Traumatic cataract is lens opacity caused by trauma, more common in younger individuals compared to age-related cataract. If unilateral cataract is found in a young person without underlying disease, traumatic cataract should be suspected first. The lifetime prevalence of ocular trauma in the general population is about 14%, with a higher incidence in children and young males. 27–65% of ocular trauma results in cataract, most of which significantly affect visual function and require surgery 3).
Traumatic cataract often accompanies damage to other ocular tissues and frequently occurs in younger age groups, posing a significant public health burden. Even in the absence of cataract that significantly affects visual function, zonular damage may cause lens subluxation, requiring surgical intervention.
Mechanisms of cataract formation
Rapid opacification: Aqueous humor enters the lens fibers due to capsular rupture.
Delayed opacification: Even without capsular rupture, traumatic force damages lens fibers, leading to opacification months to years later.
Typical appearance: Rosette-shaped or stellate opacities.
Characteristics of traumatic cataract
Common age group: Children and young males
Associated ocular injuries: Iris damage, zonular damage, vitreous prolapse, etc.
Urgency: Emergency extraction is required in cases of capsule rupture or elevated intraocular pressure.
Clinically, a major distinction is made between mechanical and non-mechanical classifications based on the mechanism of injury.
| Classification | Mechanism | Characteristics |
|---|---|---|
| Blunt trauma | Ocular contusion, ocular concussion | Progresses gradually over months to years after injury. May be associated with angle recession and zonular rupture. |
| Penetrating trauma | Perforating wound, laceration, contused wound | A metallic fragment or similar object perforates the corneosclera and enters the lens and vitreous. Rapid cataract formation occurs immediately after injury. |
| Foreign body | Intraocular foreign body retention | Forms siderosis lentis (iron cataract) and chalcosis lentis |
| Infrared cataract | Chronic infrared exposure | Glassblower’s cataract. Characterized by posterior subcapsular opacity |
| Electric cataract | Lightning strike / electric shock | Characterized by cortical and subcapsular opacity |
| Radiation cataract | X-rays / gamma rays | Posterior subcapsular opacity. See separate article “Radiation cataract” |
| Drug-induced | Steroids, etc. | See separate article “Effects of steroids on the eye” |
Size of the blunt trauma object and opacity pattern:
Siderosis lentis and chalcosis lentis:
If an iron foreign body remains in the eye, it forms siderosis lentis, presenting characteristic opacities. Copper foreign body remnants cause chalcosis lentis. If a foreign body is suspected, CT and other imaging for localization and early removal are necessary.
Visual acuity and intraocular pressure
Preoperative visual acuity is useful for predicting postoperative best-corrected visual acuity. Regarding intraocular pressure, asymmetrically low pressure may suggest open globe injury or cyclodialysis cleft. Elevated intraocular pressure may reflect lens-induced glaucoma, hyphema, or angle-recession glaucoma.
Pupillary findings
Relative afferent pupillary defect (rAPD) is seen in traumatic optic neuropathy and is an indicator of postoperative visual prognosis. Cataract alone does not cause rAPD.
Anterior segment findings
| Site of finding | Evaluation points |
|---|---|
| Cornea | Degree of opacity, impact on IOL calculation |
| Anterior chamber | Hemorrhage, lens material, vitreous prolapse |
| Iris | Transillumination defect, iridodialysis, mydriasis disorder, posterior synechiae |
| Lens | Opacity location, anterior capsule rupture, subluxation, Vossius ring |
In blunt trauma, if findings such as posterior synechiae, anterior capsule opacification, or localized cortical opacification are observed in only one eye, traumatic cataract is strongly suspected. Also carefully observe the difference in anterior chamber depth between the eyes, the presence or absence of angle recession, zonular rupture, vitreous prolapse into the anterior chamber, and retinal dialysis.
Diagnostic System
The Birmingham Eye Trauma Terminology (BETT) system is used for recording trauma.
Imaging Tests
Yes. In perforating trauma, the lens capsule is damaged and aqueous humor enters, causing rapid opacification immediately after injury. Small wounds (e.g., from a needle) may result in only localized anterior subcapsular opacification, but large wounds (e.g., from a cutter) lead to rapid spread of opacification. In contrast, in blunt trauma, even without capsular rupture, metabolic disturbances and osmotic changes due to external force can occur, and opacification often progresses gradually over months to years after injury.
The diagnosis of traumatic cataract itself is easy, but it is important to determine that the cause is trauma. Since cataract surgery for traumatic cataract is more likely to be a difficult case compared to routine cataract surgery, thorough preoperative evaluation is essential.
