Intraocular Pressure In Right Eye Research Articles

Effect of alternate nostril breathing exercise on autonomic functions, ocular hypertension, and quality of life in elderly with systemic hypertension and high-tension primary open-angle glaucoma

Investigating the response of ocular hypertension and quality of life to a 4-week alternate-nostril breathing exercise (ANBE) in older adults with systemic hypertension (SH) and high-tension form of primary open-angle glaucoma (HTF-POAG) was our aim. Sixty older adults with SH and HTF-POAG were randomly assigned to the ANBE group (n=30, received morning and evening 30 min sessions of daily ANBE) or the control (waitlist) group (n=30). Right-eye intraocular pressure (IOP), left-eye IOP, blood pressure, short-form-36 survey (SF36S), rates of respiration and radial-artery pulsation, hospital anxiety and depression scale (depression subscale abbreviated as HADS-D and anxiety subscale abbreviated as HADS-A), and glaucoma quality-of-life 15-item questionnaire (GQoL-15) were assessed. All measurements were improved in the ANBE group only. In conclusion, a 4-week ANBE could be an adjunctive modality to improve HADS-D, rates of respiration and radial-artery pulsation, HADS-A, blood pressure, IOP, GQol-15, and SF36S in older adults SH and HTF-POAG.

The evaluation of normal ocular parameters in two breeds of hedgehogs.

The purpose of this study was to evaluate conjunctival microflora and measure normal tear production and intraocular pressure (IOP) in two breeds of hedgehogs (long-eared hedgehogs and Brandt's hedgehogs). Forty-eight hedgehogs from two different breeds were chosen for the study. Tear production was measured using the Schirmer tear test (STT) and phenol red thread test (PRTT) in both eyes. IOP was measured using a rebound tonometer. To perform microbiological sampling one drop of tetracaine was instilled in the eyes. Two sterile microswabs were used to collect samples for the microbial and fungal culture. All the microswab samples were transferred in phosphate-buffered saline (PBS) to the laboratory for culture. Two MacConkey and two blood agar media plates were employed for each eye. Oneplate of sabouraud dextrose agar (SDA) was used for the fungal culture for each eye. Standard biochemical tests were performed to identify the isolated organisms. The mean STT and PRTT values were 1.6 ± 0.1mm/min and 2.4 ± 0.3mm/15 s in long-eared hedgehogs and 2.2 ± 0.1mm/min and 2.5 ± 0.3mm/15 s in Brandt's hedgehogs, respectively. Mean (SD) Intraocular pressure of right eyes in long-eared hedgehog and Brandt hedgehog were 19.7 ± 1.4mmHg and 19.2 ± 2.4mmHg, respectively. In the left eyes of long-eared hedgehog and Brandt hedgehog mean (SD) IOP were 19.8 ± 1.5mmHg and 19.5 ± 2.1mmHg, respectively. In long-eared hedgehogs, the most common bacteria were Staphylococcus epidermidis and Bacillus spp. In Brandt's hedgehogs, 24 out of 48 eyes had Staphylococcus epidermidis, which was the most commonly isolated bacterial species. This study established reference intervals for IOP, STT and PRTT in hedgehogs and recognised and compared ocular conjunctival microflora in two breeds of hedgehogs.

Comparison of intraocular pressure and retinal nerve fibre layer thickness in pre-menopausal and post-menopausal women attending outpatient department of BSMMU

