scholarly journals Development and Testing of a Mobile Phone App for Risk Estimation of Gas Volume Expansion and Intraocular Pressure Elevation in Patients With Intravitreous Gas or Air Tamponade: Interobserver Assessment Study (Preprint)

2019 ◽  
Author(s):  
Zhaotian Zhang ◽  
Fei Li ◽  
Haochuan Zhang ◽  
Zhipeng Miao ◽  
Yantao Wei ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Mobile Phone ◽  
Volume Expansion ◽  
Vision Loss ◽  
Risk Estimation ◽  
Likert Scale ◽  
Air Volume ◽  
Post Operation ◽  
Iop Elevation ◽  
Boyle’S Law

BACKGROUND Pars plana vitrectomy (PPV) with intravitreous tamponade of gas or air has been widely used for a series of vitreoretinal diseases. It is estimated that 100,000 patients per year undergo PPV globally, and half of them were subsequently tamponaded with gas or air. According to Boyle’s law (P1V1=P2V2), patients with an intravitreous remnant of gas or air will be under high risk of intraocular pressure (IOP) elevation and subsequent vision loss owing to the expanded intravitreous gas or air when traveling post operation to a place with a significantly higher altitude. We always explain to patients why postoperative travel is potentially risky. Emergency cases of elevated IOP caused by postoperative traveling would sometimes come to surgeons. However, there have been few disease education or reference tools for both the surgeons and patients to have better communication. OBJECTIVE The aim of this study was to introduce and evaluate a mobile phone app developed by surgeons (the authors) for preliminary risk estimation of volume expansion and IOP elevation in patients with intravitreous gas or air when traveling to a place of higher altitude. METHODS The app was developed on the iOS and Android operating systems. Boyle’s law (P1V1=P2V2) was the theoretical basis of the app. Intravitreous gas or air volume and altitude values were independent factors to deduce the risk report. Consecutive patients underwent vitrectomy, and those with an intravitreous remnant of gas or air were recruited. The surgeons judged the vertical height of the fluid/gas interface through the dilated pupil; the patients were instructed to judge it according to their visual field when looking straight ahead and line it out on a chart included in the app. Finally, all the patients were required to fill a Likert scale–based questionnaire with 2 main items to evaluate the participants’ user experience and attitudes toward the app. RESULTS A total of 50 patients were included (30 males and 20 females). All patients could independently operate the app to complete the test. The median heights of the fluid/gas interface independently judged by the surgeon and patients were 40% (range: 10%-75%) and 41% (range: 9%-78%), respectively (P=.63). The median altitude of the participants’ destinations was 150.0 m (range: 0-3490 m). The Bland-Altman analysis revealed a good agreement between the surgeons’ and patients’ judgments (bias of −0.3%), with 95% limits of agreement of −5.8% to 5.3%. Overall, the Likert scale revealed a positive attitude from the patients toward the app. CONCLUSIONS The app is reliable for patients to have preliminary risk estimation of intravitreous gas or air volume expansion and IOP elevation if travel to a place of higher altitude is planned. The surgeons could also use it as a platform for better disease communication.

scholarly journals Retinal ganglion cell dysfunction in mice following acute intraocular pressure is exacerbated by P2X7 receptor knockout

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Y. M. Wang ◽  
Vickie H. Y. Wong ◽  
Pei Ying Lee ◽  
Bang V. Bui ◽  
Stefanie Dudczig ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Ganglion Cell ◽  
Retinal Ganglion Cell ◽  
P2x7 Receptor ◽  
Field Size ◽  
Multielectrode Arrays ◽  
Retinal Ganglion ◽  
Post Injury ◽  
Genetic Ablation ◽  
Iop Elevation

AbstractThere is increasing evidence for the vulnerability of specific retinal ganglion cell (RGC) types in those with glaucoma and in animal models. In addition, the P2X7-receptor (P2X7-R) has been suggested to contribute to RGC death following stimulation and elevated IOP, though its role in RGC dysfunction prior to death has not been examined. Therefore, we examined the effect of an acute, non-ischemic intraocular pressure (IOP) insult (50 mmHg for 30 min) on RGC function in wildtype mice and P2X7-R knockout (P2X7-KO) mice. We examined retinal function using electroretinogram recordings and individual RGC responses using multielectrode arrays, 3 days following acute IOP elevation. Immunohistochemistry was used to examine RGC cell death and P2X7-R expression in several RGC types. Acute intraocular pressure elevation produced pronounced dysfunction in RGCs; whilst other retinal neuronal responses showed lesser changes. Dysfunction at 3 days post-injury was not associated with RGC loss or changes in receptive field size. However, in wildtype animals, OFF-RGCs showed reduced spontaneous and light-elicited activity. In the P2X7-KO, both ON- and OFF-RGC light-elicited responses were reduced. Expression of P2X7-R in wildtype ON-RGC dendrites was higher than in other RGC types. In conclusion, OFF-RGCs were vulnerable to acute IOP elevation and their dysfunction was not rescued by genetic ablation of P2X7-R. Indeed, knockout of P2X7-R also caused ON-RGC dysfunction. These findings aid our understanding of how pressure affects RGC function and suggest treatments targeting the P2X7-R need to be carefully considered.

