WO1992006716A1

WO1992006716A1 - Contact lens cleaning means

Info

Publication number: WO1992006716A1
Application number: PCT/GB1991/001777
Authority: WO
Inventors: Victor Anthony Ifejika
Original assignee: Victor Anthony Ifejika
Priority date: 1990-10-12
Filing date: 1991-10-11
Publication date: 1992-04-30
Also published as: GB9022233D0

Abstract

A cleaning solution comprising a saline solution and a surfactant is used in conjunction with an electromechanical device in an agitational procedure for cleaning contact lenses. After the cleaning cycle is complete, the cleaning solution is discarded and rinsing is carried out in a fresh saline solution, preferably once only.

Description

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This invention relates to the use of proprietary contact lens solutions, which are utilized as described in the method of the invention, to effect the superior cleaning of contact lenses when used in conjunction with electro-mechanical contact lens cleaning devices.

Generally, there are two solutions required for the cleaning of contact lenses. These are, a concentrated surfactant solution and a sterile saline solution. The surfactant is a cleaning solution and is usually applied from a plastic container designed to dispense the surfactant in droplets, each droplet being sized in the range of from 0.025 to 0.10 ml. The saline is a rinsing solution and is usually applied from an aerosol can, enabling the saline to remain sterile so that fresh saline is dispensed with each application.

Contact lenses are often conventionally cleaned by a person manually applying the surfactant and saline solutions to the lenses for the removal of surface deposits thereon. This procedure is often referred to as a manual cleaning regimen and is usually performed on a daily basis.

In the conventional method of cleaning contact lenses, approximately 3 droplets of surfactant solution are applied to each surface of the first lens which is rubbed gently between thumb and forefinger for 15 to 20 seconds. The lens is then placed in the palm of one hand where re-iterations of applying saline solution and gently rubbing with the forefinger of the other hand are repeated until the surfactant has been rinsed off the surfaces of the lens. The above procedure is again carried out on the second contact lens.

The conventional method of cleaning contact lenses can lead to the lenses becoming infected if a person with dirty hands manually applies the surfactant and saline solutions to the lenses. The conventional method of cleaning contact lenses can lead to accidental tearing or loss by a person mishandling the lenses. The conventional method of cleaning contact lenses can become tedious, making it difficult for the person manually performing the regimen to comply with the regimen and to maintain consistent cleaning results. Generally there will be a temptation for the procedure to be carried out insufficiently frequently and incompletely.

It is an object of the present invention to enable all of the above problems to be obviated or substantially reduced and to provide a cleaning regimen which can be efficiently carried out.

Accordingly, in one non-limiting aspect of the present invention, there is provided a cleaning solution for cleaning contact lenses which comprises a saline solution and a surfactant, the surfactant being in a dilute concentration in the saline solution, and which cleaning solution is present in a single container. In a second non-limiting aspect of the present invention, there is provided a kit of agents for use in the cleaning of contact lenses, the kit comprising a first container containing a sterile saline solution, a second container containing a concentrated surfactant solution, and an electro-mechanical agitational device. In a third non-limiting aspect of the present invention, there is provided a method of cleaning contact lenses which includes a method of preparing a cleaning solution for cleaning contact lenses, which cleaning solution comprises a mixture of saline solution and surfactant, the surfactant being in a dilute concentration in the saline solution, and which cleaning solution is placed in a receptacle together with the lenses to be cleaned; cleaning the lenses by subjecting the contents of the receptacle to electro-mechanical agitation, ceasing the agitation, discarding the mixture of saline solution and surfactant from the receptacle and introducing fresh saline solution into the receptacle; rinsing the lenses by subjecting the contents of the receptacle to electro-mechanical agitation, ceasing the agitation and obtaining the contact lenses.

In the method of the invention, the cleaning solution preferably comprises a saline solution and a surfactant, the surfactant being in a dilute concentration in the saline solution. However, the surfactant may alternatively be diluted by a diluent which is not the saline solution and may be for example a disinfectant solution.

