Assessment of intraocular pressure measurement between Goldman applanation tonometer, rebound tonometer, non-contact tonometer, and its correlation with central corneal thickness

Purpose: To compare readings of intraocular pressure (IOP) taken with the Goldmann applanation tonometer (GAT), the non?contact tonometer (NCT), and the rebound tonometer (RBT), and to compare their correlation with central corneal thickness (CCT). Methods: This was a prospective, cross?sectional, observational study to which patients above 18 years of age were enrolled. A total of 400 eyes of 200 non?glaucomatous patients underwent IOP recordings using the GAT, NCT, and RBT, and CCT was also noted. Informed consent of the patients was taken. The IOP readings taken via the three methods were compared and correlated with CCT. Paired t test was used to compare the two devices. Simple and multivariate linear regression analyses were used to study the relationship between factors. A P value less than 0.05 was considered significant. Correlation was determined using the Pearson correlation coefficient, and a Bland–Altman graph was plotted. Results: Mean IOP measured by the NCT was 15.65 ± 2.80 mmHg, by the RBT was 14.23 ± 3.05 mmHg, and by the GAT was 14.69 ± 2.97 mmHg. The mean CCT was 510.61 ± 33.83 microns. The difference between mean IOP recorded by the NCT and that by the RBT was 1.41 ± 2.39 mmHg, between the NCT and GAT was 0.95 ± 2.03 mmHg, and between the GAT and RBT was 0.45 ± 2.22 mmHg. The difference between the IOP values was statistically significant (P < 0.005). All tonometers showed a statistically significant correlation with CCT, but it was observed that the NCT had a stronger correlation (0.4037). Conclusion: The IOP readings taken by all the three methods were comparable; however, RBT values were closer to GAT values. CCT did influence the IOP values, and this should be kept in mind while evaluating.

Comparison of the corrected intraocular pressure by tonopachy with that of Goldmann applanation tonometry in normal and glaucomatous patients

Purpose: To compare corrected intraocular pressure (IOP) by tonopachy with that of Goldmann applanation tonometry (GAT) in normal and glaucomatous patients. Methods: In this cross-sectional study, IOP and central corneal thickness (CCT) were measured in 426 eyes (213 normal eyes and 213 glaucomatous eyes) of 426 patients by tonopachy followed by GAT and ultrasound pachymetry. IOP was corrected for CCT by in-built formula in tonopachy and Ehlers correction factor for Goldmann tonometer. Limits of agreements were assessed using Bland朅ltman plots. Intraclass correlation coefficient was calculated to estimate the absolute agreement between single and average measurements of IOP and CCT of tonopachy with that of Goldmann tonometer and ultrasound pachymetry respectively. Results: Mean corrected IOP measured with tonopachy and GAT in glaucomatous eyes was 17.63 � 5.04 mmHg and 19.42 � 5.83 mmHg, and in controls it was 13.4 � 2.5 mmHg and 16.2 � 3.1 mmHg, respectively. Limits of agreement ranged from �63 to +9.25 mmHg for total population (mean = 2.31), �01 to +9.59 mmHg (mean = 1.79) for glaucoma group and �99 to +8.65 mmHg (mean = 2.83) for controls. Intraclass correlation coefficient for IOP measurement between tonopachy and Goldmann tonometer was 0.84 for total population, 0.85 for glaucoma group, and 0.63 for controls, respectively. Conclusion: Corrected IOP obtained by tonopachy showed moderate agreement with GAT and it is more in glaucoma patients than controls. Thus, tonopachy can be used as a screening tool, but cannot replace GAT.

