contact lens care
Coming Out of the Fog With GP Solutions
BY JENNIFER L. SMYTHE, OD, MS, FAAO

In a busy practice, it can be difficult to take the time to consider forming new habits. The care system we automatically select for gas permeable patients is a prime example of one of those habits. The contact lens industry is in a process of dynamic change with new formulations of all of our favorite systems as well as the introduction of new products. Oftentimes we look at these newer products as problem solvers rather than our system of first choice. However, if a product is powerful enough to solve problems ­ maybe we should be considering it more often as our first in line for dispense.

Figure 1. Surface "fog" on a FSA lens

Foggy Lenses

Maintaining a clean, wettable surface is key in successful GP wear. Unfortunately, surface drying and deposition can compromise the superior optics of GP lenses. This compromise often leads to complaints of intermittent or persistent blur and the perpetual "fogging" that we often hear our GP patients describe. There is no question that the majority of new GP lenses dispensed are manufactured from fluorosilicone/acrylate (FSA) materials. These fluorinated materials have many positive qualities, including oxygen permeability, machineability, stability and wettability. FSA materials also have a lower propensity for protein deposition. However, in certain individuals, our work-horse materials can be lipophilic. These patients present with waxy, greasy films and areas of non-wetting on the lens surfaces. There are many sources of these lipid deposits, including cosmetics, face and hand creams, soaps and even normal meibomian gland secretions. The use of a lens care system that incorporates an overnight soak in a surfactant is an effective means of both solving the problem of lens fogging and also preventing these deposits in the first place

	Figure 2. A combination of a digital rub and an overnight soak in the Lobob Optimum C/D/S emulsifies these deposits.

One such system is Optimum by Lobob (Lobob Laboratories, Inc.). With proper instruction this system is easy to use and does provide a very clean and wettable lens surface. Patients simply perform a digital surfactant rub initially with either the Cleaning/Disinfecting/Storing (C/D/S) solution or the Extra-Strength Cleaner (the difference is the concentration of the ingredients), then an overnight soak in the C/D/S further dissolves deposits. In the morning patients rinse the C/D/S off with saline and then use a few drops of the Wetting/Rewetting drops on the lens prior to insertion.

Another advantage of Optimum is the non-sensitizing preservative that is used in both the C/D/S and the Wetting/ Rewetting drop: purified benzyl alcohol. Benzyl alcohol is a bipolar molecule with a low order of polarity, therefore; it has little interaction with the lens surface. This is important because it has negligible binding to the lens surface and is less likely to cause another type of "fog:" foggy corneas.

Dr. Smythe is an associate professor of optometry at Pacific University and in private group practice in Beaverton, Oregon.