@article {836941,
	title = {Validity and Reliability of a Novel Ocular Pain Assessment Survey (OPAS) in Quantifying and Monitoring Corneal and Ocular Surface Pain.},
	journal = {Ophthalmology},
	volume = {123},
	number = {7},
	year = {2016},
	month = {2016 Jul},
	pages = {1458-68},
	abstract = {PURPOSE: To validate the Ocular Pain Assessment Survey (OPAS), specifically designed to measure ocular pain and quality of life for use by eye care practitioners and researchers. DESIGN: A single-center cohort study was conducted among patients with and without corneal and ocular surface pain at initial and follow-up visits over a 6-month period. The content of the OPAS was guided by literature review, a body of experts, and incorporating conceptual frameworks from existing pain questionnaires. The Wong-Baker FACES Pain Rating Scale served as the gold standard for measuring the intensity of ocular pain. PARTICIPANTS: A total of 102 patients aged 18 to 80 years completed the OPAS at the initial visit. A total of 21 patients were followed up after treatment. METHODS: Indices of validity and internal consistency (Spearman{\textquoteright}s rank-order, rs, or Pearson{\textquoteright}s correlation coefficients, rp), and coefficient of reliability (Cronbach{\textquoteright}s α) were determined in addition to equivalence testing, exploratory factor analysis (EFA), and diagnostic analysis. MAIN OUTCOME MEASURES: Eye pain intensity was the primary outcome measure, and interference with quality of life (QoL), aggravating factors, associated factors, associated non-eye pain intensity, and self-reported symptomatic relief were the secondary outcome measures. RESULTS: The OPAS had criterion validity at both initial (rs\&nbsp;= 0.71; n\&nbsp;= 102; P \&lt; 0.01) and follow-up visits (rs\&nbsp;= 0.97; n\&nbsp;= 21; P \&lt; 0.01). Equivalence tests yielded OPAS and gold standard equivalence for both the initial and follow-up visits. The EFA supported 6 subscales (eye pain intensity at 24 hours and 2 weeks, non-eye pain intensity, QoL, aggravating factors, and associated factors) confirming multidimensionality. Cronbach{\textquoteright}s α \&gt;0.83 for all subscales established strong internal consistency, which correlated with the gold standard, including 24-hour eye pain intensity and QoL interference scores (rp\&nbsp;= 0.81, 0.64, respectively P \&lt; 0.001). At follow-up, reduction in pain scores was accompanied by improvement in all dimensions of the OPAS. Percentage change in QoL correlated to percentage change in the gold standard (rp\&nbsp;= 0.53; P\&nbsp;\&lt; 0.05). The OPAS was sensitive (94\%), specific (81\%), and accurate (91\%), with a diagnostic odds ratio\&nbsp;\&gt;50. CONCLUSIONS: The OPAS is a valid, reliable, and responsive tool with strong psychometric and diagnostic properties in the multidimensional quantification of corneal and ocular surface pain intensity, and QoL.},
	issn = {1549-4713},
	doi = {10.1016/j.ophtha.2016.03.006},
	author = {Qazi, Yureeda and Hurwitz, Shelley and Khan, Sarosh and Jurkunas, Ula V and Dana, Reza and Hamrah, Pedram}
}
