Demographic Characteristics of Normal Tension Glaucoma Seen in a Suburban Tertiary Hospital

Abstract

Introduction: Normal Tension Glaucoma (NTG) is a form of glaucoma in which there are distinct demographic characteristics and associated factors to its development. Identifying these characteristics helps early diagnosis and prevention of blindness. Aim of the study is to identify the various demographic characteristics and associated factors with the diagnosis of NTG in patients presenting to the glaucoma clinic of a tertiary hospital. Methods: All consecutive newly diagnosed glaucoma patients attending the eye clinic of EKSUTH, Ado Ekiti, from January 2012 to December 2014 were selected for the study. They all had thorough ocular and systemic examination. The patients with diagnosis of normal tension glaucoma had a protocol prepared for the study administered on them. Demographic data, family history of glaucoma, history of migraine, hypertension, and use of antihypertensive drugs at night were obtained from them. Data were analysed using SPSS version 18 and presented as tables, and figures, in frequencies, and percentage. Result: A total of 1265 patients were newly diagnosed to have glaucoma, of these, 864(68.3%) were POAG, 336(26.6%) were secondary glaucomas, 48(3.8%) normal tension glaucoma, 12(0.9%) angle closure glaucoma and 5(0.4%) were developmental glaucoma. Among the NTG patients, 30(62.5%) were females and 18(37.5%) males, (M:F =1.7:1) Age range was between 30years to 68years, median age of 59.3years. The identifiable associated factors in NTG patients include; family history of glaucoma 33(68.8%), hypertension and use of antihypertensive at night before sleep 24(50%), history suggestive of sleep apnea 6(12.5%), migraine headaches 10(20.8%) and thyroid disease 2(4.2%). No statistically significant association of these factors with severity of visual field defect in the subjects studied. Conclusion: This study suggests that age and positive family history of glaucoma are important demographic characteristics for consideration in diagnosis of NTG.