scholarly journals Using tropicamide and phenylephrine without cyclopentolate for pupil dilation in cataract surgery reduces postoperative intraocular pressure rise

2020 ◽  
Vol 17 (3) ◽  
pp. 285-289
Author(s):  
Rachel Xuan ◽  
Keith Ong
Keyword(s):  
Intraocular Pressure ◽  
Retrospective Study ◽  
Cataract Surgery ◽  
Medical Records ◽  
Pressure Rise ◽  
Pupil Dilation ◽  
The Other ◽  
Sample Population ◽  
Iop Elevation ◽  
Larger Sample

The aim of this retrospective study was to evaluate whether intraocular (IOP) elevation post-cataract surgery can be reduced by using tropicamide and phenylephrine only, without cyclopentolate. Medical records across two surgical facilities were analyzed. One surgical facility (Cohort A) used a combination of tropicamide, cyclopentolate, and phenylephrine preoperatively, while the other (Cohort B) used tropicamide and phenylephrine only. Of patients in Cohort A, 63.6% (n = 7) had a higher IOP in the operated eye, while it was only 27.3% (n = 3) in Cohort B. Therefore, it is preferable to exclude the use of cyclopentolate in the preoperative dilation regimen of patients undergoing cataract surgery. However, a study with a larger sample population is required to further evaluate the significance of these results.

scholarly journals Intraocular pressure elevation precedes a phagocytosis decline in a model of pigmentary glaucoma

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 174 ◽  
Author(s):  
Yalong Dang ◽  
Susannah Waxman ◽  
Chao Wang ◽  
Priyal Shah ◽  
Ralitsa T. Loewen ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Trabecular Meshwork ◽  
Ex Vivo ◽  
Pigment Dispersion ◽  
Pigmentary Glaucoma ◽  
Fluorescent Microspheres ◽  
Phagocytic Capacity ◽  
Pressure Transducers ◽  
Intraocular Pressure Elevation ◽  
Iop Elevation

Background: Outflow regulation and phagocytosis are key functions of the trabecular meshwork (TM), but it is not clear how the two are related in secondary open angle glaucomas characterized by an increased particle load. We hypothesized that diminished TM phagocytosis is not the primary cause of early ocular hypertension and recreated pigment dispersion in a porcine ex vivo model. Methods: Sixteen porcine anterior chamber cultures received a continuous infusion of pigment granules (Pg), while 16 additional anterior chambers served as controls (C). Pressure transducers recorded the intraocular pressure (IOP). The phagocytic capacity of the trabecular meshwork was determined by fluorescent microspheres. Results: The baseline IOPs in Pg and C were similar (P=0.82). A significant IOP elevation occurred in Pg at 48, 120, and 180 hours (all P<0.01, compared to baseline). The pigment did not cause a reduction in TM phagocytosis at 48 hours, when the earliest IOP elevation occurred, but at 120 hours onward (P=0.001 compared to C). This reduction did not result in an additional IOP increase at 120 or 180 hours compared to the first IOP elevation at 48 hours (P>0.05). Conclusions: In this porcine model of pigmentary glaucoma, an IOP elevation occurs much earlier than when phagocytosis fails, suggesting that two separate mechanisms might be at work.

scholarly journals Systematic review and meta-analyses of trendelenburg and prone position on intraocular pressure in adult patients undergoing surgery

2019 ◽  
Author(s):  
◽  
Sharon Ann Van Wicklin
Keyword(s):  
Intraocular Pressure ◽  
Prone Position ◽  
Vision Loss ◽  
Meta Analysis ◽  
Adult Patients ◽  
Trendelenburg Position ◽  
Time Points ◽  
Comprehensive Search ◽  
Meta Analyses ◽  
Difference Effect

