Angle closure glaucoma

Angle Closure GlaucomaModerator: Dr. Shivanand Bubanale

Presentor: Dr. Arushi Prakash

Contents Glaucoma- definition - history Angle closure glaucoma –definition classification Grading of angle width Mechanisms of angle closure glaucoma Epidemiology Provocative tests Acute primary angle closure glaucoma clinical presentation treatment

sequalae Plateau iris configuration Pseudoplateau iris syndrome

Contents Phacomorphic Glaucoma Secondary angle closure glaucomas Neovascular glaucoma Iridocorneal endothelial syndrome Posterior polymorphous dystrophy Epithelial downgrowth Fibrovascular ingrowth Flat anterior chamber Iridoschisis Inflammatory glaucomas Ciliary body glaucoma Intraocular tumors Nanophthalmos

Contents Posterior Scleritis Central retinal vein occlusion Post ocular surgery glaucomas Retinopathy of prematurity Microspherophakia

Glaucoma Glaucoma is a group of disorders characterized by a progressive optic

neuropathy resulting in a characteristic appearance of the optic disc and specific pattern of irreversible visual field defects that are associated frequently but not invariably with raised intraocular pressure.

History of GlaucomasHistory of Glaucomas

05/03/23

History of GlaucomasTerm acute glaucoma first used by Lawrence to

describe severe ocular inflammationMacKenzie emphasized firmness to touch Von Graefe observed progressive optic disc

cupping and stressed the importance of elevated intraocular pressure and the beneficial effect of iridectomy

Curran and Banzinger introduced the concept of physiologic obstruction of aqueous humor flow through the pupil from the posterior chamber to the anterior chamber (pupillary block)

Curran reported success with surgical peripheral iridectomy in eyes with shallow anterior chambers but not in eyes with chambers of normal dephth

The introduction of gonioscopy and the recognition of synechial angle closure provided the basis for the differentiation of open angle and angle closure glaucomas

Rosengren demonstrated that anterior chamber in eyes with “acute congestive glaucoma” was significantly shallower than in normal eyes

Lowe investigated biometry of eyes with angle closure glaucoma

And introduced the concept of polygenic inheritance

Becker introduced acetazolamide

Before that, eyes with acute angkle closure glaucoma were prepared for surgery by intensive miotic therapy, purges and the application of leeches

Use of hyperosmotic agents to withdraw fluid from the eye began with

intravenous urea then, intravenous mannitol

and finally, oral agents

Surgical treatment of angle closure glaucoma has been revolutionized with the development of laser iridotomy and iridoplasty.

Angle closure Glaucomathe term “angle closure” refers to occlusion of

the trabecular meshwork by the peripheral iris, obstructing aqueous outflow.

It may be- Primary- in an anatomically predisposed eyeSecondary- to another ocular condition

Nomenclature and Classification

Historically the angle-closure glaucoma nomenclature has been confusing:

conditions were sometimes classified by the time course of the disease,

sometimes by the effects of the angle closure, and

sometimes by the presumptive pathophysiology of the angle closure

Nomenclature and Classification

Angle-closure glaucoma has been described by the adjective pairs congestive/non-congestive and compensated/uncompensated.

These terms have been abandoned because they lack specificity.The congestion and corneal decompensation are usually a function of the rapidity with which the pressure rises, or reflect underlying causal phenomena such as uveitis.Similarly the terms acute, subacute, and chronic have often

been used to reflect the time course and/or presence of symptoms. Abrupt and total angle closure is acute; recurrent and self-

limiting episodes of closure with elevated intraocular pressure (IOP) are subacute; and asymptomatic elevated IOP or peripheral anterior synechiae is chronic. Although these and similar temporal terms (e.g., ‘latent ’ and

‘imminent’) have long had currency, four-fifths of patients presented entirely without symptoms

Twenty-first century consensusclassification

The new classification of primary angle-closure disease relies on three simple categories:

IOP measurement, Gonioscopy,and disc and visual field evaluation. In other words, the presenting patient’s clinical examination alone determines

the staging of the disease, regardless of the presence, absence, or reliability of symptom history, alleged duration, intermittency of problems, etc.


1. Primary angle closure SUSPECT (PAC suspect):

greater than 270° of irido-trabecular contact absence of peripheral anterior synechiae (PAS)normal IOP, disc, and visual field. In other words, the suspect eye has normal IOPs, optic nerves and visual fields, i.e., no signs

of clinical glaucoma, but whose angle before indentation gonioscopy is graded as a Shaffer grade 2 or less, without PAS on compression.

The angle is at risk.


2. Primary angle CLOSURE (PAC): greater than 270° of irido-trabecular contact

with either elevated IOP and/or PAS normal disc and visual field examinations. In other words, angle closure demonstrates

irido-trabecular contact in 75% of the angle, with either PAS or elevated IOPs, but without disc and visual field changes.

The angle is abnormal in structure (PAS) or function (elevated IOP).


3. Primary angle-closure GLAUCOMA (PACG):

Greater than 270° of irido-trabecular contact elevated IOPoptic nerve and visual field damage. In other words, angle closure glaucoma

manifests the criteria of closure above, plus demonstrable disc and/or visual field changes.

The angle is abnormal in structure and function, with optic neuropathy.

05/03/23

To apply this classification mastery of gonioscopy is required

Irido-trabecular contact needs to be identified as present or absent,

and then discriminated as either appositional (by indenting and revealing angle structures) or synechial,

while documenting the latter’s extent (in terms of degrees or total clock hours)

A goniolens larger than the corneal diameter may allow better resolution of angle structures, but successful indentation to view deeper into the angle is usually not possible.

Newer Imaging Technologies

05/03/23

1. Ultrasonic biomicroscopy (UBM)With tissue penetration of 4 mm, a UBM’s resolution typically includes angle structures as well as imaging of the anterior lens and anterior ciliary processes; images appear as radial slices of one portion of the angle

Ultrasonic biomicroscopy of angle closed(star) in darkness-induced dilation

Ultrasonic biomicroscopy of angle opened (star) in light-inducedmiosis.

