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Xin C, Wang N, Wang H. Intraocular Pressure Fluctuation in Primary Open-Angle Glaucoma with Canaloplasty and Microcatheter Assisted Trabeculotomy. J Clin Med 2022; 11:jcm11247279. [PMID: 36555897 PMCID: PMC9780827 DOI: 10.3390/jcm11247279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/26/2022] [Accepted: 12/01/2022] [Indexed: 12/13/2022] Open
Abstract
Background: Schlemm’s canal (SC) targeted procedures constitute a promising therapy for open angle glaucoma (POAG), safer and less invasive. However, little attention was paid to the intraocular pressure (IOP) variation in patients receiving these procedures, which is the risk factor for POAG progression. This study is to evaluate the IOP variation in eyes with POAG after modified canaloplasty (MC) and microcatheter assisted trabeculotomy (MAT). (2) Methods: POAG with good IOP in office hours after MC or MAT and age-matched normal subjects were recruited in this prospective coherent study. IOP in sitting and supine positions and 24-h IOP was measured. Aqueous vein and blood reflux into the SC were examined. (3) Results: Among 20 normal subjects, 25 eyes with MC eyes and 30 eyes with MAT were recruited in this study. Aqueous veins are frequently located in the inferior nasal quadrants in all groups. No pulsatile signs were observed in an aqueous vein in the MAT group but they were observed in 68% of the MC group. Blood reflux in the SC could be seen in all the operated eyes. The IOP in the sitting position was not significant different among groups (p = 0.419). Compared to normal, the IOP increased dramatically after lying down for 5 min in the MC and MAT groups (PMC vs. normal = 0.003, PMAT vs. normal = 0.004), which is similar for IOP change after lying down for 60 min (PMC vs. normal < 0.001, PMAT vs. normal < 0.001). In terms of diurnal IOP, subjects were stable in the MAT group (p < 0.01), variable in the normal group (p = 0.002), and most fluctuant in MC group (p < 0.001). (4) Conclusions: MC and MAT reduce the IOP but present aberrant short-term IOP regulation, which should be paid attention to in clinical settings.
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Chu YC, Chang PY, Wang JK, Huang TL, Hsu YR. The IOP lowering effects of "planning" selective laser trabeculoplasty in open angle glaucoma. Front Med (Lausanne) 2022; 9:1013260. [PMID: 36275811 PMCID: PMC9582459 DOI: 10.3389/fmed.2022.1013260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose To investigate whether the planning of selective laser trabeculoplasty (SLT) influences the intraocular pressure (IOP) in patients with open angle glaucoma (OAG). Methods In this retrospective case-control study conducted on patients with OAG who planned to undergo SLT treatment (SLT group) or a visual field examination (VF group), we collected the demographic data, IOP on the planning day and on the scheduled day of the SLT treatment or VF examination. ΔIOP was defined as the IOP change between the planning day and the scheduled day. We used multivariable regression analyses and linear mixed model to evaluate the association between the abovementioned factors and ΔIOP in the VF group and the treatment eye (SLTt) and fellow eye (SLTf) of the SLT group. Results One hundred and fifty-three eyes of 102 patients with OAG were included, of which 51 patients in the SLT group and 51 patients in the VF group. The ΔIOP was −1.92 ± 2.77 mmHg in the SLTt, −0.65 ± 2.47 mmHg in the SLTf and −0.08 ± 1.73 mmHg in the VF group (P < 0.05). Both multivariable regression analysis between the VF and SLTt group and linear mixed model in the SLT group showed significant negative association between the ΔIOP and SLT arrangement (P < 0.05). There was no significant association between ΔIOP and age, gender, baseline IOP, IOP fluctuation, nor SE. Conclusions The IOP was significantly reduced in patients with OAG after “planning” of SLT treatment, even without actual performing the laser treatment in our retrospective case-control study.
