Sleep and Breathing

, Volume 19, Issue 4, pp 1345–1345 | Cite as

Response to Akar et al., regarding our study “Side effects to continuous positive airway pressure treatment for obstructive sleep apnoea”

  • Martin UlanderEmail author
  • Anders Broström
Letter to the Editors


Continuous Positive Airway Pressure Ocular Surface Disease Index Ophthalmological Examination Akar 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

We would like to thank Akar et al. for their interest in our study [1], and for their comments on it.

Side effect data were collected using SECI (Side Effects to Continuous Positive Airway Pressure (CPAP) Inventory), which is a self-report instrument for CPAP side effects that was developed by our group for a previous study [2]. That is, eye irritation as well as other side effects were reported by the patients, and were not based on an ophthalmological examination. We did not use the Ocular Surface Disease Index as our study did not focus specifically on eye-related side effects. In the interest of reducing the number of items (SECI itself in the version used in the study contains 45 items), it was deemed inappropriate to include specific questionnaires for each particular side effect. We agree that it would be valuable to assess the correlation between item 5 in SECI (i.e. irritated eyes) and the results of an ophthalmological examination, but that was not part of the aim of the study in question. Our main interest in self-reported CPAP side effects stems from the fact that they may affect treatment adherence, which is documented to be suboptimal in many studies [3]. Although there may be an association between objective findings and subjective reports with regard to those side effects that can be assessed objectively (e.g. eye irritation, but not, for example anxiety), self-reported CPAP side effects are more complex, as other factors (e.g. personality, see ref. 2) may affect the perceived prevalence and severity of side effects. If side effects are of importance for adherence, it is more likely that a patient’s perception of irritated eyes, for example, is associated with adherence rather than the tear film break-up time, although objective ophthalmological findings are likely to be related to perceived subjective symptoms. What medical, psychological and treatment-related factors that may lead to certain side effects is of course an important and interesting research question in its own right, but not what our study aimed at investigating. In conclusion, we do not think that our findings contradict the findings reported by you, especially as our aims, and therefore, our study design differ from yours.


Conflicts of interest

None of the authors have any conflicts of interest to disclose.


  1. 1.
    Ulander M, Johansson MS, Ewaldh AE, Svanborg E, Broström A (2014) Side effects to continuous positive airway pressure treatment for obstructive sleep apnoea: changes over time and association to adherence. Sleep Breath 18:799–807CrossRefPubMedGoogle Scholar
  2. 2.
    Broström A, Strömberg A, Mårtensson J, Ulander M, Harder L, Svanborg E (2007) Association of Type D personality to perceived side effects and adherence in CPAP‐treated patients with OSAS. J Sleep Res 16:439–447CrossRefPubMedGoogle Scholar
  3. 3.
    Wozniak DR, Lasserson TJ, Smith I (2014) Educational, supportive and behavioural interventions to improve usage of continuous positive airway pressure machines in adults with obstructive sleep apnoea. Cochrane Database of Systematic Reviews 2014, Issue 1. Art. No.: CD007736Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.Department of Clinical NeurophysiologyLinköping University HospitalLinköpingSweden
  2. 2.Department of Clinical Neurophysiology, Institution for Clinical and Experimental Medicine, Faculty of Health SciencesLinköping UniversityLinköpingSweden
  3. 3.Department of Nursing, School of Health SciencesJönköping UniversityJönköpingSweden

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