Traumatic Dislocation of Implanted Collamer Phakic Lens: A Case Report and Review of the Literature

INTRODUCTION

Phakic intraocular lenses (p IOLs) have been used for decades in refractive surgery, particularly for patients with very high correction [1]. Multiple styles are available, including iris fixated anterior chamber PIOLs, angle fixated anterior chamber PIOLs, and posterior chamber PIOLs. The Implantable Collamer Lens (ICL; Staar Surgical, Monrovia, California, USA) is a phakic IOL that is placed in the posterior chamber without any fixation. Long term studies have generally found these lenses to be efficacious and safe [2, 3]. Here we present a case report of ICL dislocation after blunt trauma and a review of the previously reported cases of ICL dislocation in general.

CASE REPORT

A 44 year-old man presented to the emergency department with blurry vision in the left eye after being struck in the eye with a pipe. The patient had bilateral ICLs placed for high myopia three years prior to presentation and had no previous complications associated with this surgery. The patient reported mild pain associated with brow and lid abrasions from the injury. In the left eye, his visual acuity at presentation was hand motions and intraocular pressure (IOP) was 22. He had 4+ red blood cells in the anteriorchamber (AC) with a blood clot located inferiorly. The superotemoporal haptic of the ICL was dislodged into the AC and entrapped in the pupillary aperture; the remaining haptics were behind the iris (Fig. 1). There was associated pigment clumping on the ICL. Fundoscopic exam revealed no abnormalities. There was no endothelial touch by the prolapsed ICL. The patient’s right eye visual acuity (VA) was 20/20 and had no abnormalities on examination other than a shallow vault between the lens and the ICL (50% of corneal thickness).

The patient was started on prednisolone acetate 1% eye drops (Allergan, Irvine, CA, USA) and atropine suflate 1% eye drops (Bausch and Lomb, Rochester, NY, USA) to the left eye. As the hyphema cleared, the vision improved to 20/30 in the left eye. Two weeks after injury, the ICL was repositioned without complication. Earlier repositioning was not possible due to the patient’s social circumstances. His post-procedure visual acuity was 20/20.

DISCUSSION

Phakic IOLs are commonly used as an alternative to laser refractive surgery with the advantages of leaving the ventral cornea untouched, inducing fewer higher order aberrations, and resulting in better optical and visual quality [1, 3, 4]. Additionally, refractive correction up to -21.0D is possible, accommodation is preserved, and implantation is potentially reversible. The ICL is an extremely thin intraocular lens with four plate haptics (foot processes) that is implanted in the ciliary sulcus. The ICL has a specially designed central vault which prevents contact between the ICL and the anterior lens capsule.

The complications associated with ICLs are rare and include early or late anterior subacpsular cataract, increase in intraocular pressure (IOP), angle closure glaucoma, transillumination defects, retinal detachments and corneal endothelial cell failure. Initial studies regarding the ICL did not report dislocation as a significant concern [4, 5]. One case report even describes a case in which ICLs were stable after a grenade explosion [6]. Subsequently, there have been five cases of ICL dislocation reported in the literature [7-11], three of which were caused by blunt ocular trauma, similar to ours (Table 1)[7, 10, 11].

Kaufer et al. reported a case of spontaneous dislocation into the vitreous cavity secondary to zonular dehiscence. The two inferior ICL footplates subluxed through ruptured zonules into the vitreous cavity. With no history of trauma, possible causes for this dislocation included eye rubbing, improper sizing of the ICL, and inherent zonular pathology. Ultimately, the lens was explanted. In a second case, reported by Kong et al. in 2010, dislocation occurred after the patient suffered severe occipital trauma in a dark room. The patient’s pupil was likely large due to scoptic conditions, and the posterior trauma forced the infero-nasal footplate anteriorly into the AC.

There have been three previously reported cases of ICL dislocation caused by blunt ocular trauma [7, 10, 11]. The patients were aged 26, 33, and 39. Two of them were males and one was a female. One of the patients was struck by a fist, and the mechanism of injury was not specified in the others. Two of the three reported patients were symptomatic with blurry vision [7, 11]. Interestingly, one of the patients was asymptomatic and the dislocated IOL was only discovered on a regularly scheduled eye exam two weeks after his blunt injury; his vision had decreased to 20/30 from 20/20 [10]. One case reported associated hyphema [11]. In one case the infero-nasal footplate was dislocated [1], in another the infero-temporal footplate [7], and in the third the two temporal footplates were dislocated [10].

All three of the reported patients were treated with repositioning of the ICL within one week of presentation [7, 10, 11]. Our patient underwent ICL repositioning two weeks after the inciting event; due to the patient’s social circumstances, an earlier surgery was not possible. One of the three reported significant lens-endothelial touch at presentation and 20/60 initial VA [7]. Three months after repositioning, this patient developed bullous keratopathy with central corneal thickness 653 microns and endothelial cell count of less than 800 cells/mm². Ultimately, DSAEK was required in this case.

CONCLUSION

A review of the cases of ICL dislocation reveals that it is a rare but real long term complication of the procedure, particularly after trauma. There is no pattern as to which footplate is dislocated. While reports suggest patients do well with repositioning of the lens, one of the most concerning sequlae is endothelial decompensation, which occurred in one of five previously reported eyes. This case presented with lens-endothelial touch, which was likely the causative factor of the corneal decompensation, rather than endothelial trauma from repeat surgery. Interestingly, some of the patients with dislocation did not have significantly reduced visual acuity. However, while the patient may be satisfied with this level of vision, early repositioning of the ICL is necessary to avoid further complications.

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