Retinal nerve fiber layer thickness evaluation in iron deficiency anemia patients using optical coherence tomography

Abstract

Background Anemia is a widespread public health problem. Iron deficiency is the most common cause of anemia. Hemoglobin (Hb) concentration was supposed to affect the retinal nerve fiber layer thickness (RNFLT). Objective The aim of this study was to evaluate the influence of iron deficiency anemia (IDA) on the peripapillary RNFLT using optical coherence tomography (OCT). Patients and methods A total of 30 patients with IDA with Hb less than 12 g/dl were enrolled in the study. Optic disk and RNFL parameters obtained by Topcon OCT in these patients were compared with those of age-matched and sex-matched nonanemic 30 individuals. The anemia group was also divided according to the Hb concentration into three groups: mild, moderate, and severe. Results The average age of the IDA cases and the controls was 23.38±9.06 years (range=15–30 years), and 25.37±7.64 years (range=15–30 years), respectively (P=0.09). The average right eye RNFLT in IDA patients was 98.20±10.98 μm compared with 106.30±14.05 μm in the control group (P=0.001), while in the left eye, it was 98.87±12.24 μm in the IDA group, and 105.30±6.59 μm in the control group (P=0.015). The average nasal and inferior RNFLT of the IDA group were thinner than the control group in the right eye (P=0.003 and 0.045, respectively) and in the left eye (P=0.016 and 0.038, respectively). There was a positive association between average RNFLT and Hb concentration in the right eye (r=0.554) and in the left eye (r=0.561), which was statistically significant (P=0.001). In addition, there was a positive correlation between nasal and inferior RNFLT and Hb concentration in the right eye (P=0.002 and 0.001, respectively) and in the left eye (P=0.001 and 0.002, respectively). The degree of thinning was related to the severity of anemia as the RNFL thinning was significantly more in severe anemia cases than in mild and moderate ones. Conclusions The peripapillary RNFLT measured by OCT was significantly thinner in the IDA patients in the average, inferior, and nasal quadrants, with more thinning in the severe than in mild and moderate groups. This finding may have a significant effect, as these pseudoglaucomatous changes could be misdiagnosed as glaucoma or other neuro-ophthalmological disorders.