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REVIEW ARTICLES
NUMBER 3-4 YEAR 2009
Pseudoexfoliation Syndrome and Cataract Surgery in Pseudoexfoliation Syndrome
1 Clinic of Ophthalmology, Timisoara

Correspondence to:
Dr. Attila Robert Crista, Clinic of Ophthalmology, Radian Belici Sq., Timisoara
Tel: +40256/204467
E-mail: aty_c@yahoo.com
REZUMAT
Sindromul pseudoexfoliativ este o boala sistemica cu manifestare primara oculara. Sindromul pseudoexfoliativ este caracterizat de producerea si acumularea progresiva de material fi brilar extracelular in diverse structuri oculare. Substanta fi brogranulara extracelulara de culoare gri albicioasa similara amiloidului este depozitata pe capsula anterioara a cristalinului, pe marginea pupilara, in zonula, in corpul ciliar, iris, trabecul, vitrosul anterior si conjunctiva. Integritatea zonulei trebuie evaluata preoperator la biomicroscop, urmarindu-se prezenta faco sau iridodonezisului. Facoemulsifi carea ultrasonica este procedeul chirurgical de preferat la pacientii cu pseudoexfoliere.

ABSTRACT
Pseudoexfoliation syndrome is a systemic disease with primary ocular manifestations. Pseudoexfoliation syndrome is characterized by the production and progressive accumulation of a fi brillar extracellular material in many ocular tissues. A grey-white, fi brillogranular, extracellular, matrix material similar to amyloid, is deposited on the anterior lens capsule, pupillary margin, zonules, ciliary body, iris, trabeculum, anterior vitreous face and conjunctiva. Zonular integrity should be evaluated preoperatively at the slit lamp by looking for the presence of phacodonesis or iridodonesis. Phacoemulsifi cation is usually the procedure of choice for patients who have a history of pseudoexfoliation.
INTRODUCTION

Pseudoexfoliation syndrome is a systemic disease with primary ocular manifestations.
Figure 1. The grey-white deposit.
The pseudoexfoliation syndrome is a relatively common but easily overlooked cause of chronic open angle glaucoma.1 Patients with pseudoexfoliation syndrome remain asymptomatic until an advanced glaucoma develops. The condition is most common in the sixth to eighth decade, with actual glaucoma developing later in this age range. There is no racial, gender or geographic predilection.2
Pseudoexfoliation syndrome is characterized by the production and progressive accumulation of a fi brillar extracellular material in many ocular tissues.
There is often increased transillumination of the iris at the pupillary margin, and there may be pigment granules on the endothelium and iris surface. A greywhite, fi brillogranular, extracellular, matrix material similar to amyloid, is deposited on the anterior lens capsule, pupillary margin, zonules, ciliary body, iris, trabeculum, anterior vitreous face and conjunctiva.2 (Fig. 1) Initially, intraocular pressure is unaffected.
Secondary trabecular block glaucoma is thought to result from a combination of “clogging up” of the trabeculum by pseudoexfoliative material and/or pigment released from the iris, as well as trabecular endothelial dysfunction.1

MORPHOPATHOLOGY

Due to accumulation of abnormal basement membrane material at the pupillary margin, there is increased apposition with the iris and subsequent erosion of iris pigment as the pupil dilates and constricts. This leads to increased iris transillumination and deposition of pigment granules on the endothelium, iris surface and trabecular meshwork similar to pigment dispersion syndrome. Because this condition involves deposition of material on the anterior lens capsule and not fl aking-off of the lens capsule, lensectomy is not a remedy. In fact, some have observed exfoliative material deposits on intraocular lens implants.1,2

CLINICAL FEATURES

Cornea: Flakes of exfoliation material may be present on the corneal endothelium. There may be a diffuse, nonspecifi c pigmentation of the central endothelium, occasionally having the pattern of a Krukenberg spindle. Pigment is characteristically deposited on Schwalbe’s line and sometimes as a wavy line or lines anterior to Schwalbe’s line (Sampaolesi line).
The number of corneal endothelial cells is reduced and central corneal thickness is also greater in eyes with pseudoexfoliation syndrom, perhaps refl ecting early corneal dysfunction. Specular microscopy is extremely useful in evaluating the cornea befor cataract surgery. These changes predispose to early corneal decompensation at only moderate rises of intraocular pressure (IOP) or after cataract surgery.1,2

Figure 2. The deposits at the lens level.
Iris: Iris changes are an early and well recognized clinical feature. Next to the lens, exfoliation material is most prominent at the pupillary border. Pigment loss from the iris sphincter region and its deposition on anterior chamber structures is a hallmark. Loss of iris pigment and its deposition throughout the anterior segment are refl ected in iris sphincter region transillumination defects, loss of the pupillary ruff, pigment dispersion in the anterior chamber after pupillary dilation, increased trabecular meshwork pigmentation, and pigment deposition on the iris surface.1,2

