Crystalline lens dislocation as a presenting sign of Streptococcus pyogenes invasive infections

<b>Introduction.</b> To describe two cases of crystalline lens dislocation as a presenting feature of invasive group A <i>Streptococcus</i> (GAS) infection and its management. <b>Case presentation.</b> We report on a 58-year-old woman and a 36-year-old man who presented in 2024 with acute vision loss and severe ocular and systemic symptoms. Both patients were found to have lens dislocation and were diagnosed with invasive GAS infection. The 58-year-old woman had a complicated clinical course leading to enucleation, while the 36-year-old man responded favourably to early and aggressive treatment with systemic and intravitreal antibiotics. The responsible GAS strains were sequence type (ST) 28 and ST433, respectively. <b>Conclusion.</b> These cases highlight the importance of recognizing crystalline lens dislocation as a potential sign of ocular GAS infection. Two specific strain types of GAS associated with these findings, ST28 and ST433, are reported. In patients with GAS sepsis presenting with corneal oedema and zonular loss, clinicians should immediately initiate treatment, including intravitreal antibiotic injections and systemic therapy. Prompt and aggressive management can be crucial in preserving ocular structures.