common cases: lens and glaucoma
TRANSCRIPT
Dr. Riyad BanayotDr. Riyad Banayot
Hypermature cataract. Note the wrinkling of the anterior capsule, the lens has liquefied and leaks out of the capsule.
A morgagnian cataract. The cortex has turned into milky liquid and the nucleus is displaced inferiorly.
A rosette cataract. This is seen in blunt trauma. Look for other signs in the posterior segment such as choroidal tear or RD
A lamellar cataract. There are opacities at various levels of the fetal nucleus. It is the most common type of congenital cataract.
A posterior subcapsular cataract. Causes include: steroid use, DM, chronic uveitis, RP, atopic dermatitis.
A droplet cataract seen in a patient with galactosaemia.
In a young patientWith bilateral cataract. Look for:
Atopic dermatitis (examine the face) Diabetic mellitus (examine fundus for DR) Retinitis pigmentosa (examine fundi for
pigmentary changes) Myotonic dystrophy (note the typical facies of
frontal balding, bilateral ptosis and delayed muscle relaxation)
With unilateral cataract. Look for: Fuch's heterochromic uveitis Trauma Chronic uveitis Retinal detachment
There is a significant shift in the fluid content of the normal lens probably related to the accumulation of sorbitol inside the diabetic lens.
The result is: Myopia or Rapid formation of subcapsular granular
cataract also called the snowstorm cataract.
Nuclear sclerotic cataract. The increased density of the nucleus
increases the refractive index, and as a result the patient develop myopia.
As a result, patients who previously needed plus lenses for reading, find that they can now read without glasses.
Phacomorphic glaucoma: Cataract can increase the lens size causing shallowing of the anterior chamber and angle closure
Phacolytic glaucoma: Lens protein leaks form the lens and elicits a macrophagic response. The inflammatory material blocks the flow of aqueous through the trabecular meshwork
Phacoantigenic uveitis: This is caused by lens protein released through a ruptured lens capsule causing a granulomatous inflammation
A posterior chamber lens showing YAG capsulotomy
An anterior chamber lens in an eye with complicated cataract operation showing hazy cornea. This is pseudophakic bullous keratopathy
An iris clip lens (Binkhorst lens). This lens is not longer favored due to the risk of iritis, lens dislodgement and corneal decompensation
Capsulorrhexis provides a stronger edge and allows phacoemulsification to be carried out safely.
The implant can be held more securely and gives a better centration.
Ideally, if the lens were to be placed in the sulcus, the power of the lens (with the same A constant) is reduced by 1/2 D from that calculated pre-operatively.
In this case, the focal point is moved anteriorly, and the patient becomes myopic.
Cystoid macular edema = Irvine-Gass syndrome. Typically seen 4-8 weeks following the cataract
extraction. More common after
intracapsular than extracapsular cataract extraction. vitreous loss presence of iris or vitreous incarceration.
Treatment is controversial and the great majority improves without treatment.
Treatment options include: Topical steroid or non-steroidal anti-inflammatory medications. Acetazolamide is often given and is believed to reduce the macular
edema. Predisposing factors:
Iris or vitreous incarceration Freeing the iris and vitrectomy can improve the edema.
• There is a circular imprint of pigment on the anterior capsule from the iris.
• This may result from previous posterior synechiae or trauma (Vossiu's ring).
• It is of no visual significance.
• Rosette cataract.• This is typical of
traumatic cataract resulting from blunt injury.
• The cataract begins in the subcapsular region and with time become buried in the cortex.
• Vision is usually reduced.
• There is a star shaped opacity in the anterior subcapsular area.
• This is seen in patient on chlorpromazine for more than 2 years.
• Vision may be normal as this type of cataract seldom causes significant visual impairment.
An aphakic eye with broad iridectomy and peripheral iridectomy.
An aphakic eye with corneal edema as a result of vitreous touch.
The patient may be wearing thick lenses or contact lenses.
In intracapsular cataract extraction, there is usually iridectomy and the presence of vitreous in the anterior chamber (examine the cornea for any decompensation due to vitreous touch).
Some patients may have extracapsular cataract extraction without implant (for example in clear lens extraction for high myopia).
In young children with aphakia, consider: Lens dislocation such as Marfan's syndrome Cataract extraction in juvenile chronic arthritis, look for
cells and flare in the anterior chamber and band keratopathy.
