Improved Evaluation of Postoperative Pain After Photorefractive Keratectomy

Postoperative pain remains an important limiting factor to the selection of photorefractive keratectomy (PRK). There is a consensus in neurology pain research that pain should be evaluated as a multidimensional concept, which differs from current practice in ophthalmology. The purpose of this paper was to validate the use of multidimensional questionnaires, such as the Brief Pain Inventory (BPI) and the McGill Pain Questionnaire (MPQ), to provide an improved analysis of pain after PRK and to better describe its temporal profile.

This prospective study included 43 eyes of 43 myopic patients who underwent unilateral PRK. After surgery, usual pain treatment was administered. All of the participants responded to the Visual Analogue Scale (VAS), the BPI and the MPQ 1, 24, 48, 72, and 96 hours after surgery. The internal consistency was evaluated, different postoperative periods were compared, and convergent validity was assessed using correlation testing.

The Cronbach alpha test showed high internal consistency for each of the questionnaire subscales. Patients reported higher postoperative pain values at the first measurement of the VAS (4.93 ± 2.38), MPQ-pain rating index (26.95 ± 10.58), BPI-pain severity index (14.53 ± 7.36), and BPI-pain interference index (22.30 ± 15.13). Almost all of the scales and subscales showed a statistically significant direct correlation with the VAS at all of the evaluation periods.

This study validated the utility of multidimensional questionnaires to expand the assessment of the PRK postoperative pain profile, including intensity and other qualitative aspects.