Traumatic Cataract
Traumatic Cataract
Introduction
Traumatic cataracts occur secondary to blunt or penetrating ocular trauma. Infrared energy (glass-blower's cataract), electric shock, and ionizing radiation are other rare causes of traumatic cataracts.
Cataracts caused by blunt trauma classically form stellate- or rosette-shaped posterior axial opacities that may be stable or progressive, whereas penetrating trauma with disruption of the lens capsule forms cortical changes that may remain focal if small or may progress rapidly to total cortical opacification.
Lens dislocation and subluxation are commonly found in conjunction with traumatic cataract. Other associated complications include phacolytic, phacomorphic, pupillary block, and angle-recession glaucoma; phacoanaphylactic uveitis; retinal detachment; choroidal rupture; hyphema; retrobulbar hemorrhage; traumatic optic neuropathy; and globe rupture.
Traumatic cataract can present many medical and surgical challenges to the ophthalmologist. Careful examination and a management plan can simplify these difficult cases and provide the best possible outcome.
Pathophysiology
Blunt trauma is responsible for coup and contrecoup ocular injury. Coup is the mechanism of direct impact. It is responsible for Vossius ring (imprinted iris pigment) sometimes found on the anterior lens capsule following blunt injury. Contrecoup refers to distant injury caused by shockwaves traveling along the line of concussion.
When the anterior surface of the eye is struck bluntly, there is a rapid anterior-posterior shortening accompanied by equatorial expansion. This equatorial stretching can disrupt the lens capsule, zonules, or both. Combination of coup, contrecoup, and equatorial expansion is responsible for formation of traumatic cataract following blunt ocular injury.
Penetrating trauma that directly compromises the lens capsule leads to cortical opacification at the site of injury. If the rent is sufficiently large, the entire lens rapidly opacifies, but when small, cortical cataract can seal itself off and remain localized.
Frequency
United States
Approximately 2.5 million eye injuries occur annually in the United States. It is estimated that approximately 4-5% of a comprehensive ophthalmologist's patients are seen secondary to ocular injury. Traumatic cataract may present as acute, subacute, or late sequela of ocular trauma.
Mortality/Morbidity
• Trauma is the leading cause of monocular blindness in people younger than 45 years.
• Annually, approximately 50,000 people are left unable to read newsprint as a result of ocular trauma.
• Only 85% patients who experience anterior segment injury reach a final visual acuity of 20/40 or better, whereas only 40% patients with posterior segment injury reach this level.
Sex
The male-to-female ratio in cases of ocular trauma is 4:1.
Age
• Work- and sports-related eye injuries most commonly occur in children and young adults.
• Between 1985-1991, a National Eye Trauma System study reported a median age of 28 years in 648 assault-related cases.
Clinical
History
• Mechanism of injury - Sharp versus blunt
• Past ocular history - Previous eye surgery, glaucoma, retinal detachment, diabetic eye disease
• Past medical history - Diabetes, sickle cell, Marfan syndrome, homocystinuria, hyperlysinemia, sulfate oxidase deficiency
• Visual complaints
o Decreased vision - Cataract, lens subluxation, lens dislocation, ruptured globe, traumatic optic neuropathy, vitreous hemorrhage, retinal detachment
o Monocular diplopia - Lens subluxation with partial phakic and aphakic vision
o Binocular diplopia - Traumatic nerve palsy, orbital fracture
o Pain - Glaucoma secondary to hyphema, pupillary block, or lens particles; retrobulbar hemorrhage; iritis
Physical
• Complete ophthalmic examination (defer in case of globe compromise)
o Vision and pupils - Presence of afferent pupillary defect (APD) indicative of traumatic optic neuropathy
o Extraocular motility - Orbital fractures or traumatic nerve palsy
o Intraocular pressure - Secondary glaucoma, retrobulbar hemorrhage
o Anterior chamber - Hyphema, iritis, shallow chamber, iridodonesis, angle recession
o Lens - Subluxation, dislocation, capsular integrity (anterior and posterior), cataract (extent and type), swelling, phacodonesis
o Vitreous - Presence or absence of hemorrhage, posterior vitreous detachment
o Fundus - Retinal detachment, choroidal rupture, commotio retinae, preretinal hemorrhage, intraretinal hemorrhage, subretinal hemorrhage, optic nerve pallor, optic nerve avulsion
Causes
Traumatic cataracts occur secondary to blunt or penetrating ocular trauma.
