Downloaded from http://bjo.bmj.com/ on August 30, 2016 - Published by group.bmj.com Clinical science Anxiety in visual field testing Shenton S L Chew, Nathan M Kerr, Aaron B C Wong, Jennifer P Craig, Chi-Ying Chou, Helen V Danesh-Meyer ▸ Additional material is ABSTRACT field reliability. One such potential variable is published online only. To view Background To determine if Humphrey visual field anxiety, which is known to adversely affect general- please visit the journal online 5 (http://dx.doi.org/10.1136/ (HVF) testing induces anxiety and how anxiety relates to ised test performance. bjophthalmol-2015-307110). visual field parameters of reliability and severity. This prospective cohort study was therefore Design A prospective cohort study at a university designed to establish if Humphrey visual field Department of Ophthalmology, fi University of Auckland, af liated private ophthalmic practice. (HVF) testing induces anxiety and whether this Auckland, New Zealand Participants 137 consecutive age-matched and may influence the reliability of the test. In addition, gender-matched patients with glaucoma undergoing the anxiety level induced was compared with that Correspondence to either HVF testing only (n=102) or Heidelberg retinal induced by Heidelberg retinal tomography (HRT) Professor Helen V Danesh- Meyer, Department of tomography (HRT) only (n=35) were enrolled. which requires minimal patient input. Ophthalmology, University of Methods Prior to testing, participants completed the Auckland, Private Bag 92019, State-Trait Anxiety Inventory questionnaire. A 5-point MATERIALS AND METHODS Auckland 1142, New Zealand; Likert scale was used to grade pretest anxiety and was Subjects [email protected] repeated after testing to grade intratest anxiety. Patients attending a glaucoma clinic at a fi Received 18 May 2015 Subjective discomfort parameters were also recorded. university-af liated private ophthalmic practice Revised 21 September 2015 Main outcome measures Anxiety scores were used were invited to participate in the study. The study Accepted 27 October 2015 to make non-parametrical comparisons and correlations adhered to the tenets of the Declaration of Published Online First between cohorts and also against visual field reliability Helsinki. In total, 137 patients provided informed 25 November 2015 and severity indices. consent to participate and participants comprised Results Trait anxiety (p=0.838) and pretest anxiety two cohorts: 102 (49 men, 53 women, mean age (p=0.802) were not significantly different between test ±SD of 62.5±11.9) who underwent anxiety ana- groups. Within the HVF group, intratest anxiety was 1.2 lysis before and immediately after HVF testing and times higher than pretest anxiety (p=0.0001), but was 35 (19 men, 16 women, mean age±SD of 64.1 not significantly different in the HRT group (p=0.145). ±12.3) who underwent an identical analysis before Pretest anxiety was correlated with test unreliability and after HRT testing. None of the participants (Spearman’s r=0.273, p=0.006), which was predictive of had known or treated anxiety disorders. worse test severity (p=0.0027). Subjects who had undergone more than 10 visual field tests had Pretest evaluation significantly lower pretest and intratest anxiety levels All subjects completed a pretest questionnaire com- than those who had not (p=0.0030 and p=0.0004, prising demographic information including age, respectively). gender, duration of follow-up for glaucoma or sus- Conclusions HVF testing induces more anxiety than picion of glaucoma and the number of previous HRT. Increased pretest anxiety may reduce HVF test HVF or HRT tests performed. To confirm parity of reliability. Increased test experience or interventions existing anxiety traits between HVF and HRT aimed at reducing pretest anxiety may result in improved groups, participants underwent an assessment of test reliability and accuracy. their anxiety traits by the State-Trait Anxiety Inventory (STAI) 2 test,6 (see online supplementary appendix 1) a 20-question test to measure ‘trait INTRODUCTION anxiety’ which evaluates a chronic proneness to Glaucoma is primarily a disease of the middle-aged anxiety or a propensity to experience state anxiety and elderly, and the second leading cause of blind- in provocative situations.56The responses to this ness worldwide.12Visual field testing is an integral widely used, validated questionnaire78were component of the clinical assessment of glaucoma recorded on a standard 4-point scale, as ‘almost and is often the basis on which disease progression never’, ‘sometimes’, ‘often’ or ‘almost always’. is monitored and treatment is instigated or modi- Participants then completed a validated assess- fied.1 It is therefore crucial that accurate and reli- ment to measure their pretest ‘state’ anxiety which able results are obtained during visual field testing describes transient feelings of apprehension in in order for patients to receive the most appropri- response to a situation at a given moment in time. ate management. This was recorded on a 5-point Likert scale, However, it has been