J CATARACT REFRACTIVE SURG - VOL 31, AUGUST 2005

Traumatic total iridectomy after clear

corneal cataract extraction

Malik Y. Kahook, MD, Michael J. May, MD

The increasing use of topical clear cornea techniques has led to an intense debate regardingwound stability. We present a case of traumatic aniridia post cataract extraction which illustratesthe importance of wound dimensions and construction.

Q 2005 ASCRS and ESCRS

We report a case of traumatic aniridia in a patient who had

uneventful clear cornea cataract extraction. This is the firstsuch case reported with a foldable silicone posterior

chamber intraocular lens (PC IOL) in the sulcus.

Traumatic aniridia is usually seen after blunt trauma to

the eye with significant globe injury including vitreous

hemorrhage and hyphema. Often, the associated injuries

preclude the immediate diagnosis of aniridia, which is

discovered only after the anterior chamber hemorrhage

resolves. Use of the clear corneal phacoemulsificationtechnique has a direct implication on the mechanism

behind traumatic aniridia.

CASE REPORT

A 53-year-old white man with a history of clear cornealcataract extraction 3 months prior previously presented to anoutside facility. The clear corneal wound was constructed inbeveled fashion with a 3.0 mm keratome blade. A smallcapsulorhexis was created during the surgery and led toimplantation of the IOL in the sulcus because of difficulties withthe bag placement. The postoperative course was unremarkablewith 20/20 uncorrected visual acuity and no iris abnormalitiesnoted. He was involved in a motor vehicle accident 5 days prior tobeing seen in our eye clinic. He had been diagnosed with ahyphema with elevated intraocular pressure and was started onlevobunolol 0.5% 2 times a day in the right eye, brimonidine2 times a day in the right eye, tobramycin and dexamethasone(TobraDex) 4 times a day in the right eye, and acetazolamide

Accepted for publication January 20, 2005.

From the Department of Ophthalmology, University of ColoradoHealth Sciences Center, Rocky Mountain Lions Eye Institute,Denver, Colorado, USA.

Neither author has a financial or proprietary interest in anymaterial or method mentioned.

Reprint requests to Malik Y. Kahook, MD, 1675 North UrsulaStreet, Campus Box F-731, Aurora, Colorado 80045, USA. E-mail:malik.kahook@uchsc.edu.

Q 2005 ASCRS and ESCRS

Published by Elsevier Inc.

500 mg by mouth 2 times a day. He gave a history of blunt traumato the right side of his face and forehead with no loss ofconsciousness. There was a hyphema with poor view thatprecluded a full examination in the emergency room. Theexamination at presentation was significant for 20/20 bestcorrected visual acuity in the right eye and 20/400 in the left eye.

Intraocular pressure was 21 mm Hg in the right eye and13 mm Hg in the right eye. Evidence of a temporal clear cornealincision of the right eye appeared healed and Seidel negative.Conjunctiva and sclera were unremarkable. There was a clearingsmall hyphema on the right side. No iris was visible in the righteye on gonioscopic examination, whereas a normal iris wasevident in the left eye. Awell-centered PC IOL in the ciliary sulcuswas noted in the right eye (Figure 1). The left lens was significantfor C4 nuclear sclerotic changes. Indirect ophthalmoscopyrevealed a significant inferior vitreous hemorrhage in the righteye. A dilated fundus examination of the left eye was unremark-able. A diagnosis of traumatic aniridia in the right eye was made,and treatment with prednisolone acetate and timolol was initiated.His recovery was prompt and uneventful.

DISCUSSION

The use of clear corneal incisions for phacoemulsifi-

cation has direct implications for wound stability in cases of

trauma. Cadaver studies have shown that wound stability

of corneal incisions varies according to architecture and

width.1,2 The use of a beveled clear corneal incision was

found to be most resistant to leakage when width was lessthan 3.0 mm. Square incisions were also found to be most

conducive to a stable wound in case of external pressure.

Unfortunately, the dimensions of square wounds needed to

accommodate current instruments would encroach on the

visual axis, making that architecture is thus undesirable.

Ernest and coauthors3 investigated the relative stabil-

ities of clear corneal wound construction versus that of

scleral corneal wounds. They found that wounds con-structed so that dimensions were square in nature were

much more resistant than those that were rectangular.

Ernest and coauthors also noted that square dimensions

0886-3350/05/$-see front matterdoi:10.1016/j.jcrs.2005.01.017

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CASE REPORTS: KAHOOK

using a scleral corneal wound were feasible, whereas those

with clear cornea entry encroached on the visual axis. They

concluded that scleral corneal wounds were more desirable

for stability.

There have been several reports of traumatic aniridia

involving pseudophakic patients. A case report by Lim and

coauthors4 documented the occurrence of total iris

extrusion after blunt trauma to a pseudophakic eye. Inthat case, cataract extraction was performed by a sclero-

corneal incision. They concluded that the presence of a PC

IOL protected the posterior structures from prolapsing

through the wound and the extruded iris.

A case of traumatic aniridia in a patient who had clear

corneal cataract extraction has been reported.5 A 91-year-

old woman suffered blunt trauma to the eye 12 months

after a successful surgery with IOL placement in the bag.She was to be missing the iris after a hyphema began to

Figure 1. Anterior segment photo of the well-centered PCIOL in the

sulcus with aniridia and no evidence of lens dislocation.

J CATARACT REFRACTIVE SURG1660

clear. She was treated with topical drops because of

increased pressure and, unfortunately, died due to cere-

brovascular complications. The authors concluded that the

clear corneal incision acted as a release valve to prevent

rupture at the limbus or near the recti muscles, which is

more typical with blunt trauma resulting in open globe.Also, in both this and our case, the anterior chamber and

posterior intraocular structures were relatively unharmed.

In our case, the silicone foldable PC IOL in the sulcus did

not appear to be compromised or dislocated. We agree with

the release-valve theory as the most likely mechanism

behind iris extrusion. Sudden pressure placed posterior to

the wound allows for momentary wound gape and iris

expulsion.

CONCLUSION

The increasing use of topical clear corneal techniques

may lead to more cases similar to ours. This emphasizes the

need for constructing optimal wounds when performing

cataract extraction. The development of smaller phaco-emulsification tips and smaller foldable IOLs will allow for

the use of square and thus more stable incisions that do not

encroach on the visual axis. More stable wounds may

decrease the likelihood of poor outcomes in case of external

pressure posterior to the incision.

REFERENCES

1. Ernest PH, Kiessling LA, Lavery KT. Relative strength of cataract incisions

in cadaver eyes. J Cataract Refract Surg 1991; 17:668–671

2. Ernest PH, Fenzel R, Lavery KT, Sensoli A. Relative stability of clear

corneal incisions in a cadaver eye model. J Cataract Refract Surg

1995; 21:39–42

3. Ernest PH, Lavery KT, Kiessling LA. Relative strength of scleral corneal

and clear corneal incisions constructed in cadaver eyes. J Cataract Re-

fract Surg 1994; 20:626–629

4. Lim JI, Nahl A, Johnston R, Jarus G. Traumatic total iridectomy due to iris

extrusion through a self-sealing cataract incision. Arch Ophthalmol

1999; 117:542–543

5. Ball J, Caesar R, Choudhuri D. Mystery of the vanishing iris. J Cataract

Refract Surg 2002; 28:180–181

- VOL 31, AUGUST 2005