Rebound Tonometers versus Other Tonometers: Agreement among Readings and the Effects of Axial Length, Ocular Pulse Amplitude, and Central Corneal Thickness on Readings

OBJECTIVE: The aim of this study was to use intraocular pressure (IOP) measurements obtained via rebound tonometry (RBT, the I-care instrument), Goldmann applanation tonometry (GAT), non-contact tonometry (NCT), dynamic contour tonometry (DCT, PASCAL), and the TonoPen to investigate the consistency of readings among methods and the influence of ocular pulse amplitude (OPA), axial length (AL), and central corneal thickness (CCT) on RBT data. METHODS: We prospectively studied 123 eyes. IOP was measured via RBT, GAT, NCT, DCT, and the TonoPen. In addition, OPA was measured via DCT, AL, and CCT. Correlations among measurements using the various methods were evaluated, as were the effects of OPA, AL, and CCT on RBT data. RESULTS: RBT data were significantly correlated with data obtained via GAT, NCT, DCT, and the TonoPen; the highest correlation was with GAT. OPA was significantly correlated with IOP measured via GAT but not with IOP measured via RBT. Both AL and CCT were significantly correlated with IOP data obtained via RBT and GAT. CONCLUSION: Significant correlations were evident among IOP measurements obtained via RBT and other tonometry methods. However, the influence of AL and CCT on IOP measurements obtained via RBT requires careful consideration and interpretation. Although the IOP values obtained by GAT were correlated with OPA values obtained by DCT, this was not true of IOP data obtained by RBT. This might be associated with characteristic of RBT which has the relatively short corneal contact time.

Agreement of intraocular pressure measured by noncontact tonometer and Goldmann applanation tonometer : a Meta-analysis / 中华实验眼科杂志

Background Noncontact tonometer (NCT) is a common application in clinical ophthalmology,while its measured value is influenced by corneal parameter.In recent years,there existed some clinical trials discussing the agreement between NCT and gold standard Goldmann applanation tonometer (GAT),but there was still lack of evidence.Objective This study was to evaluate the agreement between NCT and GAT by applying evidence based medicine (EBM) method.Metbods A systematic literature retrieval was conducted from the MEDLINE,EMbase,CBM disc and CNKI database with the limitation of publishing time until June 2016.The literatures were screened according to the inclusion and exclusion criteria.The sample size,average age,sample characteristics and follow-up time were extracted.The value of intraocular pressure measured by NCT and GAT were analyzed.The overall effect size was analyzed using Review Manager 5.3 (from The Cochrane Collaboration) as weighted mean difference (WMD).There existed heterology in this study.Radom effect mode was used to evaluate and compare the difference between NCT and GAT value.Results Twenty four articles were retrieved.Six comparison studies incorporated with 478 eyes were included for Meta analysis.After random effects model was performed for correction.Intraocular pressure measured by NCT was 0.02 mmHg larger than that by GAT (1 mmHg =0.133 kPa).There was no significant difference in the measurement value of IOP between the two instruments (WMD =0.02,95％ CI:-0.59 to 0.63,P =0.95).Funnel chart method showed that literature publication bias existed in this study.Conclusions Normal persons' IOP obtained from NCT and GAT showed a good reproducibility.More comparison studies are needed to support this result.

Can higher end tonometers be used interchangeably in routine clinical practice.

Context: Precise intraocular pressure (IOP) measurement is important in glaucoma practise. Various instruments are available today to accurately measure IOP. Thus, the question arises about which instrument to use and whether all of them can be used interchangeably. Aims: To assess the agreement between noncontact tonometer (NCT), rebound tonometer (RBT), Goldmann applanation tonometer (GAT), and dynamic contour tonometer (DCT) in measuring IOP. Subjects and Methods: 499 eyes of 250 patients were evaluated during a period of 24 months from September 2010 to August 2012 and measurement of IOP by NCT, RBT, GAT, and DCT was done in the given sequence. The agreement was assessed by use of the Bland–Altman plot keeping GAT as a gold standard technique. Results: The mean IOP value of NCT, RBT, GAT, and DCT was 15.9 ± 5.5, 15.9 ± 5.8, 15.9 ± 4.9, and 16.0 ± 4.7 mm of Hg, respectively. The limits of agreement of GAT with DCT, NCT, and RBT were found to be +5.4 to −5.2, −4.7 to +4.6, and −5.2 to +5.1 mm of Hg, respectively. Conclusions: A positive and strong correlation was found between newer tonometers and GAT, but the limit of agreement was clinically unacceptable. The use of a single tonometer should be practised at a glaucoma clinic for a patient at each follow‑up.

