Comparison of the iCare tonometer with the Goldmann tonometer in Malawi

• Published in: Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft 2012-11, Vol.109 (11), p.1098-1102
• Main Authors: Hohmann, J, Schulze-Schwering, M, Chirambo Nyaka, T, Moyo, V, Kayange, P C, Doycheva, D, Batumba, N H, Spitzer, M S
• Format: Article
• Language: ger
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Equipment Design; Equipment Failure Analysis; Female; Glaucoma - diagnosis; Glaucoma - epidemiology; Humans; Malawi - epidemiology; Male; Manometry - instrumentation; Manometry - statistics & numerical data; Middle Aged; Prevalence; Reproducibility of Results; Risk Assessment; Sensitivity and Specificity; Young Adult
• ISSN: 1433-0423
• DOI: 10.1007/s00347-012-2599-7

The risk for glaucoma is 4-5 times higher in patients from sub-Saharan Africa. Thus, especially in developing countries an easy and effective method for assessing the intraocular pressure (IOP) is needed. In this hospital-based survey 150 eyes were divided into 3 groups concerning the IOP (group I  23 mmHg) and underwent examination with ultrasound pachymetry followed by iCare tonometry (ICT) and Goldmann applanation tonometry (GAT). Agreement of the measurements by two tonometers was assessed with the Bland-Altman method and the influence of the central corneal thickness (CCT) on the ICT measurements was determined. The mean difference between the IOD measured with GAT and ICT was 0.84 ± 2.63 mmHg. The differences were similar in all three groups (0.77-0.97 mmHg), however, the standard deviation in group III (4.04 mmHg) was greater than in groups I (1.98 mmHg) and II (1.79 mmHg). The mean CCT was 513.51 ± 36.22 µm. The agreement of measurements by GAT and ICT was good for lower IOP values but less accurate in patients with higher IOP values (group III). A dependency of the CCT on the ICT measurements was observed. In comparison to other countries the lowest CCTs were found in Malawian patients.