Traumatic fracture of flexible anterior chamber intraocular lenses

Carlo Capoferri, MD, Saulo Vacchi, MD, AIdo Tafi, MD, Ida Maria Voglini, MD

ABSTRACT

Two patients had fracture of a flexible, open-loop, anterior chamber intraocular lens (IOL) caused by ocular trauma. Case 1 was a 78-year-old woman with a three-point­fixation IOL. The two portions of the fractured lens were removed from the anterior chamber. Visual acuity at 10 months postoperatively was hand motion as a result of corneal decompensation. Case 2 was a 36-year-old man with a four-poi nt-fixation IOL that broke and dislocated into the vitreous. A pars plana vitrectomy was performed; the two lens portions were removed and exchanged with a sutured posterior chamber lens. Best corrected visual acuity 4 months postoperatively was 20/20. In both cases, the lens fracture took place at the loop-optic junction and with minimal visible damage to the eye structures. J Cataract Refract Surg 1997; 23:1418-1420

Flexible anterior chamber intraocular lenses (IOLs) are widely used for primary and secondary implan­

tation. Their flexibility allows surgeons to position them more easily in the eye and supposedly renders them more resistant to damage and thus less harmful to eyes with bulbar trauma. To our knowledge, there have

been no reports of traumatic fracture of such lenses. We describe two cases of flexible anterior chamber IOLs that broke inside the patient's eye as a result of globe contusions.

Case Reports Casel

A 78-year-old woman presented at the emergency unit of our hospital reporting pain, redness, and loss of vision in her left eye. She had been hit by a fragment of wood while chopping 2 hours previously. She had had an intracapsular cataract extraction in the left eye in 1981 and secondary

From the Department of Ophthalmology, Regional Hospita4 Aosta, Italy. Dr. Capofirri is now at the Department of Ophthalmology, FatebeneftateUi e Oftalmico, Milano, Italy.

Reprint requests to Carlo Capofirri, MD, Via delle Stelline 5, 20146 Milano, Italy.

implantation of a single-piece, poly(methyl methacrylate) (PMMA), "tripod" anterior chamber 10L with two flexible open loops (model AM-55, Amplimedical) (Figure 1). At the last evaluation, 3 months before the trauma, the 10L was correctly positioned, the cornea was clear, and best corrected visual acuity (BCVA) was 20/20.

On examination, the optic and the inferior two-point

fixation loop had rotated upside-down, with intermittent corneal endothelial touch. The cornea was hazy because of edema, particularly in the lower third. The superior haptic fragment of the 10L was not detectable (Figure 2). After the visible portion of the 10L was removed, the free-floating broken loop was detected under the hazy inferior cornea and removed.

Corneal decompensation, which had spread to the entire cornea during surgery, had not recovered by 10 months postoperatively, and visual acuity was hand motion. Despite good clinical and echographica1 data, the patient repeatedly refused a corneal graft.

Case 2 A 36-year-old man presented at our emergency unit

reporting redness and reduced vision in his left eye. He had been hit by a metal fragment while hammering 1 hour earlier. He had had an extracapsular cataract extraction in his left eye in 1992, with posterior capsule rupture and implantation in the anterior chamber of a single-piece, PMMA, four-point-

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CASE REPORTS: CAPO FERRI

Figure 1. (Capoferri) Case 1. The explanted IOL (left) com­

pared with an intact sample (right). Note the break at the transition

between the optic and haptic.

fixation, Kelman-type 10L with two flexible open loops (model Z, Domilens).

On examination, only the inferior haptic was visible inferonasally in the anterior chamber (Figure 3). The optic with the superior loop was detected in the lower anterior vitreous. Trying to make it drop from the vitreous back into the anterior chamber through the dilated pupil failed because a vitreal strand was withholding the loop (Figure 4). The patient was referred to a vitreoretinal surgeon. A pars plana vitrectomy was performed 18 days after the trauma, the broken 10L was removed through a corneoscleral incision, and a sutured posterior chamber lens was implanted.

