| Objectives:To approach the accuracy and reliability of introcular pressure (IOP) measured by Reichert Ocular Response Analyzer (ORA),to compare and analyze the relationship between central corneal thickness (CCT) and IOP value measured by ORA,Goldmann applanation tonometry (GAT) and Non Contact Tonometer (NCT).Then to study the clinical utility of the corneal hysteresis (CH) and corneal resistane factor (CRF) measured by ORA in normal, glaucoma patient and suspect, undergone kerato-refractive surgery subjects.Method:Chose84healthy individuals (168eyes) for IOP measuring from November2009to March2010randomly. IOP was measured by ORA and NCT devices,then CCT was measured by A-ultrasond (A-US). Then compared the measuring values of these tonometries with each other and correlated them with CCT seperately. Also, Chose31glaucoma and suspect (62eyes) for IOP measuring. IOP was measured by ORA and GAT devices, then CCT was measured, by A-ultrasond (A-US). In addition, chose other51individuals (102eyes) undergone kerato-refractive surgery to this study. IOP was measured by ORA and NCT devices, then CCT was measured by A-ultrasond (A-US). CH, CRF, IOPg and IOP corneal-compensated (IOPcc) were provided by the ORA device. Then use SPSS to analyze the data.Results:The normal intraocular pressure values, ORA Goldmann IOP value measured analog (Goldmann-correlated IOP value, IOPg) was17.90±4.17mmHg, corneal compensated IOP (Corneal-Compensated Intraocular Pressure, IOPcc) was18.34±4.00mmHg; NCT IOP value was17.44±3.54mmHg. IOPcc, IOPg, NCT was good correlation between intraocular pressure, the mean value between each were significantly different. CCT was536.20±29.17μm. NCT IOP measurements and CCT medium level of the correlation coefficient was0.429; and IOPcc shows only low levels of weak correlation between CCT, the correlation coefficient was0.258. Significantly higher than normal male IOPg to female, IOPcc no significant difference, IOPcc, IOPg no correlation with age. Normal CH and CRF were 10.13±2.11mmHg and10.90±2.31mmHg, with age, gender was no significant correlation. CH and CCT has low correlation coefficient of0.277; CRF and CCT medium level of the correlation coefficient of0.466.Glaucoma and suspected glaucoma IOPg was19.16±4.10mmHg, IOPcc was19.91±4.44mmHg; GAT IOP value of18.91±3.75mmHg. Glaucoma and suspected glaucoma IOPg, IOPcc, GAT correlation among good, average significantly higher than among IOPcc and IOPg, GAT IOP. There is no significant difference between GAT IOP values and IOPg. GAT IOP and CCT has medium level correlation and the correlation coefficient of0.344. Patients with glaucoma and suspected glaucoma CH and CRF were9.83±2.13mmHg and11.03±2.11mmHg. Compared with the normal group, glaucoma and suspected glaucoma IOPg, IOPcc significantly higher than the normal group, and CH, CRF, CCT was no significant difference.After corneal refractive surgery, LASEK patients were followed up by IOPg was13.26±3.52mmHg, IOPcc was16.64±3.29mmHg, NCT IOP value was14.13±3.61mmHg, CH was8.01±1.60mmHg, CRF was7.70±1.82mmHg, CCT was447.59±43.75μm; LASIK patients were followed up by IOPg was13.10±5.29mmHg, IOPcc was16.70±5.25mmHg, NCT IOP value was13.91±4.99mmHg, CH was7.83±1.52mmHg, CRF was7.50±1.75mmHg, CCT was447.96±46.22μm. Compared with normal subjects, patients after corneal refractive IOPg, IOPcc, NCT IOP, CCT, CH, CRF were lower, but IOPcc decreased no significantly than NCT IOP. Between LASEK surgery group and LASIK surgery group,IOPg, IOPcc, NCT IOP, CCT, CH, CRF were no significant difference.Conclusion:ORA IOP measurement with high repeatability, It has good consistency with GAT, NCT and less impact with the measurement of central corneal thickness. ORA CH and CRF measurement parameters can reflect the biomechanical properties of the cornea. Normal CH, CRF value has no significant difference between men and women, and age but low levels of correlation with CCT. In glaucoma and suspected glaucoma patients, CH, CRF value has no significant difference compared to normal controls. The CH value in patients afler corneal refractive surgery was significantly lower than the normal value and also the CRF. But there was no significant difference between LASEK surgery group and LASIK surgery group. ORA IOP measurements may be more closer to the real value than GAT, NCT value, especially after corneal refractive surgery. |
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