10.01 Normal Lens
10.02 Magnified lens (PAS stain)
10.03 Equatorial lens
10.04 Normal cortical Lens fibers
Nick’s Tips: The normal lens can be identified by its shape and position in the eye and by the absence of definable cellular features such as nuclei (except in the cell of the anterior capsule and the lens bow). Additionally, the long fibrous cell lacking nuclei that run parallel to the adjacent capsule unambiguously identify lens under the microscope. Phakia in pseudophakia or phacoemulsification comes from the Greek, “Phakos” meaning lentil (a small bean roughly the shape of the lens).
- 9-10 mm diameter
- 5mm anterior to posterior
- Responsible for about 1/3 or 20D of refracting power of the eye
- Surrounds entire lens
- Type IV collagen basement membrane
- Thickest anteriorly –12-21 µm
- Thinnest posteriorly –2-9 µm (so be careful in cataract surgery).
- Single layer of cuboidal cells
- Present only anterior to lens equator
- Basal surface towards anterior lens capsule
Nucleus and Cortex
- Oldest lens fibers (embryonic and fetal) are most central
- Lens fibers are continuously laid down peripherally
- Lens fibers originate from lens epithelial cells at the equatorial lens bow
- As lens epithelial cells de-differentiate into lens fibers, they lose all cellular organelles and nucleus
- Support the lens
- Can be damaged by surgery, trauma, or pseudoexfoliation
- Attach from lens mid-periphery to ciliary body processes
- Lens originates from surface ectoderm.
Nick’s Tips: important to remember the causes of spontaneous lens subluxation and the common direction in which the lens dislocates in each syndrome.
10.06 External slit lamp photo
- Fibrillin gene mutations on chr15. Zonulesare composed primarily of fibrillin-1
- Lens dislocates up and out.
- Axial myopia often present.
- Check for skeletal and cardiovascular anomalies including fatal dissecting aortic aneurysm
- Patients tall and long spidery fingers and toes
10.07 External Slit Lamp photo
- superotemporal dislocation with spherophakia.
- Patients short and short fingers
- Associated with defects in FBN1 –fibrillin 1 gene
- Associated with lenticular myopia
- Associated with lens dislocation leading to pupil block and angle closure glaucoma
10.09 External Slit lamp photo
- defect in cystathionine β-synthase –affects disulfide bonds in aggregation of fibrillin-1
- Lens classically dislocates down and in.
- Light skin color, blond, tall –similar to marfan’s patients.
- Progressive mental retardationoMany die from venous and arterial thromboses
- Increased risk of thromboembolic complications from general anesthesia
- May have pupil block glaucoma
- Sulfite oxidase deficiency
- Associated with seizure and severe neurologic deficits
- Molybdenum Cofactor deficiency
- Associated with or cause of sulfite oxidase deficiency
- Similar symptoms
- Collagen mutation
- Failed induction of lens formation
- Associated with PAX6 gene mutations
- Lens formation begins, but lens is extruded or absorbed before birth
- Often associated with congenital infections such as rubella
Nick’s Tips: Rarely associated with pediatric ciliary body neoplasm –most common is medulloepithelioma
- Notch in lens
- Typically inferonasal
- Often associated with ciliary body coloboma
- Absence of zonular fibers in region of coloboma
- Conical (lenticonus)or spherical (lentiglobus) shaped anterior bulge in the lens
- Has an oil-drop appearance on retroillumination during slit lamp exam.
- Bilateral cases associated with Alport Syndrome(Autosomal dominant: lenticonus, anterior polar cataract, retinal and iris neovascularization, deafness, and hemorrhagic nephritis)
- Mutations in type IV collagen are associated with lenticonus and Alport Syndrome
- Mutation on COL4A5 gene on X chromosome –X-linked inheritance
- Deformity of the posterior surface of the lens
- Oil droplet appearance as in anterior lenticonus
- Usually sporadic and unilateral
- Associated with Alport Syndrome
- Associated with Oculocerebralrenal Syndrome of Lowe (X-linked: congenital cataract, systemic acidosis, renal rickets, hypotonia)
10.10 External slit lamp photo
Nick’s Tips: The history of trauma or surgery and the presence of lens material and giant cells confirms the diagnosis.
