When diabetic retinopathy is not the whole story: Acute myeloid leukaemia presenting as bilateral haemorrhagic retinopathy with optic disc swelling

Purpose: To report acute myeloid leukaemia (AML) presenting with bilateral retinopathy initially attributed to diabetic retinopathy in a young adult with type 1 diabetes, and to highlight the features that should prompt haematological investigation.

Methods: Retrospective case report: review of clinical records, multimodal retinal imaging and haematological and neuroimaging findings. Oral informed consent was obtained from the patient.

Results: A 34-year-old woman with a 17-year history of type 1 diabetes, who had never attended diabetic eye screening, presented with four days of sudden, painless bilateral blurred vision (VA Right 6/18, Left 6/30). There was no headache, diplopia or red desaturation and the anterior segments were normal. Fundoscopy showed widespread dot-and-blot haemorrhages and roth spots without neovascularisation; OCT showed bilateral cystoid macular oedema and optic disc swelling. HbA1c was 53 mmol/mol and blood pressure 155/93mmHg. Severe non-proliferative diabetic retinopathy was initially suspected. Full blood count showed marked pancytopenia (WBC 2.81 ×10⁹/L, haemoglobin 62g/L, platelets 17 ×10⁹/L) with circulating blasts on the blood film. Bone marrow examination confirmed AML with adverse-risk cytogenetics and chemotherapy was started. The retinal findings were re-attributed to leukaemic retinopathy. MRI brain report showed bilateral posterior choroidal thickening and enhancement, consistent with leukaemic infiltration. The retinal findings were re-attributed to leukaemic retinopathy. Follow up in 6 weeks revealed the following findings, vision improved to (VA Right 6/9, Left 6/9) although OCT showed worsening DMO with subretinal fluid. The plan was for leukaemia treatment to continue and for continuous monitoring by medical retina team.

Conclusion: Leukaemic retinopathy can closely mimic severe diabetic retinopathy, and a known diagnosis of diabetes invites anchoring. Sudden bilateral visual loss, Roth spots, optic disc swelling, and retinopathy atypical of or disproportionate to the diabetic history should prompt an urgent full blood count and film, which may reveal life-threatening systemic disease.