Refractive errors and ocular biometry components in thalassemia major patients

Ocular biometry, anterior chamber morphometry, and their relationship with serum ferritin levels in children with beta thalassemia major

Background

Ocular biometry and anterior segment evaluations are important to determine ocular development and pathological changes, especially in thalassemia patients in Mediterranean countries such as Turkey.

Objectives

The objectives of this study were to compare ocular biometry and anterior segment parameters in children with thalassemia major and healthy controls and to examine the relationship between ferritin levels, anthropometric measurements, and ocular parameters.

Design

This is a prospective case-control study.

Methods

The height, weight, body mass index, and occipitofrontal circumference values of the participants were recorded. Anterior and vitreous chamber depth, lens thickness, axial length, central corneal thickness, anterior chamber volume, iridocorneal angle, pupil diameter, and mean keratometry were measured. Measurements were compared between patients and healthy children, and between patients with ferritin levels above and below 1000 ng/mL.

Results

This study included 40 patients and 45 controls. Height, weight, and body mass index were significantly lower while ferritin level and occipitofrontal circumference were significantly higher in patients compared with the controls (p < 0.001 for all). There were no statistically significant differences in the other ocular parameters (p > 0.05). In comparisons between patients with ferritin levels below (n = 15) and above 1000 ng/mL (n = 25), there were no significant differences in age, height, weight, body mass index, occipitofrontal circumference, or ocular parameters (p > 0.05). Occipitofrontal circumference and mean keratometry value were positively correlated in patients with ferritin levels below 1000 ng/mL (r = 0.573, p = 0.025), while body mass index was negatively correlated with pupil diameter in patients with ferritin levels above 1000 ng/mL (r = -0.469, p = 0.018).

Conclusion

Children with thalassemia showed significant growth retardation and large occipitofrontal circumference but did not differ from controls in terms of biometrics and anterior segment morphology. Our results demonstrated a positive correlation between the occipitofrontal circumference and mean keratometry value in children with ferritin levels below 1000 ng/mL and a negative correlation between body mass index and pupil diameter in children with ferritin levels above 1000 ng/mL.

Increased Endothelial Cell Density in Childhood Patients With Thalassemia Major

PURPOSE

We aimed to compare specular microscopy, biometric, refractive, and anterior segment topographic parameters in children with thalassemia major (TM) with normal children of the same age.

MATERIAL METHOD

This cross-sectional study included 55 eyes of 55 patients with TM and 63 eyes of 63 age-sex-matched healthy children; all patients with TM were receiving treatment with blood transfusions every 3 to 4 weeks and an oral iron chelator deferasirox (DFX) (ICL670) tablet. A comprehensive ophthalmic examination was performed, including refraction (spherical equivalent), best-corrected visual acuity, slit-lamp bio microscopy, specular examination, optical biometry, intraocular pressure, anterior segment topography, and fundus examination.

RESULTS

Endothelial cell density (ECD) was 3,138 in the TM group and 2,996 in the control group (P=0.003). The mean central corneal thickness was significantly thinner in the TM group (P=0.010). Flat keratometry (K1) was 43.5 D in the study group and 42.9 D in the control group (P=0.039). The mean anterior chamber depth (ACD) was shallower in the TM group (P=0.004); axial length (AL) was significantly shorter in the TM group (P=0.002).

CONCLUSION

This study shows that there are differences in ECD, AL, keratometry values, ACD, and anterior segment parameters of pediatric patients with TM compared with healthy controls.

Ocular findings in patients with transfusion-dependent β-thalassemia in southern Iran

Background

Ocular involvement may occur via several mechanisms in patients with transfusion-dependent β-thalassemia (TDT) mainly chronic anemia, iron overload and iron chelator toxicity. We aimed to evaluate the frequency of abnormal ocular findings and their relationship with hematologic parameters in TDT patients.

Methods

In this cross-sectional study from January 2018 to January 2019, a total of 79 patients with TDT over the age of 18 who were on iron-chelation therapy (ICT) were consecutively investigated. All patients were registered at the Thalassemia Comprehensive Center affiliated with Shiraz University of Medical Sciences, Shiraz, Southern Iran. Complete ophthalmic examination was performed by an expert ophthalmologist. Clinical and hematologic parameters were collected from the patients´ medical records.

Results

The mean age ± standard deviation (SD) of the patients was 28.4 ± 5.6 years (range: 18–43). Twenty-four patients (30.4%) were male and 29 (36.7%) were splenectomized. The mean ± SD of the best-corrected visual acuity (VA) was 0.960 ± 0.086 decimal, (range: 0.6–1), 0.016 ± 0.046 logMar, (range: 0–0.2). The frequency of patients with VA > 0.1 logMar was 3 (3.8%). The mean intraocular pressure (IOP) was 14.88 ± 3.34 (6–25) mmHg. Fundus abnormalities were observed in 8 patients (10.1%), consisting of increased cup-disk ratio (3.8%), vessel tortuosity (2.5%), retinal pigment epithelium degeneration (2.5%), myelinated nerve fiber layer (1.3%), and internal limiting membrane wrinkling (1.3%). No significant association was observed between fundus abnormalities, VA, or IOP with hematologic parameters (P > 0.05). TDT patients with diabetes mellitus had significantly higher IOP (P = 0.010) but similar frequency of fundus abnormalities with non-diabetic patients (P > 0.05).

