Changes in the Anterior Chamber of the Eye during Acute Hypoglycaemia in Humans

1993 ◽  
Vol 85 (1) ◽  
pp. 101-104 ◽  
Author(s):  
D. A. Hepburn ◽  
C. V. Clark ◽  
A. C. H. Pell ◽  
B. McIver ◽  
B. M. Frier
Keyword(s):  
Anterior Chamber ◽  
Plasma Glucose ◽  
Sagittal Plane ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Autonomic Response ◽  
Plasma Adrenaline ◽  
Pupillary Constriction ◽  
Autonomic Reaction ◽  
Soluble Insulin

1. The changes in the volume and depth of the anterior chamber of the eye during acute insulin-induced hypoglycaemia were examined in nine healthy non-diabetic subjects (aged 23–31 years). The dimensions of the anterior chamber of the eye were measured by a photogrammetric technique, with Polaroid photographs taken of the lower half of the mid-sagittal plane of the eye at an angle of 55° at a magnification of × 16. Photographs were taken before and at regular intervals after the induction of acute hypoglycaemia using an infusion of unmodified (soluble) insulin at 2.5 m-units min−1 kg−1. Plasma adrenaline was measured regularly throughout the study. 2. Plasma glucose fell from 4.5 ± 0.2 mmol/l (mean ± SEM) to a nadir of 1.0 ± 0.1 mmol/l (P <0.01), which coincided with the onset of the acute autonomic reaction. Plasma adrenaline rose from 0.3 ± 0.1 nmol/l to a peak of 3.2 ± 0.6 nmol/l (P <0.01) at 15 min after the autonomic reaction. 3. The volume of the anterior chamber decreased by 8.2% from 284.7 ± 21.5 μl at baseline to 264.5 ± 17.0 μl (P <0.01) at the onset of the autonomic reaction. No significant alteration in axial anterior chamber depth was evident, but peripheral anterior depth decreased from 2.25 ± 0.20 mm at baseline to 2.07 ± 0.14 mm (P <0.05) at the onset of the autonomic response. Pupillary constriction was demonstrated in all subjects, which was most marked at 10 min after the autonomic reaction (baseline 5.0 ± 0.2 mm versus 10 min after reaction 3.7 ± 0.2 mm, P < 0.001). 4. This study has demonstrated an alteration in the dimensions and a reduction in volume of the anterior chamber of the eye in humans during acute insulin-induced hypoglycaemia. These changes in the anterior segment of the eye are probably mediated by autonomic mechanisms which are stimulated by hypoglycaemia.

scholarly journals Changes in anterior segment optical coherence tomography following pars plana vitrectomy without tamponade

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Alireza Khodabande ◽  
Massood Mohammadi ◽  
Hamid Riazi-Esfahani ◽  
Shahab Karami ◽  
Massood Mirghorbani ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Pars Plana Vitrectomy ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Optical Coherence ◽  
Mean Values ◽  
Iop Measurement ◽  
Pars Plana ◽  
The Mean

Abstract Background To evaluate changes in anterior segment morphology on anterior segment optical coherence tomography (AS-OCT) following pars plana vitrectomy (PPV) without tamponade. Methods Patients who underwent PPV without tamponade for epiretinal membrane were evaluated. Eligible patients underwent intraocular pressure (IOP) measurement and AS-OCT preoperatively as well as 1 month and 6 months post-operatively. Anterior chamber width (ACW), anterior chamber depth (ACD), trabecular iris angle (TIA), angle opening distance at 500 and 750 µm (AOD), and trabecular iris space area at 500 and 750 µm (TISA) at four quadrants were recorded and analyzed. Additionally, the mean values of TIA (MTIA), AOD (MAOD), and TISA (MTISA) for each eye (mean of four quadrants) were analyzed. Results 23 patients completed the study. The mean age of participants was 56.4 ± 3.6 years of age and 13/23 (56%) were female. Mean IOP of patients was 18.1 ± 1.1, 18.3 ± 1.1, and 18.1 ± 1.2 preoperatively,1 month post-operatively, and 6 months post-operatively, respectively. (p = 0.83). No difference was detected post-operatively in measurements of ACW, ACD, MTIA, MAOD500, MAOD750, MTISA500, and MTISA750. Conclusion Pars plana vitrectomy without tamponade was not associated with changes in anterior chamber morphology.

