Evaluation Of Intraocular Pressure Measured With Slit Lamp-Mounted St500 Rebound Tonometer In Real World And His Correlation With Intraocular Pressure Measured With Goldmann Applanation Tonometer.
Published 2025 - 43rd Congress of the ESCRS
Reference: FP29.12 | Type: Free paper | DOI: 10.82333/h38z-3603
Authors: Aida Kasumović Bećirević* 1 , Armin Kasumović 2 , Ines Matoc Kasumović 2 , Sanja Sefić Kasumović 1 , Mirko Jankov 3
1Ophthalmology,Eye Polyclinic "Dr. Sefic",Sarajevo,Bosnia and Herzegovina, 2Ophthalmology,Eye Polyclinic "Dr. Sefic",Sarajevo,Bosnia and Herzegovina;Ophthalmology,University Clinical Center "Sestre milosrdnice",Zagreb,Croatia, 3Ophthalmology,LaserFocus - Centre for Eye Microsurgery,Belgrade,Serbia;Ophthalmology,IROC Institut for Refractive and Ophthalmic Surgiery,Zurich,Switzerland
Purpose
To evaluate of the repeatability and agreement of intraocular pressure (IOP) measurement with slit-lamp mounted rebound tonometer ST500 (ST500, iCare Finland Oy) in real world and compare with intraocular pressure measured with Goldmann Applanation Tonometer (GAT, Haag-Streit AT900, Switzerland).
Setting
Glaucoma Unit of Ophthalmology Department of Hospital da Luz Arrábida, Porto, Portugal
Methods
Prospective,cross-sectional observational study in real world.The participants were normal, glaucoma suspect and glaucoma patients in glaucoma centre.The agreement and repeatability of the IOP measurements was assessed by calculating the mean and variance of the difference between the first and second measurements using Wilcoxon test.Intraclass correlation coefficients (ICCs) were computed to interpret the level of agreement between measurements with each tonometer and between both tonometers.Calculation of Pearson's Coefficient to quantify the relationship between the measurements of the tonometers was done.Bland-Altman analysis was used to assess whether the difference in IOP between tonometers depend on the mean of the tonometers values.
Results
A total of 162 measurements.Sixteen eyes (9.9%) were excluded.Sixty-nine eyes were under medical therapy for IOP.The mean IOP of the ST500 and GAT is 14.78 ± 3.01 mmHg (IQR 8.80-23.10) and 14.11 ± 2.69 mmHg (IQR 7.90-21.00), with no significant difference (p=0.26 for ST500, p=0.47 for GAT).The mean difference between first and second measurements was 0.10 ± 1.27 mmHg (ST500) and 0.11 ± 1.01 mmHg (GAT).ICC values for intratonometer repeatability were excellent: 0.96 (95%CI: 0.94-0.97) for ST500 and 0.96 (95%CI: 0.95-0.97) for GAT.Intertonometer ICC was 0.89 (95%CI: 0.84-0.92), with strong Pearson’s correlation (0.80, 95%CI: 0.74-0.85).Bland-Altman analysis showed ST500 overestimated IOP by 0.66 mmHg (95%LoA: -2.90 to 4.22) compared to GAT.
Conclusions
This study showed that the new slit lamp-mounted ST500 tonometer had an excellent repeability and strong correlation with GAT. Certainly, it will be useful in a clinical setting.
The mean IOP value obtained by the ST500 is higher than 0.66 mmHg that obtained by the GAT. Although, the coefficient of determination (r2=0.64) suggests moderate to strong correlation and prediction is possible in 64% of cases, the accuracy is not absolute as there is still 36% of the variation that is not explained by the model.