Ординатура / Офтальмология / Учебные материалы / Clinical Diagnosis and Management of ocular trauma

Toxic Anterior Segment Syndrome

257

Proactive reporting to local regulatory authorities and

Conclusion

seeking support from colleagues, as well as academic

TASS outbreaks have become of major concern in

and public health resources is advisable.10,27

the ophthalmology community. The assembly of the

CASE AND OUTBREAK DEFINITION

TASS task force and the numerous recent studies on

the subject has assisted in controlling TASS outbreaks.

Postoperative anterior segment inflammation of

The final task force report concluded that there was

unknown cause occurring within 48 hours of surgery

no one factor attributable to TASS outbreaks but rather

with one or more of the following features: anterior

multiple potential etiological factors. It appeared that

chamber response 2+ or greater, fibrin, membranes,

cleaning and sterilization of instruments for cataract

corneal edema without significant vitritis.10 Criteria for

surgery was the most important of the identified factors.

a TASS outbreak have not been established as they

It is recommended that all reusable cannulas and

have for conditions such as DLK.28 However, any

instruments be thoroughly flushed with sterile,

occurrence of more than two affected patients should

deionized/distilled water after cleaning at the conclusion

raise concerns and merit investigation since this may

of each case.29

rapidly escalate.

Although TASS outbreak reports, at least in the

DATACOLLECTION

United States, now appear to be declining it is

important to constantly monitor and improve cleaning

Suggested data include; demographics, VA before and

and sterilization protocols. Growing awareness resulting

after surgery, symptoms, clinical features, day of

in early diagnosis and treatment, with prompt

surgery, day of onset and diagnosis, any associated

dissemination of new information will hopefully

conditions, subsequent management and outcome. It

eliminate TASS as a significant complication of modern

is important to record details of the surgical procedure

cataract surgery.

including instrument preparation and specifically any

staffing or procedural changes made prior to the onset.

References

Retrospective collection of data is difficult and it is

recommended to collect data and note changes as they

1. Monson MC, Mamalis N, Olson RJ. Toxic anterior

happen making the creation of an epidemic curve less

segment inflammation following cataract surgery. J

problematic.

Cataract Refract Surg 1992;18:184-9.

MICROBIAL INVESTIGATIONS

2. Breebaart AC, Nuyts RMMA, Pels E, et al. Toxic

endothelial destruction of the cornea after routine

Bacterial culturing, biofilm sampling and analysis of

extracapsular cataract surgery. Arch Ophthalmol 1990;

108:1121-5.

steam distillate and BSS for endotoxin may help

3. Kreisler KR, Martin SS, Young CW, et al. Postoperative

determine the cause of the outbreak. The sterilizer

inflammation following cataract extraction caused by

reservoir, internal tubing of the sterilizer, ultrasound

bacterial contamination of the cleaning bath detergent.

baths, cannulas and air and water supplies have proved

J Cataract Refract Surg 1992;18:106-10.

to be useful sampling areas.10,12,13

4. Nelson DB, Donnenfeld ED, Perry HD. Sterile

TASS investigations are often difficult and require

endophthalmitis after sutureless cataract surgery.

careful planning. It is usually best to designate one

Ophthalmolgy 1992; 99:1655-7.

5. Liu H, Routley I, Teichmann KD. Toxic endothelial cell

staff member to manage the outbreak, including data

destruction from intraocular benzalkonium chloride. J

collection and media consultation. Another important

Cataract Refract Surg 2001; 27:1746-50.

issue to consider is the disclosure of TASS as a further

6. Jehan FS, Mamalis N, Spencer TS, et al. Postoperative

risk of cataract surgery, particularly during a TASS

sterile endophthalmitis (TASS) with the MemoryLens. J

outbreak.

Cataract Refract Surg 2000; 26:1773-7.

Once an investigation has been concluded dissemi-

7. Eleftheriadis H, Cheong M, Saneman S, et al. Corneal

nation of the findings will help other practitioners solve

toxicity secondary to inadvertent use of benzalkonium

chloride preserved viscoelastic material in cataract

their TASS outbreaks or hopefully avoid them. The

surgery. Br J Ophthalmol 2002; 86:299-305.

TASS task force is one example of how this sharing

8. Werner L, Sher JH, Taylor JR, et al. Toxic anterior

of knowledge has likely reduced the risk of further

segment syndrome and possible association with

outbreaks.

ointment in the anterior chamber following cataract

surgery. J Cataract Refract Surg 2006; 32:227-35.