Effect of light backscattering from anterior segment structures on automated flare meter measurements

2021 ◽  
pp. 112067212110393
Author(s):  
Murat Hasanreisoglu ◽  
Cem Kesim ◽  
Duygu Yalinbas ◽  
Mervenur Yilmaz ◽  
Nur Sena Uzunay ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Scattered Light ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Laser Flare Photometry ◽  
Aqueous Flare ◽  
Group I ◽  
Lens Density ◽  
Laser Flare ◽  
Group Ii

Background: To evaluate effect of maximal anterior cortical lens density, iris scatter and anterior chamber depth on laser flare photometry. Methods: Patients diagnosed with clinical uveitis were enrolled in the study. Clinical flare gradings were recorded upon the Standardization of Uveitis Nomenclature. Aqueous flare was measured with an automated device (Kowa FM-700). Back-scattering from anterior cortical lens and anterior iris surface was calculated from Scheimpflug images. A curvilinear regression model was used to calculate estimated values for each clinical grade. These values were used to split cases in Group I (laser flare photometry lower than estimated) and Group II (laser flare photometry higher than estimated). Mean anterior chamber depth, pupil aperture, maximal anterior cortical lens density and iris scatter values were compared between two groups. A stepwise multiple regression analysis was performed to determine the effect of clinical flare gradings and ocular parameters on aqueous flare measurements. Results: The study included 228 eyes of 114 cases. Scheimpflug images were obtained from 105 eyes. Estimated aqueous flare measurements (in photons/milliseconds) were 4.87, 8.50, 14.81, 25.83, 45.04 and 136.93 for 0, 0.5+, 1+, 1.5+, 2+ and 3+ clinical flare respectively. Group II had higher maximal anterior cortical lens density than Group I (96.6 ± 37.1 vs 77.9 ± 17.1 pixel unit, p = 0.001). The measured aqueous flare was significantly related to clinical flare, maximal anterior cortical lens density and pupil aperture (adjusted R2: 0.480, p < 0.001). Conclusion: The back-scattered light from anterior cortical lens could affect laser flare photometry measurements. This effect might be quantified by Scheimpflug imaging.

scholarly journals Anatomical and Visual Effects of Implantable Phakic Contact Lens on Correction of Myopia

2022 ◽  
Author(s):  
Mahmoud Ekram ◽  
Ahmed Mohamed Kamal Elshafei ◽  
Asmaa Anwar Mohamed ◽  
Mohamed Farouk Sayed Othman Abdelkader
Keyword(s):  
Visual Acuity ◽  
Anterior Chamber ◽  
Contact Lens ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Case Series ◽  
Care Group ◽  
Case Series Study ◽  
Significant Difference ◽  
The Mean

