observed regardless of care system and also PCS results on tears of CL wearers were found different compared to non-wearers regardless of care system. The only observed remedy for tear instability of CL wearers was found to be the administration of artificial tears. CONCLUSIONS: Worsening of EEC of CL wearers using H2O2 is attributed to H2O2 scarce cleaning efficacy, which can be solved by adding a CL detergent solution. The origin of TF instability is found to be different. A remedy was found to be the administration of artificial tears, whose effect could be attributed either to the role of specific components or to rinsing and replacement of TF during wear.

Cytotoxic and inflammatory effects of contact lens solutions on human corneal epithelial cells in vitro.

PURPOSE: To ascertain the effect that four contact lens (CL) multipurpose solutions (MPS) have on the viability and release of pro-inflammatory cytokines from human corneal epithelial cells (HCEC). METHODS: HCEC were exposed to four different MPS at various concentrations for 18 hours. The cells were also exposed to phosphate buffer, borate buffer, and PHMB. The cell viability was evaluated using the alamarBlue assay. The release of pro-inflammatory cytokines was measured using a Multiplex electrochemiluminescent assay. RESULTS: MPS-A, MPS-B and MPS-C all reduced cell metabolic activity p < 0.05 from control with MPS-A showing the greatest cytotoxic effect (maximum reduction, 90.6%). In contrast, MPS-D showed no significant reductions in cytotoxicity except at the highest concentration tested (19% reduction at 20% MPS concentration). Of the four cytokines evaluated MPS-C showed a substantial increase in the release of IL-1ß, IL-6, IL-8, and TNF-α at higher concentrations when compared to control p < 0.05. At the 20% concentration of MPS-A and MPS-B the release of IL-1 ß increased p < 0.05 but the release of IL-6, IL-8, and TNF-α decreased. MPS-D did not cause a change in the release of cytokines IL-1ß, IL-6, IL-8 and TNF-α p > 0.05. Exposing the cells to borate buffer and PHMB caused an increase in the release of TNF-α p < 0.05. CONCLUSIONS: This investigation demonstrates that at different concentration levels, several of the MPS tested showed a decrease in viability and an increase in the release of inflammatory cytokines from HCEC. The borate buffer component as well as PHMB appears to contribute to this pro-inflammatory reaction.

[Contact lens-related Fusarium keratitis: a case report].

We aim to highlight the key factors for a good outcome of fungal keratitis. We describe a case of contact lens-related Fusarium keratitis in a young girl. After identification of Fusarium spp under direct microscopic examination and in culture, a prolonged treatment with topic natamycin 5% was started and administered for five months with restitutio ad integrum of the eye. Prompt microbiological diagnosis and a specific and prolonged treatment are essential for correct management of Fusarium keratitis.

Water Exposure is a Common Risk Behavior Among Soft and Gas-Permeable Contact Lens Wearers.

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.

Effect of the osmolarity change in multipurpose solutions induced by an improper contact lens case cleaning procedure.

PURPOSE: To determine whether variations in multipurpose disinfecting solution (MPDS) storage osmolarity from inappropriate contact lens (CL) case cleaning affect ocular surface integrity and wearer comfort. METHODS: There were twenty contact lens cases (study CLCs) in the study group. Ten were filled with ReNu Multiplus(®) and 10 with SoloCare Aqua™ (MPDS-1 and -2, respectively) and kept closed for 8h; the cases were then emptied and kept open for air-drying for 16h. This procedure was carried out every day for two months. Storage solution osmolarity was measured on days 0, 15, 30, 45 and 60. Ten subjects were then fitted with both month-old lenses stored in the study CLCs and with new lenses stored in new cases with fresh solution for 24h (control CLCs). Symptoms, tear osmolarity and percentage of subjects whose conjunctival hyperaemia and ocular surface staining scores changed were determined after 1h of wear. RESULTS: Study CLC osmolarity increased in both solutions after two months (p<0.05). For MPDS-1 there were differences in stinging between study CLCs and control CLCs after 10min of CL wear (p=0.04), and in comfort after 10 (p=0.035) and 60min wear (p=0.042). Significant (p<0.05) differences between study CLC and control CLC groups were also found for MPDS-2 in limbal hyperaemia (study: 50% change; control: 0% change) and bulbar and corneal staining (study: 80% change; control: 20% change). CONCLUSION: The stored-MPDS osmolarity increase caused by air-drying the CLCs could affect the ocular surface. This increase might reduce lens wear comfort.

Dendritiform Keratopathy Associated with Exposure to Polyquarternium-1, a Common Ophthalmic Preservative.