The relationship between central corneal thickness and intraocular pressure in healthy and glaucomatous eyes, a systematic review and Meta-analysis / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To evaluate the relationship between central corneal thickness and intraocular pressure in healthy and glaucomatous eyes of adults. To make up to date summary of the results of studies done on the association of central corneal thickness measurements and intraocular pressure measurements in Glaucoma patients and in healthy subject. ●METHODS: To identify relevant studies a search of MEDLINE and Science Direct databases for studies investigating the relationship between central corneal thickness ( CCT ) and intraocular pressure ( lOP ) was conducted. The Search period was from Sep. 10th to Oct. 28th of 2015. Search key words included: central corneal thickness, intraocular pressure, glaucoma, ocular hypertension, exfoliative glaucoma, applanation tonometry, pachymetry, primary open angle glaucoma, Goldmann applanation tonometry. Ln addition, a manual search of “The Year Book of Ophthalmology” Journals 2004 to 2006 lssues in the Southern Medical University Library English language section was done. The following exclusion criteria applied:1) non-English media studies;2 ) studies done before 2005; 3 ) case series and case reviews; 4 ) studies involving treatment protocols or surgical techniques; 5 ) studies comparing glaucomatous eyes with other conditions such as diabetes, hypertension or cardiovascular disease as secondary variables; 6 ) studies with children as study subjects; 7 ) studies with animal subjects. ●RESULTS: There were 12 observational studies and 1 case control study included. Compared to control subjects, patients had significantly increased lOP ( SMD:0. 50, 95% Cl:0. 30~0. 70, Z=4. 88, P ● CONCLUSION: It has been established that glaucomatous eyes tend to have thinner CCT and higher lOP compared to normal eyes.

Reactivation of Ocular Toxoplasmosis – A Case Report

Ocular toxoplasmosis is the commonest cause of posterior uveitis and is usually the result of an acquired infection caused by the protozoan Toxoplasma gondii,here we present report of case of spontaneous reactivation of toxoplasmosis in a 14-yr old girl. with reactivation o oocular toxoplasmosis.

Comparison of Rebound Tonometry and Goldmann Applanation Tonometry in Restrictive Thyroid Eye Disease

PURPOSE: To compare the intraocular pressure (IOP) measured using the rebound tonometer (RT) and Goldmann applanation tonometer (GAT) in the primary position and upgaze in restrictive thyroid eye disease (TED). METHODS: We measured the IOP in 30 subjects (54 eyes) who visited an ophthalmologist between May 2014 and May 2015. This study included 16 healthy volunteers (32 eyes) and 14 TED patients (22 eyes). The outcome measurements were the comparison of IOP readings; both intergroup and 2 measurements using the RT and the GAT for patients with restrictive TED and the control group. Upgaze IOP was measured on the central cornea with a 20-degree chin-down posture. RESULTS: Both TED patients and controls showed an increase in IOP in upgaze compared with primary position (p < 0.001). There was a significant difference in mean differential IOP between patients and controls measured using RT and GAT, respectively (p < 0.001). In the control group, there was no significant difference between the 2 instrument readings in upgaze as well as primary position for patients with restrictive TED (p = 0.853 in TED; p = 0.260 in controls). CONCLUSIONS: Based on our results, the mean IOP in conventional upgaze was significantly increased in TED patients compared to primary position using both the RT and GAT and no difference in RT readings compared with GAT readings. The RT can be used to establish IOP since no significant difference between the upgaze and the primary position readings was observed in patients with restrictive TED and is a simple and effective diagnostic tool unrelated to the position and the direction of gaze.