Abstract Purpose: To evaluate the anatomical effects of implantable phakic contact lens (IPCL) (Care Group, India) on anterior segment and its visual outcomes .Patients and methods: In a prospective interventional case series study, 60 highly myopic eyes of 32 patients were subjected to IPCL implantation in the Ophthalmology Department of Minia University Hospital, Egypt from January 2019 to June 2021. All patients had complete ophthalmic examination and were followed up for 1 year. Pentacam was used for preoperative and postoperative estimation of anterior chamber depth (ACD), anterior chamber angle (ACA), anterior chamber volume (ACV) and IPCL vault in the 1st, 3rd, and 12th months. Assessment of corneal endothelium was done using specular microscope preoperatively and after 12 months. Preoperative and postoperative refraction and visual acuity were measured. Results: There was a statistically significant decrease in ACD, ACA, and ACV. There was no significant difference between preoperative and postoperative mean intraocular pressure (IOP) by the 12th month (P=0.163). The mean preoperative endothelial cell count (ECD) was significantly reduced from 2929.3±248 cells/mm2 to 2737.9±303 cells/mm2 at the 12th month (P<0.001). with a statistically highly significant improvement of mean Log Mar uncorrected visual acuity (UCVA) from 1.48±0.19 preoperatively to 0.46±0.11 by the end of follow up (P<0.001) with insignificant difference between preoperative best corrected visual acuity (BCVA) and postoperative UCVA (P=0.209). In the 12th month, the mean vault was 240±540 μm. No sight threatening complications occurred.Conclusion: Although IPCL induced anatomical changes, it was safe and effective for correction of high myopia.

scholarly journals Anterior Chamber Angle and Volume Do Not Change after Myopic Laser-Assisted In Situ Keratomileusis in Young Patients

2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Ertuğrul Tan Yassa ◽  
Cihan Ünlü
Keyword(s):  
Anterior Chamber ◽  
Anterior Segment ◽  
Young Patients ◽  
Anterior Chamber Depth ◽  
Ablation Depth ◽  
Anterior Chamber Angle ◽  
Chamber Volume ◽  
The Mean ◽  
Chamber Angle

Purpose. We aimed to investigate whether anterior chamber angle, depth, and volume change after myopic laser-assisted in situ keratomileusis (LASIK) in young patients. Methods. This retrospective study included 29 eyes of 29 patients (15 females and 14 males) between the ages of 18 and 39 years who underwent LASIK for the treatment of myopia. In addition to complete ophthalmic examination, anterior chamber angle (ACA), central anterior chamber depth (ACD), and anterior chamber volume (ACV) were measured by using a Sirius rotating Scheimpflug camera combined with Placido disc corneal topography (CSO, Florence, Italy). Preoperative and postoperative values were compared using paired t-tests. Linear regression was used to evaluate the relationship between changes in refraction and changes in ACA, ACD, and ACV as well as between attempted maximum ablation depth and changes in ACA, ACD, and ACV. Results. The mean age of the study population was 25.5 ± 6.2 years. The mean preoperative and postoperative spherical equivalent values were −3.30 ± 1.92 D and −0.18 ± 0.29 D, respectively. ACV and ACA were not significantly changed after surgery; however, central ACD was significantly decreased (preoperatively = 3.366 ± 0.316 mm vs postoperatively = 3.3 ± 0.298 mm) with a mean difference of 0.066 ± 1.121 mm. There were no significant relationships between changes in refraction and anterior segment dimensions or between attempted maximum ablation depth and anterior segment dimensions. Conclusion. Measurements with Sirius showed that ACA and ACV did not change; however, central ACD significantly decreased after myopic LASIK in young patients, indicating that the preoperative central ACD value should not be used interchangeably with the postoperative central ACD value.

scholarly journals Evaluation of Anterior Segment’s Structures in Tilted Disc Syndrome

2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Ercan Ozsoy ◽  
Abuzer Gunduz ◽  
Ersin Ersan Demirel ◽  
Tongabay Cumurcu
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Control Group ◽  
Tilted Disc Syndrome ◽  
Chamber Volume ◽  
Significant Difference ◽  
Tilted Disc

