Neuropathic dry eye is one of the most frequent complications of corneal refractive surgery. While its incidence decreases significantly throughout the first six months postoperative, little is known about the inflammatory status of the ocular surface during this process. Although researchers recently found that there is a recovery in clinical variables at six months post-op, they noted that ocular surface homeostasis is not completely restored.

This prospective study analyzed clinical and tear molecule concentration changes from baseline to six months after advanced surface ablation for myopia correction in 18 eyes of 18 subjects who had bilateral corneal refractive surgery.

At one, three and six months post-op, the team measured clinical variables, including uncorrected distance visual acuity, symptoms, conjunctival hyperemia, tear osmolarity and stability, corneal fluorescein staining, conjunctival lissamine staining, Schirmer test and corneal esthesiometry. They evaluated a panel of 23 pro- and anti-inflammatory cytokines/chemokines concentration in tears preoperatively.

The investigators discovered that uncorrected distance visual acuity improved significantly from baseline to one-month post-op, symptoms improved and tear osmolarity decreased significantly by three months and mechanical corneal threshold decreased between one and three to six months. They noted that IL-4, IL-5, IL-6, IL-13, IL-17A and IFN-γ tear levels significantly increased at all three checkpoints. They added that IL-2 and VEGF also significantly increased at one and six months; whereas, IL-9, IL-10 and IL-12 only significantly increased at six months.