INVESTIGATION

9. Hellinger WC, Hasan SA, Bacalis LP, et al. Outbreak of

toxic anterior chamber syndrome following cataract

Suspect everything.

surgery associated with impurities of autoclave steam

258

Clinical Diagnosis and Management of Ocular Trauma

moisture. Infect Control Hosp Epidemiol 2006;

www.ascrs.org/press_releases/Toxic-Anterior-Segment-

27(13):294-8.

Syndrome-Outbreak-Preliminary-Report.cfm.

10. Holland SP, Morck DW, Chavez G, Lee, TL. Toxic anterior

20. The American Society of Cataract and Refractive Surgery

segment syndrome. In Agarwal A (Ed). Refractive Surgery

(ASCRS) (2005). Press release May 22, 2006: TASS

Nightmares: Conquering Refractive Surgery Catastrophes.

Outbreak Update. Retrieved June 1, 2006, from http:/

Thorofare, NJ: SLACK Incorporated. In press.

/www.ascrs.org/press_releases/upload/Update

11. Mamalis N, Edelhauser HF, Dawson DG, et al. Toxic

Briefing.doc.

anterior segment syndrome. Review/update. J Cataract

21. Parikh C, Sippy BD, Martin DF, Edelhauser HF. Effects

Refract Surg 2006; 32:324-33.

of enzymatic sterilization detergents on the corneal

12. Holland SP, Chavex G, Morck D, Mathias. Toxic Anterior

endothelium. Arch Ophthalmol 2002; 120:165-72.

Segment Syndrome After Cataract Surgery Associated

22. Whitby JL, Hitchins VM. Endotoxin levels in steam and

with Short-Cycle Sterilization presented at the ASCRS

reservoirs of table-top steam sterilzers. J Cataract Refract

Symposium on Cataract, IOL and Refractive Surgery, San

Surg 2002; 18:51-2.

Francisco, USA , March 17-22, 2006. Available at

23. Meltzer, DW. Sterile hypopyon following intraocular lens

www.ascrs.org. Accessed June 12, 2006.

surgery. Arch Ophthalmol 1980; 98:100-4.

13. Holland SP, Morck D, Lee T. Update on toxic anterior

24. US Food and Drug Administration. (2006). Patient

segment syndrome. Current Opinion in Ophthalmology.

advisory Feb 13th 2006; FDA-Requested Recall - Cytosol

In press.

Laboratories, Inc. Product Contains Dangerous Levels of

14. Van Gelder RN. Applications of the polymerase chain

Endotoxin. Retrieved Feb. 14, 2006, from http://

reaction to diagnosis of ophthalmic disease. Surv

www.fda.gov/bbs/topics/news/2006/NEW01315.html.

Ophthalmol 2001; 45(3):248-58.

25. Holland SP, Mathias RG, Morck DW, et al. Diffuse

15. West ES, Behrens A, McDonnell PJ, et al. The incidence

lamellar keratitis related to endotoxins released from

of endophthalmitis after cataract surgery among the US

sterilizer reservoir biofilms. Ophthalmol 2000; 107(7):

medicare population increased between 1994 and 2001.

1227-33.

Ophthalmology 2005; 112:1388-95.

26. Rietschel ET, Brade H. Bacterial endotoxins. Sci Am 1992;

16. Wallin T, Parker J, Jin Y, et al. Cohort study of 27 cases

267:54-61.

of endophthalmitis at a single institution. J Cataract

27. Mamalis, N. TASS outbreaks: What should we do?

Refract Surg 2005; 31:735-41.

Cataract and Refractive Surgery Today, July 2006;53-5.

17. Duffy RE, Brown SE, Caldwell KL, et al. An epidemic of

28. Bigham M, Enns CL, Holland SP, et al. Diffuse lamellar

corneal destruction caused by plasma gas sterilization;

the toxic endothelial cell destruction syndrome team.

keratitis complicating laser in situ keratomileusis;

Arch Ophthalmology 2000;118:1167-76.

postmarketing surveillance of an emerging disease in

18. Moshirfar M, Whitehead G, Beutler BC, et al. Toxic

British Columbia, Canada, 2000-2002. J Cataract Refract

anterior segment syndrome after Verisyse iris-supported

Surg 2005; 31:2340-44.

phakic intraocular lens implantation. J Cataract Refract

29. The American Society of Cataract and Refractive Surgery

Surg 2006; 32(7):1233-7.

