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
Why is a cycloplegic agent included in treatment of iritis?
A cycloplegic agent prevents 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? (Name at least 4)
- 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?
Bonus points if you can name non-infectious and infectious causes
Inflammation of the choroid (choroiditis) and retina posterior to the base of the vitreous
Common non-infectious causes:
Sarcoidosis
Birdshot chorioretinopathy
Behcet’s disease
Presumed ocular histoplasmosis
Certain medications
Vogt-Koyanagi-Harada syndrome
Common infectious causes:
Toxoplasmosis
Syphilis
Tuberculosis
Herpes family of viruses
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?
More cells in vitreous than 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
Anteriorly positioned ciliary process body that push the peripheral iris forward
(appositional change)
*The mechanical position of the CB against the TM crowds the angle and obstructs aqueous outflow
* double hump sign on gonio
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
* can present with physiologically enlarged blind spot
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 blunt 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
Which polar congenital cataract can grow large and decrease vision? Anterior or posterior?
Posterior polar congenital cataract
Elsching pearls
Transparent clusters of proliferating lens cells
* Elschnig pearls are one of the various morphologies of regenerative posterior capsular opacification (PCO)
* cystic proliferation of residual lens epithelial cells on capsule after CE
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)
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 are the signs of ICE?
(Iridocorneal endothelial syndrome)
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
*hypertonic drop used to reduce corneal swelling
* improve vision for patients with Fuch’s
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
What is Marfan’s syndrome?
A condition caused by abnormal connective tissue affecting the heart, eyes, and skeletal system.
Marfan’s syndrome is autosomal dominantly inherited.
What ocular manifestations are associated with Marfan’s syndrome?
1) High myopia
2) lens subluxation (up and temporal)
3) iridodonesis
4) phacodonesis
5) premature cataracts
6) glaucoma
7) retinal detachments.
These manifestations result from the structural abnormalities in connective tissue.
What is lens subluxation?
A condition where the crystalline lens is displaced from its normal position.
In Marfan’s syndrome, lenses frequently subluxate superiorly and temporally.
True or False: In Marfan’s syndrome, accommodation can remain intact despite lens subluxation.
True.
This is because the lenses are usually still somewhat attached to the zonules.
List at least three systemic conditions associated with high potential for lens subluxation.
- Marfan’s syndrome
- Homocystinuria
- Ehlers-Danlos syndrome
- Weill-Marchesani syndrome
- Crouzon disease
- Acquired syphilis
- Aniridia
These conditions can lead to similar ocular issues as seen in Marfan’s syndrome.
What medication might patients with Marfan’s syndrome be prescribed and why?
High blood pressure medication to decrease strain on blood vessels due to increased fragility.
This is important to manage vascular complications associated with the syndrome.
Fill in the blank: Marfan’s syndrome is inherited in an _______ manner.
[autosomal dominant].
This means that only one copy of the mutated gene from an affected parent can cause the disorder.
What are iridodonesis and phacodonesis?
Iridodonesis is the tremulousness of the iris; phacodonesis is the tremulousness of the lens.
Both conditions can occur due to lens subluxation.
What is the most commonly reported complication of YAG capsulotomy?
A temporary rise in intraocular pressure
Intraocular pressure (IOP) is a critical parameter in eye health and can indicate various complications.
What are some possible explanations for the elevation in intraocular pressure after YAG capsulotomy?
- Deposition of debris in the trabecular meshwork
- Pupillary block
- Inflammatory swelling of the ciliary body or iris root
Understanding the mechanisms behind IOP elevation helps in managing and mitigating complications.
In which group of patients is the rise in intraocular pressure more pronounced after YAG capsulotomy?
Patients with glaucoma and those in which higher pulse energies are used
Higher pulse energies during the procedure can lead to increased stress on ocular structures.
What are other possible complications of YAG capsulotomy? (Name at least 4)
- Movement/displacement of the IOL
- IOL damage/pitting
- Uveitis
- Cystoid macular edema
- Retinal tear or detachment
- Pupillary block glaucoma
- Macular hole
- Retinal hemorrhage
Each of these complications can significantly impact visual outcomes and patient quality of life.
True or False: A rise in intraocular pressure is a rare complication of YAG capsulotomy.
False
It is the most commonly reported complication, highlighting the need for monitoring post-procedure.
What is a neodymium:yttrium-aluminum-garnet (Nd:YAG) capsulotomy?
A common, non-invasive, and quick procedure that creates an opening in the membrane covering the posterior aspect of an intraocular lens implant.
What is the typical setting for the Nd:YAG laser during a capsulotomy?
-1 ml/pulse (which may be increased if necessary).
Where is the laser typically focused during the Nd:YAG capsulotomy?
Central on the visual axis.
What pattern is followed to create openings during a Nd:YAG capsulotomy?
Cruciate pattern.
What is the target aperture size for the opening created in a Nd:YAG capsulotomy?
3 mm or larger.
What technique is recommended for placing shots during the Nd:YAG capsulotomy?
Shots placed along tension lines will result in the largest opening per pulse.
What is commonly prescribed to patients following a YAG capsulotomy?
Topical steroids.
How often are topical steroids typically prescribed after a YAG capsulotomy?
Three to four times daily for several days.
True or False: Nd:YAG capsulotomy is an invasive procedure.
False.
What type of cataracts may lead to slightly disrupted color vision?
Nuclear sclerotic type
This type of cataract is characterized by yellowing of the lens.
What effect does the yellowing of the lens have on color perception?