In a menopausal lady, a reduced level of estrogen hormone leads to changes in the intraocular pressure (IOP) and retinal nerve fiber layer (RNFL) thickness in the eyes. This comparative study was carried out in the Outpatient Departments (OPD) of the Community Ophthalmology and Ophthalmology of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, from April 2017 to June 2019 to identify any difference in IOP and RNFL thickness in pre-menopausal and post-menopausal women aged 40-65 years. In this study, 60 pre-and post-menopausal women were included. Participants 40-50 years old with irregular menstruation were classified as group A, while those 51-65 years old with no menstruation for at least 12 months were classified as group B. More than one-fourth (26.7%) of participants had HTN in group A and 53.3% in group B. HTN was significantly associated with group B. The rise in menopausal age had a significant impact on the mean IOP and RNFL. The mean IOP in right eye (RE) was 11.80 (3.31) mm of Hg in Group A and 15.63 (3.01) mm of Hg in Group B. The mean IOP in left eye (LE) was 12.27(3.78) mm of Hg and 15.47(2.84) mm of Hg in Group A and Group B, respectively. The mean IOP of both eyes was 12.03±3.48 mmHg in Group A and 15.55±2.82 mmHg in Group B. The mean difference of IOP in RE, LE and both were statistically significant between the two groups. The mean RNFL in RE was 103.97±7.42 μm in Group A and 98.90±}6.21 μm in Group B. The mean RNFL in LE was 101.87±6.69 μm and 97.97±6.65 μm in Group A and Group B, respectively. The mean RNFL of both eyes was 102.92±7.77 μm in Group A and 98.45±7.86 μm in Group B. The mean RNFL was statistically significant between the two groups. Post-menopausal women are at an increased risk of developing elevated IOP and thin RNFL than premenopausal women. BSMMU J 2022; 15(2): 61-64

COMPARING THE EFFECT OF CHRONIC HYPERGLYCEMIA ON INTRA OCULAR PRESSURE IN DIABETIC PATIENTS

Objective: To compare the effect of chronic hyperglycemia on intra ocular pressure (IOP) in diabetic patients. Material and Methods: This cross-sectional study was conducted at Pathology & Ophthalmology Departments of PNS Shifa Hospital, Karachi from February to May 2022. A total of 215 patients of Diabetes Mellitus having age between 40 to 70 years were included. HbA1c was used to categorize patients into two groups. Good glycemic control group (HbA1c <7%) and Poor glycemic control group (HbA1c >7%). IOP (mmHg) of both eyes was measured in both groups by applanation tonometer. Median comparison of IOP in both groups was done by Mann-Whitney U-test. To determine correlation between HbA1c levels and IOP, Pearson correlation was applied. Results: Out of 210 patients 110(51.2%) patients had HbA1c < 7% while 105(48.8%) had HbA1c > 7%. Good glycemic control group had lower median IOP in both right (14.5 mmHg IQR 14-16) & left eye (15mmHg IQR 14-16) as compared to poor glycemic control group having median IOP in right eye (20mmHg IQR 19-22) & left eye (21 mmHg IQR 18-23). The difference was found to be statistically significant (p value <0.001). Pearson correlation showed a significant positive linear correlation between HbA1c and right eye IOP (r = 0.898, p value <0.01) and left eye IOP (r = 0.883, p value <0.01). Conclusion: Patients with poor glycemic control had higher IOP as compared to good glycemic control. Chronic hyperglycemia is associated with raised IOP in diabetics. Key Words: Diabetes mellitus, Intra ocular pressure, HbA1c

Evaluation of Intraocular Pressure in Thyroid-associated Orbitopathy.

Elevated intraocular pressure in thyroid associated orbitopathy may lead to development of secondary glaucoma in them. This study evaluated IOP in primary gaze correlation with clinical activity score in them. A cross-sectional study was conducted from November 2020 to October 2021.Information on age, gender, thyroid function test, intraocular pressure, cup-disc ratio and clinical activity score were recorded. Purposive sampling was done. Statistical analysis was done using Statistical Package for Social Sciences version 21. Total of 74 thyroid dysfunction patients was included in the study. There were14.86% patients with raised intraocular pressure. The mean intraocular pressure in hyperthyroidism was 15.4 ± 1.92 mm Hg and 15.48 ± 2.11mm Hg on right and left eyes respectively and in hypothyroidism, it was 15.08 ± 2.7mmHg and 15.12 ± 3.02 mmHg on right and left eyes respectively. The mean clinical activity score was 1.06 ± 1.23 mmHg. The mean intraocular pressure in eyes in active stage (n=9) was 16.3 ± 3.4 mm Hg, which was not significantly different from the mean intraocular pressure of 15 ± 2.4 mm Hg in inactive eyes (64), p= 0.1. Clinical activity score showed a significant correlation (p=0.03) with intraocular pressure in right eyes whereas it showed no significant correlation with intraocular pressure in left eyes (p=0.37). In this study elevated intraocular pressure occurred in about 1 in 7 thyroid associated orbitopathy. It also had positive correlation with clinically activity score in right eyes. Regular intraocular pressure measurement should be done in thyroid associated orbitopathy to prevent intraocular morbidity.

