Dry eye in thalassemia.

Abstract

β-Thalassemia is an autosomal recessive single gene disorder with mutations in the b-globin gene, resulting in faulty b-chain production, insufficient erythropoiesis, abnormal destruction of red blood cells, and consequent anemia.[1] Patients with thalassemia major are diagnosed in the early years of life and require lifelong blood transfusions and might also need subsequent iron chelation therapy. Patients with thalassemia intermedia (TI) can present with moderate anemia that does not require blood transfusions.[2] Dry eye has been reported to be one of the ocular associations of thalassemia, along with cataract, color blindness, visual field defects, pseudoxanthoma elasticum, and retinal pigment epithelium degeneration.[1,3,4] Case Report A 2-year-old boy was brought by his mother with complaints of intolerance to light. Ocular examination showed diffuse corneal punctate epithelial erosions, immediate break up of tear film, corneal haze, and severe intolerance to light. The systemic evaluation revealed frontal bossing and malar prominence [Fig. 1c] suggestive of hemolytic facies, pallor, cutaneous xerosis [Fig. 1d], hepatosplenomegaly, developmental delay, and microcephaly. Thalassemia screening performed at 1 year of age showed microcytic hypochromic anemia, anisopoikilocytosis, and tear-drop cells on a peripheral blood smear. Although his serum ferritin level was 20.2 ng/ml, his Mentzer index (11.2) was strongly suggestive of thalassemia. High-performance liquid chromatography (HPLC) showed a low fetal hemoglobin (<0.8%) and elevated HbA2 level (3.4%). Following this evaluation, the child had been started on oral iron and folate therapy. His mother also had chronic dry eye and typical facial features of thalassemia [Fig. 1e] along with a history of chronic anemia for which she was put under treatment with oral iron supplements by her treating physician. Her ocular examination revealed pallor of the palpebral conjunctiva, decreased tear film height, diffuse corneal epithelial erosions with scarring, and peripheral conjunctivalization [Fig. 1a and b]. Fundus examination was normal in both eyes, and the best corrected visual acuity was 6/12 in the right eye and 6/18 in the left eye. Both the mother and child were treated with preservative-free eye drops and lubricants along with supportive lifestyle measures. In concurrence with the clinical and hematological picture, a differential diagnosis of TI was made, and they were referred to a higher center for further management.Figure 1: (a and b) Diffuse slit-lamp image showing a lusterless cornea, corneal scarring, and peripheral conjunctivalization. (c) Image of 2-year-old showing frontal bossing. (d) Dry and scaly skin (cutaneous xerosis) of lower limbs. (e) Image of the mother showing frontal bossing and malar prominenceDiscussion Features of the thalassemia trait and TI can closely resemble iron deficiency anemia (IDA). However, differentiating the two conditions is important as hemoglobin may not improve with oral iron therapy in TI and might in turn precipitate an iron overload. Major differentiating points between IDA and TI are that TI shows normal serum ferritin levels and raised HbA2 levels (>3.2%), and anemia is unresponsive to iron therapy.[2] Studies have also shown that hepcidin, which is involved in the regulation of iron absorption and transport is suppressed in TI, leading to increased intestinal iron absorption, which can be worsened by prolonged oral iron therapy.[5] Conjunctival squamous metaplasia, goblet cell loss, and lower tear film break-up time have been reported in thalassemia patients with ocular surface disorders.[6] It has been postulated that accumulation of iron in the lacrimal glands has cytotoxic effects, consequently leading to aqueous deficiency and dry eye.[3] With advancing diagnostic and treatment modalities for thalassemia, it is imperative to identify associated ocular abnormalities to ensure comprehensive management. Differentiation between IDA and TI is crucial to avoid mismanagement of the latter with oral iron therapy as an iron overload might possibly precipitate ocular surface disorders. Conclusion Appropriate and timely management of dry eyes is necessary to improve patient comfort and alleviate the sequelae of ocular surface disorders. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Aravind eye hospital, Pondicherry. Conflicts of interest There are no conflicts of interest.