24 Iris and Ciliary Body

277 ACCOMMODATIVE SPASM 367.53

(Spasm of the Near Reflex)

Cameron F. Parsa, MD

Baltimore, Maryland

ETIOLOGY/INCIDENCE

Accommodative spasm refers to an episodic, excessive contraction of the ciliary muscle. In some cases, it may result from the direct effects of parasympathomimetic drugs such as pilocarpine. In general, however, the term is used to describe spontaneous excess parasympathetic activity as part of the near reflex triad (e.g. accommodation, miosis, and convergence). The term is often used interchangeably with spasm of the near reflex, although not all components of the near reflex triad may always be apparent. Just as accommodation, convergence, and miosis may be present to different degrees, so, too, may the symptoms vary in patients with spasm of the near reflex.

Short-lived, episodic, isolated symptomatic spasm of the near reflex in nearly all cases is considered to be functional in origin (this should not be misinterpreted to indicate that it is voluntary). A high incidence of personality disorders is noted in individuals in these instances, and nonphysiologic visual loss may be an associated sign in some. Nevertheless, an examination should be performed to ensure that accompanying signs (e.g. nystagmus, papilledema, ataxia, endocrine abnormalities) are not overlooked and that associated disease is not missed.

The exact anatomic locus for episodic spasm of the near reflex remains unknown in the rare cases with underlying organic disease; presumably, it may arise from disruption at a number of sites. Any condition that may stimulate pathways of the near reflex, or supranuclear control, have been reported to cause accommodative spasm:

●Posterior fossa tumors;

●Central nervous system infections;

●Head trauma;

●Cerebrovascular injuries;

●Metabolic or toxic disorders;

●Vestibular disorders.

Morphine can provoke spasm of the near reflex via the supranuclear inhibition of parasympathetic inhibitory neurons, and excessive alcohol intake also may cause temporary spasm.

DIAGNOSIS

Clinical symptoms

Patients may present with one or more of the following symptoms:

●Blurred vision;

●Diplopia;

●Brow ache (bilateral), headache.

Attacks accompanied by ‘discomfort’ may prompt some patients to squint their eyelids, mimicking photophobia; excessive convergence effort may produce:

●Frank esotropia with diplopia;

●Unilateral or bilateral limitation of abduction.

Functional episodes of spasm are generally brief, typically lasting only seconds to minutes. When produced by head trauma, symptoms, though milder, may last for years, often without discernable miosis. Spasm can also be sustained when physiological in nature, to improve acuity when refractive error is poorly corrected.

Clinical signs

●Excessive accommodation, resulting in pseudomyopia (up to 10 diopters), easily noted when comparing manifest to cycloplegic refractions.

●Marked bilateral miosis, which may increase further on attempted abduction.

●Variable, intermittent convergence.

●Monocular occlusion of either eye (interrupting the stimulus for convergence) allows full abduction, as well as pupillary dilation.

●Oculocephalic testing (doll’s head maneuver) demonstrating full range of eye movements.

In cases associated with organic disease, visual input may not be necessary to maintain spasm, and diagnostic signs present in functional cases (e.g. pupillary dilation during monocular occlusion) may be absent. An investigation for underlying disease should be initiated at this point. Rarely, occlusion of an eye can fail to ‘break’ an attack even in functional cases. Such so-called monocular or unilateral cases of accommodative spasm simply require the occlusion of the dominant eye to block the visual input, alleviating the spasm. It should be remembered that in functional cases, any attention directed to the eyes, including monocular occlusion, may precipitate an attack.

Body Ciliary and Iris • 24 SECTION

Accommodative spasm can also result from physiologic efforts. Prolonged monocular near work causing overaccommodative effort (i.e. instrument myopia or instrument accommodation) may also habituate an individual to develop accommodative spasm whenever binocularity is interrupted. Furthermore, miosis can also be invoked as part of the nearreflex triad for the purposes of improving acuity, with symptoms then related to excessive convergence.

Differential diagnosis

When excessive convergence is the presenting component of the triad, the differential diagnosis may include:

●Sixth nerve palsies;

●Thyroid eye disease (involving the medial rectus muscles);

●Simple convergent strabismus;

●Divergence insufficiency. In some cases, however, poorly corrected refractive errors or presbyopia can elicit compensatory miosis to help improve acuity via the near-reflex triad, with or without accommodative ability. Over a sustained period, the associated excessive convergence input to the medial rectus muscles may itself cause alterations producing a divergence insufficiency;

●Oculomotor apraxia or horizontal gaze palsy (congenital or acquired) with convergence substitution movements;

●Substitutive convergence movements in response to other underlying disorders (e.g. myasthenia, multiple sclerosis, stroke, etc.). Activation of the near reflex may be elicited to assist in horizontal gaze or to reduce a potential exotropia. However, in most instances, the near reflex is not invoked in primary gaze;

●Parinaud’s syndrome, which can mimic some aspects of spasm of the near reflex, such as excessive accommodation and convergence; however, pupillary near-light dissociation, not miosis, is a feature of Parinaud’s syndrome.

TREATMENT

Ocular

Intermittent attacks of accommodative spasm may occur over periods lasting from weeks to years. Treatment is generally based on the relief of symptoms but may take a variety of forms, often depending on whether the patient also manifests excessive convergence. Younger patients tend to present complaining of blurring of vision from the excessive accommodation; the combination of:

●Cycloplegics, such as atropine, to break the accommodative component; and

●Refractive correction for distance with reading addition will eventually provide symptomatic relief from associated problems in most cases. If cycloplegic therapy is discontinued, however, symptoms may recur. Paradoxically, minus lenses have also been used to correct some degree of pseudomyopia and provide clearer vision; over time, one may be able to reduce the power of the lenses.

Although this last approach is well accepted by some patients, particularly those with spasm consequent to head trauma, it would have no effect in reducing the convergent drive and diplopia or any other symptomatology; its success in some patients may be related to functional pathogenesis.

Patients with presbyopia who present with spasm of the near reflex may complain of excessive convergence rather than blurred vision. Approaches focused on accommodative efforts

alone in this population may work in fewer instances. Aside from the correction of any refractive error to reduce the drive for acuity-enhancing miosis:

●Monocular occlusion can be used therapeutically, as well as in diagnosis; if the episodes of spasm are brief and infrequent, closing of one or both eyes during an attack may be the most practical treatment. If episodes are very frequent or long, monocular occlusion with a patch may be preferred, similarly, glasses with the medial third of each lens frosted or with semi-translucent tape placed to occlude vision while the eyes are converged may resolve excessive convergent drive.

Supportive

In patients with attacks that are episodic, reassurance and a careful explanation of the condition should be provided; in certain cases, psychiatric counseling may be of benefit. In several reports, barbiturate or benzodiazepine use, occasionally with hypnotic suggestion of orthotropia, provided temporary relief, underscoring the supranuclear and functional origin of this entity in the near totality of episodic cases. Particularly in patients with isolated sustained findings, however, an underlying physiologic need, i.e. accommodative or miotic compensation for refractive error, may be at fault. Only in rare instances, either from previous head trauma or with other pathology noted on examination is organic disease is the cause.