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Affiliation(s)
- Yi-Ching Chu
- Department of Ophthalmology, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Pei-Yao Chang
- Department of Ophthalmology, Far Eastern Memorial Hospital, New Taipei City, Taiwan,Department of Medicine, National Taiwan University Hospital, Taipei, Taiwan,Department of Healthcare Administration, Asia University, Taichung, Taiwan,Department of Electrical Engineering, Yuan Ze University, Taoyuan City, Taiwan,*Correspondence: Pei-Yao Chang
| | - Jia-Kang Wang
- Department of Ophthalmology, Far Eastern Memorial Hospital, New Taipei City, Taiwan,Department of Medicine, National Taiwan University Hospital, Taipei, Taiwan,Department of Electrical Engineering, Yuan Ze University, Taoyuan City, Taiwan,School of Medicine, National Yang Ming Chiao Tung University, Hsinchu, Taiwan,Department of Healthcare Administration and Department of Nursing, Oriental Institute of Technology, New Taipei City, Taiwan
| | - Tzu-Lun Huang
- Department of Ophthalmology, Far Eastern Memorial Hospital, New Taipei City, Taiwan,Department of Electrical Engineering, Yuan Ze University, Taoyuan City, Taiwan
| | - Yung-Ray Hsu
- Department of Ophthalmology, Far Eastern Memorial Hospital, New Taipei City, Taiwan,Department of Medicine, National Taiwan University Hospital, Taipei, Taiwan,Department of Electrical Engineering, Yuan Ze University, Taoyuan City, Taiwan
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Du R, Xin C, Xu J, Hu J, Wang H, Wang N, Johnstone M. Pulsatile Trabecular Meshwork Motion: An Indicator of Intraocular Pressure Control in Primary Open-Angle Glaucoma. J Clin Med 2022; 11:jcm11102696. [PMID: 35628823 PMCID: PMC9142929 DOI: 10.3390/jcm11102696] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 03/27/2022] [Accepted: 04/13/2022] [Indexed: 01/03/2023] Open
Abstract
(1) Background: To investigate the value of pulsatile trabecular meshwork (TM) motion in predicting the diurnal intraocular pressure (IOP) fluctuation of primary open-angle glaucoma (POAG). (2) Methods: This cross-sectional study recruited 20 normal patients and 30 patients with POAG. Of the POAG group, 20 had stable diurnal IOP and 10 had high IOP fluctuation. A clinical prototype phase-sensitive optical coherence tomography (PhS-OCT) model was used to measure TM pulsatile motion with maximum velocity (MV) and cumulative displacement (CDisp). (3) Results: MV and CDisp were higher in the external region in both normal and POAG patients. All MV and CDisp reduced significantly in the POAG group (p < 0.001). In the POAG group, except MV in the external region (p = 0.085), MV and CDisp in the nasal area were significantly higher than those in the temporal area (p < 0.05). The MV and CDisp in the external region in the nasal area of POAG patients with high IOP fluctuation were much lower than those with stable IOP (pEMV3 = 0.031, pECDisp3 < 0.001); (4) Conclusions: Pulsatile TM motion reduced in POAG patients relevant to the level of diurnal IOP fluctuation. This study presents the segmental variance of TM stiffness in human living eyes and suggests the clinical potential of the measurement of pulsatile TM motion with PhS-OCT for the evaluation of diurnal IOP fluctuation.
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Affiliation(s)
- Rong Du
- Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China; (R.D.); (J.H.); (H.W.); (N.W.)
| | - Chen Xin
- Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China; (R.D.); (J.H.); (H.W.); (N.W.)