The method of the invention is in fact particularly suited to use with an electro-mechanical agitational device. Although several such devices are commercially available, preferred is the electro-mechanical agitational device according to 089/00429. Here, the contents of the receptacle are subjected to combined vibration and reciprocating agitational motion in a linear or rotary sense. More specifically, there is described and claimed in 089/00429; a cleaning apparatus for cleaning contact lenses, comprising: an electrically operated motor; a support arm; vibration generating means operating within a frequency range of 10 to 100 Hz, preferably 20 to 45 Hz, more preferably 35 to 45 Hz; tank means for receiving contact lens cleaning fluid, and a contact lens holder for insertion therein of at least one contact lens, the interior of the contact lens holder communicating with the interior of the tank means to enable unimpeded transfer of cleaning fluid to take place therebetween; in which apparatus, the contact lens holder is directly coupled to said motor by means of the support arm and the support arm is drivable by the motor thereby to impart reciprocating motion to the holder in a rotational or linear sense and said vibration generating means is operable during said reciprocating motion such that the at least one contact lens is subject to both said motions simultaneously. When performing the method of the invention in conjunction with an electro-mechanical agitational device according to W089/00429, the contact lenses may be cleaned for between 30 and 120 seconds prior to rinsing. Preferably the contact lenses are cleaned for 60 seconds and rinsed for 30 seconds.

In the method of preparing a cleaning solution, the volume of surfactant required to clean both lenses is equivalent to the volume of surfactant recommended for the cleaning of one lens in the manual cleaning regimen. The surfactant may be present in a concentration of from 0.10 to 1.00 ml of surfactant per 5.00 ml of saline solution. A presently preferred concentration is 0.25 ml of surfactant per 5 ml of saline solution, representing a 1:20 ratio which may typically be obtained by using 6 droplets of surfactant per 5 ml of saline solution. It is explained that the value of 5 ml of saline solution is used because this the amount of saline solution preferred for lens cleaning purposes. If the surfactant is present in higher concentrations, the cleaning efficiency of the cleaning solution is increased; however the lenses will require 2 rinses instead of the single rinse which is preferred. As each rinsing requires 5 ml of fresh saline solution a single rinsing will be more economical in the use of saline solution.

In a further operating step, the contact lenses may be disinfected. This step being unnecessary should the surfactant have been diluted in a diluent which is a disinfectant solution. The saline may be any commercially available saline solution formulated for the rehydration and rinsing of contact lenses. Preferably the saline solution comprises preservative-free sodium chloride and deionised water. Such a saline solution can be obtained in sterile form under the Trade Mark LENS PLUS.

The surfactant may be any commercially available surfactant which has been formulated for the cleaning of contact lenses and the removal of surface deposits thereon. Preferably the surfactant comprises a cleaning agent, a solvent, a colleting agent, sodium chloride and deionised water. Such a surfactant can be obtained in concentrated form under the Trade Mark MIRA LOW.

The invention will now be illustrated with reference to the following Examples:

EXAMPLE I 0.25 ml of MIRAFLOW surfactant was applied into a receptacle followed by 5 ml of LENS PLUS saline solution. A pair of contact lenses were inserted into a lens retaining apparatus and the lens retaining apparatus placed into the receptacle such that the lenses were immersed in the solution and the receptacle sealed. The sealed receptacle was attached to an electro-mechanical agitational device which subjected the contents of the receptacle to a combination of vibration and reciprocated agitational motion for 60 seconds, thereby cleaning the lenses. The agitation was stopped, the receptacle detached from the electro-mechanical agitational device and the lens retaining apparatus removed in order to discarrd the mixture of surfactant and saline solution now contaminated by impurities from the lenses.

5 ml of fresh LENS PLUS saline solution was then applied into the receptacle and the lens retaining apparatus replaced into the receptacle such that the lenses were immersed in the solution and the receptacle sealed. The sealed receptacle was attached to the electro-mechanical agitational device which subjected the contents of the receptacle to combined vibration and reciprocated agitational motion for 30 seconds, thereby rinsing the lenses. The agitation was stopped, the receptacle detached from the electro-mechanical agitational device and the lens retaining apparatus removed in order to obtain the lenses.

The obtained lenses were found to be extremely clean and they tended to sparkle when viewed. The obtained lenses were able to be worn without any eye irritation and possessed good clarity.