- Follows accidental or surgical trauma to the lens
- Anti-lens protein IgG present
- Granulomatous inflammation (mutton fat keratic precipitates (kp) and giant cells)
- Neutrophils and giant cells in layer immediately adjacent to lens material
- Lymphohocytes and plasma cells in middle layer
- In long-standing inflammation, an outer capsule of fibrovascular connective may be present
10.11 External slit lamp photo
- Liquefied cortical material enters the anterior chamber
- Extensive non granulomatous inflammation.
- Protein-laden macrophages and lens protein obstruct TM.
- Treat with cataract extraction with IOL and irrigation of anterior chamber.
P. acnes Endopthalmitis
Nick’s Tips: Clinical history of cataract surgery and chronic granulomatous inflammation, gram + cocci bacteria associated with lens capsule.
- Usually occurs 2 months to 2 years after cataract surgery
- May occur after YAG capsulotomy (bacteria released from capsular bag).
- Granulomatous inflammation in anterior chamber and vitreous
- May have hypopyon and keratic precipitates
- Similar syndromes have been reported with other low virulence infections (S. epidermidis, Corynebacterium, Achromobacterand some fungi.)
Persistent Fetal Vasculature (Previously called persistent hyperplastic primary vitreous (PHPV))
10.13 External slit lamp photo
10.14 Gross cross-section globe
Nick’s Tips: Understanding the embryology of the lens is helpful in understanding the basics of the persistent fetal vasculature syndrome, which is a spectrum of remaining structure that can be very mild or severe and vision threatening. Also an important cause of leukocoria, the causes of which should be memorized and understood due to their association with life and vision threatening conditions.
- Retrolentalresidual fetal vessels and connective tissue that is connected to the ciliary body processes. As the eye grows, this created traction.
- Eyes with persistent fetal vasculature will commonly be small and hyperopic.
- Ingestion of silver (usually colloidal silver)
- Bluish tint to skin
- Darkfield microscopy can show silver particles clearly
Chalcosis / Wilson’s Disease
- Moderate copper content foreign body (high copper content causes intense inflammation)
- Wilson’s disease –disorder of copper metabolism
- Inherited disorder ATP7B gene (autosomal recessive) –transfers copper into bile and incorporates it into ceruloplasmin.
- Usually diagnosed aged 5-35
- Copper accumulates in tissue
- Can causeliver failure
- Neuropsychiatric symptoms –cognitive deterioration, clumsiness, frontal lobe disorders
- Treated with chelating agents such as d-penicillamine
- Copper deposits in cornea (Kayser-Fleisher ring) and lens (sunflower cataract)
Nick’s Tips: look for history of high IOP and degenerating epithelium and cortical fibers.
- White flecks just beneath the lens capsule
- Seen after episode of very high intraocular pressure
- Focal necrotic lens epithelial cells under capsule
- Degenerated subepithelial cortical material present
Nick’s tips: Look for history of metallic foreign body and Prussian blue stain
- Lens epithelial degeneration and necrosis
- Iron containing foreign body
- Prussian blue staining shows iron in epithelial cells
10.16 Posterior view of nuclear sclerotic cataract using Miyake view
10.17 Brunescent cataract
10.18 Dense nuclear cataract
10.19 Nuclear cataract
Nick’s Tips: nuclear cataract usually looks like homogenous eosinophilic sheet. Gaps are artifacts of processing, but as the lens hardens, there are fewer gaps and greater eosinophilia with increasing density of cataract.
- Common age associated cataract
- Compression of lens fibers due to lifelong continuous production –old cells gradually degenerate and have no cellular machinery for repair.
- Accumulation of urochrome pigment
- May have birefringent calcium oxalate crystals
- Change in refractive index (more myopic) and lens size (more hyperopic) cause changes in refraction.
