2009-12, Bowden, Tim, Nosch, Daniela, Harknett, Tony

Introduction: This study investigated the modality, type and duration of contact lens wear as well as compliance and hygiene related issues (hand and case hygiene, use of tap water, dozing and overnight wear) in the UK and Germany. Questionnaires were collected anonymously from 417 UK and 767 German patients attending optometric practices for contact lens appointments. It is the seventh of a series of contact lens wearer profiles conducted since 2000. Results: The proportion of rigid gas permeable lenses worn was significantly higher at 55.4% in Germany, compared to 16.1% in the UK. Overall, a significantly larger proportion of German participants used tap water to rinse their lenses and cases (P < 0.001). Also, German respondents changed their lens cases less frequently (p < 0.001). Fewer UK than German respondents stated they washed their hands before lens insertion (p = 0.009), removal (p = 0.01), before eating (p < 0.001). German participants were less likely to wash their hands before preparing food (p = 0.042) and after using the toilet (p = 0.002). The two sample groups differed significantly regarding the care regimens they used for their CLs (p < 0.001). Conclusion: The differences between Germany and the UK highlighted in this study were caused by differences in legal regulations, plumbing and practitioners’ guidance. Although many of the questions relating to hygiene differed statistically between the two participating sample groups, the absolute differences in figures were not considered to be large.

2007-09, Nosch, Daniela, Mavrikakis, Ioannis, Morris, Judith, Ong, Gek L.

Purpose: To explore the success of the application of a computerised videokeratography (CVK) software system for the fitting of rigid gas permeable (RGP) contact lenses (CLs) on irregular corneal surfaces and compare it to the standard diagnostic fitting procedure. Methods: This was a comparative prospective study, over a 1-year period (2004–2005). It included 41 RGP CL wearers (68 eyes) with irregular corneal surfaces. Of these, 51 (75%) had keratoconus, 7 (10%) corneal scarring (infectious or traumatic), 6 (6.82%) corneal transplants, 2 (2.9%) astigmatism, and 2 (2.9%) aphakia. Each eye was being re-fitted with a new RGP CL based on a topographical measurement in conjunction with a CL fitting software programme. The performance of the CLs was evaluated regarding visual outcome, fitting characteristics, and efficiency of the fitting procedure. Results: Of the 68 eyes, 53 (77.94%) chose the CL fitted using the CVK software system, 9 (13.24%) chose the CL fitted using the standard procedure, and 6 (8.82%) showed no preference for either CL. There was a statistically significant improvement regarding visual outcome [contrast sensitivity at the spatial frequencies of 0.66 ( p = 0.029), 3.40 ( p = 0.008), and 17 ( p = 0.032), subjective vision ( p = 0.009)], fitting characteristics [grading scale ( p = 0.00), lens comfort ( p = 0.00) and daily wearing time ( p = 0.002)], and efficiency [number of trial lenses required ( p = 0.00)] with the CL fitted using the CVK software system. Correlating factors for the likely preference for the CL fitted using the CVK software system were subjective vision ( p = 0.004), lens comfort ( p = 0.009), and convenience of the fitting procedure ( p = 0.023). Conclusion: The application of a CVK software system for the fitting procedure of RGP CLs on irregular corneal surfaces was a safe procedure and shown to be more successful and efficient than the standard diagnostic fitting method.