Lens Solutions Research Articles

Contact lens-related microbial keratitis: recent outbreaks

This paper reviews the literature generated on atypical contact lens-related infections and their relationship with particular contact lens solutions since 2005. Atypical soft contact lens-related infections are on the rise. Specifically, there has been an insurgence of Acanthamoeba keratitis and Fusarium keratitis. The rise in these infections was associated with Advanced Medical Optics Complete MoisturePlus (AMO, Santa Ana, California, USA) and ReNu with MoistureLoc (Bausch and Lomb, Rochester, New York, USA) respectively. Contact lens solutions in general are more effective against bacteria than fungal species or Acanthamoeba. Multipurpose solutions and no rub formulas may have diminished antimicrobial activity and are not as effective under real world conditions. There have been epidemic increases in Acanthamoeba and fungal keratitis associated with particular contact lens solutions. Further study of these atypical species is necessary. Greater emphasis should be placed upon efficacy of contact lens solutions rather than ease of use.

Endotelite e ceratoneurite herpética

Relatamos um caso de endotelite que se expressou inicialmente como uma cerato-neurite em pacientes usuarios de lente de contato gelatinosa e de inadequado uso de solucao salina . Trata-se de uma paciente de 41 anos, branca feminina, que se queixava de intensa dor no olho esquerdo e que ao exame biomicroscopico revelou edema corneano microcistico e ceratoneurite radial. Foram realizadas cultura e biopsia corneana e todos testes foram negativos. O tratamento com excelente resposta terapeutica reduziu o edema da cornea e aliviou a dor ocular consistiu de dexametasona 0,1% topica sob a forma de pomada e acyclovir oral .

Bilateral Acanthamoeba ulcer in a user of disposable soft contact lenses: a tragic incident or a consequence of the aggressive policy of soft contact lens trading?

This is the report of a case of bilateral Acanthamoeba keratitis in a 19-year-old woman who bought a pair of disposable soft contact lenses in a boutique. She wore this same pair of lenses for 3 months daily without the appropriate care. This led to bilateral corneal transplantation with cataract extraction and also trabeculectomy in the right eye. When last seen, both grafts were crystal clear but the visual acuities were far from satisfactory. She also had bilateral secondary glaucoma, barely controlled by topical medication. Actually, the physical features and the wearing time characteristics of the disposable soft contact lenses created unprecedented difficulties to the medical surveillance of their wearers. Without the right assistance they tend to become careless regarding routine cleaning. They also feel free to buy less expensive lenses, to use saline instead of lens solutions, to violate the limits of wearing time and to extend the use over the sleeping period. Additionally, the aggressive marketing and the wide distribution of these lenses increase the chances that economically or educationally unprepared people will acquire them. The question that remains is: Is the present case an accidental event or an example of what is likely to happen in the future if the indiscriminate selling of disposable soft contact lenses continues to evolve?

Impact of Contact Lens Group on Antifungal Efficacy of Multipurpose Disinfecting Contact Lens Solutions

To evaluate and compare the in vitro effectiveness of multipurpose contact lens solutions (MPDS) to inhibit fungal colonization of Food and Drug Administration (FDA) contact lens groups. Contact lenses from FDA groups I (low water content, nonionic), II (high water content, nonionic), III (low water content, ionic), and IV (high water content, ionic) were placed in sterile contact lens cases with 2 mL of ReNu MultiPlus, ReNu with MoistureLoc, or OPTI-FREE RepleniSH. Each contact lens-multipurpose solution combination was challenged with 0.1 mL of 10(6) colony-forming units/mL of Fusarium oxysporum and incubated at room temperature. Contact lenses and aliquots from phosphate-buffered saline rinse solutions, multipurpose solutions in cases, and lens cases were sampled at 24, 48, and 72 hours, plated on Sabouraud's agar, incubated at room temperature, and observed for growth (i.e., adhesion) for 1 to 7 days. Used multipurpose contact lens solutions met or exceeded the 1-log reduction requirement of the FDA stand-alone test. Viable fungal colonies were recovered from group II lenses after 24 hours of storage in all three multipurpose solutions. Colonization was also detected with at least one contact lens-multipurpose solution pairing from groups I, III, and IV. Fungi were not recovered from lens-solution combinations after 24 hours or from phosphate-buffered saline solutions or lens cases at any period. Antifungal activity of contaminated multipurpose solutions may be insufficient to prevent fungal colonization of contact lens materials despite meeting or exceeding the FDA stand-alone test criteria. Colonized lens may increase the risk of fungal keratitis.