Direct ophthalmoscopy on a high myopic patient with aphakia requires relatively low minus (concave) power on the ophthalmoscope.
Image magnification Spherical aberration A “jack-in-the-box” ring
scotoma Reduced visual field Physical
inconvenience Cosmetic appearance
30% Pin cushion effect Prismatic effect
Weight of glasses Eyes appear large
An phakic eye which is myopic with an axial length of 31mm is equal to -21D.
Clear lens extraction can fully correct a myopic eye measuring -21D.
A subluxated lens in the superior nasal direction. (Marfan's syndrome)
Arachnodactyly (long fingers) in a Marfan's patient
High arch palate in a Marfan's patient
If the eye is not dilated: Iridodonesis (abnormal tremor of the iris) Phacodonesis (abnormal movement of the lens) Deep AC depth or vitreous herniation into AC.
Signs of Marfan's syndrome Superior nasal subluxation of the lens; Arachnodactyly;
High arch palate; Arm span longer than height In homocystinuria:
Downward subluxation of lens; Same features as Marfan's syndrome; Patient tends to be mentally subnormal and may have fair hair.
In Weill-Marchesani's syndrome: Mental retardation; short stature; stubby fingers
look for pseudoexfoliation syndrome look for signs of trauma which is the most
common cause of subluxated lens.
Trauma Hypermature cataract Anirida High myopia Congenital glaucoma Ehler-Danlo's syndrome Hyperlysinaemia
Optical problems including: Astigmatism Monocular diplopia
Uveitis Pupillary block glaucoma
Marfan’s syndrome Homocystinuria
Cardiac arrhythmia Arterial thrombosis Spontaneous pneumothorax
This is pseudoexfoliation syndrome.Pupil dilatation is poor and there is risk of zonular dialysis.
The patient has hyper-extensibility of the joint. This is a sign of Ehler-Danlos's syndrome. The patient is at risk of lens subluxation.
This patient has physical signs of ankylosing spondylitis (stiff back and kyphosis).
The problems encountered will include: - Posturing of the patient during operation - Poorly dilated pupil due to anterior synechiae
Right Eye K1 = 42.75 K2 = 42.50 AL = 21.75 mmRefraction= - 8.25 DVA = 6/24
Left EYEK1 = 42.25K2 = 42.50AL = 22.00 mmRefraction= - 7.55 DVA = 6/24
• This patient's biometry shows average keratometry readings and axial lengths but high minus refraction.
• These changes are seen in patients with significant nuclear sclerosis. The lenses are likely to be large and hard.
• A large lens will give a shallow anterior chamber making capsulorrhexis difficult for the inexperienced surgeon.
• A hard nucleus increases the phaco time and in the hand of inexperienced surgeon complications such as corneal edema is increased.
lens
Cystic bleb indicating a functioning trabeculectomy
Adrenochrome pigments on the lower lid tarsal conjunctiva seen with topical adrenaline use
Physical signs of the treatment the patient is receiving
Physical signs for possible causes (e.g. PDS, PXF)
Physical signs indicating the severity of the condition
Surgery (Traby, tube, iridectomy) Poor drainage is suggested by an absence of
bleb or a dome-shaped vascularized bleb caused by subconjunctival fibrosis
Constricted pupil (Pilocarpine) Heterochromia iridis (Latanoprost) Adrenochrome (adrenaline)
Most common cases of 2ry OAG with anterior physical signs are:
Pigment dispersion syndromePseudoexfoliation syndromeIridocorneal endothelial (ICE) syndromeFuch's heterochromic cyclitis.
Advantages:Reduced post-operative leakageLess trauma to the cornea
Disadvantages:Smaller blebPoorer scleral exposureHigher chance of button holes
Advantages:Better exposure of limbusMore diffuse bleb due to the lack of a posterior scar line to limit the extension of the blebEasier technique & less timeDisadvantages:Frequent wound leaksRisk of corneal trauma
Low IOPLow IOPWound leakage
Patching. Re-suturing is needed if
leakage fails to stop after 24-48 hours
Excessive drainage No leakage Patching may be useful.
Choroidal effusion Persistent marked
shallowing of AC with hypotony
If it persists for 10-14 days post-op, surgical drainage is needed plus AC reformation.
