‘Zero 6'Extra Thin Soft Contact Lenses: Report on Clinical Trials

Abstract

The development of micro‐thickness soft contact lenses to increase available oxygen to the cornea beneath the lens has exposed new problems for the patients in lens handling and lens durability. A newly designed lathe‐cut lens of only 0.06mm centre thickness, known as Zero 6, has been developed to overcome problems of shape stability and increase lens durability.The results of a clinical trial conducted on 410 patients over a period of 15 months are reported. The results showed the lens to be well tolerated by the eye and easily handled by the patient. A low breakage rate of 1.7% confirmed that the lens plastic has the durability required of micro‐thickness lenses. A new approach to the prescribing of the lens based on sagittal height showed good correlation with tolerance data from the trial. Ninety‐three percent of patients were successfully fitted with the lenses recommended by the manufacturer's Indicated Lens Table, based on mean keratometer reading and horizontal visible iris diameter. Two percent of patients were not satisfactorily fitted and 6.6% required lenses different to those recommended.