Comparative analysis of Maklakov and automated ocular tonometry methods of intraocular pressure measurement

Abstract

PURPOSE. To study the factors affecting the results of intraocular pressure (IOP) measurement by different ocular tonometry methods.MATERIAL AND METHODS. The study involved 72 patients (128 eyes) aged 22 to 86 years. IOP was measured in all patients using Corvis ST tonometer, Topcon ST-800 pneumotonometer, iCare IC 100 portable tonometer, and Maklakov applanation tonometer. The results of IOP measurements were analyzed depending on the following factors: age, gender, presence of glaucoma or suspicion for glaucoma, presence of refractive errors, axial length of the eye, thickness of the cornea.RESULTS. The greatest difference in IOP values was observed between the Maklakov method (tonometric IOP) and iCare IC 100 device (true IOP). In some cases (9–22%), tonometric IOP obtained using the Maklakov method was equal or lower than the values obtained with other methods.Results of the correlation analysis confirmed the high correlation of the IOP values obtained with Topcon CT-800, iCare IC 100 and Corvis. On the other hand, IOP values obtained with the Maklakov method had lower correlation dependence with IOP values obtained using other tono metry methods. The strongest correlation of IOP and corneal thickness was observed when using Topcon CT-800. The IOP value obtained with the Maklakov method had the lowest correlation dependence with corneal thickness.CONCLUSION. The lowest correlation dependence of Mak lakov IOP measurements with IOP values obtained using Topcon CT-800, iCare IC 100 and Corvis indicates that the reliability of the Maklakov method significantly depends on the compliance with the examination technique.