Traumatic anterior lens dislocation: A case report

The Journal of Emergency Medicine, Vol. 17, No. 4, pp. 637– 639, 1999 Copyright © 1999 Elsevier Science Inc. Printed in the USA. All rights reserved 0736-4679/99 $–see front matter

PII S0736-4679(99)00052-9

Clinical Communications

TRAUMATIC ANTERIOR LENS DISLOCATION: A CASE REPORT Karin E. Netland,

MD,*

Jorge Martinez, MD, Peter A. Netland,

JD,*

Owen J. LaCour III,

MD,*

and

MD, PhD†

*Section of Emergency Medicine, Louisiana State University School of Medicine, Medical Center of Louisiana, New Orleans, Louisiana and †Department of Ophthalmology, University of Tennessee, Memphis, Tennessee Reprint Address: Karin E. Netland, MD, Section of Emergency Medicine, LSU School of Medicine, Medical Center of Louisiana, 1542 Tulane Avenue, New Orleans, LA 70112

e Abstract—A 45-year-old man presented to the emergency department complaining of decreased vision and pain in the left eye after blunt trauma to the eye. On evaluation, the vision was limited to detecting hand motions, and the intraocular pressure was 37 mmHg. Secondary acute angleclosure glaucoma, with pupillary block due to anterior dislocation of the lens, was diagnosed. The intraocular pressure remained elevated after medical therapy, and the patient underwent intracapsular cataract extraction and anterior vitrectomy. The possibility of elevated intraocular pressure due to lens dislocation or other types of secondary glaucoma should be considered after blunt ocular trauma. © 1999 Elsevier Science Inc.

tion of the crystalline lens may also occur. Traumatic loss of lens zonule fibers may be partial or complete. After complete disruption of the lens zonules, the lens may dislocate posteriorly or, less commonly, into the anterior chamber. Dislocation of the crystalline lens may result in vision loss that can be corrected with optical aids or surgical treatment. We report a case of traumatic lens dislocation into the anterior chamber in a patient following blunt ocular injury. Prompt recognition of this problem facilitates visual rehabilitation and may avoid development of vision-threatening glaucoma.

e Keywords— blunt trauma; ocular injury; lens dislocation; pupillary block; glaucoma

CASE REPORT A 45-year-old male presented to the Emergency Department (ED) at Charity Hospital in New Orleans complaining of decreased visual acuity and pain in the left eye. The patient stated that he had sustained a kick to his left eye 2 days before presentation, and had noted gradually worsening symptoms after the injury. The patient reported decreased vision in both eyes since childhood, and had been diagnosed with cataracts. His medical history included scoliosis, angina, and a seizure disorder. His surgical history included appendectomy, multiple stab wounds, and chest tube placement.

INTRODUCTION Blunt trauma to the eye results in a sudden compressive deformation of the globe, displacing the cornea and the anterior sclera posteriorly with a compensatory expansion of the globe in the equatorial direction (1,2). This results in tissue damage that may manifest as radial sphincter tears of the iris, hyphema, angle recession, cyclodialysis, peripheral retinal tears, or other injuries. If the lens zonule fibers are damaged, dislocation or luxa-

RECEIVED: 8 May 1998; FINAL ACCEPTED: 8 October 1998

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Upon arrival, the vital signs were normal (heart rate of 88 beats per minute, blood pressure of 144/70 mmHg, and temperature of 36°C) and remained stable throughout his stay. Eye examination revealed a visual acuity of 20/400 in the right eye and detection of hand motions in the left eye, with no improvement of vision in either eye with pinhole correction. Ocular motility examination was normal. The pupil was reactive on the right and nonreactive on the left, with no afferent pupil defect. The conjunctiva of the left eye was hyperemic, and the anterior chamber was shallow peripherally. The crystalline lens was dislocated into the anterior chamber in the left eye. The lenses in both eyes were cataractous, and the retina was attached in both eyes. The intraocular pressure, measured by Goldmann applanation tonometry, was 12 mmHg in the right eye and 37 mmHg in the left eye. Despite oral administration of acetazolamide and topical administration of apraclonidine 0.5%, the intraocular pressure remained elevated. Secondary acute angle-closure glaucoma was diagnosed, with pupillary block due to the anteriorly dislocated lens. The patient was admitted and treated surgically with intracapsular cataract extraction and anterior vitrectomy. The intraocular pressure was improved following surgery, and the patient was discharged home; he was lost to subsequent follow-up.

