Lifestyle and Refractive Factors Affecting Progressive Addition Lens Preference Padmapriya Ramamoorthy 1, James E Sheedy 2 and John Hayes 2 1 The Ohio State University College of Optometry, 2 Pacific University College of Optometry ABSTRACT Aim: To determine if a patient’s lifestyle and daily visual needs can predict PAL design preference. Secondary objectives were to study if the refractive status and correction influence PAL preference. Methods: 34 PAL wearers were classified by self-screening into two groups based upon whether they had greater far or greater near visual needs. In a randomized, double- masked clinical trial, each subject was fitted with two PAL designs - one with a large far viewing zone and another with a large near viewing zone. Subjects wore each design for 2 weeks and simultaneously compared both for 1 final week. Questionnaires on vision and several visual tasks were used to assess subjects’ satisfaction and preference. The final overall preference was compared against their initial preference determined by their visual needs. Results: For 24 out of 34 subjects the initial PAL preference based on individual visual needs, matched their final PAL preference (χ 2 p = 0.03). The far group was more consistent with 11 out of 13 subjects accurately predicting the far PAL at the beginning. The near group was more variable with a final near PAL preference in only 13 of 21 subjects. Regression analysis for prediction of final PAL preference revealed that the amount of cylinder in a subject’s prescription (p = 0.01) affected the final PAL preference. The prediction model accurately classified the final preference of 30 out of 34 subjects (88.2% accuracy). Conclusions: PAL design preference varies with patient needs. Subjects with far visual needs clearly prefer PAL designs with superior far characteristics while those with near visual needs prefer PAL designs with better near features. Further assessment is required to draw results that are more conclusive in the near group. MATERIALS & METHODS RESULTS 34 subjects completed study Average age was ± 5.91 years and 64.7% were female Summary statistics of subjects’ spectacle prescription Table 1: Descriptive Statistics of Refractive Correction Parameters RESULTS (cont’d) PAL preference There was a significant association between a subject’s initial and final PAL preference (Chi square statistic Χ 2 1 = 4.65, p = 0.034) of the 13 subjects in the far group preferred the far PAL (final PAL preference),2 subjects preferred the near PAL. - In the near group, 11 of 21 subjects had a final near PAL preference while 10 subjects preferred the far PAL (Chi square p = 0.034). Analysis of the Final Questionnaire Scores The final overall preference score for the far group ( ) was significantly greater (p = 0.001) from the mid-point indicating preference for the far lens. The mean score of the near group ( ) was not significantly different from the mid-point indicating no preference for either lens. The final scores indicated a significantly greater preference for the far lens in the far group for questions addressing: far straight-ahead vision (p=0.007), peripheral vision through the far component of the PAL (p=0.03), driving and moving (p=0.002), following a moving object (p=0.009), adjustment (p=0.009), climbing stairs and curbs (p=0.012), locating proper area of the lens for different viewing distances (p=0.016), and clear far vision without lowering chin too much (p=0.023). Prediction of PAL preference Logistic regression analysis to predict PAL preference Significant predictors - Presence of cylinder in spectacle prescription (p = 0.01), predicted far PAL preference - Interaction term between myopia, initial near PAL preference and amount of sphere in prescription (p = 0.03) 88% accuracy in prediction of PAL preference CONCLUSIONS LITERATURE CITED CONTACT INFORMATION Based on individual visual requirements, there exist differences in the PAL preference characteristics of the population. 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 Subjects with far visual needs clearly prefer PAL designs Near group needs better designs and more assessment Implications of findings Implications of findings - Industrial implications: Need better lens designs for - Industrial implications: Need better lens designs for segmented populations segmented populations - Clinical implications: Customized care for patients based - Clinical implications: Customized care for patients based on their specific needs on their specific needs 1. Sheedy JE. Progressive addition lenses – matching the specific lens to patient needs. Optometry 2004; 75:83- specific lens to patient needs. Optometry 2004; 75: Sheedy et al. Progressive addition lenses – measurements and ratings. (In press) measurements and ratings. (In press) 3. Hays et al. Psychometric properties of the National eye institute-Refractive error quality of life instrument. eye institute-Refractive error quality of life instrument. Ophthalmology 2003;110:2292:2301. Ophthalmology 2003;110:2292: Preston, J. (1998). Progressive Addition Spectacle Lenses: Design Preferences and Head Movements Lenses: Design Preferences and Head Movements while Reading. Optometry/ Physiological Optics. while Reading. Optometry/ Physiological Optics. Columbus, OH, The Ohio State University: 222. Columbus, OH, The Ohio State University: Fowler CW, B. A., Bench BP, Kempster AJ. (1994). A wearer comparison of two progressive addition wearer comparison of two progressive addition spectacle lenses. Vision Science and its Applications spectacle lenses. Vision Science and its Applications Washington DC, Optical Society of America Washington DC, Optical Society of America. Technical Digest Series Vol 2: 6-9. Technical Digest Series Vol 2: 6-9. Subjects Patient Inclusion criteria 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 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 ACKNOWLEDGEMENTS This research was supported by the Center for Ophthalmic Optics Research 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 Overview of study design METHODS (cont’d) Individual factors and lifestyle screening 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 Clear Distant Viewing Clear Near Viewing Areas of Blur (a) Far > Near Viewing area (b) Near > Far Viewing area PAL Selection Top-rated pools of distance and near vision lenses Based on: - Distance and near ratings by Sheedy, Hardy et al Maximal difference between the two ratings - Equalized astigmatism ratings Far PALs: Shamir Genesis, Vision Ease Outlook and Zeiss Gradal Top Near PALs: Shamir Piccolo, Signature Kodak Concise and AO Compact 18 far/near or near/far combinations were randomly assigned to the subjects in a double-masked manner. Preference Assessment Preference between the 2 PALs for a variety of functional visual aspects Clarity of vision Far (distant), intermediate & near Far (distant), intermediate & near Viewing straight-ahead and through lens periphery Viewing straight-ahead and through lens periphery Clarity of vision during driving, viewing moving objects Clarity of vision during driving, viewing moving objects Ease of lens use while performing specific activities Ease of lens use while performing specific activities Ease in adaptation Ease in adaptation Overall Lens Preference Overall Lens Preference Sample question and response scale Refractive ComponentAverageSDRange Sphere0 D to D Cylinder-0.58 D0.380 to -1.5 D Spherical equivalent-0.27 D to D Near add+2.24 D to D Table 1: Descriptive Statistics of Refractive Correction Parameters N = 34 PAL Preference Final PAL Preference Total Distance (Far)Near (Count (% of Total) listed in each cell) Initial PAL Preference Distance (Far) 11 (32.4)2 (5.9)13 (38.2) Near10 (29.4)11 (32.4)21 (61.8) Total21 (61.8)13 (38.2)34 (100) Table 2: Comparison of Subjects’ Initial and Final PAL Preference Far PAL Near PAL Near PAL Far PAL Figure 1: Prediction of PAL preference based on regression model James E. Sheedy Director of Optometric Research Vision Performance Institute T: E: