Iris/Lens Flashcards
Iris colobomas are located?
Inferior nasally
True or false
Iris colobomas are only bilateral
False
They can be unilateral or bilateral
What is an ICL?
Implantable collamer lens
* corrective lens implanted behind the iris and in front of the lens without removal of crystalline lens
What is an RLE?
Refractive lens exchange
* removal of clear crystalline lens and replaced with corrective posterior chamber intraocular lens implant
Conductive keratoplasty is suited for what refractive error?
Low hyperopes (less than 3 D with 0.75 D astigmatism or less)
* surgery steepens cornea
Remnant of hyaloid system previously attached to lens
Mittendorf dot
* benign
* located on posterior aspect of crystalline lens
Should a patient with a subluxated lens be dilated?
NO!!!
* may cause lens to be dislocated into anterior chamber which can block TM leading to development of glaucoma
Why can’t a patient with plateau iris be dilated?
Dilation can cause iris root to block TM leading to angle closure
Peter’s anomaly
White opacity caused by central defect in descemet’s membrane and posterior corneal stroma
Failure of lens to completely detach from surface epithelium during 4-7 wks gestation.
* central corneal opacity
No Tx
Treat if IOP high
What are the three types of zonular cataracts?
- Nuclear
- Lamellar
- Capsular
Which zonular cataract involves only fetal or embryonic nucleus and varies densities?
Nuclear
Which zonular cataract is confined to area between nucleus and cortex?
Lamellar
Which zonular cataract affects either the posterior or anterior capsule?
Capsular
“Blue dot” cataract
Cerulean cataract
* lenticular periphery
* congenital cataract, doesn’t affect VA
Sutural cataract
Located within Y sutures and tends to be genetic
* bilateral and does not interfere with vision
What is the primary treatment for iritis?
A cycloplegic agent to prevent or promote breakdown of synechia
Synechia refers to adhesions that can form between the iris and other structures of the eye.
How does a cycloplegic agent aid in pain management for iritis?
By controlling pupil size and avoiding unnecessary movement of the iris muscles
Movement of the iris can be painful for patients with iritis.
What type of eyewear is helpful for managing associated photophobia in iritis?
Tinted lenses
Photophobia is light sensitivity that can occur with iritis.
What should be prescribed to reduce the inflammatory response in iritis?
A potent topical steroid
Topical steroids are used to control inflammation in various ocular conditions.
What is crucial to do after signs of iritis have resolved when using topical steroids?
Slowly taper the use of the steroid
Tapering is important to prevent rebound inflammation, which can occur if steroids are stopped abruptly.
When is it necessary to treat iritis with a topical antibiotic?
Only if there is a risk of infection due to a compromised cornea
Topical antibiotics are not routinely used in iritis unless there are specific infection concerns.
Initial tx for anterior uveitis
Homatropine BID and Pred-Forte (brand name) q1h
* cycloplegic to prevent formation of synechia and control pupil size helps with light sensitivity
* potent topical steroid to reduce inflammatory response (slow taper once signs resolved to reduce risk of rebound inflammation)
What is iritis also known as?
Anterior uveitis
What symptoms do patients with iritis typically report?
- Photophobia
- Lacrimation
- Pain
- Decreased visual acuity
What causes iritis?
Inflammation of the iris or both the iris and the anterior portion of the ciliary body (iridocyclitis)
What are keratic precipitates?
Deposits on the corneal endothelium that vary in size and distribution depending upon the etiology of the iritis
What clinical signs may indicate iritis?
- Cells and flare
- Sluggish and slightly constricted pupils
- Irregular pupil margins
- Iris nodules (in granulomatous inflammation)
What is the difference in cell count between the anterior chamber and the vitreous chamber in iritis?
The number of cells in the anterior chamber should exceed the number observed in the vitreous cavity
What are the two categories of endogenous anterior uveitis?
- Granulomatous
- Nongranulomatous
What are the clinical features of granulomatous anterior uveitis?
- Insidious onset (occurs gradually)
- Minimal pain
- Mild aqueous flare
- Minimal cells in the anterior chamber
- Large mutton-fat keratic precipitates
- Iris nodules
Granulomatous uveitis systemic diseases: sarcoidosis, TB, herpes zoster
What are the typical features of non-granulomatous anterior uveitis?
- Acute onset
- Moderate amount of pain
- Marked injection of the conjunctiva
- Heavy cells and flare
- Small keratic precipitates
- Absence of iris nodules
What is posterior uveitis associated with?
Inflammation of the choroid and retina posterior to the base of the vitreous
What symptoms may patients with posterior uveitis report?
- Recent onset of floaters
- Blurred vision due to choroiditis of the macular region
What VF defect can choroiditis of the macular region cause?
central scotoma
In posterior uveitis, how do the number of vitreous cells compare to those in the anterior chamber?
The vitreous cells will outnumber those observed in the anterior chamber
Which ocular surgeries increase risk of developing neovascular glaucoma in an eye with iris neovascularization?
Cataract surgery
Vitrectomy
* cause inflammation which can stimulate neovascularization
Plateau Iris configuration
Normal central anterior chamber depth with abnormally anterior placed ciliary processes
What is the pars plicata?
Portion of ciliary body that produces aqueous humor
First line treatment for plateau iris?
LPI (laser peripheral iridotomy)
* to counteract possibility of pupillary block
* if LPI doesn’t keep angle open next step is argon laser peripheral iridoplasty
What are the common s/s of oculocutaneous albinism?
