PURPOSE: To explore the effectiveness and practicality of intraoperative fluorescein angiography (IOFA) in both common and rare retinal diseases. METHODS: We conducted a case series study involving three patients with vascular abnormality from various causes. A custom-designed, single-photon ultra-wideband spectral light source and integrated filters were utilized to perform IOFA. The cases included one patient with diabetic retinopathy, one with Coat's disease, and one with familial exudative vitreoretinopathy (FEVR). IOFA was performed, and individualized treatment was conducted based on the angiographic findings. RESULTS: All three patients had successful IOFA, and two of them also underwent pars plana vitrectomy (PPV) guided by the IOFA results. Postoperative outcomes were favorable, with controlled disease progression and improved or stable vision. The diabetic retinopathy patient's vision improved significantly post-surgery, the Coats disease patient's retinal detachment resolved without recurrence, and the FEVR patient showed no further bleeding on follow-up. CONCLUSION: The integration of an enhanced light source and filters reduced the transition time from standard surgical mode to angiography mode to just 10 seconds. Moreover, this study demonstrates that IOFA can effectively guide PPV surgeries and treatment for both common and rare retinal vascular diseases, offering a promising direction for personalized retinal disease management. In addition, further research and clinical trials are warranted to confirm the efficacy of IOFA-guided targeted retinal photocoagulation, particularly in diabetic retinopathy-induced vitreous hemorrhage.