Newer Imaging Technologies

05/03/23

2. Anterior segment ocular coherent tomography (AS-OCT)uses infrared light while examining a sitting patient without direct ocular contact, Images comprise a 180°-diameter slice of the anterior segment, currently limited to but a few clock hours (e.g., 3–9 o’clock scan), but dramatically capture the pupil and irido trabecular configuration in high definition.

Anterior segment ocular coherent tomography 180°image ofnarrow angles pre iridotomy

Classification by mechanisms

Angle closure can be caused by one or a combination of the following:(1) Abnormalities in the relative sizes or positions of the anterior segment structures

(2) Abnormalities in the absolute sizes or positions of the anterior segment structures

(3) Abnormal forces in the posterior segment that alter the anatomy of the anterior segment

Mechanisms of Angle Closure Glaucoma

I. Pupillary Block A. Relative pupillary block (primary angle

closure) B. Miotic- induced angle closure C. Posterior synechiae 1. Crystalline lens 2. Intraocular lens 3. Anterior hyaloid face

Mechanisms of Angle Closure GlaucomaII.Plateau Iris A. True plateau iris B. Pseudoplateau iris- iris and ciliary body

cysts

05/03/23

III. Lens Induced angle closure A. Intumescent lens (phakomorphic) B. Anterior lens subluxation 1. Trauma 2. Exfoliation syndrome 3. Hereditary disorders C. Drug sensitivity e.g. Sulfonamides


IV. Malignant (ciliary block) glaucoma A. Phakic B. Pseudophakic C. Aphakic


D. Assosiated with other conditions 1. After panretinal photocoagulation 2. After scleral buckling procedures 3. After central retinal vein occlusion 4. Intraocular tumors 5. Posterior scleritis 6. Retrolenticular tissue contracture a. Retinopathy of prematurity b. Persistent hyperplastic primary

vitreous 7. Uveal effusion from adjacent inflammation a. Posterior scleritis b. Aquired immunodeficiency syndrome

Pupillary block Glaucoma

05/03/23

Pupillary block is the fundamental mechanism underlying the spectrum of Primary Angle Closure disease

It may be absolute, as when then iris is completely bound down to the lens by posterior synechiae

But, most often is a functional block, termed relative pupillary block.

Pupillary block Glaucoma

05/03/23

Its pathophysiology involves: (1) lens– iris apposition at the pupil, with

resultant bowing forward of the peripheral iris as aqueous pressure builds up in the posterior chamber;

and (2) an anatomically predisposed eye that allows the anterior displaced peripheral iris to occlude the trabecular meshwork.

05/03/23

05/03/23

Other Demographic risk Factors

05/03/23

• AGE• Commonly seen with the most frequency in

the 6th and 7th decades of life• Several age-associated changes can

include progressive relative pupillary block from a combination of

1.increasing lens thickness,2.more anterior positioning of the lens, 3.and pupillary miosis

05/03/23

These age-related changes increase the contact between the iris and lens, potentiate pupillary block and reduce anterior chamber depth and volume.

Estimated central anterior chamber depth decreases 0.01mm/year

05/03/23

however, PACG with pupillary blockcan occur in patients of any age, and rarely

even in children –though the etiologies among the young are

almost always developmental or secondary

05/03/23

GENDER2 to 3 times more commonly seen in

women than menBecause of shallow anterior chambers

HEREDITYMost cases of PACG with pupillary block are

sporadic in natureShallow anterior chambers and narrow

angles have been reported as more common in relatives of patients with PACG than in individuals whose relatives do not have the disorder

Refractive error

05/03/23

prevalence much higher in individuals with hyperopic eyes,

which typically have shallow anterior chambers

and short axial lengths Although rare, angleclosure glaucoma can

occur in myopic eyes

Other Risk factors

05/03/23

Occurs more commonly in the winter months.

attributed to low levels of illumination, increased cloudiness, changeable weather, Central corneal thickness – a recently

recognized risk factor for POAG – does notseem to have an association with PACG

Ocular risk factors and mechanisms

05/03/23

Ocular risk factors cluster around a variety of findings, each of

which reflects smaller ocular dimensions:1. Shallow anterior chamber both centrally and

peripherally. 2. Decreased anterior chamber volume.3. Short axial length of the globe.4. Small corneal diameter.5. Increased posterior corneal curvature (i.e.,

decreased radius of posterior corneal curvature).6. Decreased corneal height.

05/03/23

7. Anterior position of the lens with respect to the ciliary body.

8. Increased curvature of the anterior lens surface.9. Increased thickness of the lens.10. More anterior insertion of the iris into the

ciliary body, giving a narrower approach to the angle recess, and possible anomalies of iris histology.

11. Thinning of the ciliary body is reportedly associated with anterior movement of the lens, increased lens thickness and decreased anterior chamber depth.

05/03/23

• Three measures in particular show particularly high correlations

with angle-closure disease:• (1) reduced axial anterior chamber depth

and volume• (2) thicker lens; and• (3) steeper radii of corneal curvature

• The biometric peculiarities of eyes predisposed to angle-closure glaucoma are accentuated by three trends associated with aging.

• First, the lens grows in thickness throughout life.• Second, the lens assumes a more anterior position

with age.• Third, the pupil becomes increasingly miotic with age.• All of these• age-associated changes increase the contact between

the iris and lens, potentiate pupillary block, and reduce anterior chamber depth and volume. It is estimated that central anterior chamber depth decreases 0.01 mm/year.

05/03/23

05/03/23

Somehow the junction of the lens and iris at the pupillary plane modulates the flow of aqueous from the posterior to the anterior chamber, but it apparently is not a simple matter of direct contact between lens and irisit includes-

iris–lens channel:It is an extremely thin (<5 microns),fluid-filled, flat, doughnut shapedpassage between the posterior iris surface and the anterior lens, circumferentially extending beyond the edges of the

pupil.

05/03/23

This dynamic and pulsatile fluid ‘structure’ provides normal

resistance to aqueous flow from the posterior to anterior chambers.

This thus functions as a relative one-way valve to sustain a minimally

higher pressure in the posterior chamber than in the anterior

chamber, hence directing anterior flow forwardThe resistance to flow has classically been

referred to as relative pupillary block

if the peripheral iris bows forward enough to cover the trabecular meshwork, the normal outflow of aqueous humor from the anterior chamber would be blocked and the IOP could increase.