Symptoms:
- nystagmus
- reduced vision
Signs:
- transillumination defects
- blonde fundus
- foveal hypoplasia
What is the most likely explanation for reduced best corrected visual acuity in oculocutaneous albinism?
Foveal hypoplasia (under developed tissue)
* lack of foveal pit formation
* leads to reduced VA, nystagmus and poor fine-detail vision (affects reading, recognizing faces)
Rubeosis iridis
Neovascularization of the iris
Megalopapilla
* enlarged optic disc not associated with any other morphological anomalies
Tx for anterior uveitis
Topical pred acetate 1% q1h and cyclopentolate 1% BID
* slow taper steroid depending on severity and response to treatment
Pt with anterior uveitis tx with topical steroid comes back for follow up and his IOP increased significantly, inflammation has not resolved, what’s the best tx for lowering IOP?
Add Alphagan 1 gtts BID
* do NOT stop steroids, steroids need to be tapered
32 WM
Familial drusen
* autosomal dominant
* harmless, small drusen, located in macular region
* VA rarely affected
Tx with amsler grid vigilance and advise pt to RTC ASAP if any changes
Christmas tree cataract caused by?
Myotonic dystrophy
*muscle tissue replaced by fibrous and adipose tissue
* genetic disorder, autosomal dominant
Rosette cataract caused by?
Trauma
* blunt ocular trauma
* develop months to years after trauma occurs
Snowflake cataract caused by?
Diabetes
* rapid onset
*caused by elevated levels of intra-ocular glucose and lenticular sorbitol causing oxidative stress
Sampaolesi line
Pigment build up on schwalbe’s line during gonioscopy
*highly indicative of pigment dispersion syndrome
Vossius ring
Secondary to ocular trauma
* posterior surface of iris rubs against anterior portion of lens causing a ring of pigment
* no treatment
*considered a cataract
Blue dot (cerulean) opacities
Congenital cataracts
*autosomal dominant
What measurements are needed to determine intraocular lens power for CE?
Axial length (A) and corneal curvature (K)
* A’s and K’s
* 0.3 mm error in axial length = 1D error
Anterior or posterior polar congenital cataracts can grow large and decrease vision?
Posterior polar congenital cataract
Elsching pearls
Transparent clusters of proliferating lens cells
Dislocated lens is up and out, caused by what?
Marfan’s syndrome
* autosomal dominant
* connective tissue disorder, defective zonules, cause bilateral lens dislocation up and out
Homoystinuria lens displacement is where?
Down and in
* enzymatic disorder, increased levels of homocysteine in body, 90% pts will have dislocated lens by their 30’s
What is UGH syndrome?
A condition occurring when a one-piece IOL is accidentally placed in the sulcus, causing the IOL haptic to rub on the underside of the iris during pupil movements.
IOL stands for intraocular lens.
What are the symptoms of UGH syndrome?
Symptoms include:
* Reduced vision
* Pain
* Photophobia
* Reduced visual fields in late stages
Photophobia refers to sensitivity to light.
What signs are associated with UGH syndrome?
Signs include:
* Uveitis (anterior chamber cells and flare)
* Glaucoma (increased IOP, ONH cupping, RNFL loss)
* Hyphema (blood in the anterior chamber)
IOP stands for intraocular pressure, ONH stands for optic nerve head, and RNFL stands for retinal nerve fiber layer.
How should UGH syndrome be treated?
Treatment includes:
* Immobilization of the iris with a topical cycloplegic (Atropine)
* Reduction of inflammation with a topical steroid
* Decreasing IOP
* Surgery may be necessary to remove or reposition the IOL
Atropine is a medication used to dilate the pupil and immobilize the iris.
What occurs when the corneal endothelium deteriorates across the anterior segment?
Contraction of the iris and secondary angle closure glaucoma
This condition most frequently occurs in women.
What are the initial symptoms of the condition described?
Patients will be asymptomatic
Symptoms may develop as iris changes occur in later stages.
What symptoms may patients complain of in later stages?
Blur and monocular diplopia
What are the signs presented by patients?
Deep anterior chamber, ‘beaten bronze’ appearance of the corneal endothelium, corneal edema, peripheral anterior synechiae
Corneal edema is due to endothelial defects.
What is the prognosis of Essential Iris Atrophy?
Worst prognosis
Characterized by severe iris thinning causing holes and a distorted/displaced pupil (corectopia).
What characterizes Chandler Syndrome?
Mild iris thinning causing a distorted/displaced pupil (corectopia)
It has a better prognosis than Essential Iris Atrophy.
What defines Iris Nevus / Cogan-Reese Syndrome?
Pigmented iris nodules
This condition has the best prognosis among the three types of iris changes.
What treatment options are available for corneal edema?
Topical hypertonic (sodium chloride, Muro 128), severe cases may require corneal transplant
How often should patients be followed up?
Every 1-3 months
Fill in the blank: Patients may benefit from _______ treatment options.
[surgical]
Etiology of corectopia (displaced, ectopic or irregular pupil)
ICE syndromes (iridocorneal endothelial)
Chronic uveitis
Trauma
Post operative
Ectopia lentils Et pupillae (corectopia associated with lens subluxation
Iris traumas associated with hyphema
Angle recession
Cycodialysis
Iridodialysis
Sphincter tears
Management/ treatment of iridodialysis
Cosmetic contact lens or surgical repair for disabling glare or diplopia/polyopia
Treatment for sphincter tears
Cosmetic contact lens or surgical repair of dilated non reactive pupil