English

BACKGROUND Glaucoma is a chronic, progressive optic neuropathy leading to irreversible blindness. Raised intraocular pressure is one of the modifiable risk factors of developing glaucoma. Regulation of intraocular pressure (IOP) is influenced by various factors and, systolic hypertension is one of them. The objectives of the study was to assess the relationship between systolic hypertension and IOP, also to see the effect of controlled and uncontrolled systolic blood pressure (SBP) on IOP in adults above 40 years of age. METHODS This study included a total of 230 known systemic hypertensive patients of age above 40 years. All the patients underwent detailed history taking, careful systemic and ocular examination. IOP was measured by Goldmann applanation tonometer, central corneal thickness (CCT) by anterior segment optical coherence tomography (OCT) and blood pressure (BP) was recorded after 5 minutes of rest. The data was recorded. RESULTS Correlation coefficient for SBP and IOP in right eye (RE) was 0.290 and for left eye (LE) was 0.354 with a probability value of P < 0.0001 which was statistically highly significant. Mean IOP for controlled SBP was 17.76 mmHg in both eyes (BE) which increased to 20.19 mmHg in RE and 20.64 mmHg in LE in uncontrolled SBP. The Z score value between controlled and uncontrolled systolic hypertensive patients in RE and LE was 6.11 and 7.06 respectively (P < 0.0001). There was an increment of IOP for every 10 mmHg in SBP by 0.56 mmHg in right eye and 0.73 mmHg in left eye. CONCLUSIONS Systolic blood pressure is significantly correlated with IOP. The uncontrolled SBP was related to higher mean IOP and mean IOP was found to increase with rise in SBP. Therefore, patients with known hypertension and glaucoma have to be regularly followed-up and should keep their BP in normal range to prevent disease progression. KEYWORDS Intraocular Pressure, Central Corneal Thickness, Systolic Blood Pressure, Adults Above 40 Years

To evaluate the retinal nerve fiber layer thickness in different types of glaucoma

Objective: Glaucoma is a multifaceted eye disease which is classified as physical damage of retinal ganglion cells which may effect in loss of vision and permanent blindness. While physical damage of glaucoma can be clinically evaluated the optic nerve head and peripapillary retinal nerve fiber layer (RNFL). Our objective is to evaluate the mean RNFL thickness in all types of glaucoma. Methodology: This prospective and cross sectional study was conducted in Glaucoma Clinic of Al Ibrahim Eye Hospital (AIEH), Karachi, for the period from May 2019 to October 2019, after ethical approval from Institutional Research Committee. A total of 64 glaucoma patients were chosen by using non-probability purposive sampling technique. The participant comprised, no known eye disease, no visual impairment, IOP below 22 mmHg, and no obvious retinal disease or defect were included while individuals having a history of ocular diseases or pathology with residual visual impairment, retinal diseases, amblyopia, and history of intraocular surgery or laser therapy were excluded from the study. The collected data were analyzed using Statistical Package for Social Sciences (SPSS) version 20. Results: 64 patients of both genders with mean age of 55.54±15.58 years. The mean intraocular pressure of right eye and left eye was 16.46±8.06 and 16.75±7.82 mmHg, respectively. The mean RNFL thickness in superior, inferior, temporal and nasal quadrant of the right eye was measured 68.23±25.44, 66.79±27.50, 51.75±12.58 and 47.73±18.82 microns, respectively while the mean RNFL thickness in superior, inferior, temporal and nasal quadrant of the left eye was measured 76.01±22.72, 67.42±21.25, 54.37±13.0 and 49.62±11.57 microns, respectively. Conclusion: Our study showed that analysis of retinal nerve fiber layer thickness with optical coherence tomography is the best tool for the diagnosis of glaucoma. It has also been observed in our study that frequency of changes in retinal nerve fiber layer thickness was mostly found in primary open angle glaucoma patients

Role of body mass index and blood pressure on intraocular pressure in elderly population