REFERENCES

Chan RV, Trobe JD: Spasm of accommodation associated with closed head trauma. J Neuro-Ophthalmol 22:15–17, 2002.

Cogan DG, Freese CG, Jr: Spasm of the near reflex. Arch Ophthalmol 54:752–759, 1955.

Dagi LR, Chrousos GA, Cogan DC: Spasm of the near reflex associated with organic disease. Am J Ophthalmol 103:582–585, 1987.

Guiloff RJ, Whitely A, Kelly RE: Organic convergence spasm. Acta Neurol Scand 61:252–259, 1980.

Ohashi T, Kase M, Hyodo T, et al: Long-lasting organic spasm of the near reflex. Jpn J Ophthalmol 32:466–470, 1988.

278 ANIRIDIA 743.45

(Congenital Aniridia, Hereditary

Aniridia)

David Sellers Walton, MD

Boston, Massachusetts

Garyfallia Katsavounidou, MS

Boston, Massachusetts

ETIOLOGY/INCIDENCE

Aniridia is a rare (1 : 80,000), genetically determined bilateral pan-ocular disorder characterized by decreased visual acuity and abnormal development of the cornea, iris, filtration angle, retina, and optic nerve and complicated by progressive keratopathy, cataracts, glaucoma, and further visual loss. Ocular examination in infancy typically reveals near-complete but variable absence of the irides. The corneas are small, abnormally thick, and possess a zone of peripheral epithelial opacifacation. Pendular nystagmus is often (90%) present. The visual

acuity is typically impaired and when tested in early childhood confirms decreased acuity between 20/200 and 20/80 related to retinal foveal hypoplasia.

Occurrence is sporadic or familial (66%), and transmission supports autosomal dominant inheritance. Haploinsufficiency secondary to a mutation of one aniridia gene (PAX6) or chromosomal deletion causes aniridia. PAX6 is located in the highly conserved PAX 6 region on chromosome 11 (11p13) and encodes a highly conserved PAX protein. Penetrance is high, and its clinical expression is variable. Over 200 PAX6 mutations have been identified. When aniridia is caused by a chromosomal deletion (11p−), the Wilms’ tumor gene (WT1), located 700 kb telomeric from PAX6, may also be affected, putting the patient at risk (50%) for a Wilms’ tumor and other abnormalities found in the WAGR syndrome (Wilms’ tumor, genitourinary anomalies, developmental delay). When aniridia is associated with a chromosomal deletion, the ocular defects seem to be clinically more severe.

COURSE/PROGNOSIS

Aniridic eyes often experience progressive visual deterioration. Visual loss occurs secondary to progressive corneal opacifacation, uncontrolled glaucoma, and cataract formation. Cortical lens opacities are present by 10 years of age, associated with slow lens growth, and progress with age. Glaucoma has been described in 5–75% of reported aniridic patients with onset typically in the first decade. Keratopathy typically progresses centripetally and may become associated with dense central dense opacifacation and secondary vision loss. These dystrophic complications of aniridia develop slowly with variable expression between patients.

DIAGNOSIS

Clinical signs and symptoms

●Diagnosis is made by ophthalmologic examination with recognition of the pathonomonic corneal opacifacation, iris hypoplasia, and foveal hypoplasia. Familial occurrence provides additional diagnostic evidence.

●Aniridic glaucoma is detected on the basis of intraocular pressure measurements associated with responsible gonioscopic abnormalities.

Laboratory findings

●Chromosomal deletion (11p−) is detected by cytogenetic analysis with the use of high-resolution banding.

●Submicroscopic deletions of the Wilms’ tumor gene are recognized with the FISH technique.

●PCR genotyping of halotypes across PAX6WT1 region for homozygosity provides evidence of a chromosomal deletion.

Differential diagnosis

●Rieger syndrome with iridocorneal dysgenesis.

●Congenital coloboma of the iris.

●Hereditary iris hypoplasia.

●Traumatic iris injury.

●Surgical iris coloboma.

●Bilateral congenital mydriasis.

●Isolated internal ophthalmoplegia.

●Gillespie syndrome.

●Primary congenital newborn glaucoma.

PROPHYLAXIS

Early goniosurgery to shift the iris insertion more posteriorly away from the trabecular meshwork may decrease the incidence or delay the onset of acquired glaucoma.

TREATMENT

Medical

●Medical glaucoma therapy for increased intraocular pressure.

Surgical

●Filtration glaucoma or glaucoma drainage device surgery for glaucoma resistant to medical therapy.

●Keratolimbal allograft for corneal epithelial decompensation.

●Cataract extraction and intraocular lens implantation.

●Occlusion therapy for acute symptomatic corneal epithelial failure.

SUPPORT GROUP

USA Aniridia Network

1138 N. Germantown Pkwy-Siute 101 Cordova, Tennessee, 38016

Ph: 901-752-8835

Fax: 901-757-4022 E-mail: info@aniridia.net Website: www.aniridia.net

REFERENCES

Chen TC, Walton DS: Goniosurgery for prevention of aniridic glaucoma. Arch Ophthalmol 117:1144–1148, 1999.

Glaser T, Walton DS, Maas RL: Genomic structure, evolutionary conservation and aniridia mutations in the human PA X6 gene. Nat Genet 2:232–239, 1992.

Gupta KB, DeBecker I, Guernsey DL, et al: Polymerase chain reactionbased risk assessment for wilms tumor in sporatic aniridia. Am J Ophthalmol 125:687–692, 1998.

Mayer KL, Nordlund ML, Schwartz GS, et al: Keratoplasty in congenital aniridia. The Ocular Surface 1:74–79, 2003.

Nelson NB, Spaeth GL, Nowinski TS, et al: Aniridia: a review. Surv Ophthalmol 28:621–642, 1984.

Riccardi VM, Sujansky E, Smith AL, et al: Chromosomal imbalance in the aniridia-Wilms’ tumor association: 11p interstitial deletion. Pediatrics 61:604–610, 1978.

279 CILIARY BODY CONCUSSIONS

AND LACERATIONS 921.3

Igor Westra, MD, MSc

Wilmington, North Carolina

ETIOLOGY

Ciliary body concussions and lacerations are injuries that usually accompany damage to other structures of the eye. Mild blunt trauma may produce a transient iritis with cells and flare

Lacerations and279ConcussionsCHAPTERBody Ciliary •

Body Ciliary and Iris • 24 SECTION

in the anterior chamber and anterior vitreous, as well as a relative hypotony. More severe blunt trauma may result in pupillary sphincter rupture, iridodialysis, angle recession, and cyclodialysis. Cyclodialysis is defined as separation of the ciliary body from the scleral spur and may be associated with hyphema, choroidal detachment, hypotony, and inflammation.