Decreases the ability to perceive shorter wavelengths (blues)
This disruption affects the patient’s overall color vision.
What happens to color perception after the removal of the crystalline lens?
Many patients report increased color perception, particularly of colors with wavelengths shorter than 500 nm
This resurgence of blue perception can last several weeks to months.
How long does the increased perception of blue typically last after cataract surgery?
Several weeks to months
After this period, color vision normalizes or returns to near-normal levels.
What visual functions typically increase after phacoemulsification, unless there is a large degree of anisometropia?
Contrast sensitivity and stereoacuity levels
Anisometropia can affect the outcomes of these visual functions.
What symptom is generally lessened after cataract surgery?
Symptoms of glare
Patients often report an improvement in glare sensitivity post-surgery.
What type of astigmatism is typically caused by the development of cataracts?
Against-the-rule astigmatism
When assessing a patient for cataract surgery, what should be evaluated?
Corneal toricity
What effect does the lenticular against-the-rule astigmatism have on the patient’s corneal astigmatism?
It cancels out a portion of the corneal astigmatism
What happens if the astigmatism is not addressed after the crystalline lens is removed?
The patient will have a residual refractive error
What options are available for correcting residual refractive error after cataract surgery?
Glasses, LASIK, or contact lenses
What are the two options for addressing astigmatism prior to cataract surgery?
Toric intraocular lens implantation or limbal relaxing incisions (LRIs)
What is the purpose of limbal relaxing incisions (LRIs)?
To flatten the steep axis of the cornea
What is the maximum amount of astigmatism that toric IOLs can neutralize?
Up to roughly 6.00 D
What is an advantage of toric IOLs over LRIs?
Better corrective long-term stability
Is long-term pain management typically needed after phacoemulsification?
No
Are vertigo and diminished depth perception common problems after cataract extraction?
No, unless there is a large degree of resultant anisometropia
What initial appearance do cortical cataracts have?
Radial opacities or spokes around the crystalline lens periphery
May not be visible without dilation
How do cortical cataracts affect vision in early stages?
Typically do not affect vision
Vision becomes increasingly affected as they progress
What is the most common symptom related to cortical cataracts?
Glare, especially from headlights while driving at night
What is nuclear sclerosis?
Yellowing and hardening of the central portion of the crystalline lens
What causes the lens to become cloudy in nuclear sclerosis?
Proteins precipitate out of the lens matrix
What color change occurs in the lens due to nuclear sclerosis?
From clear to yellow/brown, referred to as lens brunescence
What occurs to the refractive power of the lens due to nuclear sclerosis?
Increase in refractive power, resulting in a myopic shift
What is a posterior subcapsular cataract (PSC)?
Lens opacities resulting from cellular migration from the equator to the posterior pole
How does PSC affect visual acuity compared to other types of cataracts?
Tends to affect visual acuity to a greater degree
What do patients with PSC typically complain of in bright light?
Decreased acuity
What happens to pupil size in bright light and how does it affect vision with PSC?
Pupils constrict, creating a small aperture covered by the pacification
What happens to pupil size in low light conditions with PSC?
Pupils dilate, allowing for greater lens exposure
Where are anterior subcapsular cataracts located?
At the anterior aspect of the lens
What can cause anterior subcapsular cataracts?
Idiopathic, secondary to trauma, or iatrogenically
Fill in the blank: Nuclear sclerosis results in a _______ shift.
myopic
True or False: Cortical cataracts can significantly affect vision in their early stages.
False
What is a Morgagnian cataract also known as?
Hypermature cataract
What happens to the cortex of the crystalline lens in a Morgagnian cataract?
It liquefies
What appearance does a Morgagnian cataract have?
A milky fluid with the nucleus of the lens suspended
What complication can arise from a ruptured Morgagnian cataract?
Phacolytic glaucoma
*leaked lens materials can block TM leading to increased IOP
* can cause decreased VA, pain, redness
When should a Morgagnian cataract be removed?
As soon as possible
What must be ensured during the removal of a Morgagnian cataract?
The eye is not exposed to the lenticular contents
What effect does compression of the cornea during axial length measurement have?
It artificially shortens the eye’s length.
How does a decreased axial length affect intraocular lens (IOL) power calculations?
It causes an IOL with a higher plus dioptric power to be implanted.
What is the expected outcome of implanting an IOL with a higher plus dioptric power?
A greater magnitude of post-operative myopia than expected.
What are the typical signs and symptoms associated with central serous maculopathy?
Signs:
* Loss of the foveal reflex
* Hyperopic shift
Symptoms:
* Potential relative scotoma
* Metamorphopsia
*reduced VA
Does the rotation of a spherical lens implant alter its power?
No, it does not alter its power.
What must be ensured for the correct positioning of a lens implant?
It must be oriented in the correct position vertically and horizontally within the capsular bag.
What prevents rotation of the intraocular lens (IOL) implant?
Haptics attached to the IOL serve to keep it stable and in place.
What happens if an intraocular lens implant is placed too far forward?
It contributes to a post-operative myopic outcome.
What is the consequence of placing a lens too far back within the posterior chamber?
It results in a post-operative hyperopic refractive error.
What additional lab testing should be requested for patient with recurrent non-granulomatous uveitis?
CBC
ESR
HLA-B27
Sacroiliac spine radiograph
- above testing should be done for any case of uveitis that is bilateral, granulomatous and/or recurrent
Pupillary block
Acute lens-iris apposition causes aqueous sequestration in posterior chamber, anterior bowing of iris and resultant 360 degrees occlusion of TM
