EFFECT OF ACUTE HYDROGEN-RICH WATER INTAKE ON INTRAOCULAR PRESSURE IN HEALTHY SUBJECTS.

PURPOSES: The primary aim of the study was to assess the response of intraocular pressure (IOP) to the acute ingestion of hydrogen-rich water (HRW) compared to hydrogen-free water (placebo) in healthy subjects. The effect of HRW intake on central corneal thickness (CCT) was also monitored. SUBJECTS AND METHODS: Twenty-four healthy volunteers (5 men, 19 women) aged between 20 and 33 were included in the study, in which one eye of each subject was measured. The study was prospective, randomized and double-blind, with crossover design. Each subject underwent two parts of the experiment, each part on a different day and in random order. In each part of experiment, a total volume of 1260 ml of HRW or placebo was administered over 15 minutes in three doses. IOP and CCT were measured before and during the course of 75 minutes from the start of the HRW or placebo intake. RESULTS: Administration of both HRW and the placebo caused a significant increase in IOP. The maximum IOP increase was 2.7 mmHg ±2.0 mmHg in minute 25 after the commencement of the experiment (HRW intake), and 1.4 mmHg ±2.0 mmHg in minute 35 (placebo intake). The values of IOP did not differ significantly between both parts, but there were significantly more clinically significant individual IOP increases after HRW intake (58%) compared to the placebo (25%). CCT did not change significantly during the experiment. CONCLUSION: The rapid intake of 1260 ml of both HRW and hydrogen-free water causes a statistically significant increase in IOP compared to the baseline in healthy individuals. In the case of HRW, the increase was also clinically significant in most of the subjects. Thus, the results indicate that acute intake of HRW may pose a higher risk than placebo intake in terms of IOP. However, in the case of risk groups such as subjects with glaucoma, ocular hypertension or suspected glaucoma, it is necessary to verify this conclusion by further studies.

Influence of cornea on intraocular pressure measurement by ICARE PRO and ORA.

AIM: To compare intraocular pressure readings (IOP) measured by ICARE PRO and ORA G3 and analyse the influence of the corneal hysteresis (CH), central corneal thickness (CCT), average central corneal radius, corneal astigmatism and age on the readings. In addition, to compare the repeatability of measurement by both tonometers. METHODS: The data was collected by IOP measurements in both eyes in 40 individuals between ages of 41 and 86 years. The number of 74 eyes (70 eyes in the case of ORA repeatability) were included to the study, remaining eyes were excluded due to incomplete data, abnormal cornea or low quality of measurement. The subjects were all diagnosed for glaucoma or were suspected of having glaucoma. In the case of ORA tonometer, the Goldmann-correlated IOP (IOPG) and corneal compensated IOP (IOPCC) were monitored. The CH was measured by ORA, CCT by ultrasound pachymeter and corneal curvature and astigmatism by autokeratometer. The effect of corneal parameters and age on IOP or on differences between tonometers were analysed by multiple linear regression. The comparison of readings from both tonometers and repeatability analysis (based on test-retest) were realised using a paired t-test and a Bland-Altman method. The level of statistical significance was set to 0.05. RESULTS: The IOP readings from both tonometers were positively correlated with CCT and negatively with CH. The effects of other monitored parameters were insignificant. The mean ICARE PRO reading did not differ significantly from IOPG but were significantly lower than IOPCC. The variability of differences was, however, high in both cases and differences were influenced by IOP and CH (ICARE PRO shown higher readings with decreasing IOP and increasing hysteresis). The lowest repeatability coefficient shown ICARE PRO, the worst IOPCC (3.0 mmHg for ICARE PRO, 3.8 mmHg for IOPG and 4.8 mmHg for IOPCC). CONCLUSION: The IOP values measured by both considered tonometers are significantly influenced by corneal hysteresis and central thickness. The effect of CCT can arise from an effect of a corneal stiffness. Regarding the high variability of mutual differences, the data from ICARE PRO and ORA are not interchangeable. The repeatability of ICARE PRO was comparable with Goldmann applanation tonometer measurement under given conditions, and better than ORA.

[OPTIC PROPERTIES OF MYOPIC CORRECTION BY ORTHOKERATOLOGY CONTACT LENSES (A CASE REPORT)]. / Optické vlastnosti myopické korekce ortokeratologickými kontaktními cockami (prípadová studie).

