Multiple transfused thalassemia major: Ocular manifestations in a hospital-based population

Abstract

Purpose:To study the ocular manifestations in multiple transfused beta-thalassemia major patients and assess the ocular side-effects of iron chelating agents.Materials and Methods:In this prospective observational study, 45 multiple transfused beta-thalassemia major children between six months and 21 years of age were enrolled and assigned groups according to the treatment regimens suggested. Group A received only blood transfusions, Group B blood transfusions with subcutaneous desferrioxamine, Group C blood transfusions with desferrioxamine and oral deferriprone and Group D blood transfusions with deferriprone. Ocular status at the time of enrolment was documented. Subjects were observed quarterly for one year for changes in ocular status arising due to the disease process and due to iron chelation therapy. Children with hemoglobinopathies other than beta-thalassemia major, congenital ocular anomalies and anemia due to other causes were excluded.Results:Ocular involvement was observed in 58% of patients. Lenticular opacities were the most common ocular finding (44%), followed by decreased visual acuity (33%). An increased occurrence of ocular changes was observed with increase of serum ferritin and serum iron levels as well as with higher number of blood transfusions received. Desferrioxamine seemed to have a protective influence on retinal pigment epithelium (RPE) mottling. Occurrence of lenticular opacities and RPE degeneration correlated positively with use of desferrioxamine and deferriprone respectively. Follow-up of patients for one year did not reveal any change in ocular status.Conclusion:Regular ocular examinations can aid in preventing, delaying or ameliorating the ocular complications of thalassemia.

Ocular abnormalities in multi-transfused beta-thalassemia patients

“…The prevalence of ocular abnormalities in the thalassemic patients has already been studied during the past decades. [ 10 11 12 13 14 15 16 17 ] In the present study, we found no significant differences in the spherical equivalent between thalassemia and normal patients, which was similar to the previous studies. [ 23 24 ] About 21.29% of our thalassemic patients had decreased visual acuity.…”

“…This observation was consistent with findings of previous studies. [ 10 11 15 ] Taneja et al . founded reduced visual acuity in 33% of their subjects which was fully correctable with corrective lenses.…”

“…Ophthalmologic changes might occur as a result of the disease itself or as side effects of iron chelators and include ocular surface disorders, cataract, angioid streak, retinal venous tortuosity, retinal toxicity, retinal pigment epithelium (RPE) degeneration and mottling, optic neuropathy, and decreased visual acuity. [ 10 11 12 13 14 15 16 17 ]…”

Retinal abnormalities in β-thalassemia major

“…Two studies documented RPE degeneration associated with deferiprone use; 86 ; 87 however, it was not possible to determine whether the degeneration was caused by iron toxicity, toxicity from prior DFO treatment, or any potential deferiprone toxicity.…”

“…Thalassemic patients may present with decreased visual acuity, color vision anomalies, night blindness, cataracts, visual field defects, and optic neuropathy. 9 ; 31 ; 36 ; 76 ; 84 ; 86 ; 87 The ophthalmic evaluation may include a dilated fundus examination (DFE), fluorescein dye retinal angiography, indocyanine green angiography, optical coherence tomography, and fundus autofluorescence. 40 ; 50 ; 53 ; 64 ; 76 ; 80 ; 91 ; 92 ; 98 Furthermore, monitoring of retinal function with ERG has been useful in β-TM patients who have nine or more years of transfusions unprotected by iron chelation therapy.…”