Soft Lens Solutions Research Articles

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.

Effectivity of Contact Lens Disinfection Systems Against Acanthamoeba culbertsoni

Thirteen commercially available contact lens solutions were tested for their ability to kill the cysts of Acanthamoeba culbertsoni. Miraflow, which contains 20% isopropyl alcohol, was the most effective at killing the cyst (94%), followed by solutions containing thimerosal (89%). The rigid gas permeable lens solutions in general were more effective than soft lens solutions. None of the solutions tested were completely cidal, but our data do suggest a combination of a good daily cleaner and disinfecting solution may be effective in reducing acanthamoeba exposure. These findings should provide guidelines for the practitioner in selecting the best disinfection system for the contact lens patient.

Contact urticaria from papain in a soft lens solution

Contact urticaria from papain in a soft lens solution

Conjunctivitis due to soft lens solutions.

In cases of conjunctivitis associated with the use of soft lenses, delayed hypersensitivity to disinfecting components of the used soft lens liquids has to be considered. In 7/15 patients, positive patch test reactions to merthiolate, chlorhexidine or the soaking solutions were observed. The significance of these findings is discussed.

Some microbiological problems with softlens solutions

Some microbiological problems with softlens solutions

A Preliminary Study of The Effect of Soft Lens Solutions on The Bcor of Soft Contact Lenses

The importance of environmental influences on soft lenses is briefly discussed. An in vitro study of the effects of two soft lens soaking solutions, Hexidin and Hydrocare, on the BCOR of three types of lenses, Hydron single curve (Contavue), Soflens (Bausch and Lomb) and Menicon 1500 (Toyo) was carried out. It was found that the storage solutions caused flattening of the lens BCOR. The effects were found to be greater for Hydrocare than Hexidin and greater for Menicon, less for Hydron and least for Soflens. The effects, at least under the conditions of this in vitro study, were reversible.

Influence of Soft Contact Lens Solutions on Rabbit Corneae

Different soft lens solutions were tested in animal experiments for their toxicity. The electron microscopic examination revealed corneal damage of considerable degree in each instance. It is suggeste