Emma Chen1,2, R. C. Andrew Symons1,3, Eleni Mayson4, Simon Skalicky1,3

Purpose: To report a case of glaucoma and the inherited red cell membranopathy hereditary spher- ocytosis diagnosed simultaneously in two individ- uals in a family.
Method: Case report.
Results: A 66-year-old man presented with cystoid macular oedema (CME) in the right eye secondary to a branch retinal vein occlusion following one- week history of blurred vision. The patient was inci- dentally found to have bilateral glaucomatous discs (cup-to-disc ratios 0.8 with SINT configuration). Optical coherence tomography of the discs revealed retinal nerve fibber layer (RFNL) thinning in the left eye, whilst RNFL findings in the right eye were obscured by the CME. The patient’s medical history

was significant for hereditary spherocytosis. His maternal grandmother, who had hereditary sphero- cytosis, was also diagnosed with glaucoma in her 60s. Hereditary spherocytosis is the most common inherited erythrocyte membrane disorder, resulting in less deformable erythrocytes and haemolytic anaemia. We hypothesized that the abnormal rheol- ogy of the less deformable erythrocytes in hereditary spherocytosis may impair perfusion to the optic nerve. Additionally, reduced surface-to-volume ratio of the erythrocytes in hereditary spherocytosis reduces oxygenation at tissue level. Free oxyhaemo- globin from haemolysis may also disrupt autoregu- lation of the peripapillary capillary network.
Conclusion: This is the first reported case of glau- coma and hereditary spherocytosis co-occurring in a family, with possible connection between the two conditions. Hereditary spherocytosis may be a risk factor for glaucoma. Whilst studies are underway to investigate the role of abnormal erythrocytes in the pathogenesis of glaucoma, examination of patients with red cell disorders for glaucoma would be interesting.