Glaucoma Flashcards
<p>What two structures make up the ciliary body?</p>
<p>Pars plana and pars plicata</p>
<p>How wide are the pars plana and pars plicata respectively?</p>
<p>4mm (pars plana)2mm (pars plicata)</p>
<p>What 3 structures make up the pars plicata?</p>
<p>ciliary muscles, ciliary vessels, ciliary processes</p>
<p>What are the 3 types of muscles that make up the ciliary muscle?</p>
<p>Longitudinal, radial and circular</p>
<p>Where do longitudinal muscles insert?</p>
<p>scleral spur</p>
<p>How does the longitudinal muscle affect IOP?</p>
<p>affects outflow facility (contraction of muscle increases outflow)</p>
<p>Which muscle fibers of the ciliary body are responsible for accommodation?</p>
<p>Circular</p>
<p>What is the blood supply of the ciliary body?</p>
<p>Anastomosis between branches of anterior and long posterior ciliary arteries</p>
<p>How many ciliary processes?</p>
<p>70</p>
<p>Name 5 functions of the ciliary body:</p>
<p>1. Suspends and alters shape of lens2. Produces aqueous3. Affects aqueous outflow4. Makes acid mucopolysaccharide component of vitreous5. Maintains blood aqueous barrier </p>
<p>Contraction of the longitudinal muscle creates what change in the lens?</p>
<p>shifts the lens forward and shallows the AC (DOES NOT CHANGE LENS SHAPE)</p>
<p>Contraction of the circular muscle creates what change in the lens? What refractive change?</p>
<p>relaxes the zonules making the lens more round with more refractive power (accommodation)</p>
<p>Relaxation of the circular muscle creates what change in the lens? What refractive change?</p>
<p>tightens the zonules making the lens flatter with less refractive power </p>
<p>By what method is aqueous humor produced?</p>
<p>Active secretion via Na+/K+ pump and carbonic anhydrase </p>
<p>How does glucose enter aqueous humor?</p>
<p>passive diffusion</p>
<p>What is the rate of aqueous production?</p>
<p>2-3microliters/min</p>
<p>What is the anterior chamber and posterior chamber volumes respectively?</p>
<p>250 microliters, 60 microliters</p>
<p>What is the rate of aqueous humor turnover?</p>
<p>1% per minute</p>
<p>What is fluorophotometry? What is it used for?</p>
<p>direct optical measurement of decreasing fluorescein concentration. Used to measure the rate of aqueous production.</p>
<p>How does the production of aqueous change daily and over a lifetime?</p>
<p>Decreases about 45% with sleep.Decreases about 2%/decade (counterbalanced by decrease outflow with increasing age)</p>
<p>What is the pH of aqueous?</p>
<p>7.2</p>
<p>Vitamin C concentration in aqueous is higher or lower than in plasma??</p>
<p>Much higher! 15x higher</p>
<p>Protein concentration in aqueous is higher or lower than in plasma??</p>
<p>Lower (provides optical clarity)</p>
<p>Name 3 functions of the aqueous?</p>
<p>1. Maintains IOP2. Provides nutrition to the lens/cornea3. removes metabolic waste</p>
<p>Blood/aqueous barrier is maintained by what cells in the ciliary body?</p>
<p>outer pigmented epitheliuminner non pigmented epithelium</p>
<p>Outer pigmented epithelium is continuous with what structure posteriorly?</p>
<p>RPE (basal lamina continuous with Bruch's)</p>
<p>Inner nonpigmented epithelium is continuous with what structure posteriorly?</p>
<p>neurosensory retina (basal lamina continuous with ILM) Site of active secretion</p>
<p>How do the inner and outer pigmented epithelium relate to each other?</p>
<p>Apex to apex</p>
<p>What is flare in the AC?</p>
