Translation and validation of convergence insufficiency symptom survey to Italian: Psychometric results


Purpose: This study aimed to translate the Convergence Insufficiency Symptom Survey (CISS) into the Italian language and assess psychometric properties of the translated questionnaire (CISS_I). Methods: The CISS_I was arranged according to guidelines for a comprehensive multistep methodologic process for translating, adapting, and validating psychometric instruments in health care research. The CISS_I questionnaire was administered to 103 volunteers (21.8 ± 2.2 years), students in higher education, at two different times. A complete optometric evaluation was performed including subjective refraction, best corrected visual acuity, near point of convergence, prism fusional ranges to blur, diplopia and recovery, TNO stereo test and prism cover test for measurement of heterophoria. Results: The performance of the CISS_I in terms of validity showed some points of weakness. Sensitivity was 42%, specificity was 74%, positive predictive value was 27% and negative predictive value was 85%. The area under the ROC curve was 0.672. On the contrary, the results showed good internal consistency of the CISS_I (Cronbach's alpha - α=0.89) and good test-retest reliability (ICC = 0.92). Rasch analysis showed good model fit (all items, except one, with infit and outfit mean square between 0.7 and 1.3), good measurement precision (person separation = 2.66) and good targeting –0,81 logits but also some evidence of multidimensionality. Conclusions: The CISS_I showed some point of weakness in terms of validity but also good psychometric properties and has been shown to be applicable to an Italian speaking population to quantify the visual discomfort associated with near vision in higher education students. The results show that high CISS_I score is not necessarily linked to convergence insufficiency, while low scores can exclude the presence of this anomaly. The CISS_I can help in interpreting and monitoring convergence insufficiency symptoms in already identified subjects, but it is not suitable for screening a general population of young adults.

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Divisions: College of Health & Life Sciences > School of Optometry > Optometry
College of Health & Life Sciences > School of Optometry > Optometry & Vision Science Research Group (OVSRG)
College of Health & Life Sciences > School of Optometry > Vision, Hearing and Language
College of Health & Life Sciences
College of Engineering & Physical Sciences > School of Engineering and Technology > Mechanical, Biomedical & Design
College of Engineering & Physical Sciences
Additional Information: © 2022 Spanish General Council of Optometry. Corrected Proof Published by Elsevier España, S.L.U. This is an open access article under the CC BYNC-ND license (
Uncontrolled Keywords: Symptom survey,CISS,Questionnaires,Near vision,Convergence insufficiency
Publication ISSN: 1989-1342
Last Modified: 18 Jul 2024 07:16
Date Deposited: 24 Oct 2022 08:37
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Related URLs: https://www.sci ... 0565?via%3Dihub (Publisher URL)
PURE Output Type: Article
Published Date: 2022-10-04
Published Online Date: 2022-10-04
Accepted Date: 2022-08-12
Submitted Date: 2022-04-03
Authors: Boccardo, Laura
Vizio, Assunta Di
Galli, Giulia
Naroo, Shehzad A (ORCID Profile 0000-0002-6373-7187)
Fratini, Antonio (ORCID Profile 0000-0001-8894-461X)
Tavazzi, Silvia
Gurioli, Massimo
Zeri, Fabrizio (ORCID Profile 0000-0003-0529-555X)

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