(ASCRS). (2005). Press release September 22, 2006:

19. The American Society of Cataract and Refractive Surgery

Toxic Anterior Segment Syndrome (TASS) Outbreak Final

(ASCRS) (2005). Press release June 22, 2006: TASS task

Report. Retrieved September 22, 2006, from http://

force. Retrieved

August 15, 2006, from http://

www.ascrs.org/press_releases/Final-TASS-Report.cfm.

260

Clinical Diagnosis and Management of Ocular Trauma

of pupil stretching techniques is a usual indication to

Masket19 and Yuguchi and coauthors20 recommends

the intraoperative use of iris hooks or other mechanical

the pupil not be stretched by the hooks to larger than

pupil dilation devices. For the iris retraction several

a 5.0 mm square because overstretching produces

devices have been introduced in the clinical practice.

irregular atonic pupils postoperatively. Novak21 suggests

The main disadvantages of these devices include the

the use of hooks with rigid pupils smaller than 3.0 mm

bulkiness and rigidity. They are difficult to insert,

(4.0 mm with a hard nucleus) and smaller than 4.0

remove, and manipulate through a small incision.

to 5.0 mm for an inexperienced surgeon. In extremely

Graether12 developed a pupil expander that

small and rigid pupils he prefers combining the use

according to his data is superior to other methods of

of hooks with a radial sphincterotomy.

pupil enlargement, causing less sphincter trauma and

During engagement of the pupillary edge with the

fewer cases of permanent pupil size alteration. Pupil

iris hook, it may catch and damage the capsule, leading

dilation technique with the hydrogel ring reported by

to an anterior capsule tear that may extend to the

Siepser6 has a potential benefits but very limited clinical

periphery. To avoid this problem, a drop of viscoelastic

use. The Perfect Pupil device (Milvella) is a disposable

material should be injected between the iris and the

polyurethane ring with the 0.24 mm flanged groove

capsule before the hook is inserted. The other useful

throughout the length of the ring and an integrated

technique is to keep the hook parallel to the iris plane

arm that allows insertion and removal from the anterior

during the insertion and to tilt it slightly posterior right

chamber at the end of surgery.11

near the pupillary edge to engage the iris only. The

Retracting the iris tissue rather than cutting it as

iris hooks may become loosened during surgery. Their

in a classic sector iridectomy is much simpler and results

tips may become dislocated, no longer holding the

in a much better postoperative pupil appearance.

pupillary edge. This can cause some problems including

Mackool13 was the first one who described a 4-point

iris aspiration and chafing from contact with the

iris retractor configuration for phacoemulsification. He

phacoemulsification needle.

developed metal iris retractors connected to small

Small degrees of pupil dysfunction are common

blocks of titanium. The latter allows for stabilization

place after cataract surgery with and without iris mani-

of the hooks during the retraction of the iris. This

pulation but usually this causes no subjective

method was enhanced with the introduction of the

symptoms. Halpern and coauthors22 found an

flexible iris retractor by de Juan and Hickingbotham.14

incidence of postoperative atonic pupil of 1.1% after

Traditionally, 4 evenly spaced retractors are placed

phacoemulsification, with pupil diameters ranging from

through limbal paracentheses 90 degrees apart from

6.0 to 8.0 mm.

one another. The corneal incision is centered on 1 of

Most of the surgical maneuvers for enlarging the

the 4 sides of the square.15 Some surgeons use iris

pupil and preventing its intraoperative constriction are

retractors in a triangular pattern decreasing the number

not safe enough. They can lead to an increased risk

of additional corneal incisions. The use of the iris hooks

of iris sphincter tear, bleeding, iris damage, posterior

may lead to the damage of the pupillary margin

capsule tears, and loss of the vitreous body. The

intraoperatively producing a semimydriatic non-

postoperative complications can include an atonic pupil

reacting pupil postoperatively.

of irregular shape with poor cosmetic result, and

Modification of the original square retractor

photophobia.

configuration is described by16 the rotation of the square

The rate of occurrence of iris prolapse has been

improveslensaccessinclearcornealphacoemulsification

reported between 0.3% and 1% in complicated cataract

by orienting the phacoemulsification needle along the

cases.23 Allan24 described one of the critical factors of

diagonal. This was called by Dupps and Oetting

iris prolapse during phaco which relates to fluid velocity.

“diamond configuration” of retractors.17 Advantages

Allan’s model considers the Bernoulli principle as the

of this technique include ease of conversion from

most important because when the velocity of fluid

phacoemulsification, optimal orientation of the maxi-

passing through the anterior chamber increases, the

mum pupil diameter nucleus expression or intracapsular

force exerted on the iris increases by the square of

lens removal, and conservation of iris tissue.

the velocity.