Comparison of two methods of tonometry in glaucoma patients:Goldmann applanation tonometer and non-contact tonometer / 国际眼科杂志(Guoji Yanke Zazhi)

? AlM: To compare the two methods for the measurement of glaucoma patients' intraocular pressure ( lOP) between Goldmann applanation tonometer ( GAT) and non-contact tonometer ( NCT) and find the laws of the two methods.?METHODS: The lOP of 108 glaucoma patients ( 206 eyes) were measured by GAT and NCT respectively.?RESULTS: ln 108 glaucoma patients, the average lOP of 206 eyes was 29. 77 ± 10. 27mmHg by GAT and 24. 59 ± 8. 58mmHg by NCT. There was significant difference between GAT and NCT (P<0. 01). The higher of lOP, the difference between GAT and NCT was greater.?CONCLUSlON: The measurement results with NCT were lower than that of GAT. The higher of lOP, the difference between GAT and NCT was greater. lt's better to measure lOP by GAT for the glaucoma patients, in order to avoid the misdiagnosis and mistreatment of glaucoma.

Rectifying calibration error of Goldmann applanation tonometer is easy.

Purpose: Goldmann applanation tonometer (GAT) is the current Gold standard tonometer. However, its calibration error is common and can go unnoticed in clinics. Its company repair has limitations. The purpose of this report is to describe a self‑taught technique of rectifying calibration error of GAT. Materials and Methods: Twenty‑nine slit‑lamp‑mounted Haag‑Streit Goldmann tonometers (Model AT 900 C/M; Haag‑Streit, Switzerland) were included in this cross‑sectional interventional pilot study. The technique of rectification of calibration error of the tonometer involved cleaning and lubrication of the instrument followed by alignment of weights when lubrication alone didn’t suffice. We followed the South East Asia Glaucoma Interest Group’s definition of calibration error tolerance (acceptable GAT calibration error within ±2, ±3 and ±4 mm Hg at the 0, 20 and 60‑mm Hg testing levels, respectively). Results: Twelve out of 29 (41.3%) GATs were out of calibration. The range of positive and negative calibration error at the clinically most important 20‑mm Hg testing level was 0.5 to 20 mm Hg and ‑0.5 to ‑18 mm Hg, respectively. Cleaning and lubrication alone sufficed to rectify calibration error of 11 (91.6%) faulty instruments. Only one (8.3%) faulty GAT required alignment of the counter‑weight. Conclusions: Rectification of calibration error of GAT is possible in‑house. Cleaning and lubrication of GAT can be carried out even by eye care professionals and may suffice to rectify calibration error in the majority of faulty instruments. Such an exercise may drastically reduce the downtime of the Gold standard tonometer.

Comparison of Portable Tonometers and Goldmann Applanation Tonometer for Intraocular Pressure Measurement

PURPOSE: To compare the intraocular pressure (IOP) measured by portable rebound tonometer and TonoPen applanation tonometer with pressure measured by Goldmann applanation tonometer (GAT) and analyze the factors affecting IOP disagreement between tonometers. METHODS: In a prospective study of 463 eyes, IOP was measured with Icare Pro(R) rebound tonometer, TonoPen AVIA(R) applanation tonometer, and GAT. Bland-Altman plot, intraclass correlation coefficient, Pearson's correlation analysis, and multiple regression analysis were performed to evaluate the agreement of IOP measured by each tonometer and the factors affecting the measurements. RESULTS: The IOP values measured by Icare Pro(R) and TonoPen AVIA(R) were consistently higher than those measured by GAT, but showed no significant differences with those measured by GAT (p = 0.307 and 0.114, respectively). In Bland-Altman plot, the IOP values measured by Icare Pro(R) and TonoPen AVIA(R) exhibited excellent agreement with those measured by GAT. Both Icare Pro(R)/GAT and TonoPen AVIA(R)/GAT differences increased with younger age (p = 0.041 and 0.049, respectively) and higher central corneal thickness (p = 0.019 and 0.035, respectively). CONCLUSIONS: IOPs measured by portable Icare Pro(R) rebound tonometer and TonoPen AVIA(R) applanation tonometer were significantly correlated with IOP measured by GAT. Therefore, such instruments can be useful when measuring IOP with GAT is difficult. However, central corneal thickness and age should be considered when measuring IOP with portable tonometers.

