NOV 09, 2011
The authors report a rare case of severe bilateral optic atrophy as a sequela of thalassemia intermedia. After treatment with blood transfusions and acetazolamide, the patient experienced decreased headaches but little visual improvement. The authors conclude that decompression of extramedullary hematopoietic tumors from thalassemia may be achieved with blood transfusions alone without the need for radiation or surgery. They say these findings suggest careful periodic ophthalmic examination of thalassemic patients.
They describe the case of a 21-year-old man with beta-thalassemia intermedia who was referred to an ophthalmology clinic for progressively decreasing, blurred vision and a headache that was global, constant, sustained and gradually increasing in intensity. Visual acuity was counting fingers at 2 meters in the right eye and hand motions in the left eye. Orbital and brain neuroimaging revealed massive diffuse expansion of the diploe of the craniofacial bones, narrowing of the optic canals and expansion of hematopoietic tissue in the sellar region with compression of the optic chiasm.
The patient was treated with regular blood transfusions and 250 mg of acetazolamide three times daily but refused surgical intervention and radiotherapy. Three months later, he reported decreased headaches but no change in vision. After 13 months, visual acuity was counting fingers at 2 meters in the right eye and at 0.5 meters in the left eye. Marked bilateral optic atrophy was present. He declined further evaluation and treatment.
The authors know of just three previously reported cases of optic atrophy secondary to expanded hematopoietic tissue in thalassemia. They conclude that a number of factors led to the optic nerve involvement and profound visual loss in their patient. First was the direct compressive effect of extramedullary hematopoietic tissue, arising from clivus and sphenoid bones, upon the optic nerves and chiasm. Second, the optic nerves were also compressed by narrowed optic canals resulting from expansion of medullary spaces of the sphenoid bone. Third, compression of the intracranial contents by expanded diploe led to raised intracranial pressure and the fundus findings of chronic papilledema. Finally, they say it is possible that the enlarged diploe may have compressed dural sinuses, impairing venous drainage and contributing to increased intracranial pressure.
The authors conclude that while therapeutic options continue to evolve in the management of thalassemia, blood transfusions should be considered as the first step in the management of these patients. Surgery and radiotherapy may also be beneficial in some cases. Bone marrow transplantation and gene therapy offer the possibility of curative treatment in the future.