- Correspondence:
| | - Jingjiang Xu
- School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China;
| | - Jianping Hu
- Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China; (R.D.); (J.H.); (H.W.); (N.W.)
| | - Huaizhou Wang
- Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China; (R.D.); (J.H.); (H.W.); (N.W.)
| | - Ningli Wang
- Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China; (R.D.); (J.H.); (H.W.); (N.W.)
| | - Murray Johnstone
- Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA;
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Pillunat KR, Herber R, Haase MA, Jamke M, Jasper CS, Pillunat LE. PRESERFLO™ MicroShunt versus trabeculectomy: first results on efficacy and safety. Acta Ophthalmol 2022; 100:e779-e790. [PMID: 34331505 DOI: 10.1111/aos.14968] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/21/2021] [Accepted: 06/17/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE To report efficacy and safety outcomes of the PRESERFLO™ MicroShunt compared with trabeculectomy, the current gold-standard treatment for advanced glaucoma, in the early and intermediate postoperative period. METHODS Institutional prospective interventional cohort study of primary open-angle glaucoma (POAG) patients scheduled for the PRESERFLO™ MicroShunt. The comparison group were POAG patients who had had received trabeculectomy and were matched for age, known duration of disease, number and classes of intraocular pressure (IOP)-lowering medications to ensure a similar conjunctival condition. The study is part of the Dresden Glaucoma and Treatment Study (DGTS), was not randomized, but used a uniform study design, with the same inclusion and exclusion criteria as well as standardized definitions of success and failure. MAIN OUTCOME MEASURES mean diurnal IOP (mdIOP, mean of 6 measurements), diurnal peak IOP, diurnal IOP fluctuations, glaucoma medical therapy, success rates, visual acuity, visual fields, surgical complications and interventions, and severe adverse events. RESULTS Fifty-two eyes of 52 patients, 26 in each group, were analysed. At 6 months, median [Q25, Q75] mdIOP was 10.8 [9.5-12.2] mmHg in the microshunt and 10.3 [7.6-11.8] mmHg in the trabeculectomy group. Reduction in mdIOP (p = 0.458), peak diurnal IOP (p = 0.539), and median diurnal fluctuation (p = 0.693) was not statistically significantly different between groups. The rate of interventions was statistically significantly higher in the trabeculectomy compared with the microshunt group (p = 0.004). None of the patients experienced severe adverse events. CONCLUSION Both procedures are equally effective and safe in lowering mdIOP in patients with POAG. Because the microshunt is less invasive with less follow-up and interventions needed postoperatively, it might be recommended earlier in the treatment of glaucoma.
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Affiliation(s)
- Karin R. Pillunat
- Department of Ophthalmology Medical Faculty Carl Gustav Carus Technische Universität Dresden Germany
| | - Robert Herber
- Department of Ophthalmology Medical Faculty Carl Gustav Carus Technische Universität Dresden Germany
| | - Maike A. Haase
- Department of Ophthalmology Medical Faculty Carl Gustav Carus Technische Universität Dresden Germany
| | - Melanie Jamke
- Department of Ophthalmology Medical Faculty Carl Gustav Carus Technische Universität Dresden Germany
| | - Carolin S. Jasper
- Department of Ophthalmology Medical Faculty Carl Gustav Carus Technische Universität Dresden Germany
| | - Lutz E. Pillunat
- Department of Ophthalmology Medical Faculty Carl Gustav Carus Technische Universität Dresden Germany
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Pyfer MF, Gallardo M, Campbell A, Flowers BE, Dickerson Jr JE, Talla A, Dhamdhere K. Suppression of Diurnal (9AM-4PM) IOP Fluctuations with Minimally Invasive Glaucoma Surgery: An Analysis of Data from the Prospective, Multicenter, Single-Arm GEMINI Study. Clin Ophthalmol 2021; 15:3931-3938. [PMID: 34594099 PMCID: PMC8478499 DOI: 10.2147/opth.s335486] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 09/13/2021] [Indexed: 01/20/2023] Open
Abstract
