2. Lens-Induced Uveitis-
• Phacoanaphylactic Uveitis -
• It is an immunological response to lens proteins in
the sensitized eyes presenting as severe
granulomatous anterior uveitis .
• Phacotoxic Uveitis –
• It is an ill understood entity. This term is used to
describe mild iridocyclitis associated with the
presence of lens matter in the anterior chamber
either following trauma or extra-capsular extraction
or leak from hyper-mature cataracts
3. • INTRODUCTION –
• Lens-induced uveitis occurs in the setting of a ruptured or
degenerative lens capsule and is characterized by a
granulomatous antigenic reaction to lens protein. Before the
modern era of microsurgery, this disease was more
common, and the diagnosis was often made histologically, as
eyes with phacoanaphylaxis were often enucleated for
intractable inflammation and secondary glaucoma.
• While lens fragments may be retained in the anterior or
posterior chamber during seemingly uncomplicated cataract
surgery, they also may be dislocated posteriorly into the
vitreous cavity during phacoemulsification of the
nucleus, usually after zonular dehiscence or posterior capsule
rupture. Lens-induced uveitis may develop, and the degree of
intraocular inflammation in these patients often is governed
by the size of the retained lens fragment, the time since
cataract surgery, the patient's individual inflammatory
response, and the extent of other intraocular manipulations.
4. • Pathogenesis -
• The term phacoanaphylaxis is probably inappropriate because
no evidence exists of a classic type I immunoglobulin E (IgE)
mediated anaphylactic reaction. The immunopathogenesis of
lens-induced uveitis is believed to be the result of
autosensitization to lens proteins. After a break in the lens
capsule and sensitization to lens proteins, an immune
complex–mediated phenomenon develops, which can be
transferred by hyperimmune serum. Type II, III, and IV
hypersensitivity reactions may be involved in the
pathogenesis.
• The disease most likely is induced by altered tolerance to lens
protein and not as a result of a rejection phenomenon of
sequestered foreign materials. The specific type of
immunological reaction in lens-induced uveitis may vary from
patient to patient, and it may depend on the type of surgery or
injury, the amount of retained lens in the vitreous cavity, and
the previous immunological status of both the patient and the
eye.
5. • Age: lens-induced uveitis are more common in
the elderly population, with a peak incidence in
the sixth to seventh decades.
• Sex: No sexual predilection exists are more
common in younger age groups.
6. • Causes:
• Lens-induced uveitis is usually the result of traumatic or
surgical disruption of the lens capsule and liberation of
lens proteins into the aqueous or into the vitreous cavity.
Posterior capsular rupture during phacoemulsification is
the most common cause of posterior displacement of
lens fragments. This complication is more common in
patients with pseudoexfoliation syndrome, zonular
dehiscence, a small pupil, friable iris, and hard nuclei or
hypermature cataracts.
• Penetrating injury of the globe may result in severe lens-
induced uveitis. The uveitis may remain undiagnosed
clinically because of hyphema, decreased corneal
clarity, and inflammation related to the trauma. A small
punctured perforation site may remain unnoticed
initially, and severe inflammation and cataract will be
present 1 week later.
7. • History-
• Lens-induced uveitis typically develops 1-14 days
after traumatic or surgical perforation of the lens
capsule. In rare instances, the inflammation may
develop several months after the disruption of the
lens capsule.
• Clinical symptoms may include severe light
sensitivity, epiphora, pain, floaters, loss of
vision, and redness of the eye.
• Decreased vision may be due to refractive error
(myopic or hyperopic shift) associated with such
factors as macular edema, hypotony, or change in
lens position.
• Visual acuity in patients with phacoanaphylactic
uveitis is quite variable, ranging from 20/20 to no
light perception.
8. • Clinically:
• The inflammation can vary from a mild anterior uveitis to a
fulminant endophthalmitis. Typically, the inflammation is
unilateral and involves only the traumatized eye.
• The most important clinical signs of lens-induced uveitis are
lid swelling, perilimbal or diffuse injection, corneal
haze, keratic precipitates (granulomatous),cells and
flare, fibrin in the anterior chamber (occasionally), peripheral
anterior synechiae, posterior synechiae, pupillary
membrane, and iris nodules.
• In the posterior segment, lens fragments, inflammatory
cells, traction bands in the vitreous, retinal
edema, inflammatory cuffing of blood vessels, cystoid macular
edema, and epiretinal membrane formation can be observed.
• If untreated, lens-induced uveitis/phacoanaphylactic
endophthalmitis may result in chronic cystoid macular
edema, cyclitic membrane formation, tractional retinal
detachment, and phthisis bulbi.
9. Phacoanaphylactic reaction to penetrating injury of lens. This patient was a
25-year-old woman whose eye was penetrated with a 27-gauge needle during
an attempt to anesthetize the eyelid for chalazion removal. One week
later, a marked uveitis was present. Notice posterior synechiae.
10. • Typical appearance of retained lens fragments in posterior vitreous
cavity. Lens material is a whitish substance that obscures fundus
details.
