Central Corneal Thickness Measurement of Non-glaucomatous Adults Attending the Eye Clinic of Ahmadu Bello University Sick Bay, Samaru, Zaria

Glaucoma

Abstract

Background: Central Corneal Thickness (CCT) is the measurement of the centre of the cornea and is a parameter for assessing the  corneal health status.1 CCT provides valid information about corneal physiological condition and possible changes associated with  diseases, trauma, and hypoxia.2 Normal mean values for CCT range between 521µm and 554µm. Due to racial and age differences, this  is an important factor to consider when measuring intra-ocular pressure (IOP).3 The CCT is reported to influence the IOP measurement during applanation tonometry, with over estimation of IOP in thicker corneas and an underestimation in thinner  corneas.The objectives of the study were; to determine the mean Central Corneal Thickness (CCT) of non-glaucomatous adults attending the Eye Clinic of Ahmadu Bello University (ABU) Samaru, Zaria and to determine the correlation between CCT and IOP, age,  gender, and refractive error 

Methods: Consenting adults who met the inclusion criteria were selected using simple random sampling. The inclusion criteria were; participants >18 years of age with no history of diabetes, contact lens wear, ocular trauma, previous eye surgery, glaucoma, corneal  scar, use of drugs that affect the cornea such as carbonic anhydrase inhibitor, prostaglandins, and steroids. An IOP of < 21 mmHg and  refractive error. The participants had visual acuity assessment for both distance and near and detailed ocular examination. The IOP  was measured using Perkins MK3 hand-held applanation tonometer taking average of 3 readings, while CCT was measured taking  average of five readings using Pacscan 300 AP ultrasonic pachymeter, in the multiple point, multiple reading mode. Data was entered  in a pretested questionnaire and analysed using Statistical Package for the Social Sciences (SPSS) version 23.0.