Differential points: If unilateral posterior synechiae, anterior capsule opacity, or localized cortical opacity is observed, suspect traumatic origin. In penetrating trauma, it is essential to assess the state of the perforation wound, lens capsule (posterior capsule rupture), posterior segment, and the presence, nature, and location of foreign bodies.
Generally, lens reconstruction is performed after opacification becomes severe and visual impairment progresses. On the other hand, urgent surgery may be necessary in some cases, such as for lens-induced uveitis due to capsular rupture (caused by lens protein leakage) or to prevent bacterial endophthalmitis after foreign body or laceration.
Traumatic cataract extraction is broadly divided into “primary extraction” immediately after open globe injury and “secondary extraction” several weeks to months after the injury.
Primary repair of open globe injury is desirable within 24 hours, and the risk of endophthalmitis is significantly lower in the group repaired within 24 hours (OR 0.39, 95% CI 0.19-0.79)1).
Indications for emergency extraction (primary):
Advantages of secondary extraction:
| Timing of extraction | Advantages |
|---|---|
| Primary | Single surgery, cost reduction, reduced amblyopia risk (children) |
| Secondary | IOL calculation accuracy, visibility, inflammation control |
Emergency surgery is common. First, suturing of the corneoscleral perforation wound is necessary. If the anterior chamber is maintained and there is a relatively small perforation only in the anterior capsule with no intraocular foreign body, standard phacoemulsification (PEA) is possible. In cases of perforation extending to the posterior capsule, foreign bodies often reach the vitreous, so simultaneous vitrectomy is required. Topical and systemic antibiotics are necessary.
Surgical indications are determined similarly to ordinary cataracts. Zonular weakness or rupture is often observed; set the ultrasound device to low perfusion and low aspiration pressure. Use capsule expanders or capsular tension rings (CTR) as appropriate. In cases of extensive zonular rupture, consider intraocular lens suturing.
Assessment of anterior capsule integrity: Use trypan blue intraoperatively to identify anterior capsule tears and visualize the capsule even in white cataracts. If a capsular tear is suspected, perform hydrodissection conservatively and carefully.
Surgery by cataract type:
IOL selection:
If the extent of the tear is 1/4 or more, use a CTR (capsular tension ring) to fix the intraocular lens within the capsule. If fixation within the capsule is not possible, suture the intraocular lens to the ciliary sulcus or fix it within the sclera (e.g., Yamane method) 6).
In cases of complete dislocation, during vitreous surgery, use liquid perfluorocarbon (LPFC/PFCL) to float the lens to the iris plane and remove it via a transscleral or transcorneal approach.
Perform regular follow-up on postoperative day 1, week 1, and month 1. Complete the course of topical antibiotics and steroids. If complications occur, monitor more frequently and adjust steroids or administer intraocular pressure-lowering medications. In cases with zonular dehiscence, be alert for the risk of intraocular lens dislocation or drop postoperatively and conduct long-term follow-up.
Traumatic cataract surgery is more challenging than routine cataract surgery. Many intraoperative difficulties are anticipated, such as possible anterior capsule rupture, lens instability due to zonular damage, difficulty in dilation due to posterior synechiae, anterior capsule fibrosis, and high risk of posterior capsule rupture. It is important to utilize auxiliary tools such as trypan blue, CTR, and Malyugin ring, and to carefully plan the surgery according to the cataract morphology and associated injuries. Adequate preparation of instruments preoperatively is also essential.
If the opacity is mild and does not significantly affect vision, observation may be possible. However, if there is capsular rupture, elevated intraocular pressure, or lens-induced uveitis (a condition where lens protein leaks and causes inflammation), emergency surgery is indicated. In children, due to the risk of amblyopia, more proactive early intervention is required compared to adults.
If the capsular bag is preserved, primary implantation is possible. If the capsule is damaged, secondary implantation can be performed via ciliary sulcus suturing or scleral fixation (Yamane method). If axial length measurement is difficult or the risk of infection is high, IOL implantation may be postponed.
Children are disproportionately affected by ocular trauma and require special management due to the risk of stimulus deprivation amblyopia, which differs from adults.
Preoperative Considerations
In children, the threshold for determining a significant impact on visual function is lower than in adults. If there is an opacity greater than 3 mm on the visual axis, extraction should be considered, and because delay increases the risk of amblyopia, primary extraction is recommended as an emergency procedure 5).
