Diplopia and Strabismus After Corneal Refractive Surgery

Introduction Diplopia and strabismus are known complications after corneal refractive surgery (CRS). Within the U.S. Armed Forces, refractive surgery is used to improve the operational readiness of the service member, and these complications could cause significant degradation to their capability. This study was performed in order to identify the incidence of strabismus and diplopia following CRS within the U.S. Military Health System. Methods A retrospective review of all patients who underwent photorefractive keratectomy (PRK) or laser-assisted in situ keratomileusis (LASIK) in the Department of Defense from January 2006 through September 2013 was designed and approved by the Naval Medical Center Portsmouth Institutional Review Board. The military health system data mart was queried for all patients who underwent one of these procedures and subsequently had an International Classification of Disease-9 code for any strabismus or diplopia through 2014 allowing at least 1 year of follow-up. We then calculated the incidence of both diplopia and strabismus for these procedures as the primary measure and the overall prevalence as a secondary measure. Results A total of 108,157 patients underwent PRK or LASIK during our study period with 41 of these patients subsequently having a diagnosis of diplopia or strabismus. After chart review, 16 of these patients were excluded resulting in 25 patients for inclusion in either the strabismus (23 patients, 0.02%) or diplopia (3 patients, 0.003%) cohorts with one patient having both. Of the 23 patients with postoperative strabismus, 4 were new cases giving an incidence of 0.004% and 2 new cases of diplopia for an incidence of 0.002%. Conclusion Diplopia and strabismus are rare complications after CRS in the U.S. military population. These procedures continue to increase the operational readiness of our service members with minimal risk of these potentially debilitating complications. Overall, this study provides support for the continued use of PRK and LASIK despite study limitations related to the use of large databases for retrospective review. Future prospective studies using delineated preoperative and postoperative examinations with sensorimotor testing included may be able to resolve the limitations of this study.