Ocular surface changes in recurrent pterygium cases post-operatively treated with 5-fluorouracil subconjunctival injections

Introduction: To investigate the ocular surface changes occurring in eyes with recurrent pterygium post-operatively treated with 5-fluorouracil intralesional injections. Methods: Retrospective observational study of recurrent pterygium cases treated with weekly intralesional injections of 0.1 mL (5 mg) of 5-fluorouracil (10 injections). Impression cytology samples taken from the lesion, the healthy conjunctivae (inferior, superior, and contralateral to injury), and the cornea before and after treatment were analyzed. Clinical ocular characteristics (including Schirmer’s test and break-up time) were evaluated during treatment. Results: A total of 15 eyes were treated, with the mean follow-up of 27 ± 8.7 months (mean ± standard deviation). Prior to treatment initiation, the ocular surface citology over the pterygium was found to be abnormal. No epithelial cells (27%) and a lower goblet cell density (73%) compared to the healthy conjunctivae (p < 0.01) were found. Squamous metaplasia was observed to some degree in the cornea (100%), pterygium (81%) and healthy conjunctivae (73%). Following treatment, pterygium composition had changed: epithelial cell number (100%) and goblet cell density (47%) had increased (p < 0.05). Goblet cell density was also increased in healthy conjunctivae (67%; p < 0.05). The degree of squamous metaplasia decreased in the cornea (67%), pterygium (45%), and healthy conjunctivae (60%; p < 0.05). No adverse effects were reported, recurrence progression was arrested, and conjunctival redness and dry-eye severity level were decreased in all cases (p < 0.01). Discussion: The cytology of ocular surface in recurrent pterygium is abnormal. After weekly intralesional 5-fluorouracil injections, it tends to normalize. The 5-fluorouracil compound is a safe and effective treatment to prevent pterygium recurrence.