Ciliary body concussions and lacerations are secondary to blunt or perforating penetrating trauma. Automobile air bag and paintball injuries are modern causes of ciliary body trauma. Lacerations of the ciliary body usually result from perforations or penetrations, as of the cornea or anterior sclera; however, some objects that penetrate the skin of the lid at or even outside the orbital rim may bypass the conjunctival sac and produce scleral and uveal penetration posteriorly. Penetrating injuries caused by small projectiles may create anterior, as well as posterior, lacerations.

COURSE/PROGNOSIS

Once the choroid is separated from the sclera, aqueous may drain into the suprachoroidal space. This commonly results in profound hypotony. Prolonged hypotony may result in irreversible complications, including iris atrophy, angle-closure glaucoma, cataract, loss of retinal pigment epithelium from crests of choroidal folds, cystoid macular edema, optic atrophy, and phthisis bulbi. Decreased function of the ciliary body may also lead to difficulty with accommodation. Other late manifestations of blunt trauma include secondary glaucoma associated with major circumferential areas of angle recession. Extensive ciliary body injuries may involve necrosis of major portions of the pars plicata and lead to extensive fibrosis or atrophy. Massive fibrosis and vascularization of the vitreous may follow, with subsequent retinal detachment.

DIAGNOSIS

●There is a history of trauma.

●Slit-lamp ophthalmoscopy and gonioscopy should be performed, looking for angle recession, hyphema, shallow anterior chamber, Tyndall effect, iris atrophy, iridodialysis cellular debris, cyclodialysis cleft, sphincter rupture, and cataract.

●Eyes injured by blunt trauma require gonioscopic evaluation. When there is a hyphema, the examination is carried out after it clears. If a hypotonous cyclodialysis cleft is suspected, use of the Goldmann three-mirror lens is recommended.

●Tonometry is performed, looking for hypotony.

●Indirect ophthalmoscopy is performed, looking for detachment, exudative detachment rupture, choroidal folds, Berlin’s edema, dialysis, retinal hemorrhages, vitreous hemorrhage, macular edema, papilledema, and optic nerve atrophy.

●Indirect ophthalmoscopy, orbital radiography, computed tomography scanning, and ultrasound evaluation may be used to locate a foreign body.

TREATMENT

Ocular

●Protection from further injury is provided by using a Fox shield.

●A topical cycloplegic, such as 1% atropine twice per day or 1% cyclopentolate four times per day, may be administered.

●Topical corticosteroids may be given four to six times per day to limit the inflammatory reaction. In the presence of hyphema, bed rest and the administration of 50 mg/kg aminocaproic acid orally every 4 hours for 5 days decrease the occurrence of recurrent hemorrhage. Tranexamic acid 75 mg/kg/day in three divided doses is another choice. Both these agents reduce the incidence of secondary bleeding through the inhibition of the conversion of plasminogen to plasmin. These oral agents may cause nausea, vomiting, dizziness and postural hypotension. They should not be used in pregnant patients or in patients with renal or hepatic impairment. Topical aminocaproic acid, one drop every 6 hours for 5 days, has been designated as an orphan drug and may be available soon in the United States. It has the advantage of minimal systemic side effects.

●Sedation and pain medication may be necessary for patient comfort.

●If a cyclodialysis cleft is found, medical treatment with 1% atropine twice a day for 2 to 6 weeks is used in an attempt to approximate the ciliary body and sclera. Unless there is significant uveitis, corticosteroids are avoided because they inhibit the scarring necessary for cleft closure.

●Reversal of hypotony by any means within 2 months results in the best visual acuity. A delay in treatment results in the loss of one to three Snellen lines of ultimate visual acuity. Spontaneous closure seldom occurs after 6 weeks.

Surgical

●If the ciliary body concussion has resulted in a shallow anterior chamber, a hypotonous cyclodialysis cleft is suspected. Pilocarpine 2% is administered to maximize the pupil constriction and open clefts. The chamber is deepened by making a stab incision and intracamerally infusing the sodium hyaluronate. Retrobulbar anesthesia is administered. A stab incision is made at the limbus, sodium hyaluronate is injected through the incision, and the pressure is adjusted to between 10 and 20 mm Hg by releasing aqueous humor. The stab incision is then closed with a single 10-0 nylon suture. The angle can then be

examined by gonioscopy, and argon laser photocoagulation can be performed. To avoid postoperative ocular hypertension, the anterior chamber is irrigated with balanced salt solution through the reopened limbal incision, and sodium hyaluronate is aspirated out through a second stab incision. These incisions are subsequently closed with 10-0 nylon, with care taken to bury the knots. A subconjunctival injection of an antibiotic such as 125 mg of cefuroxime should be given. Atropine 1% one drop twice a day and an antibiotic drop, such as moxifloxacin or gatifloxacin one drop three times per day, are given. Corticosteroids are avoided.

●In a few cases, hidden clefts may be found by injecting fluorescein into the anterior chamber and making sclerostomies over the ciliary body in all four quadrants. Detection of fluorescein in the suprachoridal fluid confirms the presence of an occult cyclodialysis cleft. Immersion B-scan ultrasound or ultrasound biomicroscopy may also be helpful.

●If medical treatment of the hypotonous cyclodialysis cleft has failed, laser treatment is administered. After expansion of the anterior chamber with sodium hyaluronate, as

described, contiguous rows of argon laser burns causing bubble formation are delivered to the scleral surface. A Goldmann lens with 100to 200-μm spot size, 0.1-second time setting, and high power settings of 2000 to 3000 mW is recommended. The uveal surface is also treated but with a lower power setting of 1000 mW, which causes an intense blanching. In cases in which prelaser anterior chamber deepening is not required, retrobulbar anesthesia is recommended for patient comfort. Atropine 1% drops twice a day are used for several weeks.

●Contact transscleral diode laser treatment of the cleft

areas has also been effective. The anterior chamber is expanded as described. The Iris ‘G’ probe (Iris Medical Instruments, Mountainview, CA) is used to apply laser to the cleft using settings of 1500 mW and 1500 milliseconds. Two rows of treatment are applied 1.5 mm posterior to the limbus for the extent of the cleft. Postoperative medical management is the same as that with argon laser treatment.

●Laser treatment is usually effective, but if several laser sessions have been unsuccessful, other surgery may be necessary. Techniques include vitrectomy and intraocular gas tamponade, ciliochoroidal diathermy, cycloplexy, cryoablation, and an anterior scleral buckling procedure.

●When surgical repair of a ciliary body laceration is performed, cultures should be taken of the wound.

●Ciliary body tissue is excised only if it is necrotic, severely traumatized, or grossly contaminated. If a cyclectomy is necessary, encircling transscleral diathermy may be indicated to decrease bleeding and subsequent ciliary body detachment.