Angle closure disease typically occurs in eyes with small anterior segments in which even a relatively small forward bow of the peripheral iris may contact the trabecular meshwork.

05/03/23

05/03/23

05/03/23

Moderate pupillary dilation is historically the most recognizable cause of increased pupillary block, frequently due to pharmacologic dilation.

the posterior vector of force of the iris sphincter muscle reaches its maximum when the pupil is moderately dilated to a diameter of 3.0–4.5 mm.

Also, in a midilated pupil, the peripheral iris is under less tension and is more easily pushed forward into contact with the trabecular meshwork.

Lastly, dilation may also thicken and bunch the peripheral iris in the angle.

In contrast, when the pupil is widely dilated, there is little or no contact between the lens and the iris and minimum pupillary block.

Therefore, acute angle-closure glaucoma rarely occurs while the pupil is in the actual process of dilating due to mydriatic eye drops: the dilation occurs rapidly enough that pupillary block does not have time to develop.

Rather, pupillary block ‘classically’ occurs as the pupil constricts over hours following dilation, presumably because the mid-dilation is prolonged as the mydriatic effect slowly reverses.

05/03/23

05/03/23

Pupillary block can also be increased by marked pupillary miosis

There are several everyday life ‘triggers’ for precipitating attacks of acute PACG

emotional upset (e.g., bad news, pain, fear, illness, an accident)

or dim illumination (e.g., in a restaurant or theater). Emotional upset is thought to dilate the pupil through

increased sympathetic tone to the iris dilator muscle, whereas dim illumination dilates the pupil through decreased cholinergic tone to the iris sphincter muscle.

Similarly, the forward movement of the lens, which occurs in a variety of situations such as reading, changes in body position, and miotic therapy, has been implicated as a trigger.

Diurnal variations in the anterior chamber depth with parasympathetic fluctuations and pupillary diameter, and diurnal variations in aqueous secretion have also been suggested as contributory factors

Provocative tests

05/03/23

These were designed to elevate IOP in conjunction with occlusion of the angle, so as to indicate which eyes ‘at risk’ merit surgical intervention.

Most provocative tests were designed to resemble ‘physiologic’ situations, in the hope that the test would mimic the natural history of the condition.

Provocative tests1) Mydriatic stimulation- A weak, short-acting parasympatholytic

agent such as tropicamide 0.5% or a weak sympathomimetic such as

hydroxyamfetamine, to mildly dilate the pupil (raise the IOP

>8mmhg is consider positive)

(2) Dark room testing to induce physiologic miosis

(3) A prone test with the head resting on one’s arms on a

table shifting the lens anteriorly without dilation;

(4) Complex pharmacologic provocations,

mixture of cycloplegics or mydriatics with pilocarpine.

Subacute or intermittent PACG presents with -unilateral headache -blurring of vision -unbroken coloured haloesWith spontaneous resolution of symptoms

Acute PACG 1)Unilateral sudden onset of pain or aching on the

side of the affected eye. 2)This pain is accompanied by blurred vision or colored haloes around lights 3)Ocular congestion and corneal edema4) and sometimes nausea, vomiting, and sweating.The pain usually occurs in the trigeminal

distribution, and is locally experienced by the patient as in the eye; or it can manifest as referred pain in the orbit, head, ear, sinuses, or teeth.

Physical findings in acute angle-closure glaucoma withpupillary block

05/03/23

• Findings during an acute attack of angle-closure glaucoma• Two of the following symptom sets: Periorbital or ocular pain Diminished vision Specific history of rainbow haloes with blurred vision IOP higher than21 mmHg• plus three of the following findings: Ciliary flush Corneal edema Shallow anterior chamber Anterior chamber cell and flare Mid-dilated and sluggishly reactive pupil Closed angle on gonioscopy Diminished outflow facility Hyperemic and swollen optic disc Constricted visual field

Acute congestive angle-closure glaucoma

• Severe corneal oedema• Complete angle closure (Shaffer grade 0)

• Dilated, unreactive, vertically oval pupil

• Shallow anterior chamber

• Ciliary injection

Signs

05/03/23

• Findings suggesting previous episodes of acute angle-closure glaucoma

Peripheral anterior synechiae Posterior synechiae to lens Glaukomflecken Sector or generalized iris

atrophy Optic nerve cupping and/

or pallor Visual field loss Diminished outflow facility

Differential diagnosis of acute angle-closure glaucoma

05/03/23

• Evidence of compromised angle on gonioscopy or shallow anterior chamber

Ciliary block glaucoma (aqueous misdirection or malignant glaucoma)

Neovascular glaucomaIridocorneal endothelial syndromePlateau iris syndrome with angle closureSecondary angle closure with pupillary block

(e.g., posterior scleritis)Cilio-choroidal detachments (bilateral)

05/03/23

• High-pressure open-angle glaucomas masquerading as acute angle closure

Glaucomatocyclitic crisisHerpes simplex keratouveitisHerpes zoster uveitisSarcoid uveitisPigmentary glaucomaExfoliative glaucoma (may have associated angle

closure)Post-traumatic glaucomaPhacolytic glaucomaSteroid-induced glaucoma

Management

05/03/23

Primary angle-closure suspect1)Prophylactic laser iridotomy is

recommended iridotomy widens the angle by about two grades

2)If significant ITC persists after iridotomy -laser iridoplasty -lens extraction

Treatment of acute PACG IMMEDIATE MEDICAL THERAPY

PROTECTION OF FELLOW EYE

LASER IRIDOTOMY IN BOTH INVOVED AND FELLOW EYE

LONG TERM GLAUCOMA SURVEILLANCE AND IOP

MANAGEMENT OF BOTH EYES

Hyperosmotic agentsRaise serum osmotic pressure removing fluid from eye

especially from vitreousIn addition, vitreous dehydration allows lens to move

posteriorly deepening AC and facilitating opening of the anglePressure decreases within 30-60 minutes after administration

and effect lasts 5-6 hrsOral glycerol 50% 1-1.5g/kgIsosorbide 1.5-2g/kg in diabetics (not metabolized)Mannitol 20% 1-2g/kg given intravenously over 45 minutes

has a greater hypotensive effect.Adverse effects- thirst, headache. Hyperosmolar coma can be

a serious complication due to severe CNS dehydration.Patients with renal or cardiovascular disease or those already dehydrated by vomiting are at risk.