10.20 External slit lamp photo
10.21 Cortical cataract from Miyake view
10.22 Morgagnian cataract
10.23 Gross morgagnian cataract
10.24 Early liquefied cortical cataract
10.25 Advanced cortical cataract
- Earliest sign is hydropic swelling of lens fibers
- Liquefactive changes in lensresulting in vacuoles of clear fluid
- Eosinophilic globules (Morgagnian globules) in spaces between lens fibers
- Late –whole lens cortex liquefies and nucleus drops in bag (Morgagnian cataract)
- Advanced cases may have phacolytic glaucoma –high IOP due to obstruction of the trabecular meshwork by lens particle and lens protein laden macrophages.
Anterior subcapsular cataract:
10.27 Trichrome Stain
- Plaque of dense collagenous connective tissue on inner surface of anterior lens capsule.
- Cells in the plaque ore of lens epithelial cell origin
- May have thin layer of redundant capsule posterior to actual capsule or thin layers of PAS-positive basement membrane surrounding lens epithelial cells.
- Often associated with inflammation and iris-lens adhesions called posterior synechiae.
Posterior subcapsular cataract:
10.28 Slit lamp photo retro-illumination
10.29 Swollen bladder cells
Nick’s Tips: Wedl cells present –lens cells swollen with lens protein containing a single nucleus -normally no nuclei in posterior lens.
- Posterior subcapsular cataract looks like a bubbly plaque on the posterior lens capsule
- Associated with:
- Ionizing radiation
- Corticosteroids (including oral, inhaled, topical)
- Chronic inflammation
- Enlarged posteriorly migrated lens epithelial cells with swelling to 5-6 X normal size
- Interferes greatly with vision, especially near vision because the opacities are located near the nodal point of the eye. Also causes glare with night driving.
Congenital Rubella Cataract:
10.30 External slit lamp photo
10.31 Gross cross-section of orbit
10.32 Congenital rubella
Nick’s Tips: Congenital Cataract can be inherited or acquired, but present at birth. Congenital cataract is an important cause of leukocoria in a child. The causes of leukocoria should be memorized both due to their importance in pediatric ophthalmology in recognizing and differentiating life and vision threatening conditions and because the Ophthalmology written and oral boards will frequently if not always address pediatric leukocora.
- Develops in 1styear of life or present at birth.
- 1/3 due to a disease syndrome
- 1/3 inherited –usually autosomal dominant –many different mutations identified
- 1/3 undetermined cause
- Posterior-polar cataracts: range from mittendorf dot (about 25% of normal adults) to persistent fetal vasculature.
- Surgery difficult due to weakened posterior capsule or hole in posterior capsule. Avoid hydrodissection.
- Rubella: fetus exposed to rubella virus in 1stor 2ndtrimester. Congential rubella has a triad of cataract, deafness, and cardiac anomalies (consult with pediatric cardiology). Rubella cataract usually nuclear and densely white. Live virus has been cultured from rubella cataracts.
- Microspherophakia, retained lens fiber nuclei, isolate rubella from cells.
Cataracts in Systemic and Environmental Conditions:
- Occurs in infants –may be first presenting feature
- Central oil droplet cataract
- Congenital absence of galactose-1-phosphate uridylyltransferase
- Due to accumulation of galactolol in the lens.
- Galactokinase deficiency
- Presenile cataracts
- Diabetes Mellitus
- Accumulation of sugar alcohols in the lens created through the hexose monophosphate shunt
- Accumulation of sorbitol (the sugar alcohol of glucose)
- Cataract cause by osmotic pressure from the excess solute in the lens
- Also associated with posterior subcapsular cataract
- Fabry Disease
- X-linked a-galactosidase A deficiency
- Accumulation of ceramide trihexoside
- Leads to posterior spokes of cataract –also verticillata in cornea
- Wilson Disease
- Sunflower cataract due to copper deposition
- May have similar cataract in chalcosis (copper containing foreign body)
- Myotonic Dystrophy
- Christmas tree cataract of polychromatic crystals in the anterior and posterior cataract and sometimes along the suture lines.