●Meticulous reconstruction of corneal and scleral lacerations by microsurgical techniques should be undertaken as soon as possible after careful evaluation. The surgical goals are to maintain the contour of the eye and obtain a liquid-tight seal.

●The loss of corneal or scleral tissue may require replacement with patch grafting.

●For corneal closure, 10-0 nylon sutures are used; 7-0 or 8-0 nonabsorbable sutures are preferred for scleral repair.

●Suturing of the ciliary body laceration is rarely indicated.

●After primary repair of the lacerations, secondary repair may be necessary for the management of associated injuries, such as disrupted lens, vitreous hemorrhage, vitreous traction, retinal breaks, and retinal detachment. Although some believe that immediate vitrectomy is preferable, a 7- to 10-day interval allows for choroidal hemorrhages to recede, decreases the risk of intraoperative hemorrhage, and allows for spontaneous separation of the posterior hyaloid, which makes the procedure safer. Safety is also enhanced by preoperative ultrasound evaluation of eyes where the view of the posterior pole is limited.

●Delay of secondary repair past 2 weeks runs the risk of severe intraocular proliferative membranes. Vitrectomy is carried out under controlled conditions with an infusion line to keep the intraocular pressure constant and instrumentation that passes through 0.88-mm sclerostomies.

●Scleral buckling may be required for retinal pathology or is placed prophylactically by some surgeons.

●Postoperative medications consist of topical antibiotics, such as moxifloxacin or gatifloxacin three times per day for 1 week, 1% prednisolone acetate four times per day for several weeks depending on inflammation, and 0.25% scopolamine twice a day for several weeks.

COMPLICATIONS

Complications include decreased accommodation, cataract, secondary glaucoma, cystoid macular edema, and phthisis bulbi.

PRECAUTIONS

When faced with a ciliary body laceration associated with a severely traumatized eye, the question of a primary enucleation may arise. Primary enucleation of traumatized eyes should be avoided, especially if there is any visual function. Patients appreciate that everything possible has been done to save their eyes. Often, traumatized eyes look better after primary and secondary repair, and occasionally remarkable recoveries occur. Sympathetic ophthalmia is a remote possibility that should be discussed with the patient. If secondary repair has failed, enucleation can still be performed within the 2-week time period that is thought to be protective from sympathetic ophthalmia.

COMMENTS

Concussions and lacerations of the ciliary body usually accompany injuries to other ocular structures; an examination that is as complete as possible should be carried out as promptly as feasible without exacerbating the injury. Delay in examination may allow hemorrhage and inflammation to obscure intraocular details. Ophthalmic ultrasound can be a valuable adjunct. Lacerations require immediate treatment, and hypotonous cyclodialysis clefts should be treated within a 2-month period. Patients with ciliary body injuries require long-term follow-up to watch for complications, such as cataract and angle recession resulting in glaucoma.

REFERENCES

Brooks AMV, Troski M, Gillies WE: Noninvasive closure of a persistent cyclodialysis cleft. Ophthalmology 103:1943–1945, 1996.

Brown SVL, Mizen T: Transscleral diode laser therapy for traumatic cyclodialysis cleft. Ophthalmic Surg Lasers 28:313–317, 1996.

Crouch ER, Crouch ER: Trauma: ruptures and bleeding. In: Tasman W, ed: Clinical ophthalmology. Philadelphia, JB Lippincott, CD-ROM, 2006:4:61.

Ormerod LD, Baerveldt G, Sunalp MA, et al: Management of the hypotonous cyclodialysis cleft. Ophthalmology 98:1384–1393, 1991.

Recchia FM, Aaberg T, Sternberg, P: Trauma: principles and techniques of treatment. In: Ryan SJ, ed: Retina. Philadelphia, Elsevier, 2006:2379– 2402.

280 FUCHS’ HETEROCHROMIC

IRIDOCYCLITIS 364.21

(Fuchs Uveitis Syndrome)

Thomas J. Liesegang, MD

Jacksonville, Florida

Fuchs heterochromic iridocyclitis is readily recognized by its classic clinical appearance, which includes heterochromia of

Iridocyclitis280 CHAPTERHeterochromic Fuchs’ •

Body Ciliary and Iris • 24 SECTION

the irides (usually the lighter iris is present in the involved eye), the absence of conjunctival inflammation, specific atrophic changes on the iris surface, minimal cell and flare, widely scattered small nonconfluent keratic precipitates, vitreous cells, the absence of posterior synechiae, a complicated cataract, and occasional glaucoma. The expanded form of the disease has been described by several authors as having additional findings and a poorer prognosis.

ETIOLOGY/INCIDENCE

Fuchs heterochromic iridocyclitis can occur at all ages in both sexes. It may present as an asymptomatic finding early in its course with minimal ocular symptoms of floaters or in some patients only after the development of a cataract. The disease is recognized in approximately 5% of patients presenting with uveitis. In approximately 10% of cases, the disease is bilateral, and clinical astuteness is required to make the diagnosis. If the disease is unilateral at presentation, it usually remains a unilateral disease. The diagnosis is made based on clinical findings; there are no distinct laboratory findings.

●From 1.2% to 4.5% of patients with uveitis.

●No racial or sexual predilection.

●From 7.8% to 10% with bilateral disease.

●No definitive HLA or familial concurrence.

●Unknown cause: probably immune (hypersecretion of plasma cells, antibodies against corneal epithelial protein, anterior chamber immune response to antigen, possibly viral).

●Cause may be multifactorial or may be initiated by multiple single stimuli.

COURSE/PROGNOSIS

●Frequently asymptomatic or mild; fluctuates over time.

●Long insidious course.

●Occasional symptoms of discomfort, ciliary injection, increase in floaters.

●Visual loss from vitreous debris, progressive cataract, glaucoma.

●Cataract surgery generally successful.

●Variable course of glaucoma, may be progressive and refractory.

●Vitreous debris possibly requiring vitrectomy.

DIAGNOSIS

Clinical signs and symptoms

Classic features

●Quiet external eye.

●Heterochromia with involved eye lighter in color:

●Paler hue to involved iris;

●In brown eyes, may be very subtle.

●Unilateral disease:

●Bilateral in 10%, frequently missed when bilateral.

●Anterior iris atrophy, especially peripupillary:

●Atrophy of anterior and posterior layers;

●Blunting, flattening, blurring, or washed-out appearance of iris crypts.

●Hyaline keratic precipitates with intervening filaments:

●Small, round, nonpigmented, translucent keratic precipitates;

●Keratic precipitates can extend up the entire back surface of the cornea;

●Cotton-wisp filaments between precipitates.

●Minimal anterior chamber cell and flare:

●Variable at each examination.

●Occasional iris crystals.

●Absence of posterior synechiae a distinguishing feature.