In penetrating trauma, promptly remove the lens and, if possible, insert an IOL. In blunt trauma, perform surgery based on the progression of the cataract.
Intraoperative considerations
In children under 2 years of age, cataract extraction is often performed simultaneously with pars plana vitrectomy. In this age group, IOL insertion is postponed and performed as a secondary procedure.
Postoperative considerations
Postoperative amblyopia treatment (optical correction and occlusion of the healthy eye) is essential. Continue aggressive amblyopia treatment combining optical correction with glasses or contact lenses and occlusion therapy of the healthy eye. Posterior capsule opacification (PCO) is a common postoperative complication in children and requires early intervention as it can lead to amblyopia if left untreated. Young patients have a strong inflammatory response and are at risk for fibrinous uveitis, so aggressive preoperative and postoperative steroid eye drop management is necessary.
In children, due to the risk of amblyopia, more aggressive early intervention is required than in adults. If there is an opacity greater than 3 mm on the central visual axis, extraction is indicated, and emergency primary extraction is recommended. Delay in surgery increases the risk of amblyopia and can lead to permanent vision loss. Postoperatively, aggressive amblyopia treatment including occlusion of the healthy eye and optical correction is necessary.
Sharp trauma (penetrating): Rupture of the lens capsule allows aqueous humor to rapidly enter the lens fibers, causing rapid opacification due to osmotic changes and metabolic disturbances. Small perforations may result in localized anterior subcapsular opacities, while large perforations lead to total rapid opacification.
Blunt trauma: Sudden deformation of the eye applies mechanical stress to the lens fibers. Even without capsular rupture, metabolic disturbances and osmotic changes are induced, leading to gradual opacification over months to years. The zonules of Zinn may also be subjected to mechanical stress and can rupture.
Lens swelling (intumescent cataract): Swelling of the lens can cause increased intraocular pressure. Leakage of lens proteins into the aqueous humor can induce lens-induced uveitis, leading to further elevation of intraocular pressure and worsening inflammation.
Mechanism of Vossius ring formation: When the eye is suddenly deformed by blunt force, the iris is pressed firmly against the anterior surface of the lens. At this time, pigment from the iris pigment epithelial cells is transferred to the anterior lens capsule surface, forming a circular ring-shaped deposit (Vossius ring) corresponding to the pupillary margin.
In predicting visual prognosis of traumatic cataract, the Ocular Trauma Score (OTS) is widely used. OTS calculates prognosis from six factors: initial visual acuity, presence of globe rupture, endophthalmitis, penetrating injury, retinal detachment, and relative afferent pupillary defect 2). A retrospective study of over 300 children showed that OTS reliably predicts visual prognosis in pediatric traumatic cataract 5).
Regarding the superiority of primary versus secondary lens extraction, conflicting data still exist and no consensus has been reached 4). A report indicates that primary repair of open globe injury within 24 hours is associated with reduced risk of endophthalmitis (OR 0.39), and early intervention is recommended 1).
For scleral-fixated IOL, sutureless fixation such as the Yamane technique is also an option. In cases without capsular support, selection of fixation method according to associated injuries and surgeon experience is important 6). For prognosis evaluation of traumatic cataract, individualized assessment combining OTS and findings from pediatric trauma studies is required 2,5).
McMaster D, Bapty J, Bush L, et al. Early versus delayed timing of primary repair after open-globe injury: a systematic review and meta-analysis. Ophthalmology. 2024.
Kuhn F, Maisiak R, Mann L, et al. The Ocular Trauma Score (OTS). Ophthalmol Clin North Am. 2002;15(2):163-165.
Shah MA, Shah SM, Shah SB, et al. Morphology of traumatic cataract: does it play a role in final visual outcome? BMJ Open. 2011;1(1):e000060.
Rumelt S, Rehany U. The influence of surgery and intraocular lens implantation timing on visual outcome in traumatic cataract. Graefes Arch Clin Exp Ophthalmol. 2010;248(9):1293-1297.
Ram J, Verma N, Gupta N, et al. Effect of penetrating and blunt ocular trauma on the outcome of traumatic cataract in children in northern India. J Trauma Acute Care Surg. 2012;73(3):726-730.
Yamane S, Sato S, Maruyama-Inoue M, Kadonosono K. Flanged intrascleral intraocular lens fixation with double-needle technique. Ophthalmology. 2017;124(8):1136-1142.
Morikawa S, Okamoto F, Okamoto Y, et al. Clinical characteristics and visual outcomes of work-related open globe injuries in Japanese patients. Sci Rep. 2020;10:1208.
