Severe Z Syndrome

with the Plate-Haptic SiliconeHinged Accommodating IOL

Leonard H Yuen, MD MPH MRCOphth Shu-Yen Lee, MD FAMS

Wei-Han Chua, MD FAMS

SINGAPORE NATIONAL EYE CENTRE (SNEC)

The authors have no financial interest in the subject matter of this poster

Background

• The Crystalens (Bausch & Lomb, USA) accommodating IOLs are gaining popularity for patients hoping to obtain functional distance and mid-range vision following crystalline lens removal

• Recently case reports of accommodating lens tilting described as “Z Syndrome” have been published following uneventful cataract surgery 1,2,3,4 particularly with the Crystalens AT45.5,6

(Bottom picture courtesy: J Cazal, MD, and C. Verges, MD)

• In a previous case series of Z syndrome, the use of Nd:YAG capsulotomy was successful in treating the lens tilt even after 9 weeks postoperatively.1 However, we believe that this treatment is effective only in mild cases.

• To our knowledge this is the first reported case of Severe Z Syndrome with the Crystalens AT52SE, which warranted intraocular repositioning of the lens to restore anatomical positioning and achieve optimal visual outcome.

Case Report

A 45-year old female high myope with a manifest refraction of OS -11.00 -0.25 x

090 (DBCVA 20/20) underwent uneventful cataract surgery.

Intraoperatively, a clear corneal incision was made and Amvisc viscoelastic was

used. A 5.5mm complete circular capsulorrhexis was done and a +10.0 dioptre (D)

Crystalens AT52SE was implanted in the bag. No complications, specifically capsular

bag rupture or zonulysis, were observed.

POD 1: UCVA 20/80 and slit lamp examination was unremarkable

POW 3: DBCVA 20/20 with a manifest refraction of OS -1.00 -1.00 x 005

POW 4: Pt noticed a decrease in UCVA. Manifest refraction OS -1.50 -2.00 x 175

POW 12: Immigrated abroad and presented to the Singapore National Eye Centre

Slit lamp examination showed a dramatic forward protrusion of the inferior optic-haptic junction that encroached into the anterior chamber beyond the plane of the dilated pupil

UCVA at this point was 20/400, with a manifest refraction of OS +1.50 -4.00 x 100 (DBCVA 20/50). A near addition of +2.00 could only achieve N18, equivalent to Snellen 20/120

Superior anterior capsular phimosis with optic capture was noted, with encapsulation of the superior haptic within the bag. The inferior portion of the optic was squeezed forward. Retro-illumination revealed capsular wrinkling.

Treatment with neodymium:YAG laser capsulotomy was considered,

but the severity of the tilting deterred the decision of doing so

and subsequent intraocular manipulation was performed.

Intraoperatively the inferior lens haptic was freed from the capsular fibrosis and

iris hooks were used to immobilize the iris and to immobilize the pupil maximally.

The superior haptic was enveloped firmly by the fibrosed capsule and thus left

unmanipulated. The optic was pressed backwards and the haptic hinges vaulted

posteriorly to its anatomical position.

First day postoperatively, UCVA was 20/25 OS;At one month, UCVA was 20/20, with a manifest refraction of plano -0.75 x 15. A +2.00D near add lens allowed her to read N5, equivalent to Snellen 20/20.

There was obvious flattening of the inferior iris:

Preop: +1.50 -4.00 x 100 Postop: Plano -0.75 x 15

ASOCT confirmed a posteriorly vaulted IOL

Pre-operative Post-operative

DiscussionThe Crystalens AT52SE is a biconvex silicone plate IOL with an enlarged 5.0 mm optic. Its hinges are designed to move anteriorly during accommodation to achieve near focus.

INTRINSIC DESIGNThe lens’ square edge design reduces posterior capsule opacity however its effectiveness is unknown in patients under 50 years of age7 as in this patient.

The hinged accommodative mechanism of the Crystalens is believed to be capsule dependent. Capsular fibrosis can however impede the axial movement, and in cases of asymmetric capsular fibrosis the IOL can decentrate.6 Its makeup of silicone material has not been shown to increase lens decentration or tilting.3,4

Pointers suggested to reduce the incidence of Z-Syndrome:1. Appropriately sized capsulorrhexis (5.5 to 6.0mm, as in this case)2. Round CCC with the anterior capsule covering the plate haptics7 3. Cortical removal7 4. Capsular polishing5

5. Ophthalmic viscoelastic devices (OVD) should also be entirely removed from behind the lens and the IOL gently nudged backwards at the final stages of cataract surgery.

We are unaware of reports of asymmetric tilting with other types of IOLs. Mild Z-Syndrome with the Crystalens were remedied by Nd:YAG capsulotomy.1

In this severe case, which resembles more like the letter “N”, surgicalrepositioning is more appropriate. Previous reports have suggested IOLexchange6 as an option however in this case IOL exchange would have been difficult as the haptic was entrenched within the superior capsule adhesions.

References

1. Yuen L, Trattler W, Boxer Wachler B. Two Cases of Z syndrome with the Crystalens after uneventful cataract surgery. J Cataract Refract Surg. 2008 Nov;34(11):1986-9.

2. Arkin C, Ozler SA, Mentes J. Tilt and decentration of bag-fixated intraocular lenses: a comparative study between capsulorhexis and envelope techniques. Doc Ophthalmol. 1994;87(3):199-209.

3. Hayashi K, Harada M, Hayashi H, Nakao F, Hayashi F. Decentration and tilt of polymethyl methacrylate, silicone, and acrylic soft intraocular lens. Ophthalmology. 1997 May;104(5):793-8.

4. Jung CK, Chung SK, Baek NH. Decentration and tilt: silicone multifocal versus acrylic soft intraocular lenses. J Cataract Refract Surg. 2000 Apr;26(4):582-5.

5. Jardim D, Soloway B, Starr C. Asymmetric vault of an accommodating intraocular lens. J Cataract Refract Surg. 2006;32:347-350.

6. Cazal J, Lavin-Dapena C, Marin J, Verges C. Accommodative Intraocular Lens Tilting. Am J Ophthalmol. 2005 Aug;140(2):341-4.

The authors believe that

there is no uniform

treatment to treat this

syndrome, however the

severity of the

configuration of the IOL

and its relation to the

capsule will help guide

the surgeon to the

appropriate management

option.