Differential Diagnoses
Cataract, Senile
Laceration, Corneoscleral
Choroidal Rupture
Sudden Visual Loss
Ectopia Lentis
Glaucoma, Angle Recession
Hyphema
Other Problems to Be Considered
Globe rupture
Orbital fractures
Retinal detachment
Secondary glaucoma
Traumatic optic neuropathy
Workup
Imaging Studies
• B-scan - If the posterior pole cannot be visualized
• A-scan - Prior to cataract extraction
• CT scan of the orbits - Fractures and foreign bodies
Treatment
Medical Care
• If glaucoma is a problem, control intraocular pressure with standard medications. Add corticosteroids if lens particles are the cause or if iritis is present.
• Focal cataract
o Observation is warranted if the cataract is outside the visual axis.
o Miotic therapy may be of benefit if the cataract is close to the visual axis.
• In some cases of lens subluxation, miotics may correct monocular diplopia. Mydriatics may allow for vision around the lens with aphakic correction.
Surgical Care
• Planning the surgical approach is of the utmost importance in cases of traumatic cataract.
• Preoperative capsular integrity and zonular stability should be surmised.
• In cases of posterior dislocation without glaucoma, inflammation, or visual obstruction, surgery may be avoided.
• Indications for surgery include the following:
o Unacceptable decreased vision
o Obstructed view of posterior pathology
o Lens-induced inflammation or glaucoma
o Capsular rupture with lens swelling
o Other trauma-induced ocular pathology necessitating surgery
• Standard phacoemulsification may be performed if the lens capsule is intact and sufficient zonular support remains.
• Intracapsular cataract extraction is required in cases of anterior dislocation or extreme zonular instability. Anterior dislocation of the lens into the anterior chamber requires emergency surgery for its removal, as it can cause pupillary block glaucoma.
• Pars plana lensectomy and vitrectomy may be best in cases of posterior capsular rupture, posterior dislocation, or extreme zonular instability.
• Automated irrigation/aspiration can be used in patients younger than 35 years.
• Lens implantation
o Capsular fixation is the preferred placement if the lens capsule and zonular support are intact.
o Polymethyl methacrylate (PMMA) capsular tension rings allow capsular fixation in cases of zonular dialysis less than 180 degrees.
o Sulcus fixation is safe if the posterior capsule is compromised but zonular support is maintained.
o Suture fixation is chosen if both capsular and zonular supports are insufficient and the angle is minimally damaged.
o Anterior chamber placement is an option if no posterior support remains and iris or ciliary body trauma prevents suture fixation.
o Aphakia may be a better choice in young children and in patients with highly inflamed eyes, as they may experience better outcomes if lens implantation is deferred.
Consultations
Vitreoretinal consultation is necessary if a pars plana approach is mandated and the surgeon is untrained in posterior segment surgery.
Follow-up
Further Outpatient Care
• Patients should receive follow-up care as needed.
Deterrence/Prevention
• Protective eyewear should be worn when participating in any high-risk activities.
• Most serious eye trauma can be avoided if proper eye and face protectors are used.
Complications
• Lens dislocation and subluxation are commonly found in conjunction with traumatic cataract.
• Other associated complications include the following: phacolytic, phacomorphic, pupillary block, and angle-recession glaucoma; phacoanaphylactic uveitis; retinal detachment; choroidal rupture; hyphema; retrobulbar hemorrhage; traumatic optic neuropathy; and globe rupture.
Prognosis
• The prognosis is dependent on the extent of the injury.
Patient Education
• Protective eyewear is important in high-risk activities to avoid injury.
• For excellent patient education resources, visit eMedicine's Eye and Vision Center. Also, see eMedicine's patient education article Cataracts.
Miscellaneous
Medicolegal Pitfalls
• The nature of the injury should be accurately documented, including location, time, and circumstances of the injury, as well as whether protective eyewear was worn.
Multimedia
Media file 1: Classic rosette-shaped cataract in a 36-year-old man, 4 weeks after blunt ocular injury.
Classic rosette-shaped cataract in a 36-year-old man, 4 weeks after blunt ocular injury.