Background. Patients undergoing surgery in the Trendelenburg and prone positions may be at risk for postoperative vision loss associated with increased intraocular pressure. The purpose of this dissertation research is to estimate the magnitude of the increase in intraocular pressure at specific perioperative time points in adult patients undergoing surgery in the Trendelenburg and prone positions. Methods. Comprehensive search strategies were used to identify eligible studies for two meta-analyses and to address the research questions. For each meta-analysis, standardized mean difference effect sizes were calculated for selected perioperative time points. Results. Using a random effects model, the meta-analysis examining the effect of Trendelenburg position, showed that intraocular pressure decreased significantly after induction and before arousal. Intraocular pressure increased significantly after abdominal insufflation and during Trendelenburg position. The meta-analysis examining the effect of prone position, showed that intraocular pressure increased significantly between induction of anesthesia and up to 10 minutes of prone position and continued to increase significantly until the end of the prone position. Conclusions. Intraocular pressure increases of the magnitude found in this research demonstrate the need for implementing interventions to reduce the risk for postoperative vision loss in patients undergoing surgery in the Trendelenburg and prone positions.

Acute Unilateral Intraocular Pressure (IOP) Elevation in the Emergency Room (ER): A Case Report

2017 ◽  
Vol 7 (2) ◽  
pp. 1-6
Author(s):  
A Lopes ◽  
D Silva ◽  
M Mota ◽  
C Vendrell ◽  
M Lisboa ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Case Report ◽  
Emergency Room ◽  
Iop Elevation

scholarly journals A Case of Sustained Intraocular Pressure Elevation after Multiple Intravitreal Injection of Ranibizumab and Aflibercept for Neovascular Age-Related Macular Degeneration

2016 ◽  
Vol 7 (1) ◽  
pp. 230-236 ◽  
Author(s):  
Hisashi Matsubara ◽  
Ryohei Miyata ◽  
Maki Kobayashi ◽  
Hideyuki Tsukitome ◽  
Kengo Ikesugi ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Macular Degeneration ◽  
Subretinal Fluid ◽  
Age Related Macular Degeneration ◽  
Intravitreal Injections ◽  
Multiple Injections ◽  
Anti Vegf ◽  
Age Related ◽  
Intravitreal Aflibercept ◽  
Iop Elevation

Intravitreal injections of anti-vascular endothelial growth factor (VEGF) agents are widely used to treat neovascular age-related macular degeneration (nAMD). Although these treatments are effective, multiple injections have recently been recommended to ensure that there is a good long-term prognosis. However, sustained intraocular pressure (IOP) elevations have been reported to develop after multiple injections of anti-VEGF agents. We present our findings of a case of uncontrolled and persistent IOP elevation after switching from intravitreal ranibizumab injections to intravitreal aflibercept injections. A 74-year-old Japanese man without a history of glaucoma underwent 22 ranibizumab injections for nAMD and suddenly developed an elevated IOP after the 22nd injection. Although the subsequent medical treatment led to normalization of his IOP, the subretinal fluid under the central fovea remained even after the 25th injection of ranibizumab. Thus, ranibizumab treatment was switched to bimonthly intravitreal aflibercept injections in conjunction with glaucoma medications. His IOP recovered to within the normal range; however, after the 11th aflibercept injection, there was a sudden elevation of his IOP in spite of the continued glaucoma medications. Due to this sustained IOP elevation, his aflibercept injections were suspended for 16 weeks. Because his IOP could not be normalized by a full glaucoma medication regimen, the patient underwent trabeculotomy, which resulted in a lowering of the IOP to normal levels. We conclude that patients who receive serial intravitreal injections of anti-VEGF agents need to be closely monitored because severe and sustained ocular hypertension can develop.

scholarly journals Intraocular pressure elevation precedes a phagocytosis decline in a model of pigmentary glaucoma

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 174
Author(s):  
Yalong Dang ◽  
Susannah Waxman ◽  
Chao Wang ◽  
Priyal Shah ◽  
Ralitsa T. Loewen ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Trabecular Meshwork ◽  
Ex Vivo ◽  
Pigment Dispersion ◽  
Pigmentary Glaucoma ◽  
Fluorescent Microspheres ◽  
Phagocytic Capacity ◽  
Pressure Transducers ◽  
Intraocular Pressure Elevation ◽  
Iop Elevation