High IOPHigh IOPAngle closure glaucoma
Non-patent iridectomy YAG iridotomy is needed.
Aqueous misdirection Patent iridectomy Most cases respond to
medical Rx (cycloplegic, B-blockers and systemic Acetazolamide.
failure to Med Rx: Nd:YAG laser to disrupt the posterior or anterior hyaloid if the eye is phakic or aphakic.
Alternatively, par plana vitrectomy is useful.
In phakic eye, pars plana vitrectomy and lensectomy
Age of patient: young more than old Race of patient: black more than other
races Type of glaucoma: traumatic, uveitic &
neovascular are more likely to fail Previous failed surgery Use of certain topical medication such as
topical adrenaline
• The iris and the lens show dandruff-like flakes.
• The flakes on the lens are arranged in a bull-eye fashion with an intermediate clear zone.
• The corneal endothelium shows pigment deposition.
• Retroillumination shows peripupillary iris transillumination.
• Look for:• Traby, OD cupping,
phacodenesis, lens sublaxation
Pseudoexfoliation syndrome
The exact source is unknown. It may be produced by the epithelium of the
lens and other tissues because the material is not confined to the eyes.
The condition is thought to be a generalized disorder of the basement membrane.
Bio-chemically, the material is made up of proteoglycan materials and has features of basement membrane.
Cataract operation does not stop its production.
About 60% of patients with pseudoexfoliation syndrome develop secondary open angle glaucoma.
Compared with primary open angle glaucoma, this type is less responsive to medical therapy.
Argon laser trabeculoplasty is useful initially to control the pressure but this is eventually lost (sometimes abruptly).
Trabeculectomy is useful and has the same success rate as POAG.
Sampaolesis' lineA line of pigment deposition anterior to Schwalbe's line
Poor pupillary dilatation. Weak zonules predisposes to zonular
dehiscence. This risk is increased with vigorous hydrodissection or excessive nucleus manipulation during Phacoemulsification.
Increased risk of posterior capsular rupture.
GlaucofleckenOpacities behind anterior lens capsule resulting from anterior epithelium necrosis
Laser peripheral iridotomy usually situated peripherally & superiorly
Surgical iridectomy Eye with previous acute glaucoma (irregular pupil)
The AC is usually shallow but may be normal in pseudophakia. The lens contains white opacities anteriorly. The iris may show atrophy from ischemic changes with irregular pupil which may react poorly to light.Peripheral iridotomy is usually present. Assess patency.
Not all cases of acute glaucoma are treated with laser iridotomies.
You may have patients who had had surgical iridectomies. With a casual examination, this may be mistaken for trabeculectomy without a functioning bleb. The clue to this is the absence of a scleral flap, glaucoflecken and iris changes
Examine the opposite eye for prophylactic treatment whether laser or surgical.
Primary angle closure glaucoma: The mechanism is due to pupillary block. The AC is shallow both centrally and peripherally.
Plateau iris syndrome: The main mechanism is caused by occlusion of the
trabecular meshwork by the anteriorly positioned peripheral iris.
Patients are younger (fourth or fifth decade of life). The AC is deep centrally. Patients with plateau iris syndrome may not respond to
laser iridotomy like primary angle closure glaucoma. Laser peripheral iridoplasty or miotic therapy may be
needed.
Shallow anterior chamber Hypermetropia Small corneal diameter Short axial length of globe Large crystalline lens
Patients with narrow angle may develop AACG when the pupil is dilated due to pupillary block.
Provocative tests may be used to identify the latent cases; the result is positive if there is 8 mmHg pressure rise in the first hour.
The provocative test may be: Physiological: for example the dark room test
in which the pressure of the test is checked when the pupil becomes dilated in the dark or
Pharmacological with 10% phenylephrine (which is reversible with thymoxamine)
Radial transillumination of the iris in the midperiphery region. This is seen with retroillumination. Each area represents area devoid of pigment epithelium
Krukenberg's spindle with diffuse illumination
Krukenberg's spindle with retroillumination
The corneal endothelium contains vertically orientated deposition of pigments (Krukenberg's spindle). The pigment may also be seen on the iris, lens and the trabecular meshwork
Pigment in the trabecular meshwork by performing gonioscopy
Any peripheral iridoctomies which may be performed in an attempt to reduce the production of pigment
look at the patient's glasses, most of this patients has myopia
Examine the optic disc for cupping
What percentage of patients with PDS develop glaucoma ? 30%30%
Patients with PDS typically shows wide fluctuation of the intraocular pressures.
