A prospective multicenter clinical trial to assess safety and efficacy of Menicon SF-P RGP lenses for extended wear

A prospective, multicenter, national clinical trial was undertaken to assess the safety and efficacy of Menicon SF-P (melafocon A) rigid gas permeable (RGP) contact lenses for extended wear in healthy human eyes. Ten investigators enrolled 167 patients (334 eyes), of which 143 (286 eyes) were initially fit with lenses for the 12-month study. Most subjects were reexamined at 18 months or more, with findings essentially unchanged from those noted at 1 year. Two hundred-two eyes (71%) completed the study. Seventy-two eyes (25%) discontinued, and 12 (4%) elected to continue extended wear. During the study, no significant adverse clinical reaction attributable to the lens was observed. Surface irritation, occasional punctate staining, and lens binding were very rare. The average wearing time was 6.2 days, mandated partially by FDA restrictions as well as patient response. As expected, keratometric shifts were principally vertical: less than 0.99 D (69%), 1.00-1.99 D (28%), and 2.00-2.99 D (4%). The majority of changes observed were toward sphericity. Two hundred lens replacements were required, 24% for adjustments in power/base curve. Only 16 lenses were replaced for warpage, and none for discoloration or crazing. Of those completing the study, 76% rated overall lens comfort and satisfaction to be very good. These results suggest that RGP lens extended wear can be safe and effective and offer patients an acceptable alternative to extended wear of disposable hydrogel lenses.