PURPOSE This study analyzes diurnal IOP data (9AM, 12PM, 4PM) from a prospective 12-month trial of the OMNI Surgical System in open-angle glaucoma (OAG) patients with the aim of evaluating effect of MIGS surgery on the amplitude of the diurnal IOP profile pre- and postoperatively. SETTING Fifteen ophthalmology practices and surgery centers located in 14 states in the United States. DESIGN Prospective, multicenter, IRB approved study. Patients treated with canaloplasty (360°) and trabeculotomy (180°). Patients had cataract and mild-moderate OAG with intraocular pressure (IOP) ≤33 mmHg on zero to four hypotensive medications. METHODS Post-hoc analysis of diurnal IOP data from the multicenter GEMINI study. Analysis includes comparison of IOP preoperatively and at month 12 for each of the diurnal time points, 9AM, 12PM, 4PM, change in magnitude of spread between the maximum IOP and minimum IOP for each patient and the proportions of patients preoperatively and at month 12 with IOPs at or below 25, 21, 18, and 15 mmHg, average variability (standard deviation of the 9AM, 12PM, and 4PM IOP) preoperatively and at month 12. RESULTS A total of 128 patients included in this analysis. IOP at each diurnal timepoint was significantly lower postoperatively (p<0.0001). The difference between highest and lowest IOP measurement for each patient averaged 2.8 mmHg preoperatively (SD 2.4, MAX 14, MIN 0) and 1.8 mmHg (SD 1.7, MAX 10, MIN 0) month 12 (P<0.00001). The proportion with IOP ≤ to 25, 21, 18, and 15 mmHg increased; 75%-97%, 27%-88%, 1%-79%, and <1%-56%, respectively. The average variability was greater at all time points preoperatively (P<0.0001). CONCLUSION This study demonstrates that eyes with OAG can benefit from an overall decreased IOP and degree of IOP fluctuations for as long as 12 months after surgical treatment with canaloplasty and trabeculotomy.
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Affiliation(s)
- Mark F Pyfer
- Northern Ophthalmic Associates, Jenkintown, PA, USA
| | | | | | | | - Jaime E Dickerson Jr
- Sight Sciences, Inc., Menlo Park, CA, USA
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, USA
| | | | - Kavita Dhamdhere
- Sight Sciences, Inc., Menlo Park, CA, USA
- Mahatma Gandhi Medical College and Research Center, Wardha, India
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Faseeh AE, Allam RS, Shalash AB, Abd Elmohsen MN. Comparison between Latanoprost, Travoprost, and Tafluprost in reducing intraocular pressure fluctuations in patients with glaucoma. Eur J Ophthalmol 2021; 31:3018-3026. [PMID: 33499676 DOI: 10.1177/1120672121990540] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To compare the efficacies of latanoprost 0.005%, travoprost 0.004%, and tafluprost 0.0015% in reducing diurnal intraocular pressure (IOP) fluctuations in patients with newly diagnosed primary open-angle glaucoma (POAG). METHODS In this prospective randomized clinical trial, 60 patients who were newly diagnosed with POAG were divided into three equal groups. Patients were examined at presentation and at second and sixth weeks. Diurnal phasing of IOP was conducted using a calibrated Goldmann applanation tonometer. IOP measurements were recorded from 8:00 am to 9:00 am, from 3:00 pm to 4:00 pm, and from 7:00 pm to 8:00 pm. RESULTS The study groups were distributed similarly in terms of age and gender (p-values: 0.76) and the participants had a mean age of 52.98 ± 13.43 years. The IOP at the day of inclusion was not statistically significant among the three groups (p-values 0.27, 0.51, and 0.64 at 8 am, 2 pm, and 8 pm, respectively). Similar nonsignificant differences were noticed on the follow-up visits. However, the tafluprost group showed a significant reduction in IOP on the follow-up visit at the second week at 8 pm (30.5% reduction, p-value: 0.03). All three drugs showed a comparable and significant reduction in IOP and IOP fluctuations. The pattern of side effects was similar in all the groups. CONCLUSION Latanoprost, travoprost, and tafluprost show a similar effectiveness in reducing the mean IOP and the diurnal IOP fluctuation in POAG. Importantly, the three drugs have comparable tolerability with insignificant differences regarding the pattern of their side effects.