●Occasional gelatinous iris nodules:

●Busacca nodules on the iris surface;

●Koeppe’s nodules at the pupillary margin.

●Vitreous humor cells:

●Dust-like or may progress to heavy, stringy veils.

●Cataract beginning with posterior subcapsular changes:

●Tendency to progress to mature white cataract.

●Occasional secondary glaucoma.

●Amsler’s sign (hyphema or filiform hemorrhage after sudden reduction in intraocular pressure during surgery or with minor trauma):

●Finding consistent with the rubeosis recognized in the expanded spectrum of disease.

●Occasional chorioretinal scars:

●Pathophysiology unclear: probably unrelated to toxoplasmosis.

●Long insidious course.

●Prognosis good.

Expanded spectrum of Fuchs’ syndrome (frequently not recognized)

●A panophthalmic disease.

●Any age affected.

●Occasionally presents with red external eye.

●Absent or reversed heterochromia (hence author’s preference for term Fuchs uveitis or Fuchs uveitis syndrome) (Figure 280.1):

●Anterior iris atrophy may allow darker posterior iris layer to dominate.

●Heterochromia may be without evident iris atrophy.

●Iris atrophy may be without evident heterochromia.

●Patchy atrophy of posterior pigmented layer of iris.

●Pupil irregular from sphincter atrophy.

●Frequent small peripheral anterior synechiae.

●Increased visibility of iris radial vessels.

●Fine iris rubeosis or gross rubeosis:

●Vessels meandering over the iris surface in some patients;

●Angiography to confirm ischemic vasculopathy and infarction.

●Spontaneous or induced hyphema.

●Cataract developing in all patients:

●Iris atrophy may progress as the cataract matures.

●Prognosis variable with cataract surgery.

●Secondary glaucoma in up to 60%:

●Initially partially inflammatory, later refractory;

●Poor prognosis with glaucoma;

●Multiple mechanisms, including peripheral anterior synechiae, rubeotic vessels, trabecular sclerosis, abnormal felt-like membrane in angle;

●Intraocular pressure may go up dramatically after YAG discussion.

a

b

FIGURE 280.1. Fuchs uveitis in a blue eyed individual. a) Subtle iris heterochromia in left eye with iris atrophy and poor iris details, slightly irregular pupil, loss of iris ruff, and early iris neovascularization superiorly. b) Normal right iris.

●Dense vitreous veils or vitreous hemorrhage:

●Occasionally, vitrectomy required.

●Increased incidence of central and peripheral corneal edema:

●Abnormal endothelial pattern on specular microscopy;

●Poor tolerance of intraocular surgery in some;

●Occasional pattern of Brown–McLean syndrome (peripheral edema);

●Cellular and humoral immune response to major corneal stromal antigen.

Laboratory findings

●No distinct histopathologic or electron microscopic findings.

●No distinctive laboratory features.

●Several research laboratories reporting immunologic findings: Significantly higher levels of TNF-α in the aqueous humor and sera; Predominant CD8+ T cell subset infiltrating the anterior chamber suggesting an antigen-driven process.

Clonal nature and predominantly CD8+ T-lymphocyte infiltration are suggestive of a viral pathogenesis, perhaps from rubella or HSV.

Differential diagnosis

●Idiopathic or viral uveitis.

●Lens-induced glaucoma.

●Pars planitis.

●Posner–Schlossmann syndrome.

TREATMENT

●In most instances, therapy not indicated.

●Occasionally, discomfort, ciliary injection, floaters treated with topical corticosteroids.

●Cycloplegics not indicated.

●Cataract surgery usually successful but higher risk of vitreous debris or vitreous hemorrhage.

●YAG discission occasionally accompanied by very high intraocular pressure.

●Glaucoma may be difficult to control; treated with topical or systemic therapy, but a high rate of glaucoma surgery.

●Laser trabeculoplasty may be contraindicated.

●Rubeotic glaucoma may require enucleation.

●For both cataract and glaucoma surgery, poorer prognosis with the expanded form of disease compared with classic presentation.

COMPLICATIONS

●Progressive cataract.

●Refractory glaucoma.

●High intraocular pressure after YAG discussion.

●Vitreous debris or hemorrhage.

●Dilated pupil.

●Occasional peripheral or central corneal edema.

COMMENTS

This entity is easily recognized in its classic form; there is a better prognosis for cataract surgery and less severe glaucoma. It is easily missed in its expanded form (which is more frequent); there is a poorer prognosis for cataract surgery and more severe glaucoma. Patients must be monitored for cataracts and glaucoma. Minimal therapy is preferred for uveitis. Since heterochromia is frequently absent, the author prefers the term Fuchs uveitis syndrome.

REFERENCES

Jones NP: Fuchs’ heterochromic uveitis: An update. Surv Ophthalmol 37:253–272, 1993.

Labalette P, Caillau D, Grutzmacher C, et al: Highly focused clonal composition of CD8(+) CD28 (neg) T-cells in aqueous humor of Fuchs’ heterochromic cyclitis. Exp Eye Res 75:317–325, 2002.

La Hey E, de Jong PT, Kijlstra A: Fuchs’ heterochromic cyclitis: review of the literature on the pathogenetic mechanisms. Br J Ophthalmol 78:307–312, 1994.

Liesegang TJ: Fuchs’ uveitis. In: Pepose JS, Holland G, Wilhelmus K, eds: Ocular infection and immunity. St Louis, Mosby, 1996.

Quentin CD, Reiber H: Fuchs heterochromic cyclitis: rubella virus antibodies and genome in aqueous humor. Am J Ophthalmol 138:46–54, 2004.

Ram J, Kaushik S, Brar G, et al: Phacoemulsification in patients with Fuchs’ heterochromic uveitis. J Cataract Refract Surg 28:1372–1378, 2002.

Iridocyclitis280 CHAPTERHeterochromic Fuchs’ •

Body Ciliary and Iris • 24 SECTION

282 CHAPTER Bombé Iris •

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284 CHAPTERMelanoma Iris •

Body Ciliary and Iris • 24 SECTION

tioned or switched to a different type. If excessive eyelid squeezing is resulting in iris prolapase, then a lid block can be helpful in reducing the pressure on the globe. Recognizing posterior misdirection of fluid as the cause of posterior pressure can be much more difficult. When no other cause is found and the anterior chamber has shallowed significantly, posterior misdirection of fluid should be suspected. This can occur during the hydrodissection of the cataract, but more commonly occurs during phacoemulsification with the infusion of fluid. Other causes of intraoperative iris prolapse, such as choroidal hemorrhage, should be ruled out prior to making the diagnosis of fluid misdirection. If fluid misdirection is the cause of iris prolapse, placing some pressure on the anterior surface of the lens can sometimes slowly result in a regression of the fluid anteriorly. Intravenous mannitol can shrink the vitreous and also be beneficial in treating fluid misdirection. If this maneuver is unsuccessful then a vitreous tap should be performed to reduce the posterior pressure.