The pressure may be normal in the clinic but can rise quickly following exercise or pupillary dilatation in the dark.
The iris is bowed posteriorly, causing it to rub against the lens zonules.
This results in the loss of the pigment epithelium resulting in transillumination and the endothelium deposition of pigment.
The vertical orientation of the pigment is due to conventional current.
It equalizes the pressures between the posterior and anterior chamber and therefore corrects the posterior bowing of the iris.
This reduces the rubbing and thus decreased pigment loss.
A tube which enters the anterior chamber through the limbus region. This is a seton used for glaucoma operation. Molteno's tube is the most commonly used
Previous trabeculectomy Presence of signs indicating the
underlying condition: Rubeosis iridis ICE syndrome
It is used for refractory glaucoma Neovascular glaucoma Previous multiple failed filtration procedures Conjunctival scarring from previous failed
filtration (making the development of a filtration bleb impossible)
Childhood glaucoma in which primary procedures have failed
All setons contain a tube and a plate. The tube is inserted into the anterior
chamber to drain the aqueous and is made up of either silicone or silastic.
The plate forms the reservoir for the drained aqueous and is made up of plastic or silicone.
The main difference between different setons is in the design of plates.
Excessive drainage leading to hypotony. Modification through valve insertion has
been made to the tube and plate to make the seton pressure-dependent.
There is iris atrophy with corectopia and polycoria Iridocorneal endothelial syndrome (ICE)
The eye may have previous glaucoma operation
The cornea may show signs of decompensation with corneal edema.
The endothelium shows guttate-like changes
A tube in the anterior chamber Signs of glaucoma in posterior segment
The main abnormality is in the corneal endothelium appears like the epithelium.
The endothelium becomes several layer thick and spreading over the TM and iris causing: Glaucoma Iris distortion
The cause is unknown.
Essential iris atrophy: There is progressive angle closure by: peripheral anterior synechiae Corectopia, polycoria and iris atrophy. T he changes are the results of pulling by the
endothelium. Iris naevus syndrome (Cogan-Reese):
Angle changes are as above Diffuse naevus covering the anterior iris. Iris nodules may or may not be present. The
nodules are the results of iris stroma protruding through the abnormal endothelium growing over the iris.
Chandler's syndrome falls between the above two entities.
The iris contains irregularly arranged blood vessels
Seton tube in the anterior chamber which may be used to treat this condition
Examine the posterior segment; Central retinal vein occlusion Diabetic retinopathy
This is neovascular glaucoma secondary to ischaemic central retinal vein occlusion.
Most common causes: Central retinal vein occlusion Diabetic retinopathy
Retinal artery occlusion Chronic retinal detachment Sickle cell retinopathy Radiation retinopathy Carotid artery occlusive disease Chronic uveitis
Small keratic precipitates scattered throughout the corneal endothelium (stellate keratic precipitates). Fuch's heterochromic cyclitis
The iris may show: Hhypochromia (best seen in the day light) Iris transillumination due to iris atrophy There may be irregular fine vessels on the iris
The patient may have posterior subcaspular cataract
The anterior chamber may have flare or cells The conjunctiva is white NO Posterior synechiae
The iris may contain abnormal iris vessels Check for the presence of trabeculectomy
Uveitis: This tends to be chronic and not responsive to steroid. Steroid may increase the risk of glaucoma and
cataract Glaucoma:
May respond initially to medical treatment Trabeculectomy is usually needed.
Bleb failure is common. Antimetabolites is recommended
Cataract: Extraction and heparin surface-modified IOL is usually
successful.
Pre-operatively: the pupil may not dilate well due to iris
atrophy Peri-operatively
Hyphema from the abnormal iris vessels is common (Amsler's sign)
The abnormal eye may be:
Hypochromic: Idiopathic Congenital Horner's syndrome Chronic uveitis Post-cataract operation Pigment dispersion syndrome Waardenburg's syndrome Post-herpes zoster iritis
Hyperchromic: Melanosis Iris naevus syndrome Rubeosis iridis Siderosis