Posture-induced Intraocular Pressure Changes Research Articles

Posture-Induced Intraocular Pressure Changes after iStent Inject W Combined with Phacoemulsification in Open Angle Glaucoma Patients

Background and Objectives: The purpose of this study was to evaluate the posture-induced intraocular pressure (IOP) changes after iStent inject W combined with phacoemulsification procedure in Japanese patients with open-angle glaucoma. Materials and Methods: We prospectively evaluated the posture-induced IOP changes after surgery. The primary outcome was the posture-induced IOP changes postoperatively. Secondary outcome measures included postoperative complications, visual acuity, visual field, and corneal endothelial cell density. Results: This study completed the prospective observation for 15 eyes (15 patients). The mean preoperative IOP with the Goldmann applanation tonometer was 16.0 ± 2.6 mm Hg with a mean glaucoma medication usage of 2.5 ± 1.2, which decreased to 14.4 ± 2.4 mm Hg (p = 0.14) and 0.5 ± 0.9 medications (p < 0.01), respectively, 12 months postoperatively. The mean baseline IOP with the ICare was 12.0 ± 2.7 mmHg in the sitting position, which significantly increased to 15.2 ± 3.8 mmHg in the lateral decubitus position (p < 0.01). This postural IOP difference was 3.2 ± 2.2 mmHg and 3.2 ± 2.4 mmHg at baseline and 12 months postoperatively, respectively, with no significant changes (p > 0.99). Conclusions: iStent inject W combined with cataract surgery reduced the IOP and the number of glaucoma medications during short-term follow-ups with high safety. However, iStent inject W did not affect the degree of posture-induced IOP changes.

Posture-induced intraocular pressure changes among patients with primary open angle glaucoma in a Nigerian Tertiary Hospital: Any implication for management.

To determine the effect of postural changes on intraocular pressure (IOP) among newly diagnosed patients with primary open-angle glaucoma (POAG). This was a cross-sectional observational study of 55 consecutive newly diagnosed patients with POAG attending Glaucoma clinics at a Federal Teaching Hospital in Abakaliki, Ebonyi state, from July to September 2017. Patients IOPs were measured in the sitting position, supine without a pillow, and supine with pillow positions using Perkin's handheld applanation tonometer. All data were analyzed with SPSS version 20.0. A total of 55 subjects were recruited comprising 30 (54.5%) males and 25 (45.5%) females, with a mean age of 50.13 ± 9.97 years and an age range of 30-79 years. The mean intraocular pressure was 27.54 ± 3.98 mmHg in the sitting position, 30.15 ± 4.41 mmHg in the supine with pillow position, and 35.22 ± 4.61 mmHg in the supine without pillow position. The mean difference of mean IOP of sitting compared to supine without the pillow was 7.68 ± 2.08 mmHg (P-value < 0.001, 95% CI: 7.12-8.24); sitting compared to supine with the pillow was 2.61 ± 1.49 mmHg (P-value < 0.001, 95% CI: 3.01-2.21), whereas supine without the pillow compared to supine with the pillow was 5.07 ± 2.24 mmHg (P-value 0.001, 95% CI: 4.47-5.68). IOP was lowest in the sitting position and highest in the supine without pillow position. There was a statistically significant reduction in IOP on the assumption of supine with pillow position compared to supine without pillow position. The use of thick pillows in supine positions (such as during sleep or relaxations) rather than lying supine without pillows may reduce IOP spikes in POAG patients. This may have a positive effect as regards treatment and progression of glaucoma.

Localization in Glaucomatous Visual Field Loss Vulnerable to Posture-Induced Intraocular Pressure Changes in Open-Angle Glaucoma

To investigate localization in glaucomatous visual field defects that are vulnerable to posture-induced intraocular pressure (IOP) changes. Prospective cross-sectional study. Ninety-three eyes of 93 newly diagnosed cases with normal tension glaucoma were examined. The IOP was measured in both the sitting and lateral decubitus positions with an Icare rebound tonometer. Visual field tests were performed with a Humphrey Field Analyzer with the Central 30-2 program using Swedish Interactive Threshold Algorithm standard strategies. The total deviation (TD) map values of 51 tested points were used for the analysis. A regression analysis was conducted to investigate relationships between TD in each point or cluster and posture-induced IOP changes. A linear mixed-effects model was used to identify factors associated with TD changes in each visual field cluster. Main outcome measures included the relationship between posture-induced IOP changes and localization of visual field defects. There were 54 women and 39 men (mean age, 53.4 ± 12.5 years). The mean IOP per Icare rebound tonometer was 15.5 ± 3.2mm Hg in the sitting position and 18.8 ± 3.1mm Hg in the lateral decubitus position. The postural IOP difference was 3.3 ± 1.8mm Hg (P< .001; range,-1.0 to 7.7mm Hg). There was a significant negative correlation between TD and posture-induced IOP changes in 4 contiguous central points located just above the horizontal meridian. A linear mixed-effects model revealed a significant association between the difference in postural IOP change and decreased TD in the superior paracentral visual field according to multivariate analysis (P= .010). Posture-induced IOP variations have been shown to be associated with glaucomatous superior paracentral visual field defects.

