ABSTRACT
A 25-year-old man suffered an isolated lens anterior capsular tear and mature cataract formation following blunt injury to his right eye. One week after the trauma, best-corrected visual acuity (BCVA) in the right eye was hand motion. B-scan ultrasonography showed that the lens posterior capsule was intact; no vitreous foreign body or retinal pathology were observed. Orbital computed tomography revealed narrowed anterior chamber and increased lens material volume and lens reflectivity in the injured right eye. The globe was intact and no bone fractures were observed. The cataractous lens material was removed by phacoemulsification and a foldable, acrylic, posterior chamber intraocular lens was implanted in the bag. Postoperative BCVA in the right eye was 20/20.
Introduction
Isolated anterior lens capsule tears due to blunt ocular trauma are rare.1,2,3,4,5In this report we aimed to describe the clinical findings, mechanism of development, and surgical treatment applied in the case of a patient with isolated anterior lens capsule rupture due to blunt trauma with a wooden object.
Discussion
Crystalline lens damage secondary to blunt ocular trauma can result in lens dislocation, subluxation or posterior capsule rupture.6,7,8
Posterior capsule rupture occurs more frequently than anterior capsule rupture.6,7,8Gampanella et al.9stated that the mechanism of posterior capsule rupture due to blunt trauma involves the anatomic relationship between the vitreous and the lens interface. According to this theory, the Wiegert ligament, which connects the anterior cortical vitreous and the posterior lens capsule, usually attaches in the midperipheral region of the lens. This connection weakens with age. Secondary to the rapid compression of the eye on the anterior-posterior axis and the expansion that immediately follows, the Wiegert ligament causes the posterior lens capsule to tear.
According to a hypothesis from Banitt et al.,3isolated anterior lens capsule tear secondary to blunt trauma probably occurs as a result of the rapid focal indentation of the cornea onto the lens (coup injury) or a rebound effect secondary to the trauma in which the vitreous applies high pressure to the lens (countrecoup injury).3
We believe that with less severe injuries, expansion following ocular compression on the anterior-posterior axis leads to posterior capsule tear, while in more severe injuries the anterior-posterior axis compression may cause anterior capsule rupture before the subsequent expansion. Especially in young patients like the current case in which the anterior hyaloid is tight, the vitreous compact, and the zonules intact, the anterior capsule rupture is limited to the equatorial plane and does not continue to the posterior capsule. The tight anterior hyaloid likely buffers the force of the direct impact but transfers the energy toward the lens due to the countrecoup effect. Therefore, although the retina and posterior pole are protected from trauma, the impact results in anterior capsule rupture because of the elasticity of the lens material. In cases like this, in which the patient is young and the tissues are resilient, the damage is limited and cataractous lens material can be removed by irrigation-aspiration alone, resulting in favorable anatomic and visual outcomes.