To identify the role of body mass index (BMI) and Blood pressure (BP) on Intraocular pressure (IOP) in elder population. Totally 50 elderly individuals without any systemic diseases were included and IOP was measured by tonometer. Total subjects divided into 3 groups based on BMI as: Group1 with BMI≥25 and Group 2 with BMI ≤ 30. Mean and standard deviation of IOP, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were statistically analysed.Out of a total of 50 Subjects, 23 (46%) subjects had normal weight, 15(30%) subjects were overweight and 10 (20%) subjects were obese. Mean age of 56.5 ± 9.5 and 56.2 ± 9.4 years in male and females (p=145). Mean BMI of 25.8 ± 3.9 and 26.4 ± 4.2 kg/m in male and females. SBP of 135.8 ± 20.4 and 128.4 ± 21.5 mmHg in male and female (p=0.02). Mean DBP of 78.5 ± 10.5 and 81.4 ± 10.5 mmHg in male and female (p=0.04). Mean CCT of right eye was 515.5 ± 31.2 and 510.2 ± 28.8 μm in male and females respectively (p=0.03). Mean IOP of right eye was 15.6 ± 2.2 and 14.9 ± 2 mm Hg in male and females respectively (p=0.25). Mean CCT of left eye was 520.4 ± 27.5 and 515.2 ± 28.5 μm in male and females respectively (p=0.03). Mean IOP of left eye was 15.1 ± 2.2 and 14.9 ± 2.1 mm Hg in male and females respectively (p=0.12). The mean IOP of right eye is highest in the overweight and obese age groups. The mean SBP is highest in the overweight and obese age groups. The mean DBP is highest in the overweight and obese age group. Hence, increase in BMI results in non-significant increase in IOP and BP as age increases in normal BMI subjects. For obese Subjects, there was positive correlation between the BMI, age, IOP, SBP and DBP. Increase in BMI resulted in increase in IOP, increase in systolic and diastolic blood pressure respectively with increase in age.Results showed positive correlation relationship between BMI and intra-ocular pressure, BMI and blood pressure and BMI and age in obese population. It indicate that subjects with higher BMI have lower ocular blood flow. Results suggest that IOP increases with increasing age and increasing BMI. Periodic checking of IOP in elderly and overweight individuals can play an important role in reducing the morbidity due to glaucoma.

Ultrasound findings in a case of Eales\u2019 disease and ocular trauma with anterior chamber cholesterolosis

BackgroundAnterior chamber cholesterolosis is a rare phenomenon which occurs mostly in chronically blind eyes. We present the anterior and posterior ultrasound findings in a case of anterior chamber cholesterolosis secondary to Eales’ disease and ocular trauma, which may contribute to the understanding of the potential mechanism of this phenomenon.Case presentationA 48-year-old man presented with “sparking” right eye, which appeared soon after the ocular trauma. Both eyes were confirmed Eales’ disease in our center 8 years ago, and right eye remained no light perception since then. Intraocular pressure of right eye measured by Goldmann applanation tonometry was 1 mmHg. Slitlamp photograph revealed multiple polychromatic large crystals in anterior chamber. Ultrasound biomicroscopy showed that anterior chamber was filled with extensive large granular substances. Dense dotted hyperechoic foci and retinal detachment was found in B-scan ultrasound examination. The right eye was diagnosed as anterior chamber cholesterolosis secondary to Eales’ disease and ocular trauma. The patient was asymptomatic, and therefore was advised to have regular follow-up.ConclusionThe findings of above imaging examinations, as well as complaint of “sparkling” eye appeared soon after ocular trauma elucidate that anterior chamber cholesterol crystals were from vitreous cavity. Any factors facilitating the communication of anterior chamber and vitreous body may lead to the occurrence of this rare phenomenon in predisposing eyes. The anterior and posterior ultrasound findings may give a clue on the potential mechanism.

Age-related decline of lymphatic drainage from the eye: A noninvasive in vivo photoacoustic tomography study