Conclusions

The frequency of ocular abnormalities in our patients was lower than the previous reports. The frequency of fundus abnormalities were similar in diabetic and non-diabetic thalassemia patients indicating close monitoring and proper management of the disease and comorbidities in these patients.

Anterior Chamber Angle, Intraocular Pressure, and Globe Biometric Parameters in the Children with &beta;-Thalassemia Major

Background

To evaluate the intraocular pressure (IOP), anterior chamber angle (ACA), and globe biometric parameters in β-thalassemia major children and the correlations of these changes.

Materials and methods

Eighty-four eyes were included (42 eyes of thalassemia patients and 42 eyes of control). All participates underwent head circumference and height measurements, full ophthalmic examination, anterior segment optical coherence tomography (AS-OCT), and A-scan biometry.

Results

The temporal angle of anterior chamber (T-ACA) was significantly narrower in thalassemia patients with p value = 0.008. While the nasal angle showed a nonsignificant narrowing with p value = 0.153. This narrowing was positively correlated with the height, and negatively correlated with the head circumference. Intraocular pressure was statistically higher in thalassemia patients with p value = 0.000. The increased IOP was positively correlated with the head circumference and the lens thickness (LT) and negatively correlated with T-ACA, axial length (AL), vitreous chamber depth (VCD), and anterior chamber depth (ACD). Axial length, ACD, and VCD significantly decreased with p value = 0.000 for all with a positive correlation with the height and a negative correlation with the head circumference. The LT increased in thalassemia group with p value = 0.000. This increase was positively correlated with the head circumference and negatively with the height. Also, there was steeper corneal curvature in thalassemia group with p value = 0.023 and 0.015 (for K₁ and K₂, respectively). No significant change was observed in corneal thickness in both groups with p value = 0.810.

Conclusion

Narrower T-ACA, increased IOP, shorter (AL, VCD, and ACD), steeper corneal curvature, and thicker lens were found in thalassemia patients.

How to cite this article

El-Haddad NSM. Anterior Chamber Angle, Intraocular Pressure, and Globe Biometric Parameters in the Children with β-Thalassemia Major. J Curr Glaucoma Pract 2020;14(1):30–36.

Ocular abnormalities in beta thalassemia patients: prevalence, impact, and management strategies

BACKGROUND

Beta thalassemia (β-thalassemia) is a hereditary disease caused by defective globin synthesis and can be classified into three categories of minor (β-TMi), intermedia (β-TI), and major (β-TM) thalassemia. The aim of our study is to investigate the effects of β-thalassemia and its treatment methods on different parts of the eye and how early-diagnostic methods of ocular complications in this disorder would prevent further ocular complications in these patients by immediate treatment and diet change.

METHODS

We developed a search strategy using a combination of the words Beta thalassemia, Ocular abnormalities, Iron overload, chelation therapy to identify all articles from PubMed, Web of Science, Scopus, and Google Scholar up to December 2018. To find more articles and to ensure that databases were thoroughly searched, the reference lists of selected articles were also reviewed.

RESULTS

Complications such as retinopathy, crystalline lens opacification, color vision deficiency, nyctalopia, depressed visual field, reduced visual acuity, reduced contrast sensitivity, amplitude reduction in a-wave and b-wave in Electroretinography (ERG), and decrease in the Arden ratio in Electrooculography (EOG) have all been reported in β-thalassemia patients undergoing chelation therapy.

CONCLUSION

Ocular problems due to β-thalassemia may be a result of anemia, iron overload in the body tissue, side effects of iron chelators, and the complications of orbital bone marrow expansion.

Evaluation of serum levels in T3, T4 and TSH in beta-thalassemic patients referred to the Abuzar hospital in Ahwaz

INTRODUCTION

Regarding the functioning of the endocrine system, and especially in the thyroid of patients with thalassemia, multiple studies in different parts of the world have reported conflicting results. The aim of this study was to assess the levels of thyroid hormones and TSH in beta-thalassemic patients in the city of Ahwaz.

METHODS

In this matched case-control study, 105 patients in the case group and 105 subjects as controls were randomly selected from clients referred to the Abuzar hospital in 2015-2016. Serum levels of T3, T4, and TSH hormones were measured using ELISA. Data was processed with the SPSS15 software and tested by using independent t-tests and logistic regression.

RESULTS

The study results showed that the serum level of T3 hormone did not significantly differ between the two groups (p> 0.05). Whereas the serum level of T4 was lower in the case group, compared to the controls, which was statistically significant (p <0.05). The serum level of thyroid stimulating hormone (TSH) in the case group was higher than the control group, and this difference was statistically significant (p <0.05). Logistic regression analysis showed significant differences in serum levels of T4 (OR: 0.58) and TSH (OR: 1.57) between the case and control groups (p<0.05).

CONCLUSION

Hypothyroidism is clear in patients with beta thalassemia. With regard to the possible effect of iron on the disorder, a blood transfusion schedule should be performed at intervals, and the desferal injection program should be done regularly to prevent hemochromatosis in patients with thalassemia major due to the effect of accumulation of iron on thyroid function and detection of hypothyroidism. This course of action will prevent incidence of this complication in patients with thalassemia major.