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Affiliation(s)
- Ahmed Essam Faseeh
- Ophthalmology Department, Faculty of Medicine, Kasr Al Ainy School of Medicine, Cairo University, Cairo, Egypt
| | - Riham Shm Allam
- Ophthalmology Department, Faculty of Medicine, Kasr Al Ainy School of Medicine, Cairo University, Cairo, Egypt
| | - Ahmed B Shalash
- Ophthalmology Department, Faculty of Medicine, Kasr Al Ainy School of Medicine, Cairo University, Cairo, Egypt
| | - Mai Nasser Abd Elmohsen
- Ophthalmology Department, Faculty of Medicine, Kasr Al Ainy School of Medicine, Cairo University, Cairo, Egypt
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Terauchi R, Ogawa S, Noro T, Ito K, Kato T, Tatemichi M, Nakano T. Seasonal Fluctuation in Intraocular Pressure and Retinal Nerve Fiber Layer Thinning in Primary Open-Angle Glaucoma. Ophthalmol Glaucoma 2020; 4:373-381. [PMID: 33242683 DOI: 10.1016/j.ogla.2020.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 10/29/2020] [Accepted: 11/12/2020] [Indexed: 11/20/2022]
Abstract
PURPOSE To detect seasonal fluctuations in intraocular pressure (IOP) in healthy eyes and eyes with primary open-angle glaucoma (POAG) and to evaluate whether these seasonal fluctuations affect retinal nerve fiber layer (RNFL) thinning in eyes with POAG. DESIGN Observational, retrospective cohort study. PARTICIPANTS Healthy population who underwent a comprehensive health check-up and patients with POAG using only topical medications were enrolled. METHODS Kaplan-Meier survival analysis was used to compare the cumulative incidence probabilities of RNFL thinning between different seasonal IOP fluctuation groups. A Cox proportional hazards model, with adjustments for potential confounding factors, was used to evaluate the association between seasonal fluctuations in IOP and RNFL thinning. MAIN OUTCOME MEASURES Intraocular pressure fluctuation rate calculated from winter and summer IOPs and RNFL thinning as determined by event-based analysis with high-definition OCT. RESULTS A total of 12 686 healthy eyes and 179 eyes of 179 POAG patients showed a significantly higher IOP in winter than in summer (healthy, 13.2 ± 3.0 mmHg vs. 12.5 ± 2.9 mmHg [P < 0.001]; POAG, 13.1 ± 2.7 mmHg vs. 11.8 ± 2.3 mmHg [P < 0.001]). In POAG patients, the mean age at initial OCT and follow-up duration were 55.1 ± 11.7 years and 98.4 ± 26.4 months, respectively. The mean deviation (MD) at first visit, MD slope, and RNFL thinning rate were -2.2 ± 3.4 dB, -0.07 ± 0.44 dB/year, and -0.44 ± 0.88 μm/year, respectively. During the study period, 85 eyes (47.5%) showed RNFL thinning progression. Kaplan-Meier analysis showed that a high seasonal IOP fluctuation rate significantly suppressed RNFL thinning (P < 0.05, log-rank test). After adjusting for confounders in the Cox analysis, the seasonal IOP fluctuation rate still showed a significantly negative association with RNFL thinning (hazard ratio, 0.98; 95% confidence interval, 0.96-0.99; P = 0.005). CONCLUSIONS Winter IOP was higher than summer IOP in both healthy and POAG eyes. The temporary IOP decline in summer, rather than a constant IOP throughout the year, may prevent glaucoma progression.
