Determinants for Anemic Retinopathy
Ramesh Venkatesh
Abstract
The World Health Organization describes anemia as a condition in which the number of red blood cells or the hemoglobin (Hb) concentration within them is lower than normal (1).The optimal Hb concentration required to meet the physiological needs varies with age, sex, high altitude of stay, smoking habits, and pregnancy status (2,3).According to the World Health Organization, anemia is defined as an Hb level <13 g/dL in men and <12 g/dL in women (1).Symptoms of anemia can include fatigue, weakness, lightheadedness, headache, pallor or jaundice, tachycardia, palpitations, chest pain, dyspnoea, cold distal extremities, and claudication (4).These signs and symptoms vary in prevalence and magnitude.The common ocular features noted with anemia are conjunctival pallor, retinal abnormalities, and posterior pole pallor (5-7).Retinal abnormalities associated with anemia include the presence of hemorrhages in all layers of the retina and choroid, Roth's spots, hard exudates, cotton-wool spots, changes in the retinal vessels, optic disc edema, and pallor (8-13).The exact mechanisms leading to these fundus abnormalities are not completely understood.About 30% of the anemic patients show fundus lesions, Objectives: To study the prevalence of fundus lesions in anaemics and define the hematological risk factors for retinopathy using the receiver operating characteristic curve analysis.Methods: For this retrospective study, patients 18 years and diagnosed with anemia with dilated fundus examination by a retina specialist from May 2019-April 2020 were included.Anemic retinopathy (AR) was present if hemorrhages in different layers of the retina, Roth's spots, exudates, cotton wool spots, retinal edema, and optic disc changes were noted.Patients with secondary anemia were excluded.Two groups were identified: Group 1: Patients with AR; Group 2: Patients with no AR with normal fundus.Demographic features, fundus findings, and hematological parameters were noted.Results: 38 (30%) eyes of 23 patients had AR; 90 (70%) eyes of 47 patients had no AR.The mean age in Group 1 and Group 2 was 54.718.9 and 58.615.3years, respectively.Low hemoglobin (Hb) [mean = 7.821.64gm/dl, p=<0.001] and hematocrit [mean = 26.935.22%, p=0.002] values were noted in the AR group.AUC values for Hb (0.737) and hematocrit (0.719) were higher for the AR group.Hb < 8.95g/dl could predict AR with 85.8% sensitivity and 68.9% specificity, and hematocrit < 30.5% could predict AR with 80% sensitivity and 53.2% specificity.On regression analysis, Hb (p<0.001) and hematocrit (p=0.000) were associated with AR. Conclusion:Retinopathy is frequently seen in severe anemic patients.It is recommended that patients having low anemia should undergo a retinal examination.