Cataract surgery reduces intraocular pressure but not posture-induced intraocular pressure changes in patients with angle-closure glaucoma

Cataract surgery leads to a sustained decrease in sitting intraocular pressure (IOP) in patients with angle-closure glaucoma (ACG). The purpose of this study is to evaluate whether cataract surgery can also reduce postural IOP changes. We prospectively examined 106 eyes from 53 patients with narrow angles scheduled for phacoemulsification. IOP was measured in the sitting, supine, and lateral decubitus positions using an ICare rebound tonometer before and 1 week, 1 month, and 3 months postoperatively. The mean baseline IOP in the sitting and lateral decubitus positions was 17.9 ± 4.8 mmHg and 21.43 ± 6.44 mmHg, which significantly reduced to 13.52 ± 3.8 and 17.46 ± 3.62, respectively, 3 month postoperatively (p < 0.001). However, postural IOP change (lateral decubitus minus sitting) at 3 months postoperatively was not significantly different from that at the baseline (3.17 ± 2.63 vs. 3.53 ± 3.38 mmHg, p = 0.85). Postural IOP change was not associated with preoperative sitting IOP, anterior chamber depth, axial length, fixed pupil, or presence of glaucomatous optic neuropathy. Patients with higher preoperative IOP exhibited greater IOP reduction after cataract surgery in every posture (p < 0.0001). In conclusion, cataract surgery reduces IOP in all postures among patients with ACG; however, it does not reduce the magnitude of postural IOP change.

The Efficacy of Deep Sclerectomy on Posture-induced Intraocular Pressure Changes.

The purpose of this study was to evaluate the efficacy of nonpenetrating deep sclerectomy (NPDS) on posture-induced intraocular pressure (IOP) changes in open-angle glaucoma (OAG). Twenty-five eyes of 25 patients with OAG that underwent NPDS were included in this study. IOP was measured with the IcarePro (ICP) tonometer in the sitting, supine, dependent lateral decubitus position (DLDP), and nondependent lateral decubitus position (NDLDP) before surgery, and at 1 and 3 months after surgery. The mean baseline IOP measured in the sitting position was 20.5±8.4 mm Hg with Goldmann applanation tonometry and 19.6±6.5 mm Hg with ICP. At 1 and 3 months after NPDS, mean IOP decreased significantly in each position (P<0.001). At each time point, mean IOP was higher in all lying positions than in the sitting position (P<0.001) and higher in the DLDP than in the supine and NDLDP positions (P<0.001 and P=0.001). Posture-induced IOP changes between the sitting and supine position, DLDP, and NDLDP, respectively, were significantly reduced by 77% (P=0.009), 60% (P=0.001), and 82% (P=0.01) at 1 month and by 79% (P=0.004), 70% (P<0.001), and 79% (P<0.001) at 3 months after surgery. The IOP fluctuation reduction was significantly inferior when considering sitting-DLDP than other postural changes. NPDS is effective in lowering the mean IOP in all body positions and also the postural IOP fluctuations. The mean IOP in the DLDP remained higher than in the other body positions. This posture should be avoided in patients with asymmetric OAG.

The Effect of Posture on Intraocular Pressure and Systemic Hemodynamic Parameters in Treated and Untreated Patients with Primary Open-Angle Glaucoma.