Lens: Deposits of white material on the anterior lens surface are the most consistent and important diagnostic feature. (Fig. 2) The classic pattern consists of three zones: a central disc corresponding roughly to the diameter of the pupil; a granular, often layered,
peripheral zone, and a clear area separating the two.
The central zone is a homogeneous, white sheet and is often absent, while the peripheral zone is always present. The clear zone is created by rubbing of the iris over the surface of the lens during pupillary movement. Phacodonesis, or looseness of the lens
because of damage to the zonules which hold the lens in place, is common and is one of the leading factors predisposing to an increase in complications at the time of cataract surgery.1,2

CATARACT SURGERY IN PSEUDOEXFOLIATION SYNDROME

When cataract surgery and IOL placement are planned, especially for a patient who has a prior history of pseudoexfoliation syndrome, it is important to evaluate the status of the zonules and careful examination of the cornean endothelial cell population before surgery with specular microscopy.
As a young specialist, it is advisable to avoid these cases which should be addressed to experienced ophtalmological surgeons.
Zonular integrity should be evaluated preoperatively at the slit lamp by looking for the presence of phacodonesis or iridodonesis. If any
question of loss of zonular integrity exists on the basis of slit lamp evaluation, the zonules must be evaluated gonioscopically – trabecular hyperpigmentation is common and is usually most marked inferiorly.3,4
A scalloped band of pigment running on to or anterior to Schwalbe line (Sampaolesi line) is also frequently seen. Pseudoexfoliation may be deposited in the trabeculum and give rise to a "dandruff-like" appearance.4
Great care must be taken during the cataract extraction to preserve the integrity of the zonules, posterior capsule, and capsular fornices. The technique used for cataract extraction when the integrity of the zonules is in question depends upon the surgeon's experience and preference.5
These operations can be performed by different techniques: intracapsular and extracapsular (MININUC, Phacoemulsifi cation).
Phacoemulsifi cation is usually the procedure of choise for pacients who have a history of pseudoexfoliation. It is indicated to use viscoelastic substances with this technique. these may be:
-cohesive, dispersive and cohesivous-dispersives. Cohesive viscoelastics provide good anterior chamber maintenance and they tend to hold together. Dispersive viscoelastics coat and protect intraocular tissues (especially endothelium). Cohesivous-dispersives viscoelastics is suitable for all surgical procedures that require viscoelastic most of all because it exhibits both cohesive and dispersive properties but also because he provides good visualization during surgery, is easy to inject, offers good protection to intraocular structures and still is easy to remove at the end of surgery.
Figure3. Endocapsular tension ring (Morcher).
A large capsulorrhexis (at least 5.5mm diameter) is made to facilitate removal of nuclear fragments with minimal stress on the zonules. Careful and complete hydrodissection and hydrodelineation are carried out so that the nucleus rotates easily with in the epinuclear bag, which decreases stress on the zonules during nuclear manipulation. A variety of special techniques are available to deal with pseudoexfoliation to minimize the likelihood of zonular ligament dehiscence or loss of nucleus. The use of an endocapsular tension ring
(Morcher) to create a circumferential distribution of forces around the zonular apparatus is an aid to prevention of zonular dehiscence.5 (Fig. 3)
These rings are left in place after surgery to help both expand and center the capsular bag postoperatively, thus keeping the lens implant from migrating away from areas of zonular dehiscence. As possible complications we mention zonular rupture, cornean oedema, luxation of the nucleus into the vitreous cavity, which may be prevented by using endocapsular tension rings and viscoelasic substances.
If no capsular support exists, both haptics may be sutured, either to the iris or trans-sclerally.
Transcleral and iris fi xation procedures are technically more diffi cult. The surgeon may opt for placement of anterior chamber the IOL.5 This options is not recommended because anterior chamber implants seem to be harmful for the cornea causing endothelial cell loss.
REFERENCES

1. Kanski JK. Clinical Ophthalmology. A systematic approach. 5th Edition, Butterworth-Heinemann, 2003, p. 229-231.
2. Cernea P, Constantin F. Glaucomul.Fiziopatologia si clinica hipertensiunii intraoculare. Editura Medicala: Bucuresti, 1979, p. 181-3.
3. Cernea P. Tratat de Oftalmologie. Editura Medicala: Bucuresti, 1997, p. 514.
4. Spalton DJ, Hitchings RA, Hunter PA. Atlas of Clinical Ophthalmology. 3rd Edition, Elsevier-Mosby: Philadelphia, 2005, p. 243-5.
5. Yanoff M, Duker JS. Ophthalmology. 2nd Edition, Mosby, 2004, p. 324-5.



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