Abstract

To determine and compare ocular characteristics and refractive errors between major thalassemia patients and normal subjects. In this study, 71 thalassemia major patients and 79 age and sex-matched healthy subjects that were selected in an ongoing manner underwent complete optometric and ophthalmic examinations, including autorefraction, subjective refraction, fluorescein tear break-up time, and pachymetry after anthropometric measurements. The results showed that the mean UCVA was better in the control group versus the thalassemia group (P<0.001), while there was no difference in BCVA between the two groups (P=0.416). Moreover, the mean spherical equivalent was 0.38±0.13 D less in the thalassemia group compared to the control group (P=0.007), while corneal power (P<0.001) and cylinder power (P=0.001) were larger in thalassemia patients. The most common type of astigmatism was against the rule pattern in thalassemia patients and with the rule pattern in the control group (P<0.001). The mean tear break-up time was 11.35±6.43 in the thalassemia group and 14.63±5.79 in the control group (P=0.001), and the mean near the point of accommodation (NPA) (P=0.009) and near the point of convergence (NPC). (P=0.003) were significantly smaller in the thalassemia group compared to the control group. These patients suffer from a myopic shift due to exaggerated responses to changes in ocular growth, dry eye secondary to goblet cell loss, and a higher prevalence of vertical astigmatism due to eyelid laxity and pressure on the cornea. Therefore, regular ophthalmological evaluations are highly recommended in these patients. © 2021 Tehran University of Medical Sciences. All rights reserved.