05/03/23

Inhibitors of Aqueous Humor SecretionCarbonic anhydrase inhibitorsAcetazolamideHighly effective in angle closure glaucomasMay open some closed angles even in prescence of

ischemic iris atrophy and paralysis of pupilAim is to give large dose quickly- 500mg intravenously,

advantageous when vomiting is present, onset is rapid

May be given orally but onset of action is not rapid After oral therapy plasma levels last for 4 to 6 hours

Adverse reactions are uncommon but there is a remote chance of sensitivity since it is a sulphonamide

05/03/23

05/03/23

β blockers - Beta adrenergic antagonists are additive with acetazolamide but have a more

prolonged onset of action than intravenous acetazolamide in acute angle closure glaucoma. They are more useful in later stages of treatment and in maintaining reduced intraocular pressure before laser iridotomy

α adrenergic agonists – by means of vasoconstriction they reduce aqueous production and increase uveoscleral flow.

05/03/23

DRUGS THAT INCREASE AQUEOUS OUTFLOW Prostaglandin Analogs- Low concentrations PGF2α

lower intraocular pressure without inducing ocular inflammation by increasing uveoscleral outflow, by increasing permeability of tissues in cilliary muscle or by an action on episcleral vessels.

Side effects include increased iris pigmentation, thickening and darkening of eyelashes. No systemic side effects

05/03/23

Topical steroids -To reduce anterior chamber inflammation

and the chance of both anterior and posterior synechiae formation, may be administered after the acute attack is broken

ROLE OF PILOCARPINE in pacg ??

WHAT MAKES THE USE OF PILOCARPINE

APPEALING? - It constricts pupil, which ‘retracts’ the

peripheral iris from its contact with the angle - So Miotic agents’ were used in managing

acute disease, and as preventive therapy for the fellow

eye or until an iridotomy can be arranged

But prophylactic’ pilocarpine in these fellow eyes may have been the precipitating cause of PACG Two major intraocular mechanic situations that

miotics exacerbate: (1) Pilocarpine’s effects on ciliary body and

zonular responses allow the lens shape to become more convex, while facilitating its anterior movement, thus shallowing the anterior chamber, with peripheral compromise of the irido-trabecular angle

(2) Miotics induce increased convexity of the iris as the lens advances which, with the simultaneous miotic-induced miosis, predisposes the lens–iris channel to greater

resistance to aqueous flow. The result is frequently an inadvertent

worsening of pupillary block.

SO WHERE PILOCARPINE CAN BE USED?

Before immediate laser iridotomy or iridoplasty - To induce miosis to maximally stretch the peripheral iris In plateau iris

IT IS NOT EFFECTIVE IN ACUTE ATTACKS - The IOP is so high that the pupillary

sphincter muscle is ischemic and unresponsive to

topical miotic agents.

WHEN TO CONSIDER THE ACUTE ATTACK BEEN TERMINATED? - Until the IOP is reduced and sustained at the lowest possible levels. Because IOP may fall temporarily with medical treatment as profound hyposecretion and hypotony can follow an acute attack of PACG- The angle is as open as physically possible on gonioscopy.

Slit-lamp maneuvers in management of acute PACG

To often accelerate corneal clarity Such Maneuvers include:1) Axially depressing the central cornea with a small gonioprism (e.g., the Zeiss four-mirror lens) or with a blunt instrument(e.g., a

muscle hook or moist cotton swab),

2. Applying digital massage to the globe after retrobulbar anesthesia.

This technique is used to dehydrate the vitreous cavity and lower IOP

3. Performing an anterior chamber paracentesis, under topical anesthesia, with a small-gauge disposable sterile needle

Laser interventions for acute PACG 1. Peripheral laser iridotomy, 2. A peripheral iridoplasty

(gonioplasty) 3. A pupilloplasty with Nd:YAG or

argon instruments, is the definitive treatment for acute angle-closure

WHEN TO DO IRIDOTOMY? DIRECTLY- if an acute attack terminated by

medical means ORWAIT 1-2 DAYS- For the cornea to clear and intraocular inflammation to subside

05/03/23

ROLE OF IRIDECTOMY

Surgical iridectomy - Is a relatively safe and simple procedure BUT invasive - complications such as cataract, bleeding,

and endophthalmitis can accur

Surgical iridectomy reserved for situations such as:

1) The laser fails to produce a patent iridotomy; 2) Laser iridotomies repeatedly close; 3) A laser is neither available nor functioningproperly; 4) Opacities of the cornea interfere with laser

treatment; 5) The patient is uncooperative or unable to sit

at the slit lamp

2) Peripheral laser iridoplasty (gonioplasty) can be use in a)Acute PACG from pupillary block -unresponsive to medical treatment where

a perforating laser iridotomy is precluded by excessive shallowing of the anterior chamber, inflammation, or corneal edema

b) plateau iris syndrome; and c) acute phacomorphic angle closure.

3) Laser pupilloplasty PRINCIPAL It interrupt pupillary block by distorting the

pupil into a tear-shaped configuration, focally interrupting decreased flow through the iris–lenticular junction, thus facilitating aqueous to flow into the anterior chamber

SURGICAL MANAGEMENT

When to go for surgical option?If IOP elevation persists despite a patent

laser iridotomy and subsequent medical therapy

1)filtering surgery alone; 2)lens extraction alone, with or without goniosynechialysis; 3) combined lens extraction with

trabeculectomy; 4)or goniosynechialysis alone

MANAGEMENT OF FELLOW EYE

-Is initiated with medical treatment to reduce the

IOP, until the acute attack is resolved and-A prophylactic iridotomy can be performed--vigorous surveillance with periodic

gonioscopic, disc, and field assessments

Instructions to patient

Need for lifelong care even when iridotomy has apparently ‘cured’ their acute glaucoma. Once optic nerve damage is demonstrated

after an acute attack – i.e.PACG is manifest – iridotomy won’t sufficiently control pressure, and supplemental medical therapy or surgery is

required. More frequent gonioscopy examination is

required

Sequelae of acute PACG

Elevated IOP- -may occur as a result of release of pigment

and other debris,-incomplete or sealed iridotomy,-unrecognized plateau iris syndrome,- inflammation,-extensive PAS, - corticosteroid administration

Visual field loss -Typical glaucomatous visual field loss

following an acute attack of PACG occurs in the minority of eyes (about 40%)

-Nerve fiber layer loss can be demonstrated in most patients whose attack’s duration was longer than 48 hours.

