Anterior Chamber Angle and Iris-Lens Contact Alteration During Pupillary Dilation

2011 ◽  
Author(s):  
Sara Jouzdani ◽  
Rouzbeh Amini ◽  
Victor H. Barocas
Keyword(s):  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Aqueous Humor ◽  
Ciliary Body ◽  
Ocular Tissue ◽  
Posterior Chamber ◽  
Pupillary Dilation ◽  
Anterior Chamber Angle ◽  
Aqueous Outflow ◽  
Chamber Angle

The aqueous humor (AH) provides oxygen and nutrients for the avascular ocular tissue specifically, the cornea and lens. AH is secreted by the ciliary body into the posterior chamber, passes through pupil, and drains into the anterior chamber (Fig. 1a). Resistance to the aqueous outflow generates the intraocular pressure (IOP), which is 15–20 mmHg in the normal eyes.

Understanding Trabecular Meshwork Physiology: A Key to the Control of Intraocular Pressure?

Physiology ◽  
2003 ◽  
Vol 18 (5) ◽  
pp. 205-209 ◽  
Author(s):  
Artur Llobet ◽  
Xavier Gasull ◽  
Arcadi Gual
Keyword(s):  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Aqueous Humor ◽  
Trabecular Meshwork ◽  
Anterior Chamber Angle ◽  
Chamber Angle

The trabecular meshwork is a tissue located in the anterior chamber angle of the eye, and it is a crucial determinant of intraocular pressure values because of its resistance to the evacuation of aqueous humor from the eye. Here we bring together classical and recent discoveries on the function of the trabecular meshwork, keys to understanding eye pathophysiology.

scholarly journals Anterior Chamber Angle Evaluation following Phakic Posterior Chamber Collamer Lens with CentraFLOW and Its Correlation with ICL Vault and Intraocular Pressure

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Sherif A. Eissa ◽  
Sherin H. Sadek ◽  
Mohamed W. A. El-Deeb
Keyword(s):  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Refractive Error ◽  
Case Series ◽  
Mean Value ◽  
Posterior Chamber ◽  
Anterior Chamber Angle ◽  
Implantable Collamer Lens ◽  
Angle Width ◽  
Chamber Angle

Purpose.To assess intraocular pressure (IOP), lens vaulting, and anterior chamber (AC) angle width, following V4C implantable Collamer lens (ICL) procedure for myopic refractive error.Methods.A prospective case series that enrolled 54 eyes of 27 patients that were evaluated before and after V4C phakic posterior chamber Collamer lens implantation for correction of myopic refractive error. Preoperative measurement of IOP was done using Goldmann applanation tonometer and anterior chamber angle width using both Van Herick slit lamp grading system and Scheimpflug tomography imaging (Oculus Pentacam). Follow-up of the aforementioned variables was at 1, 6, and 18 months postoperatively, together with ICL vault measurements.Results.The mean baseline IOP of11.69±2.15showed a statistically significant (P=0.002) increase after 1 month that remained unchanged at 6 and 18 months postoperatively, with mean value of16.07±4.12,16.07±4.10, and16.07±4.13, respectively. Pentacam AC angle width showed a statistically significant decrease at 1(P=0.025), 6(P=0.016), and 18(P=0.010)months postoperatively, with mean preoperative value of40.14±5.49that decreased to25.28±5.33,25.46±5.44, and25.49±5.38, at 1, 6, and 18 months, respectively. Mean ICL vault showed moderate correlation with Pentacam AC angle width at 1(r=-0.435)and 6(r=-0.424)months.Conclusion. V4C ICL implantation resulted in decrease in AC angle width and increase in IOP, within acceptable physiological values at all time points.

scholarly journals The Effects of Prostaglandin Analogs on Intraocular Pressure in Human Eye for Open Angle Glaucoma

2020 ◽  
Vol 10 (2) ◽  
pp. 176-180
Author(s):  
Shabab Akbar ◽  
Sapna Ratan Shah
Keyword(s):  
Fluid Flow ◽  
Intraocular Pressure ◽  
Aqueous Humor ◽  
Trabecular Meshwork ◽  
Ciliary Body ◽  
Open Angle Glaucoma ◽  
Posterior Chamber ◽  
Open Angle ◽  
Permeable Channel ◽  
Aqueous Outflow

The effects of Prostaglandin Analogs on intraocular pressure and increased aqueous outflow via trabecular meshwork into the schlemm’s canal has been studied in this present research paper. Aqueous humor is an outflow, which flows at the back of the iris in the posterior chamber all the way through the pupil aperture, out into the anterior chamber, and drain from the eye via drainage slope. The eye keeps on making aqueous humor in the ciliary body and it passes through the trabecular meshwork into the scheme of the canal, the key drainage from the eye and it finally goes to the “collector channels” and due to the less amount of aqueous humor fluid flow from the drainage angle, the pressure in the eye starts to increase. For this study, the canal of Schlemm is assumed as a permeable channel. And it is connected by trabecular meshwork. The inner layer of the canal's wall has been assumed as permeable. And the aqueous humor drains into the canal through this porous tissue wall. The objective of this paper is to discuss the effect of prostaglandin analogs on intraocular pressure as the Prostaglandin Analogs work by increasing the outflow of aqueous from the eye.