Comparison of Intraocular Pressure Measured by Non-Contact Tonometer, Rebound Tonometer, Tono-Pen, and Goldmann Applanation Tonometer

PURPOSE: To compare the level of accuracy of intraocular pressure (IOP) measurements attained by non-contact tonometer (NCT), rebound tonometer (RT) Icare(R), and Tono-Pen (TONO-PEN AVIA(R)), using Goldmann Applanation tonometer (GAT) as a reference value and to explore their clinical usefulness. METHODS: In a prospective study of 71 normal eyes, IOP was measured with NCT, RT, Tono-Pen and GAT. The IOP values of were then compared between the eyes. RESULTS: RT showed statistically most significant agreement with the GAT [ICC 0.811, 95%CI 0.712-0.878]. In analysis of Bland-Altman plots, NCT showed the smallest mean bias (+0.2 mm Hg) and widest CI (95%CI; +/-5.05 mm Hg), RT showed relatively small mean bias (-0.7 mm Hg) and narrowest CI (95%CI; +/-3.75 mm Hg). CONCLUSIONS: There was a significant agreement between the RT and the GAT measurements. We expect RT to be considered as a reliable alternative when IOP measurement with GAT is not feasible.

Comparison of Icare Rebound Tonometer with Goldmann Applanation Tonometry

PURPOSE: To compare Icare rebound tonometer (IRT) and Goldmann applanation tonometer (GAT) and investigate the clinical usefulness of IRT. METHODS: In a retrospective study of 131 eyes with glaucoma and glaucoma suspect, intraocular pressure (IOP) was measured with IRT and GAT. The correlation between IRT and GAT and the influence of refractive error (spherical equivalent; SE) and central corneal thickness (CCT) were analyzed. RESULTS: A distinct correlation between IRT and GAT was found. IOP measured with GAT was 2.23 +/- 3.16 mm Hg higher than with IRT (p or = -5 diopter) was measured relatively lower than in hyperopic eyes (SE < -5 diopter) with GAT (+1.50 +/- 0.68 mm Hg) and IRT (+1.88 +/- 0.75 mm Hg). CONCLUSIONS: IRT showed strong correlation with GAT, but IOP measured approximately 2 mm Hg lower. The IOP tends to measure lower at low CCT and in myopic eyes.

Comparison of Rebound Tonometer, Non-Contact Tonometer, Goldmann Applanation Tonometer and the Relationship to Central Corneal Thickness

PURPOSE: To compare the level of accuracy of intraocular pressure (IOP) measurements of a rebound tonometer (RT) Icare(R), and non-contact tonometer (NCT), using Goldmann Applanation tonometer (GAT) as a reference to evaluate the influence of central corneal thickness (CCT) on IOP readings in the Korean population. METHODS: In a prospective study of 273 eyes, IOP was measured with RT, GAT, and NCT and compared to CCT measurements. Patients were assigned to one of 3 groups based on IOP measurements of GAT and 1 of 2 groups based on CCT. The comparison of the IOP values of RT, GAT, and NCT was performed between the IOP and CCT groups, and the differences among tonometers were evaluated. RESULTS: The RT showed statistically significant correlation with the GAT compared to the NCT. The CCT was related to RT measurements. The RT values compared to the GAT was underestimated in thin corneas and overestimated in thick corneas. CONCLUSIONS: There was a significant correlation between the RT and the GAT measurements compared with the NCT. However, RT is influenced by CCT and correlates less with GAT in low IOP ranges, suggesting that corneal thickness should be taken into consideration during such measurements.

