Electronic liquid crystal lenses for the correction of presbyopia

Abstract

Purpose: Over the past 20 years, many studies have reported the success of multifocal contact lenses (MFCLs) compared to monovision (MV), with only partial success being reported for MFCLs. Chronologically it appears there has been a gradual improvement in the performance of MFCLs. This study investigated whether this change in success is reflected in clinical practice. Method: Lens fit data collected from 2005 to 2009 by the International Contact Lens Prescribing Survey Consortium was reviewed for patients over 45 years old. A similar survey conducted from 1988 to 1989 was also reviewed and compared. Twelve published (Pubmed.gov) reports of clinical trials involving MFCLs and MV were reviewed to assess their relative performance over this time in controlled clinical studies. Results: 16,680 presbyopic lens fits in 38 countries were reviewed. 29% of fits were with MFCLs, 8% MV and 63% single vision (SV). This compared to 9% with MFCLs, 29% MV and 63% SV in the previous survey conducted in Australia during 1988-89. The ICLPSC results from Australia alone were 28% MFLCs and 13% MV, suggesting a substantial increase in usage of MFCLs over 20 years. The literature review indicates the reported level of visual acuities (VA) with MFCLs compared to MV has remained equivalent over this time period, yet clinical preference has switched fromMV to MFCLs. Conclusions: In 2010, more MFCLs than MV are being fit to presbyopes as compared to 1988–1989. This increased usage is possibly due to their improved visual performance, although reported VA do not appear to have changed. This suggests that patient-based subjective ratings are currently more representative of visual performance than VA.