We aim to determine whether lymphatic drainage from the eye changes with age. Using quantitative photoacoustic tomography, groups of young and older mice were studied in the live state. 10 CD-1 mice of 2–3 months (5M/5F) were studied in addition to 13 older mice of 12–13 months (6M/7F). In each of 23 mice, near-infrared tracer (a near-infrared dye, QC-1 conjugated with Bovine Serum Albumin) was injected into the right eye, and imaging of ipsilateral cervical lymph nodes was performed with laser pulses at 11 different wavelengths prior to and 20 min, 2, 4 and 6 h after injection. Mean pixel intensities (MPIs) of nodes were calculated at each imaging session. The areas under the curves (AUC) were calculated for both groups of mice and compared using the t-test. The slopes of MPI of each region of interest were compared using the linear mixed model before and after adjusting for sex, body weight and intraocular pressure of the right eye. The mean intraocular pressure of right eyes before injection was similar in older and younger groups (12.77 ± 2.01 mmHg and 12.90 ± 2.38 mmHg, respectively; p = 0.888). In each mouse, the photoacoustic signal was detected in the right cervical lymph nodes at the 2-h time point following tracer injection into the right eye. At the 4 and 6 h imaging times, a steady increase of tracer signal was observed. Areas under the curve in the right cervical nodes were decreased significantly in older mice compared to younger mice (p = 0.007). The slopes of MPI in the nodes were significantly decreased in old mice compared to young mice both before and after adjusting for sex, body weight and intraocular pressure of the right eye (p = 0.003).In conclusion, lymphatic drainage from the eye is significantly reduced in older eyes. This finding suggests that impaired lymphatic clearance of aqueous humor, proteins and antigens from the eye may contribute to age-related disease of the eye such as glaucoma and inflammatory eye disease.

Systematic bias in real-world tonometry readings based on laterality?

In research settings, the first eye examined tends to have a higher intraocular pressure (IOP) than the second. We sought to verify whether clinicians in Yorkshire, UK, measure IOP in right eyes before left and whether such behavioural factors affect IOP readings at the population level. We observed 128 IOP measurements taken by 28 ophthalmologists using Goldmann applanation tonometry (GAT) over a 4-month period in 2018, recording which eye was examined first. All IOP measurements on electronic patient records for Leeds Teaching Hospitals NHS Trust, UK, between January 2002 and June 2017 were extracted, yielding IOP readings for 562,360 eyes, analysed for evidence of systematic bias in IOP measurement. Right eye IOP was measured before left in 112/128 observations (87.5% (95% CI: 75.2%-94.2%)). For IOP measured by GAT, there was no statistically significant difference (p = 0.121) between right and left eye IOP (mean IOP 16.95 and 16.96 mmHg, respectively). Even values of IOP were reported more frequently than odd values (136,503/214,628 (63.6%) were even). Identical IOP readings for both eyes were recorded in 124,392/254,380 patients (48.9%) who had both eyes measured. Our study found no IOP difference based on laterality, but strong evidence of certain trends associated with IOP measurement by GAT, such as a preference for even values and the same IOP being recorded for both left and right eyes. Such effects may be explained by behavioural aspects of GAT and suggest that there are substantial opportunities for improvement in the way GAT is utilised in real world settings.

INTRA OCULAR PRESSURE

Introduction: The ideal optical properties of the eye requires support of state of the eye-ball which is normally regulated by the intraocular pressure (IOP). There is variation in the measurements of IOP with Goldmann applanation tonometry if the thickness of the central cornea is not uniform, the IOP is high when cornea is thicker and vice versa. Therefore, the central corneal thickness (CCT) is thought to affect the IOP readings, however, as shown, the evidence available remains controversial. The aim of the study was to determine correlation between CCT and IOP. Objectives: To determine the correlation between the Central Corneal Thickness (CCT) and Intra Ocular Pressure (IOP). Study Design: A cross-sectional study. Placeand Duration: Department of Ophthalmology, Aga Khan University Hospital, Karachi from July to December, 2014. Methodology: During the study period of six months total 431 participants were purposively sampled according to the set criteria. Variables included were age, gender, CCT, and IOP. Correlation between IOP and CCT was assessed by using Pearson correlation test, P value of < 0.05 was considered significant. Results: Out of 431 participants, 239 (55.5%) males and 192 (44.5%) females. The mean age was 34.9 ranging from 20 to 50 years. The mean central corneal thickness of right eye was 529 μm with SD ± 39.5 and range of 473-591 μm. The mean intraocular pressure of right eye was 14.7 μm, SD ± 3.1 with a range of 9-21 mmHg. The left eye mean central corneal thickness was 533, SD ± 29.6 with range of 481-589 μm. The mean intraocular pressure of left eye was 15.6, SD ± 3.1 with a range of 10-21 mmHg. Strong positive correlation was found (P-value < 0.001) between central corneal thickness andintra ocular pressure for both eyes. Conclusion: There is positive correlation between CCT and IOP. Therefore, along with the routine ophthalmic examination for intraocular pressure measurements pachymetry should also be considered for accurate interpretation of the results.

