Agreement between rebound (iCare IC200), Goldmann applanation tonometer, and noncontact (air puff) tonometer in the immediate postoperative period following vitrectomy.

Abstract

Purpose: To compare intraocular pressure (IOP) measurements using the Goldmann applanation tonometer (GAT), iCare (IC 200) rebound tonometer, and noncontact tonometer (NCT) in patients undergoing vitreoretinal surgery in the immediate postoperative period.

Methods: This cross-sectional comparative study included 75 eyes of 75 patients. IOP measurements were obtained in the sitting position using NCT, iCare, and GAT during the first postoperative day. iCare measurements were also obtained in the supine position.

Results: The average IOP by GAT, NCT, and iCare was 15.6 ± 7.3 mmHg, 16.5 ± 7.2 mmHg, and 15.4 ± 7.8 mmHg, respectively. The intraclass correlation (ICC) for the three tonometers was excellent (>0.9, p < 0.001), except for very high IOPs and very low IOPs, where the agreement was only good to moderate, especially with NCT-GAT (ICC 0.55-0.75) when compared to iCare-GAT (ICC 0.77-0.98). Bland-Altman plot showed GAT-iCare had a better agreement (LoA - 2.40-3.32) than GAT-NCT (LoA - 5.92-4.06). Overall, differences in IOP were within ± 3 mmHg in 88% of eyes for GAT-NCT and 92% for GAT-iCare. The study found a significant difference in IOP values in the supine position (mean IOP = 17.2 ± 9.3) compared to the sitting position (mean IOP = 15.4 ± 7.8) (p < 0.001). Still, no significant difference was observed across different tamponade groups (p = 0.109).

Conclusion: The iCare (IC 200) shows good agreement with GAT as well as NCT in postvitrectomized eyes.