Purpose. To evaluate anterior segment’s structures by Pentacam in patients with tilted disc syndrome (TDS).Methods. Group 1 included forty-six eyes of forty-six patients who have the TDS. Group 2 including forty-six eyes of forty-six cases was the control group which was equal to the study group in age, gender, and refraction. A complete ophthalmic examination was performed in both groups. All cases were evaluated by Pentacam. The axial length (AL) of eyes was measured by ultrasound. Quantitative data obtained from these measurements were compared between two groups.Results. There was no statistically significant difference for age, gender, axial length, and spherical equivalent measurements between two groups (p=0.625,p=0.830,p=0.234, andp=0.850). There was a statistically significant difference for central corneal thickness (CCT), corneal volume (CV), anterior chamber angle (ACA), and pupil size measurements between two groups (p=0.001,p=0.0001,p=0.003, andp=0.001). Also, there was no statistically significant difference for anterior chamber depth (ACD), anterior chamber volume (ACV), and lens thickness (LT) measurements between two groups (p=0.130,p=0.910, andp=0.057).Conclusion. We determined that CCT was thinner, CV was less, and ACA was narrower in patients with TDS. There are some changes in the anterior segment of the eyes with tilted disc.

The effect of mydriasis on moderate-to-high myopic eyes with implantable collamer lenses V4 and V4c

2019 ◽  
Vol 30 (3) ◽  
pp. 462-468 ◽  
Author(s):  
Yi Zhu ◽  
Jing Zhang ◽  
Haobin Zhu ◽  
Jili Chen ◽  
Jibo Zhou
Keyword(s):  
Observational Study ◽  
Anterior Chamber ◽  
Corneal Endothelium ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Central Hole ◽  
Pressure Equilibrium ◽  
Before And After ◽  
Icl V4c

Purpose:To evaluate the vault change and anterior segment movement induced by mydriasis in moderate-to-high myopic eyes with implantable collamer lenses (ICL).Setting:Shanghai, ChinaDesign:A prospective consecutive observational study.Methods:A total of 45 eyes of 24 patients with ICL V4 implantation and 128 eyes of 65 patients with ICL V4c implantation were included and analyzed. Anterior chamber depth, posterior corneal endothelium-to-ICL distance, and vault before and after mydriasis were measured by Pentacam (Oculus, Wetzlar, Germany) at 1, 3, and 6 months after surgery.Results:Significant vault increases and anterior chamber depth increases induced by mydriasis were noted in both ICL V4 and V4c groups at 1, 3, and 6 months postoperatively. The corneal endothelium-ICL distance increased significantly in eyes with implanted ICL V4c after mydriasis at 3 and 6 months. Moreover, mydriasis-induced vault increases were greater in the ICL V4 group than in the ICL V4c group at 3 and 6 months. In eyes with implanted ICL V4c, mydriasis-induced vault increases were significantly greater at 1 month than at 3 and 6 months.Conclusion:Mydriasis results in a general vault increase in eyes with implanted ICLs. The adjustment of the pressure equilibrium via the central hole of the ICL V4c has an important role in vault change. The mydriasis-induced vault increases tend toward stability after 3 months postoperatively. Mydriasis is relatively safe in eyes with ICL implantation.

scholarly journals Distribution of White-to-White Corneal Diameter and Anterior Chamber Depth in Chinese Myopic Patients

2021 ◽  
Vol 8 ◽  
Author(s):  
Guihua Xu ◽  
Guanrong Wu ◽  
Zijing Du ◽  
Shanqing Zhu ◽  
Yunxiang Guo ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Age Groups ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Distribution Patterns ◽  
Normal Range ◽  
Cross Sectional ◽  
Significant Difference ◽  
Study Population ◽  
Corneal Diameter

Purpose: To investigate the distribution of white-to-white (WTW) corneal diameter and anterior chamber depth (ACD) in Chinese myopia patients.Methods: This was a cross-sectional observational study conducted at five ophthalmic centers. Anterior segment biometry was performed in 7,893 eyes of the 7,893 myopic patients using Pentacam, and the WTW and ACD were recorded. The distribution patterns of WTW and ACD were evaluated and the correlation between WTW and ACD was analyzed statistically.Results: There were 4416 (55.95%) males and 3477 (44.05%) females. The age of the study population was 25.14 ± 5.41 years. Distribution of WTW was slightly positively skewed (Skewness = 0.0076, Kurtosis = 0.3944, KS P = 0.020) with a mean of 11.65 ± 0.38 mm and a 95% normal range of 10.91–12.39 mm. A significant difference in WTW was found among different myopia groups (P &lt; 0.001). The ACD was normally distributed (Skewness = 0.899, Kurtosis = 0.027, KS P = 0.086). The mean ACD was 3.25 ± 0.26 mm and the 95% normal range of was 2.74–3.75 mm. A significant difference in ACD was also found among different myopia groups (P = 0.030). There was a significant correlation between WTW and ACD (r = 0.460, P &lt; 0.001).Conclusions: In our study, 95% of the Chinese myopic patients had a WTW within 10.91–12.39 mm and an ACD within 2.74–3.75 mm. ACD and WTW were significantly different among different myopia, gender and age groups. WTW was positively correlated with ACD.