DISCUSSION Eye problems are relatively common in the general patient population, accounting for 3– 6% of visits to the Emergency Department (3,4). Traumatic injuries account for the majority of acute eye problems, followed by inflammatory disorders (4). Among injured patients, there is a 3:1 to 6:1 male:female ratio, with the peak age for eye injuries in the late 20s (4 – 6). Although traumatic lens dislocation is a relatively uncommon sequel of blunt ocular injury, it is important to recognize this injury because it may be associated with vision-threatening glaucoma. The patient described here developed pupillary block glaucoma after traumatic anterior dislocation of the crystalline lens. Our patient presented with symptoms and findings expected with traumatic lens dislocation, including pain, vision loss, and dislocated crystalline lens. The lens was dislocated anteriorly into the anterior chamber, which resulted in pupillary block glaucoma in this patient. The most common cause of lens luxation-subluxation in most large series has been trauma (7). Certain predisposing factors for lens dislocation such as Marfan’s syndrome, homocysteinuria, and spherophakia were not present in our patient (7). His history of cataracts probably did not predispose him to lens dislocation, although his reduced vision may have impaired his ability to avoid the injury.

In addition to the type of injury described in our patient, air bag injuries may be associated with traumatic lens dislocation (8,9). Diagnosis of traumatic lens dislocation is based on the history and examination. Symptoms include blurring of the vision, or monocular diplopia and distortion when the lens remains partially in the visual axis. The lens may be readily visualized when displaced into the anterior chamber, or may be viewed after pupillary dilatation when dislocated posteriorly. Iridodonesis, a tremor of the iris after rapid eye movements, may be a helpful finding associated with occult posterior dislocations. Careful examination is important to identify the presence or absence of pupillary block. Pupillary block is due to resistance to aqueous flow between the iris and lens because of their close approximation at the pupil, causing increased pressure of the aqueous humor in the posterior chamber. This increased pressure of the aqueous humor in the posterior chamber forces the peripheral iris forward over the trabecular meshwork, which results in closure of the anterior chamber angle. Slit lamp examination and gonioscopy confirm the presence of angleclosure. If the intraocular pressure is elevated, the diagnosis of angle-closure glaucoma is confirmed. A simple test to detect the possibility of pupillary block uses a flashlight beam directed from the temporal toward the nasal side of each eye (10). In eyes with shallow anterior chambers that may be susceptible to or may have developed angle-closure glaucoma, the relatively forward position of the iris will cause the nasal side to be in shadow. Depending on the position of the lens and the vitreous, lens dislocation may be associated with glaucoma, which is a vision-threatening complication of this injury (1,2). The dislocated lens may cause pupillary block by preventing the flow of aqueous humor from the posterior chamber through the pupil into the anterior chamber, where it normally exits the eye in the iridocorneal angle. Pupillary block may lead to angle closure with a precipitous increase in the intraocular pressure. Vitreous prolapsed into the anterior chamber can also cause acute glaucoma, and synechia or scarring in the anterior chamber angle may lead to chronic glaucoma. In anterior lens dislocations, prolonged contact of the lens with the corneal endothelium can result in permanent decompensation of the cornea. Treatment of glaucoma associated with lens dislocation depends on the mechanism of the glaucoma (2). Careful examination is important to identify the presence or absence of pupillary block glaucoma. If pupillary block is present, medical treatment with antiglaucoma medications or cycloplegia may be attempted. Lensectomy may be required to improve vision impaired by an opacified lens in the visual axis, to relieve intractable

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pupillary block glaucoma, or to alleviate lens-cornea touch in anterior dislocations. The technique for lensectomy depends on the location of the dislocated lens. Surgical removal may involve a planned extracapsular cataract extraction or phacoemulsification, intracapsular cataract extraction, or pars plana lensectomy with vitrectomy (2). The patient we present in this report was treated

successfully with intracapsular extraction and anterior vitrectomy. The prognosis for patients with traumatic dislocation of the lens is good with prompt recognition of this type of injury and treatment of glaucoma. Urgent ophthalmologic consultation is necessary. The outcome may be poor if prolonged anterior lens dislocation results in corneal decompensation, or if glaucoma associated with lens dislocation is not promptly recognized and treated.

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6. Glynn RJ, Seddon JM, Berlin BM. The incidence of eye injuries in New England adults. Arch Ophthalmol 1988;106:785–9. 7. Streeten BW. Pathology of the lens. In: Albert DM, Jakobiec FA, eds. Principles and Practice of Ophthalmology, edn. 1. Philadelphia: W. B. Saunders; 1994:2225–32. 8. Onwuzuruigbo CJ, Fulda GJ, Larned D, Hailstone D. Traumatic blindness after airbag deployment: bilateral lenticular dislocation. J Trauma 1996;40:314 – 6. 9. Ghafouri A, Burgess SK, Hrdlicka Z, Zagelbaum BM. Air bagrelated ocular trauma. Am J Emerg Med 1997;15:389 –92. 10. Juang PSC, Rosen P. Ocular examination techniques for the emergency department. J Emerg Med 1997;15:793– 810.