INTRODUCTION: Orthokeratology lenses present a special type of hard contact lenses, which is used especially for myopic correction. The lenses are applied during the night, when thanks to their special shape cause temporally (reversible) change of the cornea shape. During the day, there is not necessary to wear any other refractive correction. Due to the wearing regimen, there is, comparing to the classical contact lenses, higher risk of health complications. For their safe use, it is necessary to pay attention to the application of lenses of adequate parameters, follow up the care and hygiene precautions, regular controls and early treatment of possible problems. The application of contact lenses should be done by experienced and well-educated expert in contact lens fitting. In the Czech Republic, this method is practically not used. AIM: The aim of the case report was to follow up the course of concrete application of orthokeratology lenses for myopic correction from the optic (refractive) point of view, and to evaluate the optic changes in the system of the eye. In the followed up subject, there were measured subjective changes in refraction, visual acuity, corneal curvature, corneal and whole eye aberrations, and corneal thickness during the period of one month after the beginning of lens application (initial phase). The same parameters were followed-up during one-month period since the termination of lens wearing for three months (second phase). The subject was a woman, 24 years old, myopic, with the refractive error in the right eye -3.0 spherical diopters and astigmatism of -0.25 cylinder in the axis 90°, and in the left eye -2.75 spherical diopters without astigmatism; without ophthalmologic or systemic diseases. The full correction of the refractive error after the orthokeratology lenses application occurred approximately after four nights (wearing the lenses overnight). Concurrently, during the day, slight recurrence to original values was evident. With the decreased refractive error, the uncorrected visual acuity improved accordingly. Further, the flattening of the central cornea was observed, e.g. increasing of the central cornea curvature diameter (maximum change was 0.22 mm in the right and 0.28 mm in the left eye) and slight thinning. The adverse accompanying optic phenomenon was increasing of the aberrations of higher orders, which presented subjectively by decreased visual acuity under mesopic conditions. One month after the termination of contact lenses wearing, all the followed-up parameters returned to original values.Key words: orthokeratology, orthokeratology contact lenses, myopic correction, hard contact lenses, rigid gas-permeable (RGP) lenses.

[Comparison of measurement of intraocular pressure by ICARE PRO® tonometer and Goldman applanation tonometer]. / Porovnání merení nitroocního tlaku ICARE PRO® tonometrem a Goldmanovým aplanacním tonometrem.

The paper compares a concordance in measuring the intraocular pressure (IOP) using two different tonometers, Goldman applanation tonometer (GAT) and ICARE PRO® tonometer. GAT is nowadays considered a standard device for measuring the IOP at the offices of ophthalmologists. Options of the measurements are however limited by necessary installation as well as use of a slit lamp where the evaluation is made subjectively by the examiner. The ICARE PRO® tonometer is a light and mobile device that allows to perform the measurement horizontally as well as vertically. The results are calculated automatically. The data for the paper was collected by IOP measurements in right and left eye in 45 individuals at the age range of 8-84 years. They were all diagnosed for glaucoma or were suspected to have glaucoma. The measurements were carried out always at the same day time. The acquired data was compared by a double select paired t-test with a significance level p = 0.05 and then analyzed by Bland-Altman method. There was no statistically important difference (p > 0.26) between the two devices. The average IOP measured by the ICARE PRO® tonometer was 18.19 mm Hg with standard deviation 3.70 mm Hg, whereas the average IOP measured by GAT was 17.94 mm Hg with standard deviation 3.66 mm Hg. It was observed that the difference in the measurements was not related to the IOP. The results show an acceptable concordance of measurements performed by the two devices. The ICARE PRO® tonometer, in comparison with its predecessor ICARE® TA01 evaluated in the past, shows a much smaller average difference in collected values compared with GAT. Based on the analysis of the collected data it may be stated that measuring the IOP by ICARE PRO® tonometer is clinically acceptable alternative to the use of GAT.

[The importance of angle kappa for centration of multifocal intraocular lenses]. / Význam úhlu kappa pro centraci multifokálních nitroocních cocek.

PURPOSE: To evaluate patient satisfaction with multifocal intraocular lens (MIOL) implants (AcrySof Restor) in relation to the size of angle kappa and precise centration of the MIOL. METHODS: Fifty-two eyes of 26 patients were included in this study. All patients underwent bilateral phacoemulsification and multifocal intraocular lens implantation (AcrySof Restor) from January 2008 to April 2010. Preoperative and postoperative examinations included slit lamp biomicroscopy, near and distance uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity and measurement of angle kappa. Precise centration of the IOL with respect to the centre of the pupil was evaluated postoperatively. Subjective photic phenomena were evaluated separately for each eye and the patients were asked to compare the perception between the right and left eye. RESULTS: Angle kappa was positive in all cases, ranging from +1° to +7°. The mean angle kappa was 2.78° and 2.10° in the right and left eye, respectively. The IOL was centred exactly to the centre of the pupil in 40 eyes. In twelve eyes there was a slight decentration of the IOL (3 nasal, 4 temporal, 2 superotemporal, 2 superior, 1 inferior). Different subjective perception of photic phenomena between the two eyes was recorded only in five patients. All these patients were among those with a decentred IOL. Temporal and superotemporal decentration of the IOL caused pronounced photic phenomena in five cases - in four cases there was a greater angle kappa of +3° to +4°. In one case of temporal decentration and a small angle kappa (+1°), the patient failed to observe a difference between both eyes. In the cases of inferior, superior and nasal decentration of the IOL, no difference between both eyes was seen. CONCLUSION: According to our results, temporal decentration of the IOL is associated with the greatest risk in multifocal IOL implantation, particularly in cases with a higher angle kappa. An evaluation of angle kappa should be a part of preoperative examination before MIOL implantation. Patients with a high angle kappa should be excluded because of a higher risk of postoperative photic phenomena. Key words: angle kappa, multifocal intraocular lens, photic phenomena.