Birhall18 assessed the effect on pupil shape and

We calculated the speed of the emulsion in the

circumference of various flexible iris hook positions.

anterior chamber during the phaco procedure with the

He confirmed that malpositioned iris hooks may

Millenium CCS (Bausch and Lomb) for US handpiece

increase pupil stretching with possible deleterious effects

settings: 1.0 mm Microflow US needle, vacuum 300 mm

on postoperative pupil function. He recommends

Hg, bottle height 85 cm, and I/A handpiece settings:

using additional fifth hook to create a pentagonal pupil

coaxial handpiece, 0.3 mm opening, vacuum 550 mm

that reduces pupil stretching by 17%.

Hg, bottle height 90 cm. For the calculation we utilized

Small Pupil Phaco: An Innovative Technique

263

viscosurgical devices to perform cataract surgery in

patients taking tamsulosin. This method uses a

combination of the two OVDs. The lower-viscosity

dispersive OVD which is highly retentive despite the

presence of moderate fluid turbulence is injected in

the periphery of the anterior chamber and covers the

endothelial layer and the iris. The viscoadaptive central

layer of Healon5, according to S.Arshinoff adds a

relatively rigid OVD roof above the surgical space and

adds rigidity to the OVD structure to keep the iris from

moving and the Viscoat in place. The BSS layer just

over the pupillary space and below viscoadaptive central

layer provides working space for the phaco tip. The

Fig. 41.7: The principle of iris pupillary margin fixation

surgeon is working in the endocapsular space and

with the curl of IQ-ring

Healon5 is not attracted into the phaco tip and the

The insertion of IQ-ring is carried out through the

OVD shell structure remains intact throughout the case.

main incision. The pupil expander is positioned

This technique gives satisfactory iris stability and permits

centrally and gently pushed at each angle with the

uneventful surgery.

help of a Sinskey hook to trap the iris in the four curls.

Cataract surgery in cases of iridoschisis may result

Once in place, the ring expands the pupillary opening

in aspiration of iris fibers flowing in the anterior

to 6.0 mm. The IQ-ring provides stable mydriasis with

chamber.5, 11 In these cases stretching the iris with various

instruments or dilating the pupil with iris retractors may

no trauma to the iris tissue and no need for additional

paracentheses. It retracts the iris away from the flow

not prevent the danger contact of US needle with the

currents and thus helps to prevent its incarceration

iris tissue and aspiration of fibers.

Intaoperative iris manipulations may lead to severe

into the US and I/A handpieces. As the result of the

postoperative fibrinoid reaction especially in eyes with

IQ-ring implantation we obtain a square, 6 mm pupil

pseudoexfoliation syndrome, chronic uveitis, glaucoma

dilation that allows for safe and comfortable maneuvers

or diabetes. Tat is why cataract surgery in the presence

during phacoemulsification.

of a small pupil remains one of the most difficult and

The ring is usually inserted at the beginning of the

challenging cases.

phaco procedure through an unenlarged 2.8 mm clear

IQ-ring

corneal incision into the pupillary aperture. The

surgeon can control the iris without significant changes

“To enhance phaco surgery in complicated small-pupil

of his accustomed technique. The capsulorhexis,

cases we designed the new device which was called

hydrodissection, phacoemulsification, and injection of

IQ-ring (Fig. 41.6). It is used in cases of pupil miosis

the intraocular lens are performed through the

refractory to dilation protocols. The device is a square,

expanded pupil with the device in place. In case of

O-shaped, temporary implant with four circular curls

necessity the ring can be inserted at any stage of the

that holds the iris at equidistant points. One-piece

operation.

design with the curls at each angle of the ring provides

Cadaver eye study using scanning electronic micro-

balanced stretching and gentle holding of the iris tissue.

scopy showed that much less damage to the pigmented

The main principle of iris pupillary margin fixation with

iris tissue was caused by the new instrument than by

the curl is represented on Figure 41.7.”

conventional iris retractors (Figs 41.8 and 41.9).

Topical anesthesia is applied using 2% lidocain, and

the paracenthesis is done at 12 o’clock. A 2.8 mm

temporal clear corneal incision is performed using the

disposable metal blade. A dispersive ophthalmic

viscosurgical device (OVD) is injected in the anterior

chamber to stabilize it and protect the corneal

endothelium. The IQ-ring is introduced into the AC

through the clear corneal phacoincision using forceps

and Sinskey hook (Fig. 41.10). The device is placed

Fig. 41.6: The general view of IQ-ring

in the AC and laid flat on the iris. It is then attached

266

Clinical Diagnosis and Management of Ocular Trauma

less traumatic implantation. It has no sharp or pointed

6.