Encystment of Acanthamoeba During Incubation in Multipurpose Contact Lens Disinfectant Solutions and Experimental Formulations

Acanthamoeba keratitis (AK) is most commonly found in contact lens wearers with poor lens care hygiene. Recent reports have indicated an increase in cases of AK in the United States associated with the use of Complete MoisturePlus multipurpose solution. This association may not appear explainable by differences in Acanthamoeba kill rates among multipurpose solutions. In this study the physiologic response of Acanthamoeba trophozoites to incubation in various contact lens solutions was investigated. Acanthamoeba trophozoites were incubated in commercial and experimental solutions and the percentage encystment and viability determined in conjunction with microscopic analysis of cyst formation. Among commercial products, MoisturePlus solution induced encystment within 6 to 24 hr of incubation. Only immature cysts formed which failed to mature even after 5 days incubation in the solution although they remained viable. Experimental formulations of MoisturePlus solution, modified by omitting key ingredients, identified propylene glycol as the agent responsible for inducing encystment. However, tests of other commercial solutions containing propylene glycol produced reduced or no encystment. The presence of propylene glycol was shown to be the key factor in inducing Acanthamoeba encystment. However, the reduced or absence of encystment in other commercial solutions containing propylene glycol suggests additional factors, such the buffering system, may be involved in the phenomenon. How these observations relate to the solution's role in the reported association with AK is unclear. Nevertheless, it is recommended that all lens care products be tested for propensity to induce Acanthamoeba encystment and formulations containing propylene glycol may warrant special scrutiny.

Cocamidopropyl Betaine

Cocamidopropyl betaine (CAPB) is an amphoteric synthetic detergent that has been increasingly used in cosmetics and personal hygiene products (eg, shampoos, contact lens solutions, toothpaste detergents, makeup removers, bath gels, skin care products, cleansers, liquid soaps, antiseptics, and gynecologic and anal hygiene products) because it induces relatively mild skin irritation. Delayed T-cell-mediated type IV hypersensitivity reactions to CAPB have been reported, and contact sensitization prevalence is estimated at between 3.0 and 7.2%. The increasing rates of sensitization led to CAPB's being named Allergen of the Year in 2004. Related impurities rendered during the manufacturing process (such as amidoamine and dimethylaminopropylamine) are thought to play a role in sensitization.

Physical Properties of Soft Contact Lens Solutions

To investigate the physical properties of commercially available soft contact lens solutions. The pH, osmolality, surface tension (ST), and viscosity of various soft contact lens solutions were measured at room temperature. Viscosity measurements were also taken at 34 degrees C. The solutions examined were Opti-Free Express (OFX), Opti-Free RepleniSH (OFR), Complete Moisture Plus (COM), UltraCare (UC), ReNu MultiPlus, Sensitive Eyes, AOSept (AO), Clear Care, SoloCare Aqua, and SoftWear saline. The peroxide solutions were measured before and after neutralization. The pH of most solutions was close to neutral (range 7.00-7.36), except for OFX and neutralized AO and Clear Care. The osmolality values of most solutions were in the 275 to 310 mOsm/kg range. OFX exhibited a significantly lower osmolality (225 mOsm/kg; p < 0.001), whereas UC was significantly higher (329 mOsm/kg; p < 0.001). Neutralized AO and SoftWear saline had ST values of approximately 67 mN/m. OFX, OFR, and SoloCare Aqua exhibited low ST values in the 30 to 35 mN/m range. The remaining solutions exhibited intermediate ST values of approximately 40 mN/m. These three groupings were significantly different (p < 0.001). The average viscosity of most solutions at room temperature was between 0.95 and 1.26 cP, except for COM (3.02 cP; p < 0.001). At 34 degrees C, the average viscosity of most solutions was between 0.70 and 0.83 cP, except for COM, which had a viscosity of 1.92 cP (p < 0.001). The un-neutralized peroxide solutions had very different pH and osmolality values from all the solutions that would directly contact the eye (p < 0.001). Their viscosity and ST values were similar (p = NS). This study detailed many physical properties of soft lens solutions that are not readily available and indicated that certain properties vary significantly among these products.