Glaucoma Problems Associated with Aniridia

2010 ◽  
Author(s):  
Peter A. Netland
Keyword(s):  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Trabecular Meshwork ◽  
Ciliary Body ◽  
Vision Loss ◽  
Visual Field Loss ◽  
Anterior Chamber Angle ◽  
Foveal Hypoplasia ◽  
Closed Angle ◽  
Chamber Angle

Glaucoma is a potentially vision-threatening problem that is commonly encountered in aniridia patients. This condition may develop at birth, or shortly thereafter. More commonly, however, glaucoma is acquired later in childhood or even young adulthood. If unrecognized and untreated, glaucoma can result in blindness. For this reason, it is important to be vigilant in watching for this condition in children affected with aniridia. Vision lost due to glaucomatous damage cannot be regained at a later time. In addition to glaucoma, children with aniridia may demonstrate other problems with their vision. They may have refractive errors, corneal or retinal problems, or abnormalities of eye movement. Foveal hypoplasia (lack of development of the retina) may limit vision in some children. In aniridia patients, cataract (opacification or cloudiness of the lens) is seen with approximately the same prevalence as glaucoma. Cataract, however, differs from glaucoma in that the vision loss due to cataract is reversible. Glaucoma is suspected in aniridia patients when there is an increased intraocular pressure. Glaucoma can be definitely diagnosed when changes of the optic nerve occur due to this elevated intraocular pressure. At the later stages of the disease, visual field loss occurs. In the normal eye, the fluid (aqueous humor) in the front of the eye (the anterior chamber) is produced by the ciliary body, which is located behind the iris (see Figure 5.1). The fluid produced from the ciliary body flows forward into the anterior chamber, where it drains from the anterior chamber angle through tissue called the trabecular meshwork. When there is an abnormal situation, the fluid exits the eye poorly or not at all, and the intraocular pressure may be increased. The fluid may be blocked from exiting the eye by a closed angle, or may flow poorly out of the eye even though the angle is open (see Figure 5.2). The angle may be closed in aniridic patients when the stump of residual iris covers the trabecular meshwork in the anterior chamber angle.

Changes in intraocular pressure and anterior chamber angle after congenital cataract extraction

2019 ◽  
Vol 23 (4) ◽  
pp. e30-e31 ◽  
Author(s):  
Jylan Gouda ◽  
Abdelrahman Elhusseiny ◽  
Reham H. Tomairek ◽  
Dina Elfayoumi ◽  
Ahmed Awadein ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Congenital Cataract ◽  
Cataract Extraction ◽  
Anterior Chamber Angle ◽  
Chamber Angle

scholarly journals The changes of anatomic and topographic characteristics of eye anterior segment after uncomplicated cataract phacoemulsification

2013 ◽  
Vol 94 (6) ◽  
pp. 853-858
Author(s):  
A A Ryabtseva ◽  
M P Yugaj ◽  
N S Nikitina
Keyword(s):  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Ultrasound Biomicroscopy ◽  
Anterior Chamber Angle ◽  
Ciliary Processes ◽  
Lens Implantation ◽  
Topographic Characteristics ◽  
Chamber Angle

Aim. To study the changes of anatomic and topographic characteristics of the eye anterior segment after uncomplicated cataract phacoemulsification using corneal incision with intraocular soft lens implantation. Methods. The data of ultrasound biomicroscopy and noncontact tonometry of 58 eyes (56 patients, 32 females, 24 males aged 54 to 78 years) before and after cataract phacoemulsification were analyzed. Paitents with survived ocular trauma, refractive keratoplasty, glaucoma, uveitis, and surgical complications (incomplete capsulorrhexis, posterior capsule rupture, ciliary zonule disinsertion, corneal burn). Apart from the common examinations (visual acuity testing, tonometry, tonography, eye A- and B-ultrasonography, biomicroscopy), all patients underwent eye ultrasound biomicroscopy. Results. Anterior chamber depth increased from 2.73±0.10 to 4.17±0.06 mm (p ≤0.001). Trabecula-iris distance measured at 500 μm from the scleral spur, increased from 0.38±0.02 to 0.47±0.02 mm (p ≤0.001). Anterior chamber angle increased from 28.69±1.87 to 42.73±1.56 degrees (p ≤0.001), the angle between the iris and the sclera increased from 32.78±1.39 to 41.36±0.84 degrees (p ≤0.001), the angle between the sclera and ciliary processes increased from 39.48±1.29 to 45.30±1.16 degrees (p ≤0.001). Intraocular pressure according to the non-contact tonometry data decreased from 18.16±1.29 to 13.55±0.95 mm Hg (p ≤0.001). Conclusion. Anterior chamber depth, trabecula-iris distance, anterior chamber angle, the angle between sclera and iris and the angle between sclera and ciliary processes increased significantly after phacoemulsification with intraocular lens implantation. Intraocular pressure decreased significantly according to the non-contact tonometry data.

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