Contrast sensitivity function in patients with beta-thalassemia major

Purpose: To investigate contrast sensitivity function in patients with beta -thalassemia major, after regular transfusion and chelation therapy, Methods: We measured contrast sensitivity at four spatial frequencies in 30 patients with beta-thalassemia major and in 30 matched normal control subj ects. All subjects underwent an ophthalmic examination that included fluore scein angiography, The contrast sensitivity results from the two groups wer e compared between them, Patients' contrast sensitivity values were correla ted to the variables age, duration of transfusion, duration of chelation th erapy and serum ferritin levels, to select the important predictors. Results: Contrast sensitivity function in all beta-thalassemic patients was significantly lower (p < 0.0001) compared to the normal control subjects, for all spatial frequencies tested. The most important predictor of contras t sensitivity loss was patients' age. Conclusion: Contrast sensitivity testing can detect early changes in the vi sual function of beta-thalassemic patients and should be considered as a mo nitor for patients under chronic transfusion-chelation therapy.