MATERIALS AND METHODS: A review of observational studies was conducted to discuss the accuracy, tolerability and ease of use of tonometers in measuring IOP in children with glaucoma.
RESULTS: Goldmann applanation tonometry (GAT) and its portable handheld versions remain the gold standard in measuring IOP. Tono-Pen (Reichert Ophthalmic Instruments, Depew, New York, USA) and rebound tonometer (RBT) both correlate well with GAT. Although both tonometers tend to overestimate IOP, Tono-Pen overestimates more than RBT. Overestimation is more remarkable in higher IOP and corneal pathologies (such as but not limited to scarred cornea and denser corneal opacity). RBT was better tolerated than other tonometers in children and was easier to use in children of all ages.
CONCLUSIONS: RBT is the preferred tonometer for measuring IOP in children with glaucoma, as it is less traumatic, time efficient and does not require fluorescein dye or anaesthesia. However, examiners should use a second tonometer to confirm elevated IOP readings from the RBT.
METHODS: This was a prospective observational study carried out at a tertiary referral centre. POAG patients on topical antiglaucoma medications and planned for phaco-ECP were recruited. WDT was performed before surgery and 6 weeks postoperatively by drinking 10 mL/kg of water in 5 min followed by serial IOP by Goldmann applanation tonometry measurements at 15, 30, 45, and 60 min. Mean IOP, IOP fluctuation (difference between highest and lowest IOP), IOP reduction, and factors affecting IOP fluctuation were analysed.
RESULTS: Twenty eyes from 17 patients were included. Baseline IOP was similar before (14.7 ± 2.7 mm Hg) and after (14.8 ± 3.4 mm Hg, p = 0.90) surgery. There was no difference in mean IOP (17.6 ± 3.4 mm Hg vs. 19.3 ± 4.7 mm Hg pre- and postoperative, respectively, p = 0.26) or peak IOP (19.37 ± 3.74 mm Hg vs. 21.23 ± 5.29 mm Hg, p = 0.25), albeit a significant reduction in IOP-lowering medications (2.2 ± 1.15 vs. 0.35 ± 0.93, p < 0.001) postoperatively. IOP fluctuation was significantly greater (6.4 ± 3.2 mm Hg vs. 4.6 ± 2.1 mm Hg, p = 0.015) with more eyes having significant IOP fluctuation of ≥6 mm Hg (11 eyes [55%] vs. 4 eyes [20%], p < 0.001) postoperatively. Factors that were significantly associated with increased postoperative IOP fluctuations were higher preoperative IOP fluctuation (β = 0.69, 95% CI 0.379-1.582, p = 0.004) and more number of postoperative antiglaucoma medications (β = 0.627, 95% CI 0.614-3.322, p = 0.008).
CONCLUSION: Reducing aqueous production with phaco-ECP does not eliminate IOP fluctuation in POAG patients. The increase in postoperative IOP fluctuation suggests increased outflow resistance after phaco-ECP.
METHODS: A retrospective, non-comparative, analytical case series of all patients who received SL-TSCPC treatment from October 2018 to April 2019 at Hospital Tengku Ampuan Afzan, Pahang, Malaysia. Data was collected during the second week, sixth week, third month and sixth month follow-up. The primary outcome measure gave success rate at six months post-treatment. Secondary measures were changes in visual acuity, mean IOP reduction, mean number of IOP lowering medications reduced and ocular side effects noted during follow-up.
RESULTS: The success rate was 43.8% (seven eyes out of sixteen eyes) at six months post-treatment. The mean IOP reduced from 43.0mmHg±14.8mmHg pre-treatment to 24.7mmHg±12.0mmHg at two weeks post treatment with 42.6% reduction. Subsequently, mean IOP at sixth week, third month and sixth month were 33.8mmHg±16.9mmHg, 35.2mmHg±14.9mmHg, and 29.0mmHg±16.2mmHg respectively. Vision maintained in 13 patients, two patients had improvement in vision however, five patients had deterioration in vision. No serious ocular side effects were noted.
CONCLUSION: Subliminal TSCPC is a safe and alternative method of lowering IOP in moderate to advanced glaucoma over 6 months duration of follow-up. As it has good safety profile and repeatability, it is a good treatment option for patients with uncontrolled glaucoma.
METHOD: A meta-analysis was conducted to determine the potential impact of isometric exercise on IOP and OPP. The literature on the relationship between isometric resistance exercise and IOP was systematically searched according to the "Cochrane Handbook" in the databases of Pubmed, Web of Science, EBSCO, and Scopus through December 31, 2020. The search terms used were "exercise," "train," "isometric," "intraocular pressure," and "ocular perfusion pressure," and the mean differences of the data were analyzed using the Stata 16.0 software, with a 95% confidence interval.
RESULTS: A total of 13 studies, which included 268 adult participants consisting of 162 men and 106 women, were selected. All the exercise programs that were included were isometric resistance exercises of the lower limbs with intervention times of 1min, 2min, or 6min. The increase in IOP after intervention was as follows: I2=87.1%, P=0.001 using random-effects model combined statistics, SMD=1.03 (0.48, 1.59), and the increase in OPP was as follows: I2=94.5%, P=0.001 using random-effects model combined statistics, SMD=2.94 (1.65, 4.22), with both results showing high heterogeneity.
