comparison of contrast sensitivity in patients with major beta-thalassemia that undergo regular transfusions and chelation therapy with Desferrioxamine (DFX) and Osveral (Deferasirox).

contrast sensitivity was measured by Freiburg software in two groups of (120 eyes) major thalassemia. One group was treated with DFX and other group within takes of Osveral. Sixty healthy eyes were considered as the control group. Normal visual acuity (20/20) and other normal finding for ocular and visual examination were considered as inclusive criteria for all groups. Contrast threshold was measured in 1, 5 and15 cpd.

comparing to the normal group; contrast sensitivity was significantly decreased in all spatial frequencies in deferoxamine group. But, Osveral group showed lower results just in lowest frequency of 1 cpd. significant decreases were seen in spatial frequency of 1cpd and 5cpd in DFX to Osveral groups. There was no correlation between duration of blood transfusion and ferritin and dose of chelator with contrast sensitivity.

contrast sensitivity problems may be seen in thalassemic patients before any other common ocular or visual problem. Treatment protocol and medications side effects may influence on visual performance and outcome. Contrast sensitivity measurement may be recommended for early detection of any visual problems in thalassemic patients.