Medical

In the early postoperative period, iris prolapse can be treated with a strong miotic. The miotic will result in constriction of the iris which occasionally pulls the prolapsed portion or the iris out of the wound. The late occurrence of an iris prolapse that is small and covered with conjunctiva can often be observed without treatment.

Surgical

If medical treatment is unsuccessful in repositioning the iris, surgery is often needed. If the iris prolapse is large and more than 96 hours old, it is better to excise the prolapsed iris because it is usually necrotic. The iris should be excised if there is any evidence of epithelial or fibrous growth on the iris. Repositioning iris with epithelium can result in epithelial ingrowth with significant complications.

REFERENCES

Allan BDS: Mechanism of iris prolapse: a qualitative analysis and implication for surgical technique. J Cataract Refract Surg 21:182–186, 1995.

Francis PJ, Morris RJ: Post-operative iris prolapse following phacoemulsification and extracapsular cataract surgery. Eye 11:87–90, 1997.

Jaffe NS, Jaffe MS, Jaffe GF: Cataract surgery and its complications. 5th edn. St Louis, CV Mosby, 1990:577–58.

Naylor G: Iris prolapse: who? when? why? Eye 7:465–467, 1993.

Taguri AH, Sanders R: Iris prolapse in small incision cataract surgery. Ophthal Surg Lasers 33(1):66–70, 2002.

286 PARS PLANITIS 363.21

(Angiohyalitis, Chronic Cyclitis,

Cyclitis, Peripheral Uveitis, Peripheral

Uveoretinitis, Vitreitis)

Sema Oruc Dundar, MD

Aydin, Turkey

ETIOLOGY/INCIDENCE

Pars planitis is an idiopathic inflammatory condition characterized by cells and debris in the vitreous and exudates and

snowbank formation along the peripheral retina and pars plana. It occurs in patients between the ages of 5 and 40 years. There is a bimodal distribution pattern with peaks between the ages of 5–15 and 25–35 years. Pars planitis is usually bilateral and frequently asymmetric in severity. It represents 4–16% of all uveitis cases seen in referral practices.

The cause of pars planitis is unknown. Histopathologic and clinical findings suggest a possible autoimmune basis. Several studies have associated HLA-DR2 with pars planitis, suggesting an immunogenetic predisposition. An association was also found with HLA-DR15, a suballele of HLA-DR2.

COURSE/PROGNOSIS

The clinical course of the disease can vary from self-limited to chronic with exacerbations. It can be divided into three categories; 10% of the patients have a self-limited course with gradual improvement, 59% suffer a prolonged course without exacerbations, and 31% show a smoldering course with exacerbations.

The visual prognosis in most patients is relatively good. The most important factor that affects the final visual outcome is the presence of macular involvement.

DIAGNOSIS

Clinical signs and symptoms

The onset is typically insidious and blurred vision and floaters are common complaints. Signs of pars planitis may include:

●Vitritis (mild, moderate, or severe);

●Mild or absent anterior chamber cellular reaction;

●Clumps of inflammatory cells visible in the vitreous;

●Exudate (snowbank) over the inferior peripheral retina and pars plana;

●Vascular sheathing, neovascularization;

●Cystoid macular edema;

●Vitreous hemorrhage;

●Cyclitic membrane formation;

●Cataract;

●Glaucoma;

●Retinal detachment;

●Retinoschisis.

Differential diagnosis

There are no specific tests that establish the diagnosis of pars planitis, which is classically made by observing a snowbank or membrane over the inferior peripheral retina and pars plana. The differential diagnosis includes sarcoidosis, multiple sclerosis, Lyme disease, toxocariasis, intraocular lymphoma and HTLV1.

TREATMENT

Systemic

The goal of therapy is to eliminate or diminish long-term visual loss. The treatment aim is not to eradicate all inflammation but to ameliorate sight-threatening complications. Some clinicians do not treat the disease until visual acuity drops to 20/40, whereas others institute treatment for visually disabling cystoid macular edema in patients with better visual acuity.

Corticosteroids are the mainstay of therapy. Patients who have bilateral disease or whose disease is recalcitrant to periocular steroids can be treated with oral corticosteroids. The

286 CHAPTERPlanitis Pars •

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dose of oral corticosteroids is usually 1 mg/kg/day for 2 to 3 weeks with a slow taper on the basis of clinical response as well as the ocular and systemic complications of such therapy. Antiulcer medications should also be prescribed. In many cases, steroids must be tapered slowly over a period of several months and alternate day therapy is essential in these patients to reduce steroid induced complications.

Other systemic immunosuppressive agents have been used to treat patients whose disease is recalcitrant to other treatment modalities. A good therapeutic response has been reported with the use of chlorambucil, azathioprine, cyclophosphamide, methotrexate and cyclosporin A. All immunosuppressive medications have significant systemic side effects.

Ocular

Periocular corticosteroids are very effective in treating many cases of pars planitis, and especially in treating unilateral asymmetric disease. They have the advantage of causing minimal systemic corticosteroid complications. Triamcinolone acetonide (40 mg/mL) or methylprednisolone acetate depot preparation (80 mg/mL) is injected.

Periocular injections may be delivered to the retroseptal space or the sub-Tenon’s space. One study has shown that the superotemporal posterior sub-Tenon’s approach is more effective in placing the steroid close to the macula than the inferior approach. The conjunctiva is anesthetized topically. The upper eyelid is retracted and the patient is instructed to look inferonasally. The needle is placed bevel toward the globe and advanced through the conjunctiva and Tenon’s capsule using a side-to-side movement in order not to penetrate the globe accidentally. The needle is kept as close to the globe as possible. The needle is advanced to the hub of needle; and the steroid injected into the sub-Tenon’s space. Injections can be repeated every 2 to 3 weeks. Two or three injections should be given over a 6 to 8 week period before concluding that injections are no effective.

Surgical

Cryotherapy of the inferior snowbank has been advocated in patients intolerant of corticosteroids. The cryotherapy is administered directly to the areas of exudates. The iceball should cover the entire area of exudate and overlap the uninvolved areas of retina and ciliary body by one probe width. A single depot injection of corticosteroids is given after the procedure. Patients are usually given at least 3 months before additional treatment is applied. Peripheral scatter photocoagulation also appears to be an effective alternative to cryotherapy in patients with neovascularization of the vitreous base.

Pars plana vitrectomy has been advocated for management of more severe complications of pars planitis, including those with persistent vitreous hemorrhage, dense vitreous debris that is not responsive to medical therapy, persistent cystoid macular edema, retinal detachment, and macular pucker.

COMPLICATIONS

Complications of corticosteroid therapy are numerous and can be seen with any mode of administration. Ocular complications from corticosteroids include the possible development of posterior subcapsular cataract and potentially elevated intraocular pressure.

