Purchase this article with an account.
Nicole A. Carnt, Mark Willcox, Scott Hau, John Dart, Cherry Radford, Victoria Evans, Fiona Stapleton; Enhancing Recruitment In Studies Involving Collection Of Genetic Material From Contact Lens Wearers. Invest. Ophthalmol. Vis. Sci. 2011;52(14):1476.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Buccal swabs are a convenient method to obtain DNA for genetic analysis, however, compliance and concerns about security of the sample are likely to decrease study participation. This study aims to determine what factors predict whether contact lens wearers will collect a buccal swab sample for genetic analysis in a contact lens wear population.
1052 contact lens wearers who attended Moorfields Eye Hospital during 2003-2005 and participated in a case control study of the risk factors for keratitis were invited to collect a buccal swab sample with a letter. Buccal swabs and instructions were mailed to wearers along with postage paid envelopes to return the samples following consent. The recruitment sample consisted of 366 cases of microbial keratitis, 241 cases of sterile keratitis and 445 other conditions. Non-responders were followed up by phone after a minimum of 2 weeks. Age, gender, type of condition and phone follow up, were investigated for association with swab return with chi square, t-test and regression.
Contact lens wearers that returned swabs were older than those who did not (37.5±11.6 vs 30.9±8.7, p<0.01), however, there was no difference in gender (p=0.9). Although a greater proportion of microbial cases returned swabs compared to sterile keratitis and other conditions (63, 17.2% vs 27, 11.2% vs 53, 11.9%, p=0.04), a higher number of microbial cases were followed up by phone (54, 14.8% vs 8, 3.3% vs 23, 5.2% p<0.01). Regression indicated age (p<0.01) and phone follow up (p=0.01) were the only independent factors predicting swab return.
Postal recruitment with supplementary phone follow up is an effective way to collect buccal swab samples in a retrospective case control study of contact lens associated keratitis. Type of condition does not appear to influence participation. Further investigation into different strategies, such as SMS and email that may increase involvement of young contact lens wearers is warranted.
This PDF is available to Subscribers Only