scholarly journals Angle stability and outflow in excisional ab interno trabeculectomy with active versus passive chamber management

2017 ◽  
Author(s):  
Chao Wang ◽  
Yalong Dang ◽  
Susannah Waxman ◽  
Xiaobo Xia ◽  
Robert N Weinreb ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Glaucoma Surgery ◽  
Training Model ◽  
Training System ◽  
Angle Stability ◽  
Ab Interno Trabeculectomy ◽  
The Right ◽  
Ab Interno

Purpose: To compare the intraoperative angle stability and the postoperative outflow of two ab interno trabeculectomy devices that excise the trabecular meshwork. The newer device has an active aspiration and irrigation port while the older requires viscoelastic to maintain the anterior chamber. We hypothesized that anterior segment optical coherence tomography (ASOCT) allows quantifying the intraoperative behavior in a microincisional glaucoma surgery (MIGS) pig eye training model. Methods: Twelve freshly enucleated porcine eyes were measured with ASOCT at baseline, at the beginning of the procedure and at its conclusion to determine the anterior chamber depth (ACD) and the nasal angle in degrees. The right and left eye of pairs were randomly assigned 24 to an active dual blade goniectome (aDBG) and a passive dual blade goniectome (pDBG) group, 25 respectively. The aDBG had an irrigation and aspiration port while the pDBG required surgery 26 under viscoelastic. We performed the procedures using our MIGS training system with a 27 standard, motorized ophthalmic operating microscope. We estimated outflow by obtaining 28 canalograms with fluorescent spheres. Results: In aDBG, the nasal angle remained wide open during the procedure at above 90° and 30 did not change towards the end (100±10%, p=0.9). In contrast, in pDBG, ACD decreased by 31 51±19% to 21% below baseline (p<0.01) while the angle progressively narrowed by 40±12% 32 (p<0.001). Canalograms showed a similar extent of access to the outflow tract with the aDBG 33 and the pDBG (p=0.513). The average increase for the aDBG in the superonasal and inferonasal 34 quadrants was between 27 to 31% and for the pDBG between 15 to 18%. Conclusion: ASOCT demonstrated that active irrigation and aspiration improved anterior 36 chamber maintenance and ease of handling with the aDBG in this MIGS training model. The 37 immediate postoperative outflow was equally good with both devices.

scholarly journals Assessment of the Capsular Tension Ring Implantation Effect on the IOL Position in the Long Term Period after Uncomplicated Phacoemulsification

2021 ◽  
Vol 18 (4) ◽  
pp. 827-832
Author(s):  
A. N. Kulikov ◽  
E. V. Danilenko ◽  
A. A. Dzilikhov
Keyword(s):  
Anterior Chamber ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Vertical Direction ◽  
Ultrasound Biomicroscopy ◽  
Position Change ◽  
Small Shift ◽  
Capsular Tension Ring ◽  
Observation Period