All immunosuppressive drugs have significant side effects and their use should be monitored by a physician expert in their

use. The major side effects of cyclosporin A are nephrotoxicity and hypertension. Therefore, kidney function and blood pressure must be checked regularly. Patients should be informed of all side effects and risks of immunosuppressive agents.

COMMENTS

Many patients with pars planitis require no treatment. As cystoid macular edema is the leading cause of significant visual loss in pars planitis, most treatment is aimed at elimination of cystoid macular edema.

Generally, treatment is not given unless there is a decrease in visual acuity. The clinician should decide the level of visual acuity to aim at treating the patients. Treatment decisions should be made on an individual basis.

REFERENCES

Henderly DE, Gentsler AJ, Rao NA, et al: Pars planitis. Trans Ophthalmol Soc UK 105:227–232, 1986.

Kaplan HJ: Intermediate uveitis (pars planitis, chronic cyclitis) — a four step approach to treatment. In: Saari KM, ed: Uveitis update. Amsterdam, Excerpta Medica, 1984:169–172.

Oruc S, Duffy BF, Mohanakumar T, et al: The association of HLA class II with pars planitis. Am J Ophthalmol 131:657–659, 2001.

Oruc S, Kaplan AD, Galen M, et al: Uveitis referral pattern in a Midwest University Eye Center. Ocular Immunol Inflamm 11:287–298, 2003.

Smith RE, Godfrey WA, Kimura SJ: Chronic cyclitis.I: course and visual prognosis. Trans Am Acad Ophthalmol Otolaryngol 77:760–768, 1973.

287 RUBEOSIS IRIDIS 364.42

Masanori Ino-ue, MD, PhD

Kobe, Japan

ETIOLOGY/INCIDENCE

Neovascularization of the iris (rubeosis iridis) is a feared complication of a variety of ischemic diseases, often resulting in a severe, usually intractable type of secondary glaucoma.

In our clinic, one-third of rubeosis iridis cases are attributable to diabetic retinopathy, 17% to retinal vein occlusion, and 13% to carotid occlusive disease. One-third are related to other causes, with post-vitrectomy and post-lensectomy procedures being the most predominant. Following central retinal artery obstruction, 1% to 2% of patients develop rubeosis iridis. These patients may have associated carotid artery obstruction. Intraocular tumors, prior retinal detachment surgery, and uveitis may also lead to rubeosis iridis.Localized anterior segment ischemia has been shown to be the cause of rubeosis iridis in Fuchs’ heterochromic iridocyclitis, pseudoexfoliation syndrome, and trauma to the anterior ciliary blood vessels during retinal detachment or strabismus surgery.

The age at the time of development of rubeosis iridis is younger in patients with diabetic retinopathy compared to patients with retinal vein occlusion or carotid occlusive disease.

Sex distribution differs depending on the etiology. Due to the prevalence of other underlying diseases, more males with carotid artery disease develop rubeosis iridis.

The increasing incidence of diabetes mellitus is a major predisposing factor for development of rubeosis iridis, with diabetic retinopathy as the most common association. Bilateral rubeosis is most often seen in patients with diabetes. Patients with underlying diabetes are also prone to develop retinal vein occlusion and carotid occlusive disease.

With the availability of newer diagnostic techniques for carotid occlusive disease coupled with the decreased incidence of rubeosis iridis after retinal vein occlusion secondary to retinal photocoagulation, carotid occlusive disease is becoming a more prominent cause of rubeosis iridis.

DIAGNOSIS

Clinical signs and symptoms

There are four stages in the clinical course of rubeosis iridis, including the pre-rubeosis stage. In may be useful to consider each stage for proper management.

In the pre-rubeosis stage, new vessels on the iris or in the angle are not clinically detectable. The many conditions that may lead to rubeosis iridis have been mentioned previously. Diabetes mellitus, hypertension and arteriosclerosis are the most important systemic predisposing factors, with previous ocular surgery an additional consideration. These patients should undergo a careful fundus fluorescein angiography and slit-lamp examination. Quantitative laser photometry with iris fluorescein angiography may be helpful in detecting occult rubeosis.

The first visible sign of rubeosis iridis appears in stage 2. Tiny tufts of new vessels at the pupillary margin, which may be difficult to detect in a dark iris, can be visualized with the slit-lamp. High magnification is essential for early detection. At this stage, the angle is not yet involved and the intraocular pressure is normal.

In the third stage, the patches of new blood vessels in the iris grow and coalesce. New thin-walled vessels start to invade the iris stroma. At the angle, vessels cross the ciliary body and scleral spur and may extend to the trabecular meshwork. On gonioscopy, the anterior chamber angle will still appear open. Some patients may present with intraocular pressure elevations.

Later, new vessels become more florid and a fibrovascular membrane begins to cover the anterior surface of the iris. The iris surface becomes flat, an ectropion uvea may be present, the pupil is dilated and the iris displaces forward.

Peripheral anterior synechiae (PAS) occur randomly. As the PAS extend and coalesce, angle closure occurs. The findings in gonioscopy are critical in the management of rubeosis iridis. Glaucoma may result from the occurrence of hyphema, the presence of PAS, or from the leakage of protein and cells from the new vessels. The intraocular pressure values in neovascular glaucoma due to carotid occlusive disease may be normal or even subnormal. An eye with low perfusion may have normal intraocular pressure values but is susceptible to damage.

Spontaneous arrest or even total regression of rubeosis iridis may occur. In such cases, the iridi have a flat and scarred appearance.

PROPHYLAXIS

As prophylaxis against the development of rubeosis iridis, patients with retinal hypoxia associated with central retinal vein occlusion and proliferative diabetic retinopathy should

undergo panretinal photocoagulation. To prevent development of rubeosis iridis in high-risk eyes after vitrectomy, extensive endophotocoagulation may be a valuable adjunct procedure. Controlling hypertension in diabetic patients is another form of prophylactic therapy. In carotid occlusive disease, panretinal photocoagulation is perceived as partially effective in preventing late-onset rubeosis iridis. Carotid artery surgery should be performed before the development of rubeosis iridis.

TREATMENT

Ocular

Eyes with diabetic retinopathy, or post-retinal vein occlusion cases that develop early stage rubeosis iridis, with minimal or no angle involvement may benefit from adequate panretinal photocoagulation. Rubeosis iridis may regress in such cases. Even in cases with carotid occlusive disease, panretinal photocoagulation may still reduce iris rubeosis to a certain degree.

In late-stage rubeosis, synechial angle closure may cause severe neovascular glaucoma. Although panretinal photocoagulation cannot reverse angle closure, it may cause regression of new vessels and prevent further closure of the angle. If patients have undergone prior filtration surgery, extensive photocoagulation should be performed.

If panretinal photocoagulation is not possible, retinal cryotherapy is an alternative procedure. Peripheral transscleral retinal diode photocoagulation is also effective in treating patients with rubeosis iridis.