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Affiliation(s)
- Ryo Terauchi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan.
| | - Shumpei Ogawa
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Takahiko Noro
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kyoko Ito
- Center for Preventive Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Tomohiro Kato
- Center for Preventive Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Masayuki Tatemichi
- Department of Preventive Medicine, Tokai University School of Medicine, Isehara, Japan
| | - Tadashi Nakano
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
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Tu S, Li K, Hu D, Li K, Ge J. Posture-Dependent 24-Hour Intraocular Pressure Fluctuation Patterns in an Intraocular Hypertension Monkey Model. Transl Vis Sci Technol 2019; 8:63. [PMID: 31293817 PMCID: PMC6602140 DOI: 10.1167/tvst.8.3.63] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 03/04/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose We investigate 24-hour intraocular pressure (IOP) fluctuation patterns and the influence of body position on IOP in a chronic ocular hypertension (COHT) monkey model. Methods We recorded 24-hour IOPs (nine time points) in the different body positions in 10 eyes with normal and eight with high IOP (with random selection of one eye of each monkey) using a Tonopen. The IOPs at various time points and in different body positions were compared. Results The average 24-hour IOPs in the immediate-supine, 10-minute supine, 10-minute seated, and immediate-seated positions in the COHT models were 28.64 ± 9.82, 25.42 ± 7.62, 23.49 ± 7.67, and 20.53 ± 7.80 mmHg, respectively. The diurnal-to-nocturnal IOP changes were 8.51 ± 2.93, 5.81 ± 3.67, 5.48 ± 2.97, and 3.59 ± 2.74 mmHg, respectively. The sudden shift between the supine and seated positions bring greater IOP variations (8.11 ± 2.85 mmHg) in the COHT monkeys, and the IOP fluctuations reached 14 to 38 mmHg when considering body position and the measurement time points. Conclusions The measurement time and body position influenced IOP. More elevated IOP occurred in the immediate-supine position and during the transient shift between the seated and supine positions. Maintaining a fixed position for sufficient time before measurement is important. Translational Relevance Glaucoma patients should focus on the importance of IOP measurements in the clinic occurring after an adequate amount of time in a fixed body position.
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Affiliation(s)
- Shu Tu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Kang Li
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Dongpeng Hu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Kaijing Li
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jian Ge
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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Morris HJ, Tang J, Cruz Perez B, Pan X, Hart RT, Weber PA, Liu J. Correlation between biomechanical responses of posterior sclera and IOP elevations during micro intraocular volume change. Invest Ophthalmol Vis Sci 2013; 54:7215-22. [PMID: 24130185 DOI: 10.1167/iovs.13-12441] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE This study tested the hypothesis that intraocular pressure (IOP) elevations, induced by controlled increase of intraocular volume, are correlated with the biomechanical responses of the posterior sclera. METHODS Porcine globes were tested within 48 hours postmortem. The first group of globes (n = 11) was infused with 15 μL of phosphate-buffered saline at three different rates to investigate rate-dependent IOP elevations. The second group (n = 16) was first infused at the fast rate and then underwent inflation tests to investigate the relationship between IOP elevations (ΔIOP) and scleral strains. The strains in the superotemporal region of the posterior sclera were measured by ultrasound speckle tracking. Linear regression was used to examine the association between ΔIOP due to micro-volumetric infusion and the scleral strains at a specific inflation pressure. RESULTS The average ΔIOP was 14.9 ± 4.3 mm Hg for the infusion of 15 μL in 1 second. The ΔIOP was greater for the faster infusion rates but highly correlated across different rates (P < 0.001). A significant negative association was found between the ΔIOP and the tangential strains in both the circumferential (R(2) = 0.54, P = 0.003) and meridian (R(2) = 0.53, P = 0.002) directions in the posterior sclera. CONCLUSIONS This study showed a substantial increase in IOP, with a large intersubject variance during micro-volumetric change. A stiffer response of the sclera was associated with larger IOP spikes, providing experimental evidence linking corneoscleral biomechanics to IOP fluctuation. In vivo measurement of corneoscleral biomechanics may help better predict the dynamic profile of IOP.
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Affiliation(s)
- Hugh J Morris
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio
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