New Cleaning System for Heavy Depositors

BY ROBERT CAMPBELL, M.D. & PATRICK CAROLINE, C.O.T., F.A.A.O.
OCT. 1997

Frequent replacement soft contact lens systems have dramatically reduced many of the complications seen with traditional yearly replacement lenses. Despite this, some patients still experience problems with surface deposition. This is borne out in electron microscopy studies by Fowler et al. which show that a variety of deposits attach to the surfaces of hydrogel lenses in as little as eight hours.

To reduce surface contamination, manufacturers have developed new lens care systems and deposit-resistant polymers, while practitioners have emphasized patient education, and have prescribed frequent lens replacement systems more often.

THE FRUSTRATIONS OF A COMPLIANT PATIENT

This month's case history involves a 32-year-old woman with a seven-year history of daily wear, custom toric soft contact lenses. Her present lenses are OD +5.25 -3.75 x 005; OS +4.75 -3.50 x 170, and are manufactured in a methafilcon A, 55 percent water material. The patient wears her lenses 14 hours a day and her visual acuity is stable at 20/30 OU. She disinfects her lenses nightly with a preservative-free hydrogen peroxide system. Despite diligent surfactant and enzymatic cleaning, new lenses were significantly spoiled within two to three months (Fig. 1).

FIG. 1: PATIENT'S RIGHT LENS AFTER THREE MONTHS OF DAILY LENS WEAR.

FIG. 2: THE CLEANER ACCESSORY PADS (EATON MEDICALS CORP.)

We recommended that the patient try The Cleaner Accessory (Eaton Medicals Corp., Memphis), a weekly disposable foam pad designed to enhance the nightly digital cleaning process (Fig. 2). After wetting the pad with preservative-free saline followed by six to eight drops of daily cleaning solution, the patient places a lens on the tip of the thumb or index finger and rubs it on the pad for 20 seconds, then rinses the lens thoroughly with saline and disinfects.

THE 30-DAY CHALLENGE

To test the efficacy of the cleaning pad, we ordered two identical lenses for the patient's right eye. Figure 3 illustrates scanning electron microscopy results on the anterior lens surface after one month of daily wear with a traditional in-the-palm cleaning technique. Figure 4 shows the second lens after one month of daily wear with nightly use of The Cleaner Accessory pad. In both cases, the patient used the same preservative-free hydrogen peroxide system for nightly disinfection with weekly enzyme cleaning.

FIG. 3: SEM 500X ANTERIOR LENS SURFACE AFTER ONE MONTH OF IN-THE-PALM CLEANING.

FIG. 4: SEM 500X ANTERIOR LENS SURFACE AFTER ONE MONTH OF FOAM PAD CLEANING.

This case illustrates the potential of an auxiliary cleaning pad to augment a patient's cleaning regimen. We have found this system to be helpful in deposit-prone individuals wearing custom soft contact lenses with parameters outside the ranges of present daily disposable or frequent replacement systems. The cleaning pad has also been helpful for individuals prone to surface deposition between frequent replacement schedules. CLS

Dr. Campbell is medical director of the Park Nicollet Contact Lens Clinic & Research Center, Minnetonka, Minn. Patrick Caroline is an assistant professor of optometry at Pacific University, Forest Grove, Ore., and director of contact lens research at Oregon Health Sciences University in Portland.