Effects of the pharmaceutical formulation of topical medications on corneal epithelial healing after phototherapeutic keratectomy.

Purpose: To determine the effect of the formulation of topical medications on the healing of corneal epithelial cells after phototherapeutic keratectomy (PTK).

Study Design: Retrospective cohort study.

Methods: We studied 271 eyes of 189 consecutive patients (aged 67.6 ± 11.8 years) who had undergone PTK for granular corneal dystrophy (n = 140), band keratopathy (n = 47), or lattice corneal dystrophy (n = 2). Postoperatively, generic or brand-named levofloxacin, 0.1% betamethasone, or 0.1% bromfenac sodium hydrate was applied topically. Patients were examined on postoperative days 1, 2, and 5 and weekly thereafter. The time to re-epithelialization was assessed by use of Kaplan-Meier and Cox proportional hazards analyses.

Results: The time to re-epithelialization was significantly longer with generic 0.5% levofloxacin, at 8.2 ± 3.5 days, than with 0.5% Cravit (levofloxacin), at 6.7 ± 3.5 days (P = 0.018), or with 1.5% Cravit, at 6.3 ± 2.6 days (P = 0.000). In addition, the time to re-epithelialization was significantly longer with generic 0.1% betamethasone (Sanbetason), at 7.3 ± 3.4 days, than with brand-name 0.1% betamethasone (Rinderon), at 6.1 ± 2.5 days (P = 0.0002). The Cox proportional hazards model indicated that the use of generic formulations for levofloxacin eye drops and 0.1% betamethasone was a significant factor that delayed corneal re-epithelialization (hazard ratio [HR] = 0.72, P = 0.002 and HR = 0.77, P = 0.006, after adjustment for age). Re-epithelialization was significantly shorter in band keratopathy than in corneal dystrophy (HR = 1.56, P = 0.004). No other factors, including age, bandage contact lens, and diabetes mellitus, were significantly associated with time to re-epithelialization.

Conclusion: Corneal epithelial healing can be significantly affected by different antibacterial or steroid eye drops. Clinicians need to be aware that a generic formulation may affect corneal epithelial healing.