Multistate Outbreak of Fusarium Keratitis Associated With Use of a Contact Lens Solution

Multistate Outbreak of Fusarium Keratitis Associated With Use of a Contact Lens Solution

Fusariumkeratitis and contact lens wear: facts and speculations

Over the past several decades mycotic keratitis has been considered a rare sequel to hydrogel contact lens wear. In 2005--2006 an upswing in the incidence of Fusarium keratitis was associated with a disproportionate use of one multipurpose contact lens solution (MPS, ReNu with MoistureLoc, Bausch & Lomb, Rochester, NY). The MPS, as manufactured and marketed, was sterile and met regulatory guidelines for antimicrobial activity. A multivariant interaction of poor hygienic practices and the contact lens paraphernalia were associated with a mostly selective contamination in or on the lens storage case by members of the F. solani/F. oxysporum species complexes from the environment of the user. A decline of the anti-fusaria properties of the MPS in the lens case appeared related to its dissociation from drying, or dilution and the potential for sorption of antimicrobial solution components (e.g., alexidine) to various hydrogel lenses. These factors and capacities of the fusaria for rapid amplification by microcycle conidiation, production of dormant resistant cells, and potential for attachment and penetration of hydrogel lenses, were linked to the occasional selective fungal survival and growth during storage of the lens in MPS. Lack of a manual rubbing-cleaning step in the MPS disinfection process was considered a risk factor for keratitis.

Use of a Human Corneal Epithelial Cell Line for Screening the Safety of Contact Lens Care Solutions In Vitro

Sodium fluorescein permeability assay, alamarBlue assay, and scanning electron microscopy were performed to study the effects of various contact lens disinfecting multipurpose solutions (MPS) on the integrity of the ocular surface epithelium by using corneal epithelial cells. The sodium fluorescein permeability and alamarBlue activity of monolayer cultures of human corneal epithelial cells were compared after exposure to ReNu MultiPlus, OPTI-FREE Express, AQuify 5 Minute, SOLO-care Plus With Aqualube, and Complete Moisture Plus contact lens care solutions for 15 minutes. Additional cell monolayers were prepared for each treatment and were analyzed with a scanning electron microscope after a 10-minute exposure. The sodium fluorescein permeability assay, alamarBlue assay, and scanning electron microscopy showed that OPTI-FREE Express was significantly more damaging to the human corneal epithelial cell monolayer than ReNu MultiPlus, SOLO-care Plus With Aqualube, Complete Moisture Plus, and AQuify 5 Minute contact lens solutions. Cell monolayers treated with OPTI-FREE Express were more permeable to sodium fluorescein and showed lower metabolic activity than cell monolayers treated with the other multipurpose solutions. This experiment shows that ReNu MultiPlus, SOLO-care Plus With Aqualube, Complete Moisture Plus, and AQuify 5 Minute contact lens solutions have a minimal effect on human corneal epithelial cells in culture, whereas OPTI-FREE Express has a higher negative effect on tight junctions, cell membranes, and overall metabolism of these human corneal epithelial cells.

Effect of storage media on human periodontal ligament cell apoptosis

The ability of storage media to preserve periodontal ligament (PDL) cell vitality has been previously evaluated. However, the mechanisms by which different storage conditions alter the functional status of PDL cells have not been determined. The purpose of the present study was to investigate, in vitro, the level of programed cell death or apoptosis in a population of PDL cells following storage under different conditions. Primary human PDL cells were plated into 24-well-culture plates and allowed to attach for 24 h. Cells were then exposed for 1 h to milk, Hank's balanced salt solution (HBSS), Soft Wear contact lens solution or Gatorade at room temperature or on ice. Culture medium was used as a negative control. Apoptosis was evaluated at 24, 48, and 72 h after treatment on quadruplicate samples by using the ST 160 ApopTag Fluorescein Direct In Situ Detection Kit. The total number of cells and the total number of apoptotic cells were counted. The results indicated that at 24 and 72 h, PDL treated with Gatorade and the contact lens solution displayed the highest percentages of apoptotic cells when compared with the other treatment groups at room temperature. Overall, cells treated on ice showed significantly lower levels of apoptosis when compared with treatments at room temperature. In conclusion, the results indicated that apoptosis plays a major role in cell death in cells treated with Gatorade and contact lens solutions in comparison to other storage solutions and that storage on ice can inhibit programed cell death.