Reproducibility and tolerability of iCare rebound tonometer and its agreement evaluation with Goldmann applanation tonometry / 中华实验眼科杂志

Background Goldmann applanation tonometry (GAT) is a gold standard of intraocular pressure measurement.But its utilization iS limited because of its complexity and high requirement of cooperation.iCare rebound tonometer (iCare RBT) is a new type of applanation tonometry,and its accuracy and safety in clinical application need to be evaluated.Objective Present study was to investigate the reproducibility and tolerability of iCare RBT and its measurement agreement with GAT over a wide intraocular pressure (IOP) range. Methods The IOP were measured in bilateral eyes of 36 glaucoma and glaucoma suspect patients by 2 examinees with iCare RBT at the 1-minute interval to assess the interobserver reproducibility.Then the IOP of both eyes from 56 Subjeets and other 52 subjects were separately measured twice for each by two operators with iCare RBT for the evaluation of intraobserver reproducibility.Finally.IOP of 182 eyes of 92 glaucoma and glaucoma suspect patients was obtained by examiner 2 with RBT first and examiner 1 with GAT subsequently at a 2.minute interval in a masked fashion to perform an agreement evaluation of two readings by using Bland-Ahman method.The tolerance of subjects to iCare RBT measurement were surveyed.Oral informed consent was obtained prior to the IOP measurement. Results Concerning the iCare RBT readings.interobserver correlation coefficients were 0.937 in the right eye and 0.887 in the left eye.Intraobserver correlation coefficients of examiner 1 were 0.986 in the left eyes and 0.969 in the fight eyes.And those of examiner 2 were 0.990 and 0.979.Mcan values of iCare RBT readings and GAT were(18.74±8.36)mmHg and(19.33±8.20)mmHg and the mean difference values(iCare-GAT)was(-0.59 4±2.60)mmHg with the 95%confidence interval of -5.80-4.60 mmHg.The correlation coefficient between two modalities of IOP measurement WaS 0.95 1.No severe pain and discomfort were complained in all the subjects during or after measurement of iCare RBT. Conclusion iCare RBT has good interobserver and intraobserver reproducibility and good tolerance.It was proved that this is a good correlation between iCare RBT readings and GAT readings.

Comparison of the intraocular pressure value measured with Goldmann applanation tonometer and non-contact tonometer / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To assess the relative agreement of GAT and NCT in IOP measurement by comparing the differences between Goldmann applanation tonometer (GAT) and non-contact tonometer (NCT) in intraocular pressure (IOP) detection.METHODS: IOP of 529 eyes of 265 volunteers were measured with both NCT and GAT, respectively.RESULTS: The measurement results of NCT were lower than that of GAT, there was significant difference between the IOP measured with NCT and GAT (19.13 vs23.43, t=22.644, P＜0.05). With the increasing of IOP values, the difference magnitude was greater, especially in IOP group that was more than 30mmHg, but the correlation coefficient became lower.CONCLUSION: The measurement results with NCT are lower than that of GAT. When the IOP with the NCT is in borderline value, it need be corrected with GAT, in order to discover the pathologically elevated IOP and avoid the misdiagnosis and mistreatment of glaucoma.

Comparison and Correlation Analysis of Intraocular Pressure Measured with the Pressure Phosphene Tonometer and the Goldmann Tonometer

PURPOSE: To compare the intraocular pressure (IOP) measured by the pressure phosphene tonometer (PPT) and the Goldmann applanation tonometer (GAT) according to the feedback of the IOP measured by GAT and the use of the dominant hand during the measurement. METHODS: In a group of 40 eyes of 40 normal subjects in their twenties and thirties without diagnostic specificity, IOP was measured with PPT three times by themselves and with the GAT by one examiner on 3 different days. In 20 eyes of the feedback group, the subjects were informed of their IOP measured by GAT and were allowed to measure with PPT again. In each group, half of the eyes (20 eyes) were assigned to use the dominant hand to measure the IOP (dominant group) and the other half (20 eyes) were assigned in the other way (nondominant group). RESULTS: In feedback, nonfeedback and dominant groups, comparison of the first day showed statistically significant differences of mean IOP. But on the third day, there were no significant differences among all 4 groups and there were significant correlations. There was a stronger correlation between the two methods in the feedback group (r=0.721) than in the nonfeedback group. The correlation coefficient of all 40 eyes was 0.605 (p<0.001). CONCLUSIONS: PPT has a strong correlation with GAT in the range of normal IOP and is thought to be more useful as a self tonometer for the measurement of both eyes with the periodical measurement of IOP by GAT in clinics.