To assess intraocular pressure (IOP), systolic, diastolic, and mean arterial blood pressure (SBP, DBP, MAP) changes in the sitting, supine, and 20° head-down (Trendelenburg) position in treated (tPOAG) and untreated (uPOAG) primary open-angle glaucoma patients and healthy controls. All participants underwent IOP and systemic BP measurements in the sitting, supine, and Trendelenburg positions during office hours. IOP and BP readings in the sitting, supine, and Trendelenburg positions were analyzed. Twenty-one tPOAG patients, 17 uPOAG patients, and 21 controls were enrolled in the study. Compared to controls, eyes in the tPOAG and uPOAG groups had significantly larger posture-induced IOP elevation upon changing from the sitting to the supine position (P = 0.020 and P = 0.032, respectively). Compared to controls, the IOP elevation in the Trendelenburg position was statistically higher for the tPOAG (P = 0.003), but not the uPOAG group (P = 0.840). All 3 groups had a similar pattern of SBP, DBP, and MAP changes. Compared to controls, posture-induced IOP changes are more pronounced in treated and untreated POAG patients.

Postural effects on intraocular pressure and ocular perfusion pressure in patients with non-arteritic anterior ischemic optic neuropathy

BackgroundTo investigate postural effects on intraocular pressure (IOP) and ocular perfusion pressure (OPP) in patients with non-arteritic ischemic optic neuropathy (NAION).MethodsIOP and blood pressure (BP) were measured in 20 patients with unilateral NAION 10 min after changing to each of the following positions sequentially: sitting, supine, right lateral decubitus position (LDP), supine, left LDP, and supine. IOP was measured using a rebound tonometer and OPP was calculated using formulas based on mean BP. The dependent LDP (DLDP) was defined as the position when the eye of interest (affected or unaffected eye) was placed on the dependent side in the LDP.ResultsIOPs were significantly higher (P = 0.020) and OPPs were significantly lower (P = 0.041) in the affected eye compare with the unaffected eye, with the affected eye in DLDP. Compared with the mean IOP of the unaffected eyes, the mean IOP of the affected eyes increased significantly (+2.9 ± 4.4 versus +0.7 ± 3.1 mmHg, respectively; P = 0.003) and the mean OPP decreased significantly (−6.7 ± 9.4 versus −4.9 ± 8.0 mmHg, respectively; P = 0.022) after changing positions from supine to DLDP. In addition, changing position from supine to DLDP showed significantly larger absolute changes in IOP (4.13 ± 3.19 mmHg versus 2.51 ± 1.92 mmHg, respectively; P = 0.004) and OPP (9.86 ± 5.69 mmHg versus 7.50 ± 5.49 mmHg, respectively; P = 0.009) in the affected eye compared with the unaffected eye. In the affected eye, there was a significant positive correlation between absolute change in IOP and OPP when changing position from supine to DLDP (Rho = 0.512, P = 0.021).ConclusionsA postural change from supine to DLDP caused significant fluctuations in IOP and OPP of the affected eye, and may significantly increase IOP and decrease OPP. Posture-induced IOP changes may be a predisposing factor for NAION development.

The Effect of Laser Trabeculoplasty on Posture-Induced Intraocular Pressure Changes in Patients with Open Angle Glaucoma.

PurposeTo investigate the effect of argon laser trabeculoplasty (ALT) on posture-induced intraocular pressure (IOP) changes in patients with open angle glaucoma (OAG).MethodsThirty eyes of 30 consecutive patients with OAG who underwent ALT were prospectively analyzed. The IOP was measured using Icare PRO in the sitting position, supine position, and dependent lateral decubitus position (DLDP) before ALT and at 1 week, 1 month, 2 months, and 3 months after ALT.ResultsCompared to the baseline values, the IOP in each position was significantly decreased after ALT (all P < 0.001). During follow-up, the mean percentage of IOP reduction was similar in the sitting and supine positions, but was significantly lower in DLDP than in the sitting or supine positions (all P < 0.05). In terms of postural IOP changes, the IOP in the supine position and DLDP was significantly higher than that in the sitting position at the same time points during the follow-up period (all P < 0.001). The difference between the IOP in the supine position and DLDP during follow-up was significant (all P < 0.001). The extent of IOP differences between any positions did not show significant changes during the follow-up period (all P > 0.05).ConclusionsALT appears to be effective in lowering the IOP in various body positions, but the degree of this effect was significantly lower in DLDP. In addition, ALT seemed to have limited effects on posture-induced IOP changes.