Differences Among Strains of the Fusarium oxysporum-F. solani Complexes in Their Penetration of Hydrogel Contact Lenses and Subsequent Susceptibility to Multipurpose Contact Lens Disinfection Solutions

To examine in vitro conditions for attachment and penetration of silicone hydrogel (SH) lenses by clinical isolates of the Fusarium oxysporum-F. solani complexes and the relative susceptibilities of the fusaria in the lens matrices to multipurpose contact lens solutions (MPSs). SH soft contact lenses were soaked in Sabouraud dextrose broth (SAB) for 2 hours and transferred to 3.0 mL of phosphate-buffered saline (PBS). The lenses were inoculated with representative isolates of both complexes and incubated on a shaker at ambient temperature. Lenses were examined daily by light microscopy before and after rinsing and rubbing in MPS. Selected lenses penetrated by fungi were rinsed and rubbed with MPS and held in MPS for 6 hours, transferred to PBS with 0.03% SAB, and examined daily. The degree and rate of lens penetration of contact lenses by isolates of the F. oxysporum-F. solani complexes varied with lens type and the strain. Isolates obtained from patients with Fusarium keratitis produced on and within lenses chlamydospores that seemed similar to those observed in lenses actually worn by patients when they developed Fusarium keratitis. Clinical isolates showed greater capacities than those of a standard test strain to penetrate lenses and to survive exposures to various MPSs. In general, isolates of F. solani were more readily removed from lenses by rubbing than were isolates of F. oxysporum. The ability of Fusarium spp. to attach to and penetrate SH lenses in vitro varies with the lens type and strain, and this ability may make infectious keratitis more likely. We recommend the incorporation of a rubbing step in the MPS disinfection of hydrogel lenses to reduce the risk of fungal keratitis.

An Outbreak of Fusarium Keratitis Associated With Contact Lens Use in the Northeastern United States

To report an outbreak of Fusarium keratitis in contact lens (CL) wearers in the northeastern United States. Over a 41-month period, all cases with culture-proven corneal ulceration secondary to Fusarium at 2 tertiary care eye centers were identified through the microbiology departments of each institution, and a retrospective review of charts was performed. Statistical analyses were performed to evaluate a possible association of Fusarium keratitis with specific CL and CL solution brands. Fifteen cases of Fusarium keratitis were reported at the 2 tertiary centers between July 2005 and May 2006 (16.4 cases/yr) compared with 6 cases over the previous 30 months from January 2003 to June 2005 (2.4 cases/yr). All 15 of the more recent cases were CL users, and none had a history of trauma. All 15 patients claimed use of ReNu brand contact lens solution when they developed keratitis. Twelve (80.0%) of 15 patients were Acuvue soft contact lens users. Ten (66.7%) of 15 patients used tap water to rinse their contact lens cases. Six (40.0%) of 15 cases have thus far required corneal transplantation. The incidence of corneal ulceration secondary to Fusarium has increased sevenfold over the reported 11-month period at 2 tertiary eye care centers in the northeastern United States compared with the previous 30 months. There seems to be an association between the recent outbreak of Fusarium keratitis among CL users and the use of ReNu contact lens solution. Medical treatment of Fusarium keratitis may be ineffective, and emergent penetrating keratoplasty (PKP) may be required in some patients. CL users and their physicians should reconsider the risks of CL use and discuss proper lens care techniques.