--Visually significant cataract--Corneal damage --Loss of endothelial cells -- superficial corneal surface burns - Corneal decompensation

Plateau iris --Plateau iris refers On gonioscopy, that

the iris assumes a steep approach at its insertion before flattening centrally

plateau iris is divided into two entities 1) ‘plateau iris configuration’ 2)‘plateau iris syndrome

PLATEAU IRIS CONFIGURATION

On Gonioscopy, The iris appears flat from the pupillary

margin to the periphery and creates a narrow angle recess and the potential for angle closure

Koeppe gonioscopy- double hump or S-sign of a peripherally elevated roll of iris is seen , where the forwardly positioned ciliary processes prevent the peripheral iris from falling backward in the supine position

many cases, plateau iris configuration is accompanied by some degree of pupillary block, which exacerbates the problem.

Therefore, it is often not possible on clinical grounds to differentiate between a pupillary block PAC and a plateau iris configuration embarrassing the angle until after an iridotomy has been performed.

In conditions precipitated by pupillary block, iridotomy will cause the iris to fall back and the peripheral chamber to deepen; whereas in plateau iris, the peripheral angle remains unchanged.

05/03/23

Patients with plateau iris configuration (and plateau iris syndrome)

should be warned to avoid agents which have a potential

for dilating the pupil These include any medication

with anticholinergic activity such as antihistamines, phenothiazine

antianxiety agents, antidepressants, and drugs used for incontinence and for diarrhea

05/03/23

-Plateau iris syndrome refers to the development of angle closure either spontaneously or after pharmacologic

dilation ,in an eye with a patent iridotomy

angle closure occurs because the ciliary processes are rotated forward.

presentation- -Seen in young patients - - Aged 30–40 years old - Occurs equally among men and womenpresents with or without symptoms occurring

days, weeks, months, or years after iridotomy or other intraocular surgery

If not diagnosed and treated properly, repeated episodes of angle closure can progress to PAC or PACG: increasing numbers of PAS, persistent elevation of IOP, and ultimate glaucomatous damage

Differential diagnosis of plateau iris syndrome 1)Extensive PAS due to any cause; 2)Imperforate or occluded iridotomy with

persistent pupillary block 3) Multiple cysts of the iris or ciliary body4) Ciliary block glaucoma 5) Open-angle glaucoma with anatomically

narrow angles(as with increasing cataract formation); and the effect of chronic topical corticosteroids or cycloplegic agents

treatment

Iridotomy.Usually the first treatment for plateau iris

syndrome Peripheral iridoplasty – If UBM imaging is available, it may be the initial Treatment since iridotomy often does not change

the anterior Segment anatomy Miotic agents can be tried to minimize pupillary dilation (e.g.,

pilcocarpine 1–2% 2–4 times a day)

Argon laser peripheral iridoplasty (gonioplasty)

- if the response to miotics is inadequate,-or if the patient is unable or unwilling to use

them longterm Filtration surgery,or glaucoma

drainage devices- If iridoplasty plus medical therapy cannot

control the IOP adequately

Cataract extraction with IOL implant -Effective in allowing the ciliary processes to move posteriorly and improve pressure control; but apposition has been documented to persist even after lensremoval

Care to be taken after an iridotomy done in plateau iris

Eyes should be examined periodically for signs

of elevated IOP, peripheral synechia and glaucomatous damage. Pupillary dilation should be undertaken

with care, even after iridotomy

•Primary cysts of the iris and ciliary body usually arise from theepithelial layers. •The cysts can be single or multiple and involve oneor both eyes•In most cases the cysts remain stationary and cause no harm. •In rare cases the cysts are sufficient in size and numberto lift the iris forward and cause angle-closure glaucoma withoutpupillary block.

MANAGEMENTIf the cysts causing angle closure are

visible -Punctured with an argon or Nd:YAG laserIf the cysts are not visible -If UBM has identified their location it is

possible to puncture them by first doing a laser iridotomy over the involved area

Medical therapy - May be required after cyst puncture if

extensive PAS are present. Filtering surgery -In a few cases where the cysts cannot be

treated with a laser

PHACOMORPHIC GLAUCOMAAn abnormal lens either compromises 1)The lens–iris channel (pupillary block) - can develop slowly with an age-related

cataract or-rapidly with a traumatic, swollen cataract.2)Mechanically pushes the peripheral irisforward into the angle structures

Usually unilateral and resembles PACG, except for the presence of Intumescent lens and A normal anterior chamber depth in the fellow eye.

TREATMENT

Medical treatment is identical to that of PACG

The definitive treatment -cataract extraction. Role of iridotomy If cataract extraction is not possible -because of extenuating circumstances (e.g.,gravely ill patient )or must be delayed

SecondaryAngle Closure Glaucomas

05/03/23

Secondary angle-closure glaucomaWhen a related or identifiable ophthalmic condition is known to be present with the

onset of angle closure, it is referred to as secondary.

(replaces the category of ‘combined (mixed) mechanism glaucoma’) Two different fundamental mechanisms:1)Anterior pulling mechanism 2)Posterior pushing mechanism

1)Anterior pulling mechanism With the anterior pulling mechanism, the peripheral iris is pulled

forward onto the trabecular meshwork by the contraction of a membrane, inflammatory exudate, or fibrous band

As the membrane, band, or inflammatory material contracts, it acts like a zipper to

form permanent PAS, which can be spotty and irregular or diffuse and quite regular.

Pupillary block plays little or no role in this mechanism.

