The objective is to evaluate the safety and efficacy of low dose and high dose CBT-001 eye drop dosed twice daily for 24 months compared to vehicle in reducing conjunctival hyperemia and preventing pterygium progression in eyes with pterygia.

Clinical Hypotheses:

1. CBT-001 dosed twice daily is more effective than vehicle in:

   • Reducing conjunctival hyperemia by demonstrating a statistically significant difference and clinically relevant improvement in the mean severity grade change from baseline.
   • Preventing pterygium progression, by demonstrating a statistically significant and clinically relevant improvement on drug vs vehicle mean difference in the change in pterygium length from baseline.

2. CBT-001 dosed twice daily maintains the above efficacies and has an acceptable ocular and systemic safety and tolerability profile when administered topically.

Inclusion Criteria:

Pterygium with conjunctival hyperemia

Exclusion Criteria:

Pterygium removal within the last 6 months