Central corneal thickness among glaucoma patients attending Menelik II Hospital, Addis Ababa, Ethiopia


Abstract Background: Glaucoma is one of the leading causes of blindness. Intra-ocular pressure is the main and only manageable of all risk factors for glaucoma. The central corneal thickness has been shown to affect the intra-ocular pressure measurement and is different among different ethnic population and subtypes of glaucoma. The central corneal thickness of different subtypes of glaucoma at Menelik II Hospital has not been determined. Objective: The objective of this study was to measure the mean central corneal thickness of different sub types of glaucoma and ocular hypertension of patients attending Menelik Hospital. Participants and Methods: A cross sectional comparative hospital-based study was carried out at the glaucoma clinic of Menelik ΙΙ Hospital to assess the pattern of central corneal thickness of patients with different subtypes of glaucoma from 01 May 2014 to 30 August 2014. Central corneal thickness was determined by taking average of six measurements using ultrasonic Pachymetry. All consecutive open angle glaucoma patients and age matched non-glaucoma patients were included in the study. Eyes with incisional surgery, corneal diseases or trauma were excluded. Data was collected entered, cleaned and analyzed using SPSS windows version 16. Level of significance was taken at 5% for association of corneal thickness measurement and glaucoma subtypes. Results: One hundred fourteen patients were examined. Twenty-three had primary open angle glaucoma, 16 had pseudoexfoliative glaucoma, 15 had Ocular hypertension, 32 had Normal tension glaucoma, and 28 were non-glaucoma patients. The mean Central corneal thickness for the group with Ocular hypertension, Primary open angle glaucoma, Pseudoexfoliative glaucoma, Normal tension glaucoma and non- glaucoma was 562.5±24.5μm, 517.5±27.5μm, 512.5±32.1μm, 488.0±32.4 μm, and 516.2±23.4μm respectively. Mean central corneal thickness in the ocular hypertension group was significantly higher (P<0.001) than primary open angle glaucoma, pseudoexfoliative glaucoma, normal tension glaucoma subtypes and non-glaucoma patients. Patients with normal tension glaucoma had significantly lower mean central corneal thickness (P<0.001) than primary open angle glaucoma, pseudoexfoliative glaucoma, subtypes, ocular hypertension and non-glaucoma group. Conclusions: Patients with ocular hypertension had a higher mean central corneal thickness. By contrast, the mean central corneal thickness of patients with normal tension glaucoma was relatively low. [Ethiop. J. Health Dev. 2018;32(1):54-59] Key words: Central corneal thickness glaucoma, intraocular pressure, pachymetry