05/03/23

Neovascular Glaucomacaused by a fibrovascular membrane that develops

on the surface of the iris and the angle. At first the membrane merely covers the angle

structures, but then it contracts to form PASAlmost always associated with some form of ocular

ischemiaHas also been refered to as – thrombotic glaucoma, hemorrhagic glaucoma, diabetic hemorrhagic glaucoma, congestive glaucoma,and rubeotic glaucoma

05/03/23

important to distinguish the terms neovascular glaucoma and rubeosis iridis

pathogenesis of neovascular glaucoma is that retinal ischemia

liberates angiogenic factors that diffuse forward and induce new vessel formation on the iris and in the angle.

Capillary occlusion or ischemia appears to be the initiating event in this process, similar to the production of an angiogenic factors by solid tumors

05/03/23

Ocular vascular diseaseCentral retinal vein occlusionCentral retinal artery occlusionBranch retinal vein occlusionBranch retinal artery occlusionSturge-Weber syndrome with choroidal hemangiomaLeber’s miliary aneurysmsSickle cell retinopathyDiabetes mellitusExtraocular diseaseCarotid artery disease/ligationOcular ischemiaAortic arch syndromeCarotid-cavernous fistulaGiant cell arteritisPulseless disease

05/03/23

Assorted ocular diseasesRetinal detachmentEales’ diseaseCoats’ diseaseRetinopathy of prematurityPersistence and hyperplasia of the primary vitreousRetinoschisisGlaucomaOpen-angleAngle-closureSecondaryNorrie’s diseaseStickler’s syndrome

05/03/23

TraumaEssential iris atrophyNeurofibromatosisLupus erythematosusMarfan’s syndromeRecurrent hemorrhagesVitreous wick syndromeOcular neoplasmsMalignant melanomaRetinoblastomaOptic nerve glioma associated with venous stasisMetastatic carcinomaReticulum cell sarcomaMedulloepitheliomaSquamous cell carcinoma conjunctivaAngiomatosis retinae

05/03/23

Ocular inflammatory diseaseChronic uveitisEndophthalmitisSympathetic ophthalmiaSyphilitic retinitisVogt-Koyanagi-Harada syndromeOcular therapyCataract excision (especially in diabetics)Vitrectomy (especially in diabetics)Retinal detachment surgeryRadiationLaser coreoplasty

05/03/23

Diabetes mellitus is associated with about one-third of the cases of neovascular glaucoma;

Central retinal vein occlusion with another third;

and a variety of conditions with the last third – with carotid

occlusive disease being the most common in the last group

05/03/23

Clinical Presentationacute onset of pain, tearing, redness, and

blurred vision some cases (weeks to months) before the onset of the pain and redness

ciliary injection, a hazy cornea from epithelial edema, a deep anterior chamber with moderate flare, a hyphema, a small pupil, and new vessels on the iris and in the angle.

Clinically the new vessels are first detected as small tufts at the pupillary margin. Occasionally new vessels are seen first in the angle if the tufts near the pupil are obscured by dark iris pigment

The neovascularization progresses over the iris surface and into the angle. The new vessels extend from the iris root across the ciliary body and scleral spur, where they arborize over the trabecular meshwork.

may be difficult to distinguish new vessels from normal iris vessels

05/03/23

Normal iris vessels

Neovascularization

Uniform size irregular sizeRadial course Irregular courseDo not branch within the iris

Branch frequently

Lie in the stroma Lie on the iris surface

05/03/23

05/03/23

Stages of neovascular glaucoma. (A) Pre-glaucoma stage with new vessels appearing at pupillary margin and in angle. (B) Open-angle glaucoma stage with new vessels spreading and fibrovascular tissue covering angle. (C) Heavy neovascularization and extensive peripheral anterior synechiae.(D) Regression stage with angle sealed and vessels less visible.

AN ACUTE EPISODE IN NVGTreated by -Maximal IOP-reduction medical therapy, -Atropine for relief and to maximally dilate

the pupil before iris mobility is lost,-Corticosteroid.-Panretinal photocoagulation or retinal cryoablation to prevent total angle closure.

If the eye has good visual potential, and if the

neovascular membrane has regressed-Filtering surgery can be successful,

especially when augmented with antimetabolites. -Glaucoma drainage implants appear to be Successful

Eyes with limited or no vision can often be made comfortable using

-Cycloplegic agents -Topical corticosteroids regardless of the IOP.

Cyclodestructive procedures

May be appropriate if the patient infirm for surgery, has too little visual potential to procede with filtrationor tube surgery, or requires immediate pain

relief.

Cyclocryotherapy is usually applied at-60°C to -80°C, using a large-tip

probe with its anterior edge 2.5 mm posterior to the limbus. Six to eight

60-second freezes are placed over half of the Circumference of the ciliary body.

Complications iridocyclitis, hypotony, pain, cataract, and phthisis bulbi.

Diode laser cyclodestruction for patients with poor vision or poor visual

prognosis and for those for whom a glaucoma drainage device operation may be inadvisable

Retrobulbar alcohol injections and enucleation are appropriate treatments for eyes either with no useful vision or with intractable

pain that does not respond to medical therapy and ciliodestructive procedures

Goniophotocoagulation direct laser treatment to new vessels in the angle it may be a useful

adjunct to panretinal photocoagulation in certain situations.ountered when full panretinal photocoagulation is not totally successful in reducing the angiogenic

stimulus. Intravitreal bevacizumab-through pars

plana

Iridocorneal endothelial syndrome

Fundamental defect is in the corneal endothelium, that forms a membrane over the anterior surface of the iris and the angle structures.

this membrane on contracting , distorts the iris and closes the angle

Clinical presentation Clinical entities – 1) Progressive iris atrophy, 2)Chandler’s syndrome, 3)Cogan-Reese syndrome

Iridocorneal endothelial syndrome

early to mid adult life,White> BlacksWomen> MenThe patients usually notice change in iris or

pupil, disturbance in their vision, or mild ocular discomfort.

Few familial cases, mostly medical and family hostories unrevealing

05/03/23

Progressive (essential) iris atrophy - corectopia and ectopion uvea(The synechiae lift the iris off the surface of the lens

The iris dissolution begins as a patchy disappearance of the stroma and progresses to full-thickness holes

‘stretch holes’- in quadrants away from pupillary displacement due to traction

‘melt holes’- without correctopia and ischaemic in nature

Early essential iris atrophy

Advanced essential iris atrophy with polycoria.