Background: Outflow regulation and phagocytosis are key functions of the trabecular meshwork (TM), but it is not clear how the two are related in secondary open angle glaucomas characterized by an increased particle load. We hypothesized that diminished TM phagocytosis is not the primary cause of early ocular hypertension and recreated pigment dispersion in a porcine ex vivo model. Methods: Sixteen porcine anterior chamber cultures received a continuous infusion of pigment granules (Pg), while 16 additional anterior chambers served as controls (C). Pressure transducers recorded the intraocular pressure (IOP). The phagocytic capacity of the trabecular meshwork was determined by fluorescent microspheres. Results: The baseline IOPs in Pg and C were similar (P=0.82). A significant IOP elevation occurred in Pg at 48, 120, and 180 hours (all P<0.01, compared to baseline). The pigment did not cause a reduction in TM phagocytosis at 48 hours when the earliest IOP elevation occurred, but at 120 hours onward (P=0.001 compared to C). This reduction did not result in an additional IOP increase at 120 or 180 hours compared to the first IOP elevation at 48 hours (P>0.05). Conclusions: In this porcine model of pigmentary glaucoma, an IOP elevation occurs much earlier than when phagocytosis fails, suggesting that two separate mechanisms might be at work.

scholarly journals PERBANDINGAN TEKANAN INTRAOKULAR LATIHAN BENCHPRESS DAN BICEPS MASS ROUTINE POLA PROGRESSIVE OVERLOAD

2020 ◽  
Vol 5 (2) ◽  
pp. 486
Author(s):  
Dian Eka Saputra ◽  
Ardizal Rahman ◽  
Andrini Ariesti
Keyword(s):  
Intraocular Pressure ◽  
Weight Training ◽  
Valsalva Maneuver ◽  
Venous Pressure ◽  
Isometric Exercise ◽  
Abdominal Pressure ◽  
Sitting Position ◽  
Iop Elevation ◽  
The Right ◽  
Lying Down

<p><em>Weight training as an isometric exercise can increase intraocular pressure (IOP) during exercise. Several mechanism theories are proposed in analyzing IOP elevation in weight training. Increased intra-abdominal pressure increases intracranial pressure thereby increasing IOP. Another theory is the Valsalva maneuver which results in an increase in intrathoracic venous pressure that is transmitted to the veins leading to the ocular so that IOP increases. IOP elevations over a period of time are at risk of causing glaucoma and blindness.<strong>Met</strong></em><strong><em>hod</em></strong><em>: </em><em>This</em><em> study’s</em><em> </em><em>sample consisted of 62 students who were given biceps mass routine and benchpress </em><em>training </em><em>with 5 sets of progressive overload patterns. IOP values were measured before training, between sets and 30 minutes after rest using a non-contact tonometry.</em><strong><em>Result</em></strong><em>: </em><em>There was a statistically significant correlation between the increase in IOP values between before exercise with the fifth set in the right eye lying position exercise (10.323mmHg) and the left eye (11.419mmHg) to the increase in the IOP value before exercise with the fifth set in the sitting position of the right eye ( 6,581mmHg) and left eye (7,435mmHg).<strong>Conclusion</strong></em><strong><em>: </em></strong><em>IOP values increase during weight training at both positions of the progressive overload pattern. The greater the training load the greater the IOP value. The lying down position gives the effect of increasing the greater IOP value.</em><em></em></p><p> </p>

scholarly journals Detecting IOP Fluctuations in Glaucoma Patients

2016 ◽  
Vol 10 (1) ◽  
pp. 44-55 ◽  
Author(s):  
Brenda Nuyen ◽  
Kaweh Mansouri
Keyword(s):  
Risk Factor ◽  
Intraocular Pressure ◽  
Clinical Practice ◽  
Vision Loss ◽  
Measurement Techniques ◽  
Dynamic Parameter ◽  
Guiding Principle ◽  
Informative Parameters ◽  
Technological Advances ◽  
Glaucoma Treatment

Lowering intraocular pressure (IOP) remains the guiding principle of glaucoma management. Although IOP is the only treatable risk factor, its 24-hour behavior is poorly understood. Current glaucoma management usually relies on single IOP measurements during clinic hours, even though IOP is a dynamic parameter with rhythms dependent on individual patients. It has further been shown that most glaucoma patients have their highest IOP measurements outside clinic hours. The fact that these IOP peaks go largely undetected may explain why certain patients progress in their disease despite treatment. Nevertheless, single IOP measurements have determined all major clinical guidelines regarding glaucoma treatment. Other potentially informative parameters, such as fluctuations in IOP and peak IOP, have been neglected, and effects of IOP-lowering interventions on such measures are largely unknown. Continuous 24-hour IOP monitoring has been an interest for more than 50 years, but only recent technological advances have provided clinicians with a device for such an endeavor. This review discusses current uses and shortcomings of current measurement techniques, and provides an overview on current and future methods for 24-hour IOP assessment. It may be possible to incorporate continuous IOP monitoring into clinical practice, potentially to reduce glaucoma-related vision loss.

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