Development of a questionnaire to assess the relative subjective benefits of presbyopia correction

Purpose To develop a standardized questionnaire of near visual function and satisfaction to complement visual function evaluations of presbyopic corrections. Setting Eye Clinic, School of Life and Health Sciences, Aston University, Midland Eye Institute and Solihull Hospital, Birmingham, United Kingdom. Design Questionnaire development. Methods A preliminary 26-item questionnaire of previously used near visual function items was completed by patients with monofocal intraocular lenses (IOLs), multifocal IOLs, accommodating IOLs, multifocal contact lenses, or varifocal spectacles. Rasch analysis was used for item reduction, after which internal and test–retest reliabilities were determined. Construct validity was determined by correlating the resulting Near Activity Visual Questionnaire (NAVQ) scores with near visual acuity and critical print size (CPS), which was measured using the Minnesota Low Vision Reading Test chart. Discrimination ability was assessed through receiver-operating characteristic (ROC) curve analysis. Results One hundred fifty patients completed the questionnaire. Item reduction resulted in a 10-item NAVQ with excellent separation (2.92), internal consistency (Cronbach a = 0.95), and test–retest reliability (intraclass correlation coefficient = 0.72). Correlations of questionnaire scores with near visual acuity (r = 0.32) and CPS (r = 0.27) provided evidence of validity, and discrimination ability was excellent (area under ROC curve = 0.91). Conclusion Results show the NAVQ is a reliable, valid instrument that can be incorporated into the evaluation of presbyopic corrections.

Visual outcomes and subjective experience after bilateral implantation of a new diffractive trifocal intraocular lens

Purpose - To assess clinical outcomes and subjective experience after bilateral implantation of a diffractive trifocal intraocular lens (IOL). Setting - Midland Eye Institute, Solihull, United Kingdom. Design - Cohort study. Methods - Patients had bilateral implantation of Finevision trifocal IOLs. Uncorrected distance visual acuity, corrected distance visual acuity (CDVA), and manifest refraction were measured 2 months postoperatively. Defocus curves were assessed under photopic and mesopic conditions over a range of +1.50 to -4.00 diopters (D) in 0.50 D steps. Contrast sensitivity function was assessed under photopic conditions. Halometry was used to measure the angular size of monocular and binocular photopic scotomas arising from a glare source. Patient satisfaction with uncorrected near vision was assessed using the Near Activity Visual Questionnaire (NAVQ). Results - The mean monocular CDVA was 0.08 logMAR ± 0.08 (SD) and the mean binocular CDVA, 0.06 ± 0.08 logMAR. Defocus curve testing showed an extended range of clear vision from +1.00 to -2.50 D defocus, with a significant difference in acuity between photopic conditions and mesopic conditions at -1.50 D defocus only. Photopic contrast sensitivity was significantly better binocularly than monocularly at all spatial frequencies. Halometry showed a glare scotoma of a mean size similar to that in previous studies of multifocal and accommodating IOLs; there were no subjective complaints of dysphotopsia. The mean NAVQ Rasch score for satisfaction with near vision was 15.9 ± 10.7 logits. Conclusions - The trifocal IOL implanted binocularly produced good distance visual acuity and near and intermediate visual function. Patients were very satisfied with their uncorrected near vision.

Editorial

Welcome to the latest issue of Contact Lens and Anterior Eye. In this issue, Kuldeep Razaida provides a fascinating look at fitting prosthetic lenses to patients in India. I had the good fortune of visiting his clinic in August 2006 at the LV Prasad Eye Institute in Hyderabad, India and was humbled by the vast expertise within the one building. The institute started in 1987 and is the brainchild of the infamous Professor Rao. I think there are few such places in the world where the clinicians work so passionately in treating such interesting patients (for details regarding the LV Prasad Eye Institute see www.lvpei.org). I was in Hyderabad courtesy of IACLE (see issue 29:5 for an editorial by Judith Morris and Sonja Cronje about IACLE) and was able to share ideas with contact lens educators from across the world (for more information on IACLE see www.iacle.org). The issue contains some regular contact lens type papers too; with our aging population readers will be particularly interested in a paper by Mike Freeman and Neil Charman looking at modified monovision with diffractive bifocal lenses. There is an article looking at visual problems with video display terminal use and a study looking at the effects of surface treatment of silicone hydrogel contact lenses. There is an interesting piece from Dr Aisling Mann of Aston University looking at tear protein analysis; this article contains one CET point too for readers who complete the attached multiple choice questions before the relevant deadline. Also, congratulations to the BCLA members who successfully undertook the Fellowship of the BCLA at this year's BCLA conference in Manchester. If you are interested in undertaking the Fellowship please look at the details on the BCLA web page (http://www.bcla.org.uk/fellowship.asp). Amongst the case reports in this issue of CLAE you will notice one from Andrew Elder-Smith, this particular case report was presented as part of his successful Fellowship submission in 2006 and was thought to be of particular good quality by the examiners who asked Andrew to kindly submit it for publication to Contact Lens and Anterior Eye as an example for potential candidates. Finally, it is my sad duty to report the death of Howard Gee earlier this year, a past council member of the BCLA. Our thoughts and prayers are with his family and friends.