<p>increase in concentration of protein</p>
<p>How does atropine decrease flare?</p>
<p>By closing tight junctions of the blood/aqueous barrier</p>
<p>What is the traditional aqueous outflow pathway? What percentage of aqueous outflow is via the traditional pathway?</p>
<p>Outflow via the TM80-85%</p>
<p>Give the structural pathway of the traditional aqueous outflow path. </p>
<p>uveoscleral meshwork -> corneoscleral meshwork-> juxtacanalicular connective tissue -> scheme's canal -> collector channels -> aqueous veins -> episcleral and conj veins -> anterior ciliary and superior ophthalmic veins -> cavernous sinus</p>
<p>What structure provides the greatest resistance to aqueous outflow?</p>
<p>Juxtacanalicular tissue (4-7micrometer pore size)</p>
<p>How many collector channels are there from Schlemm's canal?</p>
<p>30</p>
<p>Uveoscleral outflow accounts for how much of the total aqueous outflow?</p>
<p>15-20%</p>
<p>Aqueous passes through what angle structure in the uveoscleral outflow tract?</p>
<p>CB -> suprachoroidal space -> CB veins, choroidal veins and scleral veins</p>
<p>A cyclodialysis cleft increases aqueous outflow through what mechanism?</p>
<p>increase uveoscleral outflow</p>
<p>What affect do cycloplegics have on aqueous outflow? </p>
<p>increase uveoscleral outflow</p>
<p>What affect do miotic agents have on aqueous outflow?</p>
<p>Decrease uveoscleral outflowIncrease TM outflow</p>
<p>Why are angle structures only visible on gonioscopy?</p>
<p>total internal reflection of the air/cornea</p>
<p>Anatomically, Schwalbe's line is...</p>
<p>Termination of Descemet's membrane</p>
<p>Name causes of increased pigmentation of TM.</p>
<p>Pseudoexfoliation syndrome, pigment dispersion syndrome, uveitis, melanoma, trauma, hyphema, darkly pigmented patients, age</p>
<p>Ddx of blood in Schlemm's canal</p>
<p>elevated episcleral venous pressure, oculodermal melanocytosis, hypotony, congenital ectropion uvea, neurofibromatosis</p>
<p>Name 7 cases of PAS</p>
<p>1. angle closure2. uveitis3. NVA4. flat AC5. ICE syndrome6. ciliary body tumors7. mesodermal dysgenesis</p>
<p>How do you tell a normal angle vessel from an abnormal angle vessel?</p>
<p>abnormal angle vessels cross scleral spur</p>
<p>DDx for abnormal vessels in the angle?</p>
<p>1. Neovascularization2. Iris neoplasm3. Fuch's heterochromic iridocyclitis (Amsler sign)</p>
<p>Angle recession is disinsertion of what two structures?</p>
<p>tear between longitudinal and circular fibers of the ciliary muscle</p>
<p>What percentage of patients with traumatic hyphema have angle recession?</p>
<p>60-90%</p>
<p>What percentage of patient's with angle recession have glaucoma?</p>
<p>5%</p>
<p>A cyclodialysis cleft is separation of what 2 structures?</p>
<p>ciliary body and scleral spurDIRECT COMMUNICATION BETWEEN AC AND SUPRACHOROIDAL SPACE</p>
<p>How are cyclodialysis clefts treated?</p>
<p>cycloplegics to relax ciliary body, argon laser, cryotherapy, suture CBB to SS, intravitreal air bubble to close superior cleft</p>
<p>Iridodialysis is....</p>
<p>disinsertion of the iris root</p>
<p>How many axons make up the adult optic nerve?</p>
<p>1.2 million</p>
<p>Retinal nerve fiber layer blood supply?</p>
<p>Central retinal artery</p>
<p>Prelaminar and laminar optic nerve blood supply?</p>
<p>Short posterior ciliary arteries</p>
<p>What is the Goldmann Fick equation?</p>
<p>IOP= F/C +EVPF is rate of aqueous formationC is facility of outflowEVP is episcleral venous pressure</p>
