Central corneal thickness and intraocular pressure in the Cameroonian nonglaucomatous population

André Omgbwa Eballe¹, Godefroy Koki², Augustin Ellong², Didier Owono², Emilienne Epée², Lucienne Assumpta Bella², Côme Ebana Mvogo¹, Jeanne Mayouego Kouam<sup>2

1</sup>Faculty of Medicine and Pharmaceuticals Sciences, University of Douala; ²Faculty of Medicine and Biomedical Sciences, University of Yaoundé, Cameroon

Aim: We performed a prospective, analytical study from 01 January to 31 March 2009 in the Ophthalmology Unit of the Gyneco-Obstetric and Pediatric Hospital of Yaounde, aiming to determine the profile of central corneal thickness (CCT) in the Cameroonian nonglaucomatous black population and its relationship with intraocular pressure (IOP).

Results and discussion: Four hundred and eighty-five patients (970 eyes) meeting our ­inclusion criteria were selected for this study. The average CCT was 529.29 ± 35.9 µm in the right eye (95% confidence interval [CI]: 526.09–532.49), 528.19 ± 35.9 µm in the left eye (95% CI: 524.99–531.40) and 528.74 ± 35.89 µm in both eyes (95% CI: 526.48–531.00), range 440 to 670 µm. The average IOP was 13.01 ± 2.97 mmHg in both eyes (95% CI: 12.82–13.19). A rise in CCT by 100 µm was followed by an increase in IOP of about 2.8 mmHg (95% CI: 2.3–3.6) for both eyes taken together. Linear regression analysis showed that corneal thickness was negatively correlated with age and IOP was positively related with age.

Conclusion: CCT in the Cameroonian nonglaucomatous black population was found to be lower compared with CCT values in Caucasian and Asian populations. On the basis of reference values ranging between 527 and 560 µm, an adjustment of IOP values by a correction factor is required for many Cameroonian patients. This will improve the diagnosis and follow-up of glaucoma by helping to detect true ocular hypertension.

Keywords: central corneal thickness, intraocular pressure, Cameroon