A Case Series of Contact Lens-Associated Fusarium Keratitis in Hong Kong

To report the clinical features and management outcomes of a cluster of Fusarium keratitis in patients that used the Bausch & Lomb ReNu MostureLoc contact lens solution. Retrospective case series. In a 1-year period starting from June 2005, we treated 12 patients with unilateral Fusarium keratitis in our tertiary care center. All patients were contact lens users that used ReNu MostureLoc contact lens solution and had no other specific predisposing conditions. Microbiological examination yielded growth of Fusarium spp. in 7 patients from corneal scrapings at presentation and from 3 patients in subsequent corneal specimens. For 2 other patients, fungi were not detected from corneal scrapings, but Fusarium spp. were isolated from their contact lenses. The infections were treated with topical natamycin and amphotericin B eye drops and with systemic itraconazole in 8 patients. The infection resolved with medical treatment in 8 eyes, a conjunctival flap in 1 eye, and a therapeutic corneal graft in 1 eye. Two eyes required tectonic corneal grafts for perforation. Two of the 3 corneal grafts failed because of graft rejection. Final visual acuities ranged from count fingers to 1.0. This cluster of Fusarium keratitis seems to be related to the use of the ReNu MoistureLoc contact lens solution. The cure rate with medical therapy was 66%. However, corneal scarring limited visual recovery. This episode highlights the need for clinical vigilance when dealing with corneal infiltrates in contact lens users.

Bilateral Simultaneous Infectious Keratitis Secondary to Contact Lens Wear: An Unusual Case Report With Rare Organisms

To report an unusual case of bilateral simultaneous hypopyon corneal ulcer in a contact lens wearer caused by polymicrobial infection with rare organisms. A case report of a 21-year-old soft contact lens wearer, who visited the emergency department with a 3-day history of pain, redness, decreased vision, photophobia, and tearing in both eyes. Examination showed a central corneal ulcer with hypopyon in both eyes. The cultures from corneal scrapings of both eyes, the contact lenses, and the contact lens solution showed heavy growth of Pseudomonas aeruginosa, Alkaligenes species, and Flavobacterium meningosepticum. The corneal ulcers healed completely with aggressive antibiotic treatment for 4 weeks. The best-corrected visual acuity after 6 months of follow-up was 20/400 in the right eye and 20/60 in the left eye. The possibility of infectious keratitis should be kept in mind for an acute red eye in contact lens wearers, and appropriate initial management is essential for a successful outcome. It is believed that this is the first report of Flavobacterium meningosepticum as a causative organism in contact lens-related keratitis.

Good Visual Outcome After Prompt Treatment of Acanthamoeba Keratitis Associated With Overnight Orthokeratology Lens Wear

To describe a patient with a good visual outcome after prompt treatment of Acanthamoeba keratitis as a complication of overnight orthokeratology lens wear. Interventional case report. A 9-year-old boy experienced pain, photophobia, and redness in his right eye 3 days after visiting a swimming pool. He had been wearing overnight orthokeratology lenses for 5 months for the correction of moderate myopia in both eyes. On examination, best-corrected visual acuity in the right eye was 20/40. A diagnosis of Acanthamoeba keratitis with the presence of the classic feature of perineural infiltrates was made. The patient responded well to treatment with polyhexamethylene biguanide and propamidine isethionate (Brolene). Culture of corneal scrapings and contact lens solution showed heavy growth of Acanthamoeba. Treatment was tapered gradually during the next 4 months, and the final best-corrected visual acuity was 20/25. Acanthamoeba keratitis may be a vision-threatening complication associated with overnight orthokeratology lens wear. It is essential for eye care professionals to fully explain and warn parents of the potential downsides that may be associated with orthokeratology. Ophthalmologists should have a high level of suspicion of this complication because prompt diagnosis and treatment can result in good visual outcome.

Attachment to and Penetration of Conventional and Silicone Hydrogel Contact Lenses by Fusarium solani and Ulocladium sp. In Vitro