Chandler’s syndrome

Chandler’s syndrome is the most common variant of the ICE - Marked corneal changes - Corectopia is minimal or absent.The endothelium has a hammered silver appearance.In contrast to the marked corneal changes, the iris

involvement is generallymild and limited to superficial stromal dissolution - Peripheral anterior synechiae form, but they are not as diffuse and do not extend as far anteriorly as in progressive iris atrophy. For this reason glaucoma is often mild

The Cogan-Reese, or iris nevus, syndrome

Occurrence of pigmented lesions of the irisPedunculated iris nodulesdiffuse pigmented lesionsSome eyes have both

05/03/23

treatmentHypertonic solutions or soft contact lenses- If corneal edema produces pain or reduced

vision if IOP is reduced eventually require - penetrating keratoplasty Goniotomy Filtering surgery or glaucoma drainage

devices are often required to control glaucoma

Posterior polymorphous dystrophyGlaucoma occurs in 10–15% of patients -presents with corneal edema, iris atrophy,

mild corectopia, and iridocorneal adhesions -maintain good vision throughout lives -cluster or linear arrangement of vesicles in the posterior cornea surrounded by a gray

haze

treatmentMost cases of posterior polymorphous

dystrophy require no treatment.Eyes with glaucoma are treated with

medication and then filtering surgery as necessary

Epithelial downgrowthEpithelial downgrowth (also called epithelial

ingrowth) occurs when an epithelial membrane enters an eye through a wound and then proliferates over the corneal endothelium, trabecular meshwork,anterior iris surface, and vitreous face

Cataract surgery is the most common cause of epithelial downgrowth.

also been reported after penetrating keratoplasty, glaucoma surgery,

penetrating trauma, and unsuccessful removal of

epithelial cysts of the anterior segment

presentation. evidence of current or past wound leak and

are hypotonic if the fistula is still functional. - a grayish white membrane with a

scalloped, thickened leading edge on the posterosuperior corneal surface. The cornea overlying the membrane may be edematous, and the iris may be drawn up to the old wound or incision.

diagnosisClinically on examinationInvolvement of the iris is dramatically

demonstrated when it is treated with large, low-energy argon laser burns (200–500 m, 100–400 mW, 0.1 second), which turn

the epithelial membrane white. (Normal iris does not respond this way.)Aqueous humor can be aspirated, passed

through a Millipore filter, and then examined to identify epithelial cells

treatmentThe treatment of epithelial downgrowth is

often difficult and unrewarding.The corneal portion of the membrane can

then be destroyed with cryotherapy or chemical cauterization.

The affected iris can be excised, and cryotherapy can be applied to any remaining membrane on the ciliary body and retina

alternative approach is to do an en-bloc excision of all involved tissues.

Fibrovascular ingrowthFibrovascular tissue can grow into an eye if there is

an open wound after penetrating trauma or surgery occurs more frequently if the trauma or surgery is

associated with hemorrhage, inflammation, or incarcerated

tissueFibrovascular ingrowth usually causes glaucoma

when the membrane covers the angle and then contracts to form peripheral anterior synechiae

Other factors contributing to the glaucoma include uveitis or pupillary block.

treatment Medical therapy. In some cases posterior glaucoma

drainage device implantation or

cyclophotocoagulation

Flat anterior chamber

A flat anterior chamber after penetrating trauma or surgery can lead to the formation of PAS and secondary angle-closure glaucoma without pupillary block

In most of the studies secondary angle-closure glaucoma was common if the anterior chamber was flat for 5 days or longer

TREATMENTFollowing re-formation of a flat anterior

chamber, the residual secondary angle-closure glaucoma is treated with standard medical therapy.

05/03/23

Malignant Glaucoma

ChoroidalDetachment

Pupillary Block

SuprachoroidalHemorrhage

Wound Leak

Central anteriorchamber

Flat or shallow

Shallow May be normal

Flat or shallow

Flat or shallow

Intraocular pressure

Normal or elevated

Low Normal or elevated

Normal or elevated

Low

Fundus appearance

Usually normal

Large, smooth,brown mass

Usually normal

Dark brown or darkred elevation

Choroidals may bepresent

Suprachoroidal fluid

Absent Present Absent Present Absent

Relief by drainage ofsuprachoroidal fluid

No Yes No Yes No

05/03/23

Malignant Glaucoma

ChoroidalDetachment

Pupillary Block

SuprachoroidalHemorrhage

Wound Leak

Relief by iridectomy

No Yes No Yes No

Patent iridectomy

Yes Yes No Yes Yes

Onset Usually within days,but may be months

Usually withinfirst week

Anytime Immediately or withinfirst few days

Usually within first fewdays but may be late withadjunctive antimetabolites

Seidel test

Negative Negative Negative Negative Positive

Iridoschisisusually bilateral and tends to involve the

lower iris quadrantsGlaucoma occurs in about 50% of the

patients and is usually related to the development of PAS in the region of the iris strands.

Elevated IOP and iridoschisis are usually managed by medical therapy.

A laser iridotomy should be performed( If pupillary block)

INFLAMMATIONInflammation can produce glaucoma through a

variety of mechanisms, Including increased viscosity of the aqueous

humor, Obstruction of the trabecular meshwork by

inflammatory cells and debris, Scarring of the outflow channels ,Elevated episcleral venous pressure,Forward displacement of the lens–iris

diaphragm,Pupillary block from posterior synechiae

PATHOGENESIS 1)Peripheral anterior synechiae

2)Posterior synechiae

3)Forward rotation of ciliary body

Management

Pupillary dilatation- (i) gives comfort and rest to the eye by

relieving spasm of iris sphincter and ciliary muscle,

(ii) prevents the formation of synechia and may break the already formed synechia,

(iii) reduces exudation by decreasing hyperaemia and vascular permeability and

(iv) increases the blood supply to anterior uvea by relieving pressure on the anterior ciliary arteries

CorticosteroidsImmunosuppresive theraphy-Antiglaucoma medical theraphy Surgical theraphy 1)Iridotomy 2)Argon laser trabeculoplasty 3)Filtration surgery4)Antifibrotic filtration surgery5)Cyclodestructive surgery

Posterior pushing (or rotational) mechanism

The peripheral iris is displaced forward by the lens, vitreous, or ciliary body The posterior pushing mechanism is often accompanied by swelling and anterior rotation of the ciliary body, which further acts to close the angle.

the role of the ciliary body in ‘pushing’ forms of secondary angle-closure glaucoma1) When the anterior uveal tract swells from

inflammation or vascular congestion, the ciliary ring is narrowed, which reduces tension on the zonules, permits the lens

to come forward, and displaces the

peripheral iris.