- Myotonia, muscular dystrophy, testicular atrophy and frontal baldness associated.
- Atopic Dermatitis
- Traumatic cataract:
- May form rapidly within hours to days of lens capsule penetration
- Vossius ring –pigment on anterior capsule from traumatic compression of iris onto lens.
- Intraocular foreign bodies may cause chalcosis or siderosis resulting in characteristic cataracts
- Sunflower cataract –copper containing foreign body or Wilson disease
- Siderosis lentis –scattered rust colored anterior foci caused by iron laden lens epithelial cells in the subcapsular region –may have iris heterochromia –Prussian Blue stain shows iron clearly.
- Radiation cataract
- Electrical cataract –lightning strike or electrocution
- Lightning often causes posterior subcapsular opacification (conduction through neuraxis of body –central)
- Electrocution frequently causes anterior opacification (extremities conduct -peripheral)
Thermal radiation –exfoliation (small scrolls of delaminated lens capsule) of anterior capsule in glass blowers exposed to intense infrared radiation. Do not mistake for pseudoexfoliation.
10.33 True exfoliation
10.34 True exfoliation
10.35 External slit lamp photo retro-illumination
10.36 External slit lamp photo
10.37 External slit lamp photo
- Eosinophilic clumps on the lens capsule called Busacca deposits
- Saw tooth patternon iris pigment epithelium covered with pseudoexfoliative material
- Deposits are composed of elastic fibers
- Appear like vertically standing iron filings
- Material is present in a characteristic pattern of central deposits and peripheral deposits with a clear intervening ring where movement of the pupil wipes the deposits from the anterior lens surface.
- Also found on ciliary body and zonular fibers and pupil margin trabecular meshwork, iris stroma and anterior chamber. Has also been found systemically
- May cause severe and aggressive secondary open angle glaucoma with rapid onset
- Damages zonules leading to difficulties with cataract surgery and spontaneous lens dislocation
- Corticosteroids –topical, oral, inhaled, intravitreal may also cause posterior subcapsular cataract.
- Ergot poisoning, metallic foreign bodies (iron or copper) can cause cataracts
- Many inflammatory conditions / uveitis have secondary cataracts
Soemmering Ring/ Elschnig Pearls:
10.39 Cross-section of gross globe
10.40 Miyake view
10.41 Miyake View
10.42 Soemmering’s ring
- Cortical material left in eye after cataract removal.
- Made up of a ring of material (Soemmering Ring) or cortical ballsof lens epithelial cells (Eschnig Pearls)
- May contract and lead to decentering of IOL
10.43 UGH syndrome
10.44 IOL glistenings
Nick’s Tips: To avoid complications, good surgical technique is essential.
- Lens glistenings are fluid-filled microvacuoles that form within the IOL
- Uveitis-glaucoma-hyphemasyndrome (occurs when haptic of one piece lens is in the sulcus). Error in surgical technique
- Lens fibers originate from which of the following structures?
a) The posterior capsule
b) The anterior capsule
c) The ciliary body
d) The lens bow
- A patient presents with oil droplet appearance to the lens on retroillumination and deafness. You should consider which of the following tests?
a) MRI brain and orbits
c) RNFL OCT
d)Complete blood count
- A 34 yo male presents to your clinic with rednessand pain OD with a history of trauma from a metallic foreign body 6 months ago. The patient eventually develops a blind and painful eye which is removed. The following histopatholgy is shown. What was the etiology of the patient’s disorder?
a) Phacoantigenic Uveitis
c) P. acnesendophthalmitis
- A patient presents with the following cataract. What predisposing factor is most likely in this presentation?
a) History of penetrating ocular trauma
b) Wilson’s Disease
- A patient presents with chronic pain, redness, and elevated intraocular pressure over the course of 6 months following cataract surgery. The patient has the following anterior segment exam. What is the most likely type lens placed.
a) 3-piece silicone
b) 1-piece acrylic multifocal
c) Plate haptic PMMA
d) 3-piece acylic
Answers: 1) D, 2) B, 3) A, 4) C, 5) B