Four months postoperatively, the cornea was clear, there was no ophthalmoscopic evidence of cystoid macular edema, and BCVA was 20/20 (with -0.50 -1.00 X 100; uncor­rected 20/30).

Figure 3. (Capoferri) Case 2. The inferior loop of the IOL still

lies in the anterior chamber. As in Case 1, the break occurred at

the loop-optic junction.

Figure 2. (Capoferri) Case 1. The broken IOL is barely visible

through the edematous cornea. The inferior two-point fixation loop

has rotated superiorly and touches the corneal endothelium.

Discussion

Intraocular lens fracture into the eyeball is uncom­mon and has rarely been reported with anterior cham­ber IOLs. We report the first cases of traumatic fracture with flexible anterior chamber IOLs.

Shammas and Milkie l reported the traumatic frac­ture of a rigid Choyce-style anterior chamber lens. Maguen and coauthors2 described the rupture of a semiflexible (Kelman Quadraflex) anterior chamber IOL, with no apparent cause. Park et al.3 also reported the fracture of a closed-loop anterior chamber IOL, with no history of trauma. Weickert and coauthors4

described the spontaneous fracture of a flexible anterior

Figure 4. (Capoferri) Case 2. The dislocated portion of the IOL (including the optic) is visible through the dilated pupil in the lower

anterior vitreous. Note the vitreous strand withholding the superior

lens loop.

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CASE REPORTS: CAPO FERRI

chamber 101. Assia et al.,5 in a study on ocular trauma in eyes with 10Ls, reported 1 case of bent or broken loop out of 11 anterior chamber lenses; no further information was available.

Flexible, open-loop, anterior chamber 10Ls are the most widely used for anterior chamber implantation (especially those with four-point, foot-plate fixation based on the Kelman design) . Unlike in other re­ports,I .5-8 ocular trauma in our patients does not seem to cause serious direct mechanical damage to the eye structures. This suggests that the flexible 10L loops absorbed much of the kinetic energy and then broke at their weakest point, namely the loop-optic junction. This might have prevented the hard 10L material from damaging intraocular structures, particularly the iris and the anterior chamber angle.

We wonder whether the fracture of 10L hap ties necessarily represents an unfavorable outcome after bulbar trauma. One could not reasonably expect a rigid 10L to resist injury and not damage intraocular struc­tures. Therefore, the preservation of the integrity of globe and anterior chamber structures might be re­garded as a partial success.

References

1. Shammas HJF, Milkie CF. Traumatic fracture of a Choyce-style anterior chamber lens. Am Intra-Ocular Implant Soc J 1981; 7:46-48

2. Maguen E, Nesburn AB, Jackman N, Macy JI. Broken semiflexible intraocular lens implant. Am J Ophthalmol 1985; 99:170-172

3. Park SB, Olson PF, Kratz RP, et al. In vivo fracture of an extruded polymethylmethacrylate intraocular lens loop. J Cataract Refract Surg 1987; 13:194-197

4. Weickert C, Fuhrmann G, Bleckmann H. Spontanbruch einer implantierten Vorderkammerlinse. Ophthalmologe 1992; 89:346-348

5. Assia EI, Blotnick CA, Powers TP, et al. Clinico­pathologic study of ocular trauma in eyes with intraocu­lar lenses. Am J Ophthalmol1994; 117:30-36

6. Biedner B, Rothkoff L, Blumenthal M. Subconjunctival dislocation of intraocular lens implant. Am J Ophthalmol 1977; 84:265-266

7. Corboy JM, Ing MR. Traumatic loss of an anterior chamber lens. Am Intra-Ocular Implant Soc J 1979; 5:54-55

8. Foster JA, Lam S, Joondeph BC, Sugar J. Suprachoroi­dal dislocation of a posterior chamber intraocular lens (letter). Am J Ophthalmo11990; 109:731-732

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