CONCLUSION: As isometric exercise may cause an increase in IOP and OPP, therefore, people with glaucoma and related high risk should perform isometric exercise with caution.
METHODS: Patients with newly diagnosed AAC were identified prospectively over a 12-month period (November 2011 to October 2012) by active surveillance through the Scottish Ophthalmic Surveillance Unit reporting system. Data were collected at case identification and at 6 months follow-up.
RESULTS: There were 114 cases (108 patients) reported, giving an annual incidence of 2.2 cases (95% CI 1.8 to 2.6) or 2 patients (95% CI 1.7 to 2.4) per 1 00 000 in the whole population in Scotland. Precipitating factors were identified in 40% of cases. Almost one in five cases was associated with topical dilating drops. Best-corrected visual acuity (BCVA) at presentation ranged from 6/6 to perception of light. The mean presenting intraocular pressure (IOP) was 52 mm Hg (SD 11). Almost 30% cases had a delayed presentation of 3 or more days. At 6 months follow-up, 75% had BCVA of 6/12 or better and 30% were found to have glaucoma at follow-up. Delayed presentation (≥3 days) was associated with higher rate of glaucoma at follow-up (22.6% vs 60.8%, p<0.001), worse VA (0.34 vs 0.74 LogMAR, p<0.0001) and need for more topical medication (0.52 vs 1.2, p=0.003) to control IOP.
CONCLUSION: The incidence of AAC in Scotland is relatively low compared with the Far East countries, but in line with previous European data. Almost one in five cases were associated with pupil dilation for retinal examination.
METHODS: This was a prospective non-randomized comparative study. Eyes with OAG and cataracts that were planned for either combined phacoemulsification and iStent implantation (iStent+CS) or phacoemulsification alone (CS) were recruited. The iStent inject (Model G2-M-IS) or iStent injectW (Model G2-W) trabecular micro-bypass stent (Glaukos Corporation, San Clemente, CA, USA) was implanted in the iStent+CS group. WDT was performed before and 3 months after surgery. WDT-IOP parameters including peak IOP, IOP fluctuation, and area under the curve (AUC) were compared between the two groups.
RESULTS: There were 20 eyes in the iStent+CS group and 16 eyes in the CS group. Both groups had similar pre-operative baseline IOP (15.6 ± 3.7 mm Hg vs. 15.8 ± 1.8 mm Hg in the iStent+CS and CS group, respectively, p = 0.883). The iStent+CS group experienced greater numerical reduction in peak IOP (2.6 ± 1.9 mm Hg vs. 1.9 ± 2.4 mm Hg; p = 0.355), IOP fluctuation (1.7 ± 2.2 mm Hg vs. 0.8 ± 2.5 mm Hg; p = 0.289), and AUC (54.8 ± 103.6 mm Hg × minute vs. 25.3 ± 79.0 mm Hg × minute; p = 0.355) than the CS group. There was more reduction in the number of anti-glaucoma medications in the iStent+CS group (1.4 ± 1.2) than the CS group (0.3 ± 0.9; p = 0.005).
CONCLUSION: Both combined phacoemulsification with iStent inject implantation and phacoemulsification alone reduced peak IOP, IOP fluctuation, and AUC, and none of these parameters showed statistically significant difference. Greater reduction in anti-glaucoma medications was seen in the combined group.
DESIGN: A cross-sectional, non-interventional study.
METHODS: The IOP measurements by handheld Icare rebound tonometer (Finland) were first performed by a primary care physician. Then the IOP was measured using Perkins Mk3 applanation tonometer (Haag-Streit, UK) by an ophthalmologist who was masked to previous readings from the Icare rebound tonometer. The mean IOP measured by each tonometer was compared. Pearson correlation coefficient was used to explore the correlation between the IOP measurements of the 2 instruments. The level of agreement between them was assessed using the Bland and Altman method.
RESULTS: A total of 420 left eyes were examined. The mean age of subjects was 38.6 ± 18.2 years. Approximately 67% of subjects were female. The mean IOP was 16.3 ± 4.0 mm Hg using Icare and 13.4 ± 2.3 mm Hg using PAT. Pearson correlation coefficient showed a moderate positive correlation between the 2 methods (r = +0.524, P < 0.001). Linear regression analysis revealed a slope of 0.28 with R² of 0.255. The mean difference between the 2 methods was 2.90 ± 3.5 mm Hg and the sample t-test revealed a statistically significant mean difference from 0 (P < 0.001). The 95% limits of agreement between the 2 methods were between -9.73 and 3.93 mm Hg.
CONCLUSIONS: The handheld Icare rebound tonometer is a reasonably acceptable screening tool in community practices. However, Icare overestimated IOP with a mean of 2.90 mm Hg higher than the PAT. Thus, using Goldmann applanation tonometer as a confirmatory measurement tool of IOP is suggested.