Vasavada A, Singh R. Phacoemulsification in eyes with a

endings that can damage the eye.

7.

small pupil. J Cataract Refract Surg 2000; 26:1210–18.

Fourth, equidistant position of the loops that holds

Lundberg B, Behndig A Intracameral mydriatics in

phacoemulsification cataract surgeryJCataractRefractSurg

the iris tissue ensure correct position of the iris and

2003; 29:2366–71.

prevents the effect of overstretching of the pupil

8.

Miller KM, Keener GT Jr. Stretch pupilloplasty for small pupil

observed in incorrect iris hooks position.

phacoemulsification (letter). Am J Ophthalmol 1994;

Fifth, IQ-ring provides sufficient room for nucleus

117:107–08.

fragmentation and removal. The device configuration

9.

Chang DF. Phaco strategies for complicated cataracts. In:

and plate design allows surgeon to work in the deep

Chang DF, ed, Phaco Chop; Mastering Techniques,

lens layers below the iris plane and the square-shaped

Optimizing Technology, and Avoiding Complications.

Thorofare, NJ, Slack 2004;173–98.

pupil formed by the ring. This provides enough space

10.

Dinsmore SC. Modified stretch technique for small pupil

for grooving and cutting the nucleus and increased

phacoemulsification with topical anesthesia. J Cataract

peripheral visualization during the chopping phase of

Refract Surg 1996; 22: 27–30.

the procedure.

11.

Auffarth G, Reuland AJ., Heger T, Volcker HE, Cataract

In summary, different techniques of nucleus

surgery in eyes with iridoschisis using the Perfect Pupil iris

disassembly in small-incision cataract surgery requires

extension system J Cataract Refract Surg 2005; 31:1877–

80.

wide and unobstructed view of the anterior portion of

12.

Graether JM. Graether pupil expander for managing the

the lens as well as the instruments inserted in the anterior

small pupil during surgery. J Cataract Refract Surg 1996;

chamber. The other important factor is sufficient

22:530–35.

manipulability of the instruments which is critical for the

13.

Mackool RJ. Small pupil enlargement during cataract

successful completion the surgery. A pupil that fails to

extraction; a new method. J Cataract Refract Surg 1992;

dilate makes cataract removal more difficult with added

18:523–26.

14.

de Juan E Jr, Hickingbotham D. Flexible iris retractor [letter].

risk. The IQ-ring adequately dilates the pupil, prevents

Am J Ophthalmol 1991; 110:776–77.

iris sphincter damage. It is easy to insert and remove.

15.

Nichamin LD. Enlarging the pupil for cataract extraction

The ring expands the pupil to 6.0 mm, protects the iris

using flexible nylon iris retractors. J Cataract Refract Surg

sphincter during surgery, and allows the pupil to return

1993; 19:793–96.

toitsnormalshape,size,andfunctionaftertheoperation.

16.

Oetting TA, Omphroy LC. Modified technique using flexible

IQ-ring is an important tool in phacoemulsification

iris retractors in clear corneal cataract surgery. J Cataract

surgery. Careful intraoperative manipulation and inser-

Refract Surg 2002; 28:596–98.

17.

Dupps WJ., Oetting TA. Diamond iris retractor configuration

tion of the IQ-ring with liberal use of OVD can help

for small-pupil extracapsular or intracapsular cataract

prevent complications. After the surgery most of our

surgery J Cataract Refract Surg 2004; 30:2473–75.

patients had pupils almost indistinguishable from the

18.

Birchall W, Spencer AF. Misalignment of flexible iris hook

appearance before surgery with the preserved func-

retractors for small pupil cataract surgery: effects on pupil

tional activity. We consider IQ-ring among the most

19.

circumference. J Cataract Refract Surg 2001; 27:20–24.

effective methods to increase the size of even very rigid

Masket S. Avoiding complications associated with iris

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small pupils during phacoemulsification surgery. We use

Refract Surg 1996; 22:168–71.

it in cases with IFIS syndrome with a great success. The

20.

YuguchiT,OshikaT,SawaguchiS,KaiyaT.Pupillaryfunctions

use of this method is highly recommended as it is likely

after cataract surgery using flexible iris retractor in patients

to reduce postoperative abnormalities in pupil size and

with small pupil. Jpn J Ophthalmol 1999; 43:20-24.

function.

21.

Novak J. Flexible iris hooks for phacoemulsification.

J Cataract Refract Surg 1997; 23:828–31.

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