Hyperbaric oxygen treatment results in a group of Turkish central retinal artery occlusion patients with a combined presence of thrombophilic mutations
Background: Central retinal artery occlusion (CRAO) is a rare ocular-ischemic syndrome causing irreversible blindness. Its pathophysiology has not been clarified, and no targeted therapies are available yet. Hyperbaric oxygen (HBO2) therapy is an approved therapy for CRAO and has been shown to improve the visual acuity of CRAO patients safely. However, further clinical data are required to classify HBO2 therapy as a type-I general agreement for CRAO.
Materials and Methods: Eleven patients with non-arteritic CRAO were enrolled. Patient demographics, medical history, detailed eye examinations, HBO2 therapy results, pre-/post- HBO2 therapy visual acuity measurements and genotypes for common thrombophilic mutations (Factor V G1691A Leiden, Factor II G20210A, MTHFR A1298C, MTHFR C677T, and PAI-1-675 4G/5G) were obtained.
Results: Six patients (54%) responded to HBO2 therapy compared to five non-responders (46%). Patients admitted before 12 hours responded well to HBO2 therapy. No systemic diseases nor advanced age were statistically correlated to CRAO. A combination of mutations rather than single mutations for each patient could be seen as responsible for CRAO. No Factor V G1691A Leiden mutations and only one FII G20210A mutation were observed. Eight patients (72%) had MTHFR 677T allele, five patients (45%) had MTHFR 1298C allele, and 10 patients (91%) had the PAI-1-675 4G allele.
Conclusion: Not a single mutation but a combination of mutations and other unknown factors probably lead to CRAO, and if intervention is timely, HBO2 therapy offers improvement in visual acuity safely.