2) When the ciliary body swells, it also rotates forward about its attachment to the scleral spur, which again loosens the Zonules and displaces the root of the iris

3) Ciliary body swelling is often accompanied by the

acumulation of suprachoroidal and supraciliary

fluid, which further rotates the ciliary body and

iris root into the angle

Ciliary block glaucoma

(aqueous misdirection, hyaloid block glaucomaand posterior aqueous entrapment)-commonly complication of a filtering procedure in eyes with pre-existing angle-closure glaucoma or shallow anterior chambers(2–4% of patients )- ‘Triggers’ laser iridotomy, miotic usage, infectious endophthalmitis, retinal conditions, hyperplastic ciliary processes

OCULAR MANIFESTATIONS - Red, painful eye is most commonly seen

after surgery for acute angle-closure glaucoma.

-The condition usually occurs immediately after surgery but may occur during surgery or months to years later;

-Its development often corresponds to the cessation of cycloplegic therapy or the institution of miotic drops

-The key is that the IOP is elevated and the anterior chamber is axially shallow without

iris Bombe.-A high index of suspicion is necessary to

make the appropriate diagnosis, since initially

the IOP may not be elevated much.

DIAGNOSIS Patent iridectomy must be established (to

rule out pupillary block)High-resolution ultrasound biomicroscopy It reveals anterior rotation of the ciliary

body against the peripheral iris and forward displacement of the posterior chamber intraocular lens, as well as a shallow central anterior chamber, all of which are reversible

DIFFERENTIAL DIAGNOSIS1) Pupillary block-patent iridectomy will rule

out

2) Suprachoroidal hemorrage - USG or Ophthalmoscopy reveal the presence of

single or multiple elevations of choroid

3)Serous choroidal effusion

treatmentTo move the lens-iris diaphragm back

and relax the ciliary muscle-Mydriatics and CycloplegicsTo decrease aqueous production-Topical β-blockers, oral or topical carbonic

anhydrase inhibitors, and α-agonists

FELLOW EYEIf a narrow angle is present in the

fellow eye, a laser peripheral iridectomy is performed

before any other surgical procedures

Nd:YAG) laser may be used in aphakic and pseudophakic patients

Pars plana vitrectomy When medical or laser therapy fails, or in

phakic eyes for which laser treatment is not a good option,

Intraocular tumors

Ocular malignant melanoma is frequently associated with glaucoma

Mechanisms, 1) Direct extension into the trabecular

meshwork 2) Seeding of tumor cells into the outflow channels 3)Obstruction of the meshwork by pigment or pigment-laden macrophages, 4)Neovascularization, 5)PAS,iridocyclitis, and hyphema

IRIS MELANOMA INVADING ANGLE

LEIOMYOMA

Nanophthalmos Refers to an eye that is normal in shapebut small in size. Ratio of the volume of the lens to the volume of the eye is 10–25% instead

of the normal 3–4%.

FACTORS IN DEVLOPMENT OF GLAUCOMA IN NANOPHTHALMOS1) Little anatomic reserve

2) Development of a choroidal effusion.(as thick

sclera obstructing flow through the vortex veins)

Frequently develop angle-closure glaucoma in

the fourth to sixth decades of life.

managementLaser iridotomy-if narrowing of angle

presentLaser gonioplasty-if angle not does not

deepen on laser iridotomyAntiglaucoma theraphyUnroofing of at least two vortex veins to

relieve venous obstruction

POSTERIOR SCLERITIS Posterior scleritis causes Choroidal effusion, Swelling, and anterior rotation of the ciliary body, as well as secondary

angle- closure glaucoma without pupillary block. Management-Antiglaucoma theraphy to control IOPSystemic NSAIDSTopical and systemic corticosteroids

Central retinal vein occlusion It interferes with the venous drainage of

the uveal tract, causing swelling and anterior rotation of the ciliary body.

It also causes transudation of fluid into the choroid, retina, and vitreous. The fluid acts

like an acutely developing posterior mass that Displaces the lens–iris diaphragm causing glaucoma

Management Antiglaucoma theraphyLaser iridotomy if pupillary block presentLaser gonioplastyIf ischemia is present –retinal ablation

should be performed

Scleral buckling procedureAfter a scleral buckling procedure, it is

common for the anterior chamber to be shallow for a few days.

In 1–2% of eyes, this condition progresses to angle-closure glaucoma without pupillary

block.Most cases of postscleral buckling angle closure glaucoma can be treated medically until the

anterior chamber deepens spontaneously

Panretinal photocoagulationPhotocoagulation may break the blood–

ocular barriers and cause a transudation of fluid into the retina, choroid, and vitreous

Most individuals with angle closure after PRP

are asymptomatic,although an occasional patient complains of ocular discomfort or

headacheMost cases managed medically

Retinopathy of prematurity Mechanisms include Neovascularization, Pupillary block, andPushing forward of the lens–iris diaphragm

POSTERIOR PUSHING MECHANISM WITH PUPILLARY BLOCK-dislocated lens

Microspherophakia-Pupillary block and glaucoma occur

through one of two mechanisms: either the lens dislocates into the pupil and anterior chamber or long zonules allow the lens to come into pupil.

Bibliography

05/03/23

# Becker-Shaffer's Diagnosis and Therapy of the Glaucomas; 8th Ed.

# Shields Textbook of Glaucoma; 2nd Ed.# American Academy of Ophthalmology BCSC. Section 10; 2011-2012

# Parson's Diseases of the Eye; 21st Ed.# Comprehensive Ophthalmology by A K Khurana; 4th Ed.

05/03/23

Health & Medicine

Angle closure glaucoma