The Dry Eye Zone

Rebecca's Blog

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Study: A pain questionnaire for neuropathic eye pain

We’re getting closer!

Definitely a sign of the times. The leaps and bounds we’e made in attention to neuropathic eye pain in recent years are SO encouraging!

The step discussed in this study is absolutely essential: It’s about measuring eye pain consistently, with a scientifically validated tool. This is the vital step towards ensuring patients in pain with no obvious cause are believed and that what they report is taken seriously as medical information. We’re not there yet but we sure are getting closer.

Pain matters.

Modification of the Neuropathic Pain Symptom Inventory for use in eye pain (NPSI-Eye).

Farhangi et al, Pain, March 2019.

Abstract

Chronic eye pain, which has previously been assumed to be due to ocular surface abnormalities (i.e., "dry eye disease"), has recently garnered attention as a potential indicator of neuropathic ocular pain in some patients. The purpose of this study was to evaluate the psychometric properties of a modified version of the Neuropathic Pain Symptom Inventory in individuals with eye pain (NPSI-Eye). Enrolled participants (n = 397) completed the NPSI-Eye, general pain severity questionnaires, dry eye symptom report, and psychological health indices. Participants also underwent mechanical pain sensitivity testing of the cornea, tear film assessment, and evaluation of the efficacy of anesthetic eye drops to relieve pain. Short-term test-retest reliability of the NPSI-Eye was excellent (intraclass correlation coefficient = 0.98, p < 0.001). Correlations between the NPSI-Eye and indicators of general eye pain were ≥ 0.65 (p < 0.001), while correlations between the NPSI-Eye and dry eye symptom severity and psychological health indices were lower (rho= 0.56, 0.32, 0.37; all p < 0.001). Individuals who reported little or no decrease in pain after anesthetic eye drops (hypothesized to indicate eye pain with at least partial central involvement) had significantly higher NPSI-Eye scores than participants whose eye pain was completely relieved by anesthetic (p < 0.05). Overall, our results support preliminary validation of the NPSI-Eye, yielding similar metrics to those reported in Bouhassira et al.'s original NPSI publication (2004). However, additional evaluation and refinement of some questions may be desirable, including the potential elimination of items that were not highly endorsed.