11. • Patient with persistently elevated intraocular pressure after cataract
surgery was found to have retained lens material and low-grade
inflammation. Retained lens material is visible in retroillumination
on downgaze
12. Typical clinical picture of retained lens material following cataract
surgery. White cortical material is easily visible in the pupillary space
13. • Lab Studies:
• Aqueous paracentesis in subtle or early cases
may reveal inflammatory cells and particulate
lens proteins without bacteria. This procedure is
performed more efficiently at the time of
anterior chamber washout and vitrectomy to
remove the inciting lenticular antigens
14. • Imaging Studies:
• If the media opacity prevents an appropriate fundus
examination, echography with A-scan and B-scan may be helpful when
evaluating the posterior pole.
▫ Suspicion for acute endophthalmitis, intraocular foreign
body, dropped lens nucleus, thickening of the choroid, retinal
detachment, and choroidal effusion are all indications for
echography if the anterior segment changes hinder examination of
the posterior segment.
▫ The shape, position, and thickness of the traumatized lens; the
presence of focal echogenic areas; and, sometimes, even the entrance
and exit wounds are recognizable by ultrasound. It is clinically
important to diagnose the isolated rupture of the posterior capsule of
the lens by echography. Such ruptures are characterized by the
irregular extension of the highly reflective posterior capsule toward
the vitreous with significantly increased thickness of the lens.
• Ultrasound biomicroscopy (UBM) may have an important role in
the evaluation of lens-induced uveitis after extracapsular cataract
extraction, revealing hidden lens particles in the posterior chamber
causing inflammation as well as lens-particles creating secondary
glaucoma
15. • Medical Care:
• Treatment may be medical or surgical. Medical therapy of phacoanaphylactic
uveitis includes topical corticosteroids and may include cycloplegics and
medication for elevated intraocular pressure as needed. Treatment should be
tailored to the individual patient and adjusted according to response. Patient
age, immune status, and tolerance for adverse effects always must be taken into
account.
• Cycloplegics: Topical cycloplegics break or prevent the formation of posterior
synechiae, stabilize the blood-aqueous barrier leading to reduced leakage of
plasma proteins, increase uveoscleral outflow, and provide mild relief of ciliary
spasm pain. The stronger the inflammatory reaction, the more frequently
applied or stronger the cycloplegic.
• Corticosteroids: Corticosteroids block the formation of arachidonic acid from
cell membrane precursors by inhibiting the action of phospholipase-
A2, cyclooxygenase, and lipoxygenase. Thus, arachidonic acid is the premier
precursor of potent inflammatory mediators, such as
prostaglandins, thromboxane, and leukotrienes. Corticosteroids frequently are
used in uveitis therapy. Topical steroid drops are given in dosages ranging from
once daily to hourly. They also can be given in an ointment form. Periocular
corticosteroids generally are given as depot-steroid injections when a more
prolonged effect is needed or when a patient is noncompliant or poorly
responsive to topical administration.
• Intraocular pressure–lowering agents: When phacoanaphylaxis is
associated with high intraocular pressure ,aqueous suppressants are indicated.
Beta-blockers, alpha-agonists, and carbonic anhydrase inhibitors are used to
lower the pressure.
16. • Surgical Care:
• If persistent or uncontrolled inflammation or elevated intraocular pressure
is not responsive to medical therapy or if such a large amount of exposed
lens material is present that medical therapy is likely to fail, then surgical
removal of the exposed lens material is indicated . The most common
situation leading to this is posterior capsular rupture with the loss of lens
fragments into the vitreous cavity during phacoemulsification . Removal of
retained lens fragments by pars plana vitrectomy generally restores good
visual function and reverses many complications in these patients. Surgical
removal of retained lens material may be necessary depending upon the
degree of inflammation, the size of the retained lens particle, and the
presence of increased intraocular pressure. Observation is indicated when
the lens fragments are small and the inflammation can be controlled.
• Retained lens fragments that are larger than one third to one half of the
total cataract usually (but not always) require surgical removal.
• Several studies demonstrate no advantage to early surgery; therefore, the
cataract surgeon may treat patients with retained lens fragments
conservatively, and then refer the patient to a vitrectomy surgeon after an
appropriate period of observation and medical therapy, unless the patient
develops retinal detachment, highly elevated intraocular pressure, or some
other condition in which posterior segment surgery is indicated more
urgently.
17. • Complications:
• Cystoid macular edema:
• Secondary glaucoma
▫ Trabecular meshwork obstruction may occur with the
accumulation of white blood cells (macrophages and
activated T lymphocytes) or their aggregations. These may
cause peripheral anterior synechiae and subsequent closed-
angle glaucoma.
▫ Obstruction may arise from inflammatory debris
(eg, proteins, fibrin, high molecular weight proteins) and
from lens particles. These proteins increase the aqueous
viscosity, which may contribute to increased intraocular
pressure.
▫ Leakage of lens proteins through the injured lens capsule
with or without leakage of serum proteins from uveal blood
vessels in lens-induced uveitis may block the trabecular
outflow causing secondary glaucoma.
• Retinal detachment
