Transitory vitreous opacities after CB-PRP intravitreal injections in dry AMD patients

Dry age-related macular degeneration currently lacks effective treatments for geographic atrophy. Cord blood platelet-rich (CB-PRP) plasma intravitreal injections are a novel therapy under investigation with promising ad interim results.

To describe the safety profile of cord blood platelet-rich plasma intravitreal injections (IVIs) in dry age-related macular degeneration (AMD) patients.

This prospective, randomized, sham-controlled, open-label experimental trial evaluated the safety of repeated intravitreal CB-PRP injections.

The study, conducted from January 2023 to January 2025, investigated the safety and efficacy of CB-PRP IVIs to slow down the progression of geographic atrophy (GA). One eye of each patient was randomly assigned to the monthly, every other month, or every 3 months arm and received 0.05 mL CB-PRP, while the other eye underwent only a sham injection. Complete ophthalmological evaluations were performed at baseline, 3-, 6-, 12-, 18-, and 24-month follow-ups. In addition, slit-lamp and fundus examinations were performed the day after the injection to exclude any adverse effect.

In a total of 328 intravitreal injections, vitreous opacities were observed in the absence of other signs of infection or inflammation only in three cases. All of them showed progressive improvement without treatment, and complete recovery was observed within 2 weeks.

Although the pathogenesis of the detected vitreous thickening was not completely clear, the most likely hypothesis was the coexistence of a slightly lower temperature of the CB-PRP sample and individual factors. This mild adverse event occurred only once in each patient involved, with no recurrence during subsequent intravitreal injections. The occurrence of this self-limiting finding after CB-PRP IVIs has not invalidated the safety profile of the procedure.