To analyze the relative capacities of Fusarium solani and Ulocladium sp. to attach to and penetrate silicone hydrogel soft contact lenses. Representative silicone hydrogel (SH, siloxy complexes) and conventional [hydroxyethylmethylacrylate (HEMA)] soft contact lenses were exposed to suspensions of F. solani and Ulocladium sp. in vitro (10 conidia/mL in phosphate-buffered saline). The lenses were incubated with shaking at ambient temperatures and examined after rinsing in a multipurpose contact lens solution (MPS) by light and scanning electron microscopy. Isolates of both genera firmly attached to and penetrated both lens types, but Ulocladium sp. did so in greater density and more rapidly than F. solani. The extent of firm attachment and time needed for penetration into the lenses varied with strain and substratum, particularly with the isolates of F. solani. Morphologic characteristics (eg, penetration pegs, microcycle conidiation, and chlamydospores) of F. solani in the SH and HEMA lenses were similar to those observed in several lenses from patients with ReNu with MoistureLoc (RML)-associated Fusarium keratitis. To our knowledge, this is the first report that F. solani produces coiled penetration pegs in the matrices of SH hydrophilic soft contact lenses similar in morphology to those found in HEMA lenses. F. solani attaches firmly to SH lenses and rarely penetrates the lens matrix, but viable fungal propagules may remain on the lens after vigorous rinsing with MPS. Failure to use a manual cleaning-disinfection procedure may help to explain the increased incidence of Fusarium keratitis associated with contact lens wear.

The Association of Contact Lens Solution Use and Acanthamoeba Keratitis

To investigate Acanthamoeba keratitis (AK) risk factors. Diagnosis of AK, a rare but serious corneal infection, has recently increased significantly at the University of Illinois at Chicago (UIC) Cornea Service. Retrospective case-control study. settings: University, tertiary care hospital. patients: Fifty-five AK cases with contact lens use were diagnosed between May 1, 2003 and September 15, 2006. Clinic-matched controls with contact lens use were recruited. Subjects completed surveys targeting lens hygiene, contact lens solution use, and water exposure. main outcome measure: Acanthamoeba keratitis. Thirty-nine (73.6%) cases and 113 (65.3%) controls participated; 38 cases had complete contact lens data. Thirty-five of 38 cases (92.1%) and 47 of 100 controls (47.0%) used soft lenses. Analysis was performed on 30 cases and 39 controls with matched pairs with soft lens use. Exclusive use of Advance Medical Optics (AMO) Complete MoisturePlus Multi-Purpose Solution was independently associated with AK in multivariable analysis (55.2% vs 10.5%; odds ratio [OR], 16.67; 95% confidence interval [CI] 2.11 to 162.63; P = .008). However, 38.8% of cases reported no use of AMO Complete MoisturePlus Multi-Purpose Solution either alone or in combination with other solutions. Although not statistically significant, additional hygiene-related variables (solution "reuse," lack of "rubbing," and showering with lenses) suggest a pattern of risk. AMO Complete MoisturePlus Multi-Purpose Solution use is independently associated with AK among soft contact lens users. However, it does not explain all cases, suggesting additional factors. Further research into environmental risk factors and hygiene practices is warranted, especially considering this is the second outbreak of an atypical, contact lens-related infection.

Allergic contact dermatitis from ophthalmics: 2007

We previously reviewed allergic contact dermatitis due to ophthalmic drugs and contact lens solutions. Since 1997, an additional 15 allergens have been reported. Here, we provide a review and discussion of these allergens.

Efficacy of contact lens storage solutions against trophozoite and cyst of Acanthamoeba castellanii strain 1BU and their cytotoxic potential on corneal cells

Acanthamoeba is a free-living amoeba causing a potentially blinding infection of the cornea. Contact lens wearers are most at risk and account for about 95% of cases. We investigated the in vitro effectiveness of 10 contact lens solutions against Acanthamoeba castellanii and their cytotoxicity on corneal cells in vitro. Contact lens solutions were evaluated for their amoebicidal activities using an inverted light microscope. To determine of their cytotoxicity on corneal cells, agar diffusion tests were performed. According to the results obtained from the tests, AVIZOR Aqua Soft Comfort and Elegance(R) showed the best amoebicidal effect on A. castellanii trophozoites. Cysts were still viable after overnight (8 h) exposure. In the case of the cyctotoxic acitivities, All In One Light, Astek, SOLO-Care Aqua, Maxima, and Horien showed no cytotoxicity on the corneal cells. ReNu MultiPlus, AVIZOR Aqua Soft Comfort, Carrera, and Elegance showed mild cytotoxicity on the corneal cells. Plurisol.M presented moderate cytotoxicity on the corneal cells. All commercial solutions examined in this study are the lack of efficacy against A. castellanii. Improvement or development of new contact lens disinfecting systems by the manufacturers is needed to prevent Acanthamoeba keratitis.