Vision-related quality of life considering both eyes: results from the German population-based Gutenberg Health Study (GHS)

Stefan Nickels,Norbert Pfeiffer,Andreas Schulz,Alexander K Schuster,Thomas Münzel,Manfred E Beutel,Heike Elflein,Robert P Finger,Christian Wolfram,Irene Schmidtmann

doi:10.1186/s12955-019-1158-1

Abstract

PurposeMost definitions of visual impairment focus on the status of the better-seeing eye only, but this approach might underestimate the influence of the worse-seeing eye on the vision-related quality of life (VRQoL).MethodsWe assessed distance-corrected visual acuity in both eyes and VRQoL using the “National Eye Institute 25-Item Visual Function Questionnaire” (NEI VFQ-25) in the German population-based Gutenberg Health Study. We calculated the Rasch-based visual functioning scale (VFS) and socioemotional scale (SES). We categorized the visual acuity of the better-seeing eye (BE) and worse-seeing eye (WE) as follows: (1) no visual impairment (VI) (< 0.32 logMAR)), (2) mild VI (0.32–0.5 logMAR), and (3) moderate to severe VI (> 0.5 logMAR). Next, the subjects were categorized as follows: both eyes with no VI (no/no), the better-seeing eye with no VI and the worse-seeing eye with mild VI (no/mild), no VI/severe VI (no/severe), both eyes with mild VI (mild/mild), light VI/severe VI (mild/severe), and both eyes with severe VI (severe/severe). We calculated the median scores for VFS and SES. We used linear regression to estimate the combined influence of BE/WE on VFS and SES.ResultsWe included 11,941 participants (49.9% female, age range: 35–74 years) with information on VRQoL and visual acuity. The median VFS/SES scores were 90/100 (no/no VI group), 84/97 (no/mild group), 81/94 (no/severe group), 70/90 (mild/mild group), 67/74 (mild/severe group), and 63/76 (severe/severe group). These differences were supported by the regression analysis results.ConclusionRelying on the function of the better-seeing eye considerably underestimates the impact of visual impairment on VRQoL.

Highlights

The assessment of visual impairment poses the analytical challenge that both eyes could be affected differently
To further elucidate the contribution of both eyes to vision-related quality of life (VRQoL), we explored in a large populationbased sample whether VRQoL is different when stratifying participants according to the visual acuity of their better-seeing eye only and compared this to considering the visual acuity of the fellow eye
Our sample consisted of 11,941 Gutenberg Health Study (GHS) participants (49.9% female; median age: 54.7 years) who completed the questionnaire without missing items necessary to calculate the VRQoL scales and with visual acuity of both eyes available

Summary

Introduction

The assessment of visual impairment poses the analytical challenge that both eyes could be affected differently. Most common definitions of visual impairment meet this challenge by focusing on the visual function of the better-seeing eye only —e.g., the definition of blindness of Nickels et al Health and Quality of Life Outcomes (2019) 17:98 with age-related macular degeneration showed that bilateral manifestation is associated with lower VRQoL than unilateral manifestation [8]. Finger et al showed that calculating patient reported utilizes based on the better-seeing eye only is likely to underestimate the impact of visual impairment [4]. We hypothesize that there will be a substantial impact of the worse-seeing eye on VRQoL

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Results

Discussion

Conclusion