Comparison of Posture-Induced Intraocular Pressure Changes in Medically Treated and Surgically Treated Eyes With Open-Angle Glaucoma

To compare the posture-induced IOP changes in medically treated eyes with those in surgically treated eyes having open-angle glaucoma (OAG) and low IOP. Fifty-one posttrabeculectomized OAG eyes with a cystic filtering bleb and 51 nonoperated, medically treated OAG eyes were studied. The IOP measured with a Goldmann applanation tonometer (GAT) was 12 mm Hg or less in both groups. It was measured in the sitting and lateral decubitus positions with a rebound tonometer. The IOP was measured in the upper eye 5 minutes after assuming the lateral decubitus position. The mean (SD) IOP measured with the GAT was 9.7 (1.5) mm Hg in the trabeculectomized eyes and 9.7 (1.4) mm Hg in the medically treated eyes (P = 0.892, unpaired t-test). In the surgically treated group, the mean (SD) IOP measured with the rebound tonometer was 10.3 (2.3) mm Hg in the sitting position and 11.3 (2.8) mm Hg in the lateral decubitus position (P < 0.001, paired t-test). In the medically treated group, the mean (SD) IOP measured with the rebound tonometer was 10.8 (2.0) mm Hg in the sitting position and 14.1 (2.9) mm Hg in the lateral decubitus position (P < 0.001, paired t-test). The greater IOP increase of 3.3 mm Hg in the medically treated group compared with the 1.0 mm Hg in the surgically treated group was significant (P < 0.001, unpaired t-test). The lower posture-induced IOP change in the successfully trabeculectomized eyes indicates that trabeculectomy will not only lead to a decrease in the IOP but also lower the posture-induced IOP change.

Posture-Induced Intraocular Pressure Changes in Eyes with Open-Angle Glaucoma, Primary Angle Closure with or without Glaucoma Medications, and Control Eyes

To compare the posture-induced intraocular pressure (IOP) changes in eyes with open-angle glaucoma (OAG), primary angle closure (PAC) with or without glaucoma medications, and healthy control eyes with normal IOPs. The IOP was measured in the sitting position (SP) and the lateral decubitus position (LDP) with a rebound tonometer. The IOP in the LDP was measured in the upper eyes 5 minutes after assuming this posture. Fifty-two patients with OAG, 52 with PAC, and 52 controls with normal IOPs were studied. The IOP in the SP measured with the rebound tonometer was 14.3 ± 4.0 mm Hg in eyes with OAG, 15.8 ± 4.5 mm Hg in eyes with PAC, and 13.9 ± 3.7 mm Hg in eyes with normal IOPs. None of these differences was significant (P = 0.060; ANOVA). The IOP in the LDP was significantly increased to 18.3 ± 4.6 mm Hg in eyes with OAG, 19.3 ± 4.4 mm Hg in eyes with PAC, and 17.3 ± 3.5 mm Hg in eyes with normal IOPs (P = 0.000 for all; paired t-tests). The postural IOP difference was +4.0 ± 2.2 mm Hg in OAG eyes, +3.5 ± 2.2 mm Hg in PAC eyes, and +3.4 ± 1.8 mm Hg in normal eyes, and these increases were not significantly different among the three groups (P = 0.309; ANOVA). The correlation between the posture-induced IOP changes and the axial length was not significant in each group. Postural IOP changes are comparable among eyes with OAG, PAC with and without glaucoma medications, and control eyes.

Effects of trabeculectomy on posture-induced intraocular pressure changes over time

To determine whether trabeculectomy affects postural-induced changes in intraocular pressure (IOP), and whether it is maintained. Thirty-six eyes of 36 patients with open-angle glaucoma who were scheduled for their initial trabeculectomy with adjunctive mitomycin C were prospectively examined. The IOP was measured in the sitting and the lateral decubitus position with an ICare rebound tonometer before, and 1, 3, and 12 months after trabeculectomy. Twenty-nine eyes of 29 patients completed this study. The mean baseline IOP measured with the ICare tonometer was 17.4 ± 4.9 mmHg in the sitting position and 21.3 ± 5.6 mmHg in the lateral decubitus position (p < 0.001). This postural IOP difference, +3.9 mmHg, was reduced to +1.3 ± 1.7 mmHg at 1 month and to +0.8 ± 1.5 mmHg at 3 months after the trabeculectomy (p < 0.001 and p = 0.004 respectively). This decrease in the degree of posture-dependent IOP change was maintained at +1.7 ± 2.2 mmHg at 1 year postoperatively (p < 0.001). In three cases, the postural IOP changes returned to the baseline level, and all three had a failed bleb. Our results indicate that trabeculectomy not only reduces the IOP but also reduces the degree of posture-induced changes in the IOP. Our findings also speculate that measuring the postural IOP changes after trabeculectomy might provide a clue on the functioning of a filtering bleb.