<p>Facility of outflow is measured by what?</p>
<p>tonography</p>
<p>Facility of outflow increases or decreases with age?</p>
<p>Decreases</p>
<p>What is normal EVP?</p>
<p>8-12 mmHg</p>
<p>What can cause EVP to increase?</p>
<p>venous obstruction, AV shunt</p>
<p>How do you measure EVP?</p>
<p>manometry</p>
<p>What is the distribution of IOP?</p>
<p>Non gaussian, skewed towards higher IOP</p>
<p>What is a normal range of diurnal variation of IOP?</p>
<p>2-6mmHg</p>
<p>How does season affect IOP?</p>
<p>IOP is higher in winter than in summer</p>
<p>How does posture affect IOP?</p>
<p>IOP is higher when you are laying down compared to sitting up</p>
<p>How does refractive error affect IOP?</p>
<p>IOP is typically higher in myopes</p>
<p>Name 3 types of tonometry.</p>
<p>1. Applanation2. non-contact3. indentation</p>
<p>What is a Schiotz tonometer?</p>
<p>A known weight indents the cornea and displaces a volume of fluid within the eye. Amount of indentation determines pressure.Falsely low with eyes with low rigidity: high myopia, retinal detachments, intraocular gasFalsely high with scleral rigidity and hyperopia</p>
<p>What is the Imbert Fick principle and what is it used for?</p>
<p>P = F/Afor an ideal thin-walled sphere, pressure inside sphere equals force necessary to flatten its surface divided by area of flattening</p>
<p>What is the diameter of the application tip?Why?</p>
<p>3.06mmAt this diameter corneal rigidity and tear meniscus pull of tonometer cancel each other out</p>
<p>Thick corneas overestimate IOP by about how much? </p>
<p>5mmHg per 70micrometersSame is true for thin corneas</p>
<p>If the patient has astigmatism, what changes need to be made with application?</p>
<p>if >1.5D of astigmatism, must align red mark with axis of MINUS cylinder</p>
<p>What is a Perkin's tonometer?</p>
<p>Portable form of a Goldmann tonometer</p>
<p>What is a Mackay-Marg tonometer? What are some examples?</p>
<p>Applanates a small area so good for corneal scars. Ex: tonopen and pneumotonometer</p>
<p>What is the Scheie classification for gonioscopy?</p>
<p>Grade 1- wide open (CBB)Grade 2- SS visibleGrade 3- only ATM visibleGrade 4- closed</p>
<p>What is the Schaffer classification system for gonioscopy?</p>
<p>Grade 1- 10% open Grade 2- 20% open Grade 3- 30% open Grade 4- 40% open</p>
<p></p>
<p></p>
<p>What is the first element of the Spaeth classification system for gonioscopy? </p>
<p>First element is a CAPITAL LETTERA- anterior to TMB- at TMC- at SSD- CBB visibleE- large CBB with indentation gonioscopy, put first impression then indent and write actual insertion in (_)</p>
<p>What is the 2nd element of the Spaeth classification for gonioscopy?</p>
<p>iridocorneal angle width in degrees from 5-45</p>
<p>What is the 3rd element of the Spaeth classification for gonioscopy?</p>
<p>Peripheral iris configurationr= regular (flat)s= steep (convex)q= queer (concave)</p>
<p>What is the 4th element of the Spaeth classification for gonioscopy?</p>
<p>Amount of pigmentation graded from 0 to 4</p>
<p>Which gonioscopy lens gives a direct view of the angle?</p>
<p>Koeppe</p>
<p>Which lenses can perform indentation gonioscopy?</p>
<p>Zeiss, Posner, Sussman</p>
<p>Which indirect viewing lens CANNOT perform indentation gonioscopy?</p>
<p>Goldmann (too big)</p>
<p>What is the degree or extent a person with normal visual fields can see in all directions?</p>
<p>Nasal- 60Superior- 60Inferior 70-75Temporal 100-110</p>