Effect of Diltiazem on Intraocular Pressure in Normal and Ocular Hypertensive Rabbits

Background; Glaucoma is a multifactorial disease involving progressive optic neuropathy and altered intraocular hemodynamics; furthermore, glaucoma can cause blindness if it is left untreated.Aim of the study: To explore effects of topical diltiazem on intraocular pressure (IOP) in each of normal and ocular hypertensive rabbits.Materials and methods: A group of 54 males of the rabbits were included in the present study. Induction of ocular hypertension was achieved by injection of hydroxy propyl methylcellulose in the anterior chamber of rabbits right eye. In addition to distilled water (as negative control), each of timolol (as positive control) and diltiazem (the tested drug) eye drops were instilled 3 times daily to right eye prophylactically for 4 days and therapeuticallyResults: Part Ι: Diltiazem (0.5%) caused highly significant (P < 0.01) reduction in intraocular pressure of right eye .
 Part ΙΙ: diltiazem, at both concentrations (0.5% and 0.25%) caused highly significant reduction (P < 0.01) in IOP at 5th and 10th days post treatment.Conclusions: Diltiazem exerted a detectable ocular hypotensive effect on the eye of rabbits when applied at concentration (0.5%) or (0.25%) 3 times daily.

Cambios de la presión intraocular en pacientes con hipertensión arterial

IntroductionChronic simple open angle glaucoma is a frequent cause of blindness because signs become evident mostly at advanced stages. ObjectiveTo determine if changes in intraocular pressure appear in patients with arterial hypertension. MethodsAn observational, prospective, transversal, analytic study was performed with a sample of hypertensive patients attending at the Cardiology Service. Intraocular pressure and optic disk excavation were measured with a Perkins tonometer and direct ophthalmoscopy. Correlation between blood pressure and intraocular pressure was estimated. ResultsA correlation between right arm diastolic blood pressure and intraocular pressure of both eyes was identified. Left arm diastolic blood pressure was correlated with intraocular pressure of right eye. Intraocular pressure did not show any correlation with patients’ age. ConclusionsIn this study we found correlation between intraocular pressure and diastolic blood pressure, but not with systolic blood pressure. It is recommended to check intraocular pressure in hypertensive patients, especially in those with persistent high diastolic pressure and family history of glaucoma.

Twenty‐four‐hour measurement of IOP in rabbits using rebound tonometer

To observe the Intraocular pressure (IOP) measurements over a 24-h period in New Zealand white rabbits. Thirty-four normal New Zealand white rabbits (68 eyes) were included in this study. The IOP values were determined with a rebound tonometer (RBT, Icare VET). Measurements were always obtained in the right eye first. The data showed that there was no significant difference in IOP between measurements, which indicated that the RBT showed good repeatability in this study (P = 0.920). There was no statistically significant difference between genders (P = 0.943). The IOP in right eyes was a little higher than left eyes (F = 45.96, P < 0.001). Comparison of the true IOP and RBT results over the entire pressure range (8-100 mmHg) revealed a statistically significant difference between them (P < 0.001). The mean difference between the RBT and true IOP (RBT-True IOP) was -22.65 ± 9.52 mmHg with 95% confidence interval (-27.1, -18.2 mmHg). In the light period (7 AM to 7 PM), the IOP was a little lower than during the dark period (8 PM to 6 AM); 9 AM and 2 PM were the lowest measurements (10 mmHg, 9.625 mmHg), and 10 AM (14.125 mmHg)was the highest measurement during the 24-h period. The IOP obtained by RBT underestimated the true IOP but the RBT had a good repeatability in IOP measurements. In the light period (7 AM to 7 PM), the IOP was a little lower than during the dark period (8 PM to 6 AM), which may be beneficial to the intervention therapy observation of glaucoma research in rabbits.

