Lifestyle and Refractive Factors Associated with Progressive Addition Lens Preference The Center for Ophthalmic Optics Research, The Ohio State University Priya Ramamoorthy, BS Optom., MS Jim Sheedy, OD, PhD John Hayes, PhD

Introduction n Gaining popularity since 1950’s –Acceptance & Satisfaction Studies Acceptance rate - 86% to 99%Acceptance rate - 86% to 99% Satisfaction rate - 72% to 92%Satisfaction rate - 72% to 92% n Research on PALs –PAL Preference Studies Numerous product comparison studiesNumerous product comparison studies Few studies on true design preferenceFew studies on true design preference –Fowler et al. (1994), Preston et al. (1998)

Introduction n Current PAL designs have significant differences in their optical characteristics (Sheedy, 2004; Sheedy, Hardy et al. 2006) n PAL designs differ significantly in far, intermediate, near zone and astigmatism characteristics n “One-for-all” design researched so far n What about differences in the preference characteristics of the population? n Visual needs of patients may differ

Study Objective n Test patient preference for PAL design based upon their daily visual requirements n Test if lifestyle, refractive status, visual correction history and/or other characteristics of the patient are related to the lens design that best suits him/her

Overall study design Patient Selection Determining lifestyle needs Subjects fitted with far and near PAL designs Phase 3 Simultaneous comparison of lenses A and B x 1 week Phase 2 Lens A/B x 2 weeks Final preference assessment Phase 1 Lens A/B x 2 weeks

Patient selection n Patient Inclusion criteria n Clinical –Corrected visual acuity of at least 20/20 in each eye –No history of significant ocular disease (except cataract) –Previous PAL Wear > 1 year n Optical Criteria –Distance prescription: < 3.50 D spherical equivalent –Near add: Between D and D –Cylinder prescription: < 1.75 D –Anisometropia (spherical equivalent): <1.50 D –Minimum fitting height: 18 mm

Clear Distant Viewing Clear Near Viewing Areas of Blur Screening n Individual Factors –Satisfied PAL wearers –Clarity of vision through the subject’s spectacles –PAL wear for at least half the waking hours –Demonstration of a clear lifestyle preference for distance or near viewing requirements (a) Far > Near Viewing area (b) Near > Far Viewing area

Selection of PALs n Top-rated pools of distance and near vision lenses n Based on: –Distance and near ratings by Sheedy, Hardy et al –Maximal difference between the two ratings –Equalized astigmatism ratings

Ratings for Distance & Near Viewing Zones (Sheedy, Hardy et al. 2006)

Preference Assessment - Final Questionnaire n Evaluates preference between the 2 PALs for a variety of functional visual aspects n Sample question: –Response scale Ease of lens use while performing specific activitiesEase of lens use while performing specific activities Ease in adaptationEase in adaptation Overall Lens PreferenceOverall Lens Preference Clarity of visionClarity of vision - Far (distant), intermediate & near - Viewing straight-ahead and through lens periphery Clarity of vision during driving, viewing moving objectsClarity of vision during driving, viewing moving objects

Results n Subjects –34 completed study –Average age ± 5.91 years –64.7% female n Refractive correction

Results – Initial vs. Final PAL Preference n n Initial PAL preference based on lifestyle visual needs matched final PAL preference in 22 of 34 subjects n n Χ 2 1 = 4.65, P =0.03 n Comparison Of Subjects’ Initial And Final PAL Preference

Final Overall Preference Scores n n Overall Preference Scores – –Far group (mean = 8.08) indicating preference for the far lens – –Near group (mean = 5.71) - no preference for either lens n n Far group – –Initial and final preference of 11 of 13 subjects was the far PAL n Near group –11 of 21 subjects preferred the near PAL design –10 subjects switched final preference to far PAL

PAL Preference Prediction n n Logistic regression analysis to predict PAL preference n n Significant predictors – –Cylindrical spectacle prescription significantly associated with far PAL preference (p=0.01) – –Interaction term between myopia, initial near PAL preference and amount of sphere in prescription (p = 0.03) n n 88% accuracy in prediction of PAL preference

Prediction of Model for Current Data Far PAL Near PAL Near PAL Far PAL

Final Overall Preference Scores n Other Final Questionnaire responses* –Far group rated high far PAL preference For almost all perceived far vision tasksFor almost all perceived far vision tasks Combination tasksCombination tasks General factorsGeneral factors –Near Group Preference not significant for either lensPreference not significant for either lens Increased variability in scoresIncreased variability in scores

Results – Clear vision extent n Clear vision extent at far, intermediate and near distances –Paired t test analyses –Near PAL > Far PAL at near (p=0.03) –Far PAL > Near PAL at far (p=0.04) n Summary statistics

Discussion n Significant association between initial PAL preference based on lifestyle visual needs and final PAL preference n Far group more consistent –Reflected in final preference score –Strong preference for the far PAL in several of their lens comparison responses n Greater variability observed in the near group n Inferences from the regression model –Cylinder in glass prescription n Optical Properties of far and near PAL designs –Near width in near PAL –Intermediate zone properties Int. ratings of far & near PALs, Need for accurate fitting, PD ToleranceInt. ratings of far & near PALs, Need for accurate fitting, PD Tolerance n Potential limitations –Screening tool inadequacy –Subjects’ judgment & far vision requirement

Conclusions n Based on individual visual requirements, there exist differences in the PAL preference characteristics of the population. –Subjects with far visual needs clearly prefer PAL designs –Near group needs better designs and more assessment n Implications of findings –Industrial implications: Need better lens designs for segmented populations –Clinical implications: Customized care for patients based on their specific needs

Acknowledgement n This research was supported by the Center for Ophthalmic Optics Research

Reference n Sheedy JE. Progressive addition lenses – matching the specific lens to patient needs.Optometry 2004; 75: n Sheedy et al.Progressive addition lenses – measurements and ratings. (In press) n Hays et al. Psychometric properties of the National eye institute-Refractive error quality of life instrument. Ophthalmology 2003;110:2292:2301. n Preston, J. (1998). Progressive Addition Spectacle Lenses: Design Preferences and Head Movements while Reading. Optometry/ Physiological Optics. Columbus, OH, The Ohio State University: 222. n Fowler CW, B. A., Bench BP, Kempster AJ. (1994). A wearer comparison of two progressive addition spectacle lenses. Vision Science and its Applications Washington DC, Optical Society of America. Technical Digest Series Vol 2: 6-9.