Comparison of intraocular pressure measured by ocular response analyzer and Goldmann applanation tonometer after corneal refractive surgery: a systematic review and meta-analysis

Abstract

Background Accurate measurement of intraocular pressure (IOP) after corneal refractive surgery is of great significance to clinic, and comparisons among various IOP measuring instruments are not rare, but there is a lack of unified analysis. Although Goldmann Applanation Tonometer (GAT) is currently the internationally recognized gold standard for IOP measurement, its results are severely affected by central corneal thickness (CCT). Ocular Response Analyzer (ORA) takes certain biomechanical properties of cornea into account and is supposed to be less dependent of CCT. In this study, we conducted the meta-analysis to systematically assess the differences and similarities of IOP values measured by ORA and GAT in patients after corneal refractive surgery from the perspective of evidence-based medicine. Methods The authors searched electronic databases (MEDLINE, EMBASE, Web of science, Cochrane library and Chinese electronic databases of CNKI and Wanfang) from Jan. 2005 to Jan. 2019, studies describing IOP comparisons measured by GAT and ORA after corneal refractive surgery were included. Quality assessment, subgroup analysis, meta-regression analysis and publication bias analysis were applied in succession. Results Among the 273 literatures initially retrieved, 8 literatures (13 groups of data) with a total of 724 eyes were included in the meta-analysis, and all of which were English literatures. In the pooled analysis, the weighted mean difference (WMD) between IOPcc and IOPGAT was 2.67 mmHg (95% CI: 2.20~3.14 mmHg, p < 0.0001), the WMD between IOPg and IOPGAT was − 0.27 mmHg (95% CI: − 0.70~0.16 mmHg, p = 0.2174). In the subgroup analysis of postoperative IOPcc and IOPGAT, the heterogeneity among the data on surgical procedure was zero, while the heterogeneity of other subgroups was still more than 50%. The comparison of the mean difference of pre- and post-operative IOP (∆IOP) was: mean-∆IOPg > mean-∆IOPGAT > mean-∆IOPcc. Conclusions IOPcc, which is less dependent on CCT, may be more close to the true IOP after corneal refractive surgery compared with IOPg and IOPGAT, and the recovery of IOPcc after corneal surface refractive surgery may be more stable than that after lamellar refractive surgery.

Corneal Hysteresis in Thais and Variation of Corneal Hysteresis in Glaucoma

“…IOPcc is less affected by corneal properties as a CCT independent IOP measurement. 49 Ehrlich et al showed better sensitivity and specificity to identify glaucoma using IOPcc compared with GAT. Applying an optimal GAT threshold at 20.9 mmHg, GAT showed area under curve (AUC) = 0.78, while using an IOPcc threshold at 18.4 mmHg, IOPcc showed AUC = 0.93, p<0.001.…”

“…Among IOPcc, IOPg, and GAT, exactly which value would be the best to represent the true IOP is still under debate. [47][48][49] The gold standard of IOP measuring is the GAT, whose accuracy is limited when applied in out-ofthe range central corneal thickness (CCT), for example, in post-refractive surgery and thinner or thicker than normal average CCT. IOPcc is less affected by corneal properties as a CCT independent IOP measurement.…”

“…IOPcc is less affected by corneal properties as a CCT independent IOP measurement. 49 Ehrlich et al showed better sensitivity and specificity to identify glaucoma using IOPcc compared with GAT.…”

How to Measure Intraocular Pressure: An Updated Review of Various Tonometers

“…In comparison with GAT, ORA has been demonstrated to significantly overestimate the IOP values, especially at high IOP levels [ 47 , 48 ]. Several authors have demonstrated that the IOPcc is less affected by corneal properties [ 48 , 49 , 50 , 51 ] and may better reflect the true IOP after refractive surgery of the cornea when compared to GAT IOP values [ 52 ].…”

Glaucoma in mucopolysaccharidoses

“…IOP should be tested by the same, individually adjusted and well-tolerated devices during follow-up of MPSs patients since different tonometry methods may result in variable IOP-values. Goldmann applanation tonometry, the gold standard for IOP measurement, was less dependent on corneal properties, making it more reliable for measuring IOP of patients with MPSs [55]. Ocular response analyzer and iCare rebound tonometer were tested and proved to be attractive alternatives to applanation tonometry in MPS patients [54].…”