Patient‐reported outcome measures in amblyopia and strabismus: a systematic review

Abstract

Background: Many patient-reported outcome measures (PROMs) have been developed and/or used to measure the impact of amblyopia and strabismus on quality of life (QoL). Identifying the one with superior quality is important for evaluating the effectiveness of novel therapy for amblyopia and for directing improved clinical decision-making in adults considering strabismic surgery. Therefore, the aim of this review is to identify all PROMs previously developed/used to study the impact of amblyopia and/or strabismus on QoL and to appraise the quality and comprehensiveness of content of the disease-specific instruments. Methods: A systematic search was carried out in the electronic databases of PubMed, Cochrane, Web of Science and PsycINFO. The quality of content and measurement properties of all the disease-specific instruments were assessed using established quality standards. Further, the content of the instruments were examined for comprehensiveness by categorising each item across the eight ophthalmic QoL domains (activity limitation, concerns, emotional well-being, social well-being, economic, convenience, symptoms and mobility). Results: Seventy-one PROMs were identified, out of which 32 were amblyopia-and/or strabismus-specific. Out of all the disease-specific instruments, just four have been subjected to modern psychometric tests and only the adult strabismus questionnaire demonstrated good measurement properties. Most of the amblyopia-specific instruments measured the impact of the treatment of amblyopia on children, while most of the strabismus-specific instruments measured concerns related to appearance and treatment outcome in adults. All instruments have gaps in their content and failed to address QoL comprehensively. Conclusion: All the existing amblyopia-and/or strabismus-specific instruments fall short of desired quality and/or comprehensiveness of content. The review identifies the need for developing an instrument with superior quality and discusses potential directions of future research.Key words: amblyopia, patient reported outcome, quality assessment, quality of life, questionnaire, strabismus Amblyopia and strabismus are common developmental conditions of childhood and are known to cause functional deficits like impaired stereoscopic depth perception and defective sensory, motor, visual cognition and prehension skills.1-3 These functional deficits manifest in the individual as imprecise or inefficient performance of real-life activities like reading, grasping and driving and affect quality of life (QoL). 4,5 Apart from the implications of these functional deficits, socially noticeable strabismus also affects the psychosocial and emotional well-being of individuals. [6][7][8][9][10] Analysis of the cost-effectiveness of screening for amblyopia and its utility are limited by the lack of evidence about the long-term impact, the degree of disability and the impact of amblyopia on QoL. 11-13Incorporating patient-reported outcome measures (PROMs) as one of the treatment outcomes is considered importa...

Functional limitations recognised by adults with amblyopia and strabismus in daily life: a qualitative exploration

“…As a next step, we are using this qualitative evidence to develop a comprehensive item bank calibrated by Rasch analysis, to measure the functional limitations posed by amblyopia and strabismus on a valid interval scale. 45,46 This scale will then be used to measure and compare the level of impacts across the different amblyopia and strabismus diagnoses.…”

The functional impact of amblyopia

“…However, many patient‐reported outcome measures instruments are directed to cosmetically obvious strabismus and its social impact and are not specific to amblyopia per se. In addition, most amblyopia‐specific questionnaires have measured health‐related quality of life during the treatment phase when the vision of the better eye is absent or degraded, and fail to address function under habitual binocular viewing conditions …”

Does non‐strabismic amblyopia affect the quality of life of adults? Findings from a qualitative study

“…Despite the prevalence, anisometropic amblyopia has drawn very little attention in quality of life (QoL) investigations, perhaps because it is considered less serious than amblyopia associated with strabismus, which has clear psychosocial and emotional consequences 9, 10 . For instance, of the 32 patient reported outcome measures developed and used to study the QoL impacts of amblyopia and strabismus, only one, the amblyopia survey, specifically evaluates the effects of non‐strabismic amblyopia in adults 11 …”