FACTORS INFLUENCING INTRAOCULAR PRESSURE Meidina Rahmah Consultant Dr. dr. Hj. Fidalia, SpM(K) dr. Prima Maya Sari, SpM Literature review OPHTHALMOLOGY DEPARTMENT OF SRIWIJAYA UNIVERSITY MOH. HOESIN HOSPITAL PALEMBANG 2015
FACTORS INFLUENCING INTRAOCULAR PRESSURE
Meidina Rahmah
Consultant
Dr. dr. Hj. Fidalia, SpM(K)
dr. Prima Maya Sari, SpM
Literature review
OPHTHALMOLOGY DEPARTMENT OF SRIWIJAYA UNIVERSITY
MOH. HOESIN HOSPITAL PALEMBANG2015
Introduction
• Normally intraocular pressure is 15.5 mmHg with SD 2.6 mmHg
• Intraocular pressure are influenced by secretion and outflow of aqueous humor
• Aquos humor is a fluid which filled anterior and posterior chamber
….. Introduction
• Disturbance of aqueous humor flow can cause increasing of intraocular pressure which lead to optical nerve damage
• It’s important to know aqueous humor flow and factors that influenced the intraocular pressure
Objective
To explain about anatomy ciliary body and anterior chamber, physiology of aqueous humor
andfactors that influenced
intraocular pressure
Anatomy & Physiology
Anatomy of the Ciliary Body
• Site of aqueous humor production • Anterior portion of the uveal tract,
whichis located between the iris and the choroid
• Consist of 2 zone anterior (pars plikata) & posterior (pars plana)
….. Anatomy
oblique
circular
longitudinal
Ciliary Muscle
Ciliary Vessels
….. Anatomy
• The major arterial circle is the immediate vascular supply of the iris and ciliary processes
• Each ciliary process is supplied by two branches of the major arterial circle:the anterior and posterior ciliary process arterioles
Ciliary Epitel
– Outer part pigmented epithelium, consist of cuboid cell and facing the stroma of theciliary process
– Inner part non pigmented epithelium,consist of collumnar epithelial, facing and lining the posterior chamber
Innervation of the Ciliary Body
Simpatis Parasimpatis
• Synapse in the superior cervical Ganglion• Postsynaptic fibers are distributed to the ciliary body vessels
• Edinger-Westphal nucleus to innervate the ciliary muscles
Anatomy of Anterior Chamber
• The iris separates the aqueous humorcompartment into a posterior and an anterior chamber
• Angle formed by the iris and the cornea is called the anterior chamber angle
• The deep of anterior chamber is varyIn normal emetrop 3 mm
• Volume 200 µL
….. Anatomy
• Anterior chamber angle is formed by: –Schwalbe’s line–Schlemm’s canal and Trabecular
meshwork–Scleral spur–Collector channel –Anterior border of the cilliary body – Iris
Schwalbe’s line- Termination of Descemet’s membrane
Schlemm’s canal- A continuos monolayer of nonfenestrated
endothelium and thin connective tissue wall
Trabecular meshwork Consists of a connective tissue coresurrounded by endothelium and may be divided into three portions: (a) uveal meshwork, (b) corneoscleral meshwork,
(c) juxtacanalicular tissue
Physiology
• Aqueous humor is a clear fluid that fillsand helps form the anterior and posterior chambers of the eye
• Secreted by the nonpigmented ciliary epithelium (NPE) from a substrate ofblood plasma.
….. Physiology
Intraocular pressure is depend on:
1. Rate of aqueous secretion2. Resistance of the outflow
channel3. Episcleral venous pressure
Functions of aqueous humor
• Brings oxygen and nutrients to cells of lens, cornea, iris
• Removes products of metabolism and toxic substances from those structures
• Provides mechanism for maintaining intraocularpressure
• High ascorbate levels protect against ultraviolet-induced oxidative products, e.g., free radicals
• Facilitates cellular and humoral responses of eye to inflammation and infection
Aqueous Humor Formation
3 mechanisms
Aqueous Humor Composition
– Inorganic ion and organic anion
–Carbohydrate–Glutation and urea–Protein–Growth modulary factors–Oxygen and CO2
Components
(mmol/kg H20)Plasma Aquos Vitreus
Na+
Cl-
HCO3-
Ascorbate
Glucosa
146
109
28
0,04
6
163
134
20
1,06
3
144
114
20-30
2,21
3,4
Aqueous Humor Outflow
Aqueous humor posterior chamber pupil anterior chamber. Aqueous humor exits the eye by passingthrough the 2 route:1.The trabecular (conventional) route
(90%)2. The uveoscleral (unconventional)
route (10%)
Factors that influenced intraocular pressure
Increase intraocular pressure
• Gender• Diurnal variation• Cardiovascular• Position • External pressure of eyeball
Factors that may increase intraocular pressureIncreasing of episclera vein pressureManuver ValsavaHold to breathUsage of tight collar atau tight necktieIncrease central vein pressureObstruction outflow of orbital veinIntubationPressure on eyeballBlefarospasmeCrying HyperthermiaHormonalHipotiroidismeThyroid eye diseaseDrugs unrelated to glaucoma therapyLysergic acid diethylamide (LSD)TopiramateCorticosteroidsAnticholinergicsKetamine
Decrease intraocular pressure• Age• Exercise• Trauma and inflamation
Factors that may decrease intraocular pressureAerobic exerciseAnesthetic drugsDepolarizing muscle relaxants such as succinylcholineMetabolic or respiratory acidosisHormonal influencesPregnancyDrugs unrelated to glaucoma therapyAlcohol consumptionHeroinMarijuana (cannabis)
Conclusion
• Intraocular pressure are influenced by secretion rate of aqueous humor andrate of outflow
• This fluid flow from posterior chamber pupil anterior chamber trabecular patyhway and uveoscleral pathway
• Intraocular pressure depends on many factors that may increase dan decrease
Thank You