PURPOSE: To describe dendritiform keratopathy associated with exposure to polyquaternium-1, a common preservative found in contact lens solutions and tear replacement products. DESIGN: Case series. PARTICIPANTS: Sixteen patients who demonstrated dendritiform keratopathy during topical ophthalmic exposure to polyquaternium-1. METHODS: Records were reviewed of all patients diagnosed with dendritiform keratopathy between 1999 and 2014 who had documented exposure to contact lens care disinfecting solutions or artificial tear solutions containing polyquaternium-1. Patients were excluded who had coexisting potential causes for dendritiform keratopathy, such as prior herpes simplex keratitis, varicella-zoster viral keratitis, the linear form of Thygeson's superficial keratitis, epithelial regeneration line, Acanthamoeba keratitis, mucus plaque keratopathy, medication-related keratopathy, or limbal stem cell deficiency characterized by conjunctivalization of the corneal epithelium. MAIN OUTCOME MEASURES: Effect of discontinuation of exposure to polyquaternium-1 on the dendritiform keratopathy. RESULTS: Sixteen patients demonstrated dendritiform keratopathy after exposure to the preservative polyquaternium-1. Thirteen patients had a history of recent exposure to contact lens disinfecting solutions (Opti-Free, Equate) containing polyquaternium-1. Three patients used a tear replacement product (Systane) containing a polyquaternium-1 preservative. Four patients were treated with antiviral medications for presumed herpes simplex keratitis; 4 patients underwent diagnostic testing for Acanthamoeba keratitis. Two additional patients were diagnosed sequentially with herpes simplex keratitis, then Acanthamoeba keratitis before referral. All dendritiform lesions resolved within 2 to 6 weeks after elimination of exposure to polyquaternium-1. CONCLUSIONS: Ophthalmic products containing polyquaternium-1 may cause dendritiform keratopathy that may be confused with infections of the superficial cornea, such as herpes simplex virus keratitis or Acanthamoeba keratitis.

Evaluation of safety and efficacy of a new multipurpose disinfecting solution on silicone hydrogel contact lenses.

PURPOSE: To evaluate the safety and efficacy of a new multipurpose disinfecting solution (MPDS) with a formulation that includes aloe vera on its composition. METHODS: This is a prospective, randomized, double-masked clinical trial with a crossover design that included seven examinations. Two different MPDSs, Avizor Alvera® (study solution) and All Clean Soft® (control solution), each were used for 1 month. Comfilcon A silicone hydrogel contact lenses were used during the trial. The main outcome variables were corneal staining and deposits on the surfaces of the contact lenses. Other parameters including ocular surface response, contact lens wettability, user satisfaction, and adverse events, were analyzed according to the International Organization for Standardization (ISO) 11980:2010 guidance for clinical investigation. RESULTS: Twenty subjects (10 women, 10 men) (mean age, 27.7±5.6 years; range, 20-41) were included. No differences between both MPDSs were found in the percentage of subjects with corneal staining >0 at day 30 (study: 35%, control: 50%; p=0.46); neither in the percentage of subjects with deposits on the surface of the contact lens >0 at day 30 (study: 26.32%, control: 52.63%; p=0.18). The study MPDS received higher rates in comfort (study: 8.14±1.09, control: 7.94±0.92; p=0.56) and satisfaction at day 30 (study: 8.63±0.91, control: 8.29±0.80; p=0.19), however the scores were not significantly different with the control MPDS. CONCLUSIONS: The clinical trial showed that the study MPDS is safe, efficient, and has acceptable physiologic tolerance, according to the ISO 11980:2010 guidance for clinical investigation.

Contact lens care solutions: a pilot study of ethnic differences in clinical signs and symptoms.

OBJECTIVES: To determine whether Asian and white subjects differ in clinical signs or subjective symptoms in response to the use of different biguanide-preserved contact lens care solutions. METHODS: Forty-two subjects (15 Asian and 27 white) wearing lotrafilcon B silicone hydrogel contact lenses used a preservative-free lens care solution bilaterally for 2 weeks, then used two biguanide-preserved solutions (solution 1: ReNu MPS; solution 2: AQuify MPS) contralaterally in randomly assigned eyes for 4 weeks. Comprehensive ocular surface examinations were performed and symptomatology questionnaires were administered every 2 weeks. Investigators were masked as to solution assignment during examinations, whereas subjects were not to avoid potential difficulties in compliance with the protocol. RESULTS: With solution 1, most Asian and white subjects had grade 2 or greater corneal staining after 2 weeks (67% and 59%, respectively) and 4 weeks (60% and 67%, respectively). With solution 2, grade 2 or greater corneal staining occurred in 40% of Asians after 2 weeks and in 13% after 4 weeks, but in only 4% of whites after 2 weeks and 0% after 4 weeks. Whites reported significantly better average comfort (P=0.046) and less dryness (P<0.001) than did Asians. CONCLUSIONS: Asians and whites differ in both ocular response to the use of contact lens care solutions and in reporting subjective symptoms. Racial and ethnic differences should be considered when evaluating and treating contact lens patients in a clinical setting.