The Differences of IOP and Factors Influencing IOP Measured by Goldmann Applanation Tonometer after Photore fractive Keratectomy and Laser In Situ Keratomileusis in Myopic Eyes between -4~-7 Diopters

To evaluate the differences and factors to be considered when measuring intraocular pressure after photorefractive keratectomy[PRK]and laser in situ keratomileusis[LASIK], we prospectively reviewed the medical records of myopic eyes between -4~-7 diopters. Among them, 14 patients, 22 eyes underwent PRK and 10 patients, 18 eyes recieived LASIK. We measured intraocular pressures by Goldmann applanation tonometry preoperatively, 1 month, 3 months and 6 months postoperatively in each group. Corneal curvatures, central corneal thicknesses were measured and compared when measuring intraocular pressure. The postoperative intraocular pressure was lower than the preoperative value in both groups[p<0.01], and the decreased amount of IOP were not statistically different in both groups[p=0.29]. Targeted ablation depth[p=0.19]and ablation diameter[p=0.16]did not show statistically significant correlation to postoperative IOP decrease. In measuring intraocular pressure after PRK or LASIK, attention should be given to the pressure and its interpretation.

The Differences of IOP and Factors Influencing IOP Measured by Goldmann Applanation Tonometer after Photore fractive Keratectomy and Laser In Situ Keratomileusis in Myopic Eyes between -4~-7 Diopters

To evaluate the differences and factors to be considered when measuring intraocular pressure after photorefractive keratectomy[PRK]and laser in situ keratomileusis[LASIK], we prospectively reviewed the medical records of myopic eyes between -4~-7 diopters. Among them, 14 patients, 22 eyes underwent PRK and 10 patients, 18 eyes recieived LASIK. We measured intraocular pressures by Goldmann applanation tonometry preoperatively, 1 month, 3 months and 6 months postoperatively in each group. Corneal curvatures, central corneal thicknesses were measured and compared when measuring intraocular pressure. The postoperative intraocular pressure was lower than the preoperative value in both groups[p<0.01], and the decreased amount of IOP were not statistically different in both groups[p=0.29]. Targeted ablation depth[p=0.19]and ablation diameter[p=0.16]did not show statistically significant correlation to postoperative IOP decrease. In measuring intraocular pressure after PRK or LASIK, attention should be given to the pressure and its interpretation.

The Use of Goldmann Applanation Tonometer in Intraocular Pressure Measurement of Eyes Wearing Soft Contact Lenses

The purpose of the study was to evaluate a modified technique of Goldmann applanation tonometry without the use of fluorescein and anesthesia in normal eyes with soft contact lenses (SCLs) and to compare this technique with the conventional method. Fifty eyes were measured using Goldmann applanation tonometer. A mean intraocular pressure(IOP)was 17.5 +/-2.33mmHg by the conventional technique and 15.2 +/-2.35 mmHg by the modified technique. We found the IOPvalues of the modified method were consistently underestimated IOP levels by approximately 2.3 mmHg than those of the conventional method (R=0.86, p<0.05). This bias appears to be affected by the fluorescent dye, not affect-ed by the presence of SCL. Our results suggest that the measurements by the modified technique can reflect the IOP measured by conventional method with correction factor of+2 .3 mmHg. The modified technique is a very convenient and simple screening method to measure IOP in patients wearing SCLs, without need for removal or staining of lenses.