Patient-reported outcome measures in amblyopia and strabismus: a systematic review.
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 (AS-20) 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.