EXAMPLE II The pair of contact lenses cleaned by the method of Example I, were compared with a similar pair of contact lenses which had been cleaned in the conventional method, by the manual application of the MIRAFLOW surfactant and the LENS PLUS saline solutions.

The lenses cleaned by the method of Example I appear to be sparkling clean and cleaner than those cleaned in the convention method. Also, the lenses cleaned by the method of Example I possessed better clarity and could be worn for a longer duration with far less eye irritation than those cleaned in the conventional method. Moreover in the method of Example I, the lenses were cleaned in a sealed and sterile environment which avoided the risk of contaminating the lenses or tearing or losing the lenses, which risk was present during the manual handling of the lenses to apply the MIRAFLOW surfactant and LENS PLUS saline solutions.

EXAMPLE III In the method of Example I, a further distinction lay in the economic use of the MIRAFLOW surfactant and LENS PLUS saline solutions. It was found that the MIRAFLOW surfactant used in Example I, was able to be very considerably reduced in both volume and concentration over that required by the conventional method; whilst still yielding better cleaning results. It is explained that a surfactant possesses high viscosity and astringency by composition and it is the residues of surfactant remaining on the lenses which contribute to the eye irritation and fatigue suffered by many contact lens wearers. In the method of Example I, it was found that the dilution of the surfactant coupled with thorough rinsing avoided the risk of surfactant remaining on the lenses, which risk was present during the manual handling of the lenses to apply the MIRAFLOW surfactant and LENS PLUS saline solutions.

The enhanced cleaning in Example 1 was concluded to be due to the specifically formulated concentration of cleaning solution used during the cleaning operation. The cleaning solution provided a suitable medium in which the lenses could achieve rapid movement and be thoroughly washed therein. In addition, the cleaning solution proved simple to prepare, convenient to use and considerably more economic in the use of the MIRAFLOW surfactant and LENS PLUS saline solutions, whilst yielding better cleaning results than by conventional means and also yielding better cleaning results than other cleaning solutions currently used with electro¬ mechanical cleaning devices.

Claims

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1. A cleaning solution for cleaning contact lenses which comprises a saline solution and a surfactant, the surfactant being in a dilute concentration in the saline solution, and which cleaning solution is present in a single container.

2. A solution as claimed in claim 1 which contains from 0.10 to 1.00 ml of surfactant per 5 ml of saline solution.

3. A solution as claimed in claim 1 or 2, which additionally contains a disinfectant.

4. A solution as claimed in any one of claims 1 to 3, wherein the surfactant comprises a cleaning agent, a solvent, a colleting agent, sodium chloride and deionised water.

5. A kit of agents for use in the cleaning of contact lenses, the kit comprising a first container containing a sterile, preservative-free saline solution, a second container containing a concentrated surfactant solution, and an electro-mechanical agitational device.

6. A kit claimed in claim 5, wherein the surfactant comprises a cleaning agent, a solvent, a colleting agent, sodium chloride and deionised water.

7. A kit as claimed in claim 5 or 6, wherein the surfactant is diluted by a saline solution or by a disinfectant solution.

8. A method of preparing a cleaning solution for cleaning contact lenses, which cleaning solution comprises a saline solution and a surfactant, the surfactant being in a dilute concentration in the saline solution.

9. A method as claimed in claim 8, wherein the cleaning solution contains from 0.10 to 1.00 ml of surfactant per 5 ml of saline solution.

10. A method as claimed in claims 8 or 9, wherein the cleaning solution additionally contains a disinfectant.

11. A method of cleaning a contact lens wherein a cleaning solution is provided, and which cleaning solution is placed in a receptacle together with the lens to be cleaned; cleaning the lens by subjecting the contents of the receptacle to electro-mechanical agitation, ceasing the agitation and discarding the saline and surfactant solution from the receptacle, introducing fresh saline solution into the receptacle and rinsing the lens by subjecting the contents of the receptacle to electro-mechanical agitation, ceasing the agitation and removing the lens from the receptacle.

12. A method as claimed in claim 11, wherein agitation of the lenses is carried out for from 30 to 120 seconds.

13. A method as claimed in claims 11 to 12, wherein the lenses are subjected to a combination of vibrational and agitational motion at a frequency of from 5 to 100 Hz, more preferably 40 to 60 Hz.