Medical

In secondary open-angle glaucoma, anti-glaucoma medications will be effective to some degree. Topical atropine (1%) twice a day, as well as topical steroids four times per day, are effective in reducing pain and decreases ocular inflammation.

In the latter stages of the disease, any medication acting on aqueous outflow is contraindicated. Medications that reduce aqueous production may be beneficial but may not be sufficient to normalize the intraocular pressure. Hyperosmotic agents may be required for temporary control of marked elevations in intraocular pressure.

Surgical

A vitrectomy–lensectomy procedure is indicated when the lens or vitreous is hazy. However, even if the media are clear, in active early-stage rubeosis iridis, vitrectomy-lensectomy is meant to be an anti-vasoproliferative surgical procedure. This surgery involves extensive endophotocoagulation to the peripheral retina. Silicone oil tamponade also supports rapid regression of rubeosis iridis.

Goniophotocoagulation refers to the direct application of laser to the angle vessels. It is effective in the early stages of rubeosis iridis, prior to the onset of open-angle glaucoma.

Filtration surgery in eyes with active rubeosis may be complicated by intraand post-operative hemorrhage leading to a high risk for late bleb failure. After adequate panretinal photocoagulation, administration of anti-glaucoma medications and topical atropine or steroids, and the use of hyperosmotic agents, trabecular filtration surgery with application of mitomycin C may be effective in regressing active rubeosis iridis.

To resolve the problem of bleb failure in filtration surgery, drainage implants are being employed. However, problems with stent and valve procedures remain.

287 CHAPTERIridis Rubeosis •

Body Ciliary and Iris • 24 SECTION

FIGURE 288.1. Iritis with pupillary membrane.

studies unless the history suggests otherwise. These include a chest radiograph, purified protein derivative (PPD) immune challenge administered subcutaneously, fluorescent treponemal antibody (FTA-ABS) and Lyme C6 peptide, to search for evidence of sarcoidosis, tuberculosis, syphilis and Lyme disease, respectively.

Patients with complaints of joint pain should be further evaluated for autoimmune and infectious arthritides, particularly lupus, rheumatoid arthritis and Lyme disease. Evaluation of the serum for the presence of antinuclear antibody (ANA), antidouble stranded DNA antibody (anti-dsDNA Ab), rheumatoid factor (RF), cyclic citrullinated peptide antibody (CCP Ab), Lyme-C6 peptide antigen and antibody, Western blot and polymerase chain reaction (PCR) could be performed.

At times, certain diagnoses will lead the differential list based upon the clinical picture, such as in a patient with hematochezia (e.g. suspected Crohn’s disease) or a patient with a classic chorioretinal distribution of inflammation (e.g. birdshot chorioretinopathy); confirmation of the diagnosis is still important. In such cases, it may be useful to search for the presence of particular human leukocyte antigen (HLA) serotypes known to be associated with uveitis. Examples include HLA B27 (ankylosing spondylitis, Reiter’s syndrome, psoriatic arthritis and inflammatory bowel disease-associated spondylarthropathy), HLA B5 and B51 (Behçet’s disease), HLA B7 (serpiginous choroiditis) and HLA A29 (birdshot chorioretinopathy).

In some patients who do not respond to therapy, a diagnostic paracentesis of the anterior chamber or vitrectomy could be quite helpful. Often, these procedures are the only way to diagnose lymphoid malignancies masquerading as uveitis.

TREATMENT

Treatment of uveitis is dependent on the etiology, duration of disease, severity and location of inflammation, as well as the potential complications of therapy. For infectious uveitis, treat-

ment is directed at the inciting organism; this generally leads to elimination of the inflammation. There are times when judicious use of steroids can help reduce collateral damage caused by inflammation. Treatment of immune-mediated uveitis is determined more by severity and location than by etiology.

Systemic

Oral steroids are the mainstay of systemic therapy against uveitis that has not responded to topical or periocular medication and that is not associated with infection or malignancy. The goal of therapy is to maximize anti-inflammatory efficacy while minimizing side effects. Often, the inflammation will not be eliminated but only reduced to a tolerable level. For the first four weeks, prednisone 60 mg daily is prescribed. Once the inflammation is controlled, a gradual tapering schedule is implemented. Pulse intravenous steroid therapy (1 gm/day methylprednisolone × 3 days) can be used as initial therapy in some patients.

A trial of immunosuppressant therapy is suggested by the International Uveitis Study Group for patients with bilateral disease, and/or vision loss below 20/50 and/or failure to respond to steroids. Currently used agents include cyclosporin A (2.5– 5 mg/kg PO daily), hydroxychloroquine, and cytotoxic agents such as azathioprine, chlorambucil, cyclophosphamide, and methotrexate (7.5–25 mg/week). Novel agents such as anti-TNF monoclonal antibody, thalidomide, tacrolimus and interferonalpha are currently being evaluated and have shown some promise. Nonsteroidal anti-inflammatory agents such as indomethacin and flurbiprofen are of limited value. Immunosuppressive therapy should be monitored closely by oncologists or rheumatologists.

Ocular

Topical therapy for iritis should include a steroid and cycloplegic. As a general rule, medications that cause lesser adverse effects provide a weaker therapeutic response.

Steroid preparations include prednisolone, dexamethasone, rimexolone and fluoromethalone; therapy should be initiated as soon as possible. Intensive therapy, such as hourly dosing or employing medication-soaked pledgets placed in the conjunctival fornices may give more rapid relief. Thereafter, drops are prescribed every 4–6 hours. Dexamethasone is available as an ointment.

Periocular steroid injection is an excellent choice for unilateral and/or posterior uveitis. For anterior uveitis, the depot site is the subconjunctival space of the inferior fornix, while for posterior inflammation, a superotemporal depot in the subTenon’s space or anterior placement with a trans-septal approach is suggested. Available preparations include dexamethasone, betamethasone, triamcinolone and methylprednisolone. Shorter acting compounds such as dexamethasone may be preferred where the risk of steroid-induced glaucoma is unknown. Injections of 1mL can be repeated every 2–6 weeks and the injection site should be varied to ensure adequate delivery of drug.

Choices of cycloplegics include cyclopentolate (0.5–2% t.i.d.), homatropine (2–5% b.i.d.), and atropine (1% b.i.d.). The inflamed eye metabolizes the cycloplegic agents more rapidly so dosing may have to be increased. However, the goal of cycloplegia is to reduce pain without maintaining constant mydriasis, so as to prevent anterior and posterior synechialization.

Glaucoma secondary to 360 degree posterior synechialization is best treated with peripheral laser iridotomy.

Vitrectomy is an option for severe vitreous opacification that has failed other therapy. Cryotherapy and laser photocoagulation may be considered for localized pars plana exudates. Cataract surgery is optimally performed in a quiescent eye. In all

288 CHAPTER Uveitis •

Body Ciliary and Iris • 24 SECTION