Effect of two tonometers on measuring normal intraocular pressure

Objective To discuss the clinical performance of ICARE rebound tonometer.Methods Intraocular pressure measurements were performed on 112 cases(224 eyes)with non-contact tonometer and ICARE rebound tonometer respectively.Results The intraocular pressure of right eyes which measured by ICARE rebound tonometer was(15.4 ±3.4)mm Hg,and the left eyes' was(15.6 ±3.2)mm Hg on average,but they were(13.5 ±2.7)mm Hg and(13.6 ±2.6)mm Hg respectively measured by non-contact tonometer There was significant difference between the two tonometer(t =4.384,4.535;P ＜0.01).Conclusions lOP measured by ICARE rebound tonometer is higher than that of non-contact tonometer when IOP is in the normal range.ICARE rebound and non-contact tonometer have a good consistency. Key words: Intraocular pressure; Intraocular pressure measurement; Icare rebound tonometer; Non-contact tonometer

Unilateral nostril breathing in intraocular pressure of right-handed healthy subjects.

The effects of unilateral forced nostril breathing on the intraocular pressures of right and left eyes was studied in 24 male and 26 female right-handed adults. In men, the forced breathing through both the right and left nostrils significantly decreased the intraocular pressures of both right and left eyes. For women, the forced breathing through right nostril did not affect the intraocular pressures of right and left eyes, and the forced breathing through left nostril also had no effect on the intraocular pressure of right eye, although it decreased the intraocular pressure of left eye significantly. These results show that unilateral forced nostril breathing decreases intraocular pressure especially in men, perhaps increasing sympathetic nervous system activity.

Central corneal thickness, radius of the corneal curvature and intraocular pressure in normal subjects using non-contact techniques: Reykjavik Eye Study.

To establish a population profile of central corneal thickness (CCT), radius of the corneal curvature (CC) and intraocular pressure (IOP) and the relationships between them using non-contact techniques. We used a population-based random sample of 415 male and 510 female Caucasians aged 50 years and older. CCT and the radius of CC were measured with Scheimpflug anterior segment photography. IOP was measured with air-puff tonometry. The mean IOP of right eyes was 15.1 mmHg (SD 3.3) among men and 15.8 mmHg among women (SD 3.1), which is a statistically significant difference. The mean radius of CC for male right eyes was 7.78 (SD 0.60) and for females 7.62 (SD 0.58) which is also statistically significant. Mean CCT for male right eyes was 0.528 mm (SD 0.041) and for females 0.526 mm (SD 0.037), which is not a significant difference. Linear regression analysis shows no relationship between the radius of CC and IOP or between age and radius of CC. Linear regression analysis of the relationship between CCT and IOP suggests higher IOP measurements with thicker corneas. There was no significant correlation between age and CCT. IOP was found to be independent of age and significantly higher in females than in males. Radius of CC was found to be age-independent and significantly steeper in females than in males. CCT appears to be independent of age and gender. Greater CCT is associated with higher mean IOP.

Intra-eye pressure range and pulse profiles in normals with the pulsair non-contact tonometer

The difference in intraocular pressure (IOP) between the highest and lowest measurements on an eye with noncontact tonometry (the range) has been reported to be less than 4 mmHg in most normals. The range of IOP to be expected with the Keeler Pulsair in normals over the age of 50 years was determined by analysing the results of IOP recordings on 741 normal individuals. Between 56% and 62% of eyes recorded a range > 4 mmHg and between 4% and 8% a range > 10 mmHg when four pulses per eye were used. Population pulse profile analysis indicated that this was not due to an erroneously high first pulse in a set of four, and that IOP asymmetry previously reported when screening females is due to a generalised tendency for IOPs in right eyes to measure higher than those recorded in the left. The occurrence of a range of IOP recordings up to 10 mmHg in an eye is relatively common with the Pulsair and individuals undergoing glaucoma screening with this instrument should not be referred purely on the basis of a large IOP range.

Hyaluronidase and sodium hyaluronate in cataract surgery.

The use of sodium hyaluronate in cataract surgery and intraocular lens implantation is often followed by a postoperative rise of intraocular pressure. A trial is described in which 10 patients underwent bilateral cataract extraction and Binkhorst intraocular lens implantation with the use of sodium hyaluronate. The enzyme hyaluronidase was instilled into the anterior chamber of the right eye only, to aid removal of sodium hyaluronate, and resulted in a statistically significant lowering of postoperative intraocular pressure in right eyes compared with left. Other uses of the enzyme are discussed.