Media file 2: Same cataract as seen in Media file 1, viewed by retroillumination
Traumatic cataracts occur secondary to blunt or penetrating ocular trauma. Infrared energy (glass-blower's cataract), electric shock, and ionizing radiation are other rare causes of traumatic cataracts.
Cataracts caused by blunt trauma classically form stellate- or rosette-shaped posterior axial opacities that may be stable or progressive, whereas penetrating trauma with disruption of the lens capsule forms cortical changes that may remain focal if small or may progress rapidly to total cortical opacification.
Lens dislocation and subluxation are commonly found in conjunction with traumatic cataract. Other associated complications include phacolytic, phacomorphic, pupillary block, and angle-recession glaucoma; phacoanaphylactic uveitis; retinal detachment; choroidal rupture; hyphema; retrobulbar hemorrhage; traumatic optic neuropathy; and globe rupture.
Traumatic cataract can present many medical and surgical challenges to the ophthalmologist. Careful examination and a management plan can simplify these difficult cases and provide the best possible outcome.
Pathophysiology
Blunt trauma is responsible for coup and contrecoup ocular injury. Coup is the mechanism of direct impact. It is responsible for Vossius ring (imprinted iris pigment) sometimes found on the anterior lens capsule following blunt injury. Contrecoup refers to distant injury caused by shockwaves traveling along the line of concussion.
When the anterior surface of the eye is struck bluntly, there is a rapid anterior-posterior shortening accompanied by equatorial expansion. This equatorial stretching can disrupt the lens capsule, zonules, or both. Combination of coup, contrecoup, and equatorial expansion is responsible for formation of traumatic cataract following blunt ocular injury.
Penetrating trauma that directly compromises the lens capsule leads to cortical opacification at the site of injury. If the rent is sufficiently large, the entire lens rapidly opacifies, but when small, cortical cataract can seal itself off and remain localized.
Frequency
United States
Approximately 2.5 million eye injuries occur annually in the United States. It is estimated that approximately 4-5% of a comprehensive ophthalmologist's patients are seen secondary to ocular injury. Traumatic cataract may present as acute, subacute, or late sequela of ocular trauma.
Mortality/Morbidity
• Trauma is the leading cause of monocular blindness in people younger than 45 years.
• Annually, approximately 50,000 people are left unable to read newsprint as a result of ocular trauma.
• Only 85% patients who experience anterior segment injury reach a final visual acuity of 20/40 or better, whereas only 40% patients with posterior segment injury reach this level.
Sex
The male-to-female ratio in cases of ocular trauma is 4:1.
Age
• Work- and sports-related eye injuries most commonly occur in children and young adults.
• Between 1985-1991, a National Eye Trauma System study reported a median age of 28 years in 648 assault-related cases.
Clinical
History
• Mechanism of injury - Sharp versus blunt
• Past ocular history - Previous eye surgery, glaucoma, retinal detachment, diabetic eye disease
• Past medical history - Diabetes, sickle cell, Marfan syndrome, homocystinuria, hyperlysinemia, sulfate oxidase deficiency
• Visual complaints
o Decreased vision - Cataract, lens subluxation, lens dislocation, ruptured globe, traumatic optic neuropathy, vitreous hemorrhage, retinal detachment
o Monocular diplopia - Lens subluxation with partial phakic and aphakic vision
o Binocular diplopia - Traumatic nerve palsy, orbital fracture
o Pain - Glaucoma secondary to hyphema, pupillary block, or lens particles; retrobulbar hemorrhage; iritis
Physical
• Complete ophthalmic examination (defer in case of globe compromise)
o Vision and pupils - Presence of afferent pupillary defect (APD) indicative of traumatic optic neuropathy
o Extraocular motility - Orbital fractures or traumatic nerve palsy
o Intraocular pressure - Secondary glaucoma, retrobulbar hemorrhage
o Anterior chamber - Hyphema, iritis, shallow chamber, iridodonesis, angle recession
o Lens - Subluxation, dislocation, capsular integrity (anterior and posterior), cataract (extent and type), swelling, phacodonesis
o Vitreous - Presence or absence of hemorrhage, posterior vitreous detachment
o Fundus - Retinal detachment, choroidal rupture, commotio retinae, preretinal hemorrhage, intraretinal hemorrhage, subretinal hemorrhage, optic nerve pallor, optic nerve avulsion
Causes
Traumatic cataracts occur secondary to blunt or penetrating ocular trauma.