Purpose: To assess the capsular tension ring implantation effect on the IOL position according to different devices in the long term period after uncomplicated phacoemulsification.Patients and methods. The study enrolled 234 patients (273 eyes) with cataract without zonular weakness. A standard examination, optical biometry and Sheimpflug imaging were performed preoperatively. In all cases phacoemulsification with IOL implantation, supported by CTR in 11 % of cases (30 eyes) was performed in 1, 3, and 6 months after surgery autorefractometry, visual acuity, biometry, OCT of anterior segment and ultrasound biomicroscopy were provided.Results. By the 3rd month a small shift of IOL towards the retina was revealed without any refraction changes. In cases with CTR implantation the anterior chamber depth was stable. According to OCT data the angle of IOL tilt in the horizontal meridian gradually decreased, the dynamics was significant from 3 months (p = 0.032). There were no changes in the vertical direction. After CTR implantation IOL position did not significantly change. There was no difference between the groups (p > 0.05) by 6 month. The phenomenon of IOL “deflection” according to OCT data was observed in 20.87 % of cases was in 1 month after operation. In the presence of CTR its frequency decreased to 15.00 %, and in the absence, it increased to 21.63 %. In every fifth case of deformation the measurements did not give us a definite reason to further consider it a “deflection” by 6 months after the operation. In 4.24 % of cases fact of IOL “deflection” was absent at the first month but appeared by the 6 month. There was not any case of CTR implantation among described cases of IOL position change.Conclusion. Fluctuation of anterior chamber depth is observed up to 3 months after uncomplicated phacoemulsification. Changes in IOL tilt angle occur throughout the observation period with a significant decrease in the horizontal plane by 6 month. Implantation of the CTR should stabilize anterior chamber depth, block the IOL tilt and also reduce the percentage of IOL deflection cases in the defined group.

scholarly journals Outcomes of a Foldable Capsular Vitreous Body Implantation: A Retrospective Study

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xiangzhong Xu ◽  
Huimin Ge ◽  
Jiajun Li ◽  
Weihong Shang ◽  
Yuke Ji ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Ocular Trauma ◽  
Silicone Oil ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Vitreous Body ◽  
Fundus Photography ◽  
Clinical Value

Background. The vitreous body is an important part of the ocular body fluid. A foldable capsular vitreous body (FCVB) is designed to treat chronic adverse complications in severe ocular trauma and silicone oil-dependent eyes. This study is aimed at investigating a method for implanting an FCVB, its postoperative efficacy, and clinical value. Methods. A retrospective analysis was performed on data from 18 patients who underwent vitrectomy and FCVB implantation for severe ocular trauma and silicone oil-dependent eyes between March 2019 and May 2020. All treated eyes underwent clinical examinations involving the best-corrected visual acuity, intraocular pressure, FCVB position, anterior segment photography, and wide-angle fundus photography regularly after surgery. Results. Eighteen eyes from 18 patients were enrolled in this study. A total of 2.00–4.20 ( 3.46 ± 0.78 ) ml of silicone oil were injected into the FCVB during surgery. The patients were followed up at 1, 2, and 4 weeks and 3, 6, and 12 months after surgery. Twelve months after surgery, visual acuity improved in 7 (38.89%) eyes. In contrast, 10 (55.56%) eyes showed no obvious improvement, and 1 (5.56%) eye had decreased vision. Intraocular pressure at 12 months was 10.13 ± 3.52  mmHg, which was comparable to that before the surgery ( t = 0.38 , P = 0.71 ). The anterior chamber depth examined by slit lamp was 2.00–3.00 cornea thickness (CT) in 7 eyes, 1.00–2.00 CT in 2 eyes, and <1.00 CT in one eye. The anterior chamber disappeared in eight eyes. There were eight eyes with clear cornea, four eyes with localized opacity, and two eyes with obvious gray-white opacity. There was no case of severe FCVB deflection, rupture, or exposure during the observation period. Conclusion. FCVB implantation is an effective and safe treatment for eyes with severe ocular trauma and silicone oil-dependent eyes. It may support retinal reattachment, slow down eyeball atrophy, reduce the risk of chronic adverse complications such as corneal endothelial decompensation, and maintain intraocular pressure and preoperative visual function.

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