To determine the usefulness of a battery of potential vision tests (PVTs) including potential acuity meter (PAM), laser interferometer (LI), critical flicker/fusion frequency (CFF), superilluminated pinhole at distance (SPH(d)) and near (SPH(n)), and optimal reading speed (ORS) by their independence of the effects of cataracts and sensitivity to macular disease (MD). Department of Optometry, University of Bradford, Bradford and Leeds General Infirmary, Leeds, United Kingdom. Potential vision test measurements were determined in 76 patients with age-related cataract and no other eye disease, 52 patients with MD and clear ocular media, and 28 patients with normal, healthy eyes. Potential vision tests were independent of the degrading effects of cataract up to a visual acuity (VA) level of 20/200 or worse (CFF), 20/125 (ORS and SPH), and 20/40 (PAM and LI). A high degree of association was found between PVT scores and distance VA in the MD group for SPH(d) (r2 = 0.93), SPH(n) (r2 = 0.89), and PAM (r2 = 0.71). A moderate correlation was found for LI (r2 = 0.55), CFF (r2 = 0.50), and ORS (r2 = 0.45). Potential acuity meter and LI showed very limited independence to moderate/dense cataracts and inaccurate predictions in patients with MD. Superilluminated pinhole was relatively unaffected by moderate/dense cataract and yet provided accurate predictions in the presence of MD and clear ocular media. Critical flicker/fusion frequency showed the greatest ability to bypass cataracts, although its ability to predict VA in patients with early MD was limited. The ORS was relatively unaffected by moderate/dense cataract, but its poor ability to predict VA in MD may limit its clinical suitability as a PVT.
1 May 2010 in Investigative Ophthalmology & Visual Science
Purpose.: To evaluate whether the Amblyopia and Strabismus Questionnaire (A&SQ) is a suitable instrument for the assessment of vision-related quality-of life (VR-QoL) in individuals with strabismus and/or amblyopia. Methods.: The A&SQ was completed by 102 individuals, all of whom had amblyopia, strabismus, or both. Rasch analysis was used to evaluate the usefulness of individual questionnaire items (i.e., questions); the response-scale performance; how well the items targeted VR-QoL; whether individual items showed response bias, depending on factors such as whether strabismus was present; and dimensionality. Results.: Items relating to concerns about the appearance of the eyes were applicable only to those with strabismus, and many items showed large ceiling effects. The response scale showed disordered responses and underused response options, which improved after the number of response options was reduced from five to three. This change improved the discriminative ability of the questionnaire (person separation index increased from 1.98 to 2.11). Significant bias was found between strabismic and nonstrabismic respondents. Separate Rasch analyses conducted for subjects with and without strabismus indicated that all A&SQ items seemed appropriate for individuals with strabismus (Rasch infit values between 0.60 and 1.40), but several items fitted the model poorly in amblyopes without strabismus. The AS&Q was not found to be unidimensional. Conclusions.: The findings highlight the limitations of the A&SQ instrument in the assessment of VR-QoL in subjects with strabismus and especially in those with amblyopia alone. The results suggest that separate instruments are needed to quantify VR-QoL in amblyopes with and without strabismus.
Contact lens wearers need to maintain optimal hygiene practices during the COVID-19 pandemic to minimise contact-lens complications including microbial keratitis and corneal infiltrative events. This online survey (UK and Ireland) explored contact lens wearers’ compliance behaviours, attitudes and concerns during the pandemic. The 60-item anonymous online survey was distributed during a 1-month period via Qualtrics (starting on 14/04/20). The survey captured: a) demographic information, b) type of lenses worn and compliance with lens wear and care procedures, c) adherence to recommendations and d) concerns associated with contact lens wear during the pandemic. Two hundred and forty seven responses were received (34.3 ± 11.7 years old, 79% female). Seventy nine percent of participants reported that they were self-isolating or rigorously following social distance advice. Fifty-six percent of participants reported using their lenses less during the pandemic. Eighty-seven percent of respondents reported following the recommended 20-second rule most times/every time and 96% used soap and water during handwashing. Eleven percent of respondents admitted not following recommendations regarding disposal of lenses and 18% would not consider ceasing lens wear if unwell (with flu/cold) during the pandemic. Respondents reported wearing their contact lenses less than usual. Good compliance with handwashing was observed but soft reusable lens wearers showed a statistically significant lower compliance with lens wear and care compared to daily disposable lens wearers (p=<0.001).