Differential Diagnoses
Cataract, Senile
Laceration, Corneoscleral
Choroidal Rupture
Sudden Visual Loss
Ectopia Lentis
Glaucoma, Angle Recession
Hyphema
Other Problems to Be Considered
Globe rupture
Orbital fractures
Retinal detachment
Secondary glaucoma
Traumatic optic neuropathy
Workup
Imaging Studies
• B-scan - If the posterior pole cannot be visualized
• A-scan - Prior to cataract extraction
• CT scan of the orbits - Fractures and foreign bodies
Treatment
Medical Care
• If glaucoma is a problem, control intraocular pressure with standard medications. Add corticosteroids if lens particles are the cause or if iritis is present.
• Focal cataract
o Observation is warranted if the cataract is outside the visual axis.
o Miotic therapy may be of benefit if the cataract is close to the visual axis.
• In some cases of lens subluxation, miotics may correct monocular diplopia. Mydriatics may allow for vision around the lens with aphakic correction.
Surgical Care
• Planning the surgical approach is of the utmost importance in cases of traumatic cataract.
• Preoperative capsular integrity and zonular stability should be surmised.
• In cases of posterior dislocation without glaucoma, inflammation, or visual obstruction, surgery may be avoided.
• Indications for surgery include the following:
o Unacceptable decreased vision
o Obstructed view of posterior pathology
o Lens-induced inflammation or glaucoma
o Capsular rupture with lens swelling
o Other trauma-induced ocular pathology necessitating surgery
• Standard phacoemulsification may be performed if the lens capsule is intact and sufficient zonular support remains.
• Intracapsular cataract extraction is required in cases of anterior dislocation or extreme zonular instability. Anterior dislocation of the lens into the anterior chamber requires emergency surgery for its removal, as it can cause pupillary block glaucoma.
• Pars plana lensectomy and vitrectomy may be best in cases of posterior capsular rupture, posterior dislocation, or extreme zonular instability.
• Automated irrigation/aspiration can be used in patients younger than 35 years.
• Lens implantation
o Capsular fixation is the preferred placement if the lens capsule and zonular support are intact.
o Polymethyl methacrylate (PMMA) capsular tension rings allow capsular fixation in cases of zonular dialysis less than 180 degrees.
o Sulcus fixation is safe if the posterior capsule is compromised but zonular support is maintained.
o Suture fixation is chosen if both capsular and zonular supports are insufficient and the angle is minimally damaged.
o Anterior chamber placement is an option if no posterior support remains and iris or ciliary body trauma prevents suture fixation.
o Aphakia may be a better choice in young children and in patients with highly inflamed eyes, as they may experience better outcomes if lens implantation is deferred.
Consultations
Vitreoretinal consultation is necessary if a pars plana approach is mandated and the surgeon is untrained in posterior segment surgery.
Follow-up
Further Outpatient Care
• Patients should receive follow-up care as needed.
Deterrence/Prevention
• Protective eyewear should be worn when participating in any high-risk activities.
• Most serious eye trauma can be avoided if proper eye and face protectors are used.
Complications
• Lens dislocation and subluxation are commonly found in conjunction with traumatic cataract.
• Other associated complications include the following: phacolytic, phacomorphic, pupillary block, and angle-recession glaucoma; phacoanaphylactic uveitis; retinal detachment; choroidal rupture; hyphema; retrobulbar hemorrhage; traumatic optic neuropathy; and globe rupture.
Prognosis
• The prognosis is dependent on the extent of the injury.
Patient Education
• Protective eyewear is important in high-risk activities to avoid injury.
• For excellent patient education resources, visit eMedicine's Eye and Vision Center. Also, see eMedicine's patient education article Cataracts.
Miscellaneous
Medicolegal Pitfalls
• The nature of the injury should be accurately documented, including location, time, and circumstances of the injury, as well as whether protective eyewear was worn.
Multimedia
Media file 1: Classic rosette-shaped cataract in a 36-year-old man, 4 weeks after blunt ocular injury.
Classic rosette-shaped cataract in a 36-year-old man, 4 weeks after blunt ocular injury.
Media file 2: Same cataract as seen in Media file 1, viewed by retroillumination
Label: Cataract
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