A Study to Evaluate the Safety and Tolerability of ONL1204 in Patients With Macula-off, Rhegmatogenous Retinal Detachment

Inclusion Criteria: 1. Males and females, ≥ 18 to 80 years old 2. Able to give informed consent and comply with all study visits and procedures 3. Patients who: 1. Present between 1 week (7 days) and 4 weeks (28 days) of a macula-off RRD (based on patient-reported history of loss of central vision) 2. For whom standard retinal reattachment surgery by means of a pars plana vitrectomy (with or without scleral buckle) and gas tamponade is indicated, and 3. In the opinion of the investigator, can safely undergo all study procedures. 4. Best corrected Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity of 20/100 to hand motion in the study eye 5. Best corrected ETDRS visual acuity in the fellow eye of 20/60 or better Exclusion Criteria: 1. Presence of giant retinal tear defined as greater than 3 clock hours or other type of complex retinal detachment in the study eye 2. Presence of vitreous hemorrhage in the study eye 3. Presence of ocular or periocular infection or intraocular inflammation in either eye 4. Intraocular Pressure \> 22 mmHg in the study eye 5. Any other significant ocular disease in the study eye including media opacity that, in the opinion of the investigator, would preclude a visual acuity of at least 20/25 following successful vitrectomy or limit adequate visibility of the retina 6. Any other ocular pathology in the study eye requiring treatment with topical ophthalmic drops or intravitreal injection 7. History of previous ocular surgery in the study eye other than uncomplicated cataract surgery with posterior chamber intraocular lens and intact posterior capsule (which must have occurred at least 6 months prior to the baseline visit) 8. Participation in other clinical trials or use of any other investigational drugs or devices within 3 months prior to study participation 9. Females who are pregnant or lactating and women of childbearing potential who are not using adequate contraceptive precautions (e.g., intrauterine device, oral contraceptives, barrier method, or other contraception deemed adequate by the investigator) 10. Known retinopathy, known hepatic disease (or history of significant chronic liver disease), or known renal disease. Patients with diabetes and no known retinopathy may be enrolled 11. History of uncontrolled hypertension 12. History of stroke, transient ischemic attack, or major cardiac surgery within 3 months prior to study, or current treatment for systemic infection 13. Any ocular or systemic condition that in the opinion of the investigator could compromise the safety of the patient, or may interfere with the safety and tolerability assessments or study procedures of the trial