identified that visual field ranging from ‘not anxious at all’ to ‘extremely testing is a patient’s least preferred clinical test used anxious’9 (see online supplementary appendix 2). in glaucoma management.34Visual field tests require active patient participation and conse- Post-test evaluation fl To cite: Chew SSL, quently may be in uenced by variables that affect Immediately after the clinical testing procedure Kerr NM, Wong ABC, et al. patient attention, concentration or physical ability (either HVF or HRT), the subjects completed an Br J Ophthalmol to perform the tests. Despite this, there is limited identical 5-point Likert scale questionnaire grading – 2016;100:1128 1133. research regarding such variables that affect visual their intratest anxiety (anxiety experienced during 1128 Chew SSL, et al. Br J Ophthalmol 2016;100:1128–1133. doi:10.1136/bjophthalmol-2015-307110 Downloaded from http://bjo.bmj.com/ on August 30, 2016 - Published by group.bmj.com Clinical science the test). Likert scales were selected over the 20 question STAI cooperation and takes approximately 5–7 min per eye, including ‘state anxiety’ questionnaire as it was felt that the significantly set-up and preparation time. Again, the eye that was tested first shorter completion times would result in a more accurate repre- was randomised. sentation of anxiety levels, given the short duration of HVF and HRT testing. Similarly, discrete scoring was used rather than a continuous visual analogue scale to simplify the recording Statistics process for subjects. A biostatistician, using SAS V.9.1.3, evaluated ordinal data non- In addition, five subjective discomfort parameters including parametrically. Spearman’s distribution-free correlation coeffi- how difficult, tiring, long, physically uncomfortable and cient was calculated, and groups compared by Wilcoxon test unpleasant the participant had found the test were also recorded (continuous non-normally distributed data), Student’s t test 2 on 5-point Likert scales (see online supplementary appendix 2). (continuous normally distributed data) or using the χ test for categorical data. Standard multiple linear regression was used to analyse multivariate models. Models were constructed using Test parameters iterative procedures (stepwise, forward and backward selection) One hundred and two participants underwent HVF testing, but encompassing the following variables: age, pretest anxiety, not HRT testing, by standard automated white-on-white perim- average test duration and subjective reporting of tests being diffi- 2 etry on a 10 cd/m background, with a Humphrey Field cult, tiring, long, uncomfortable and unpleasant. These variables Analyzer II (Carl Zeiss Meditec, Dublin, California, USA) using were included based on external clinical judgement and have the SITA 24-2 standard algorithm. Test duration was approxi- been identified by participants as relevant factors in a qualitative mately 5 min per eye. HVF parameters recorded included mean investigation into HVF testing.4 deviation (MD), pattern SD (PSD), fixation losses (FLs), false positives (FPs), false negatives (FNs) and test duration. Visual fields were considered unreliable if FP or FN exceeded 33% or – FL exceeded 20%.10 12 HVF data for right and left eyes was averaged for correlation with anxiety and discomfort scores. The eye that was tested first was randomised. Participants were tested in individual rooms with distractions kept to a minimum. A technician was present with the patient at all times. As a basis for comparison, 35 participants underwent HRT testing (HRT-3, versions 2.01/3.04 HRT; Heidelberg Engineering, Heidelberg, Germany) but not HVF testing. HRT-3 is a confocal scanning laser ophthalmoscope that images the optic nerve head. Image acquisition requires minimal patient Table 1 Demographics for HVF and HRT groups HVF HRT Demographic Age (years) 62.7 (27–92) 64.1 (35–86) Gender (M:F) 0.92:1 1.19:1 Duration since diagnosis First visit 8% 20% <2 years 29% 26% 2–5 years 35% 40% >5 years 27% 14% Previous number of tests 0 2% 23% 1 15% 11% 2–5 43% 54% 6–10 22% 11% >10 17% 0% Trait anxiety (out of 80)* 33 (20–60) 33 (22–48) Reliability Average fixation losses (%) 7.7 (0–56.2) – Average false positives (%) 2.8 (0–18.0) – Average false negatives (%) 3.1 (0–34.5) – Severity Mean deviation (dB) −3.4 (−27.6 to 2.1) – Pattern SD (dB) 3.9 (1.2–12.9) – Average test duration (seconds) 329 (249–513) – Values in parentheses represent the range of the demographic. Figure 1 (A) Trait anxiety and pretest anxiety for Humphrey visual *Median values for ordinal and categorical data. fi HRT, Heidelberg retinal tomography; HVP, Humphrey visual field. eld participants, r=0.18, p=0.068. (B) Trait anxiety and pretest anxiety for Heidelberg retinal tomography participants, r=0.28, p=0.101. Chew SSL, et al. Br J Ophthalmol 2016;100:1128–1133. doi:10.1136/bjophthalmol-2015-307110 1129 Downloaded from http://bjo.bmj.com/ on August 30, 2016 - Published by group.bmj.com Clinical science RESULTS trend of decreased intratest anxiety compared with pretest Demographics anxiety (p=0.145) (figure 2A, B).