Controversies regarding the classification and management of traumatic cataract in the pediatric age group: A review

Traumatic cataract

In traumatic cataract, it is imperative for surgeons to understand the fact that a traumatic cataract is not a senile cataract. The injury is rarely limited to the lens alone, and it may be associated with injuries to the zonules, posterior capsule, and posterior segment. A patient with a traumatic cataract should be informed regarding the visual outcome and the high risk of intraoperative complications.

At no stage should an ophthalmologist subject patients to half-completed or compromised surgery because of a lack of expertise or infrastructure. If the facility is not equipped to provide after-hours care, including the availability of a surgeon with the full armamentarium of equipment, instruments, and materials, as well as knowledgeable staff, it is better not to contemplate performing primary lens removal. Most of the hospitals worldwide do not have all the state-of-the-art facilities required for performing cataract extraction and IOL implantation in case a patient with open or closed globe injuries presents during late hours.

Optical rehabilitation is crucial because an IOL may not be implanted in all cases.²¹ Orthoptic treatment following optical correction, including the patching and monitoring of visual regain, is vital because amblyopia is an important factor.²¹

In conclusion, children with OGI cannot simply be treated as young adults. The age of patients and the effects of amblyopia should be considered as additional negative prognostic factors.

This study was approved by the hospital’s ethical committee and was conducted in accordance with the Declaration of Helsinki. Written consent in the local language was obtained for using information in this article.

Controversies regarding epidemiology and incidence

The incidence of traumatic cataract varies in different regions of the world, mainly based on retrospective studies or eye injury registries. The variation in the incidence results from different demographic conditions, age, sex, environment, and socio-economic conditions.⁴ In the pediatric age group, the incidence of traumatic cataract also varies.^4–6 Varying incidence in the pediatric population has been reported in studies, most of which were retrospective, including small databases. Studies on traumatic cataracts in children have reported an incidence of 25% in southern India and 12% and 46% in western India.^4–6

Controversies regarding ocular trauma classification

This is a proposed classification based on the improvised BETT system [Figure 1].

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Figure 1:

Modified BETTS classification. BETTS: Birmingham eye trauma terminology. IOFB: Intraocular foreign body.

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Landmark for zone III OGI

The International Ocular Trauma Classification has defined zone III injuries as those extending 5 mm beyond the limbus [Figure 2]. The length of 5 mm was determined arbitrarily based on the justification that injuries in that zone may not extend into the pars plana. Therefore, any injury not involving zone III or the pars plana region is predicted to have a favorable prognosis.

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Figure 2:

Diagrammatic representation of extend of wound in relation to recti insertion. LR: Left rectus, MR: Medial rectus.

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Demarcation is 5.6–6.3 mm long temporally and 4.6–5.2 mm nasally.^22,23 Of particular surgical importance is the distance from the external corneoscleral limbus to the end of the ciliary body at the ora serrata, which marks the beginning of the pars plana. This distance of the ora serrata from the corneoscleral limbus almost coincides with and overlaps with the spiral of Tillaux, the imaginary line along the insertion of all rectus muscles.²³ Knyazer et al. identified risk factors for posterior OGI that result in poor visual outcomes.¹⁴ A significant risk factor noted in our study was the posterior extent of the wound, which affected the final vision outcome and correlated with the insertion of the rectus muscle, termed the ‘spiral of Tillaux’. Radial scleral lacerations extending beyond the rectus insertion were often associated with poor outcomes. In addition, we observed favorable outcomes in cases with zone III injuries not extending beyond the recti insertion. Therefore, it would be more appropriate to define the landmark for zone III injuries with reference to the rectus insertion (spiral of Tillaux) rather than the conventional definition; that is, injuries extending 5 mm beyond the limbus.

Surgeons must realize that a traumatic cataract is not a senile cataract. The injury is rarely limited to the lens alone but may also be associated with the zonules, posterior capsule, and posterior segment. A patient with a traumatic cataract should be warned regarding the potential visual outcome and the high risk of intraoperative complications.

Controversies regarding the morphology of traumatic cataract in children

No standard morphological classification is available even for adults. Although attempts at grading have been made, they were arbitrary.²⁴ The morphology of traumatic cataracts depends mainly on the type of injury and the time interval between the injury and intervention.

On the basis of lenticular opacity, cataracts are classified as total [Figure 3]; white soft, with soft material floating in the anterior chamber with a broken anterior capsule [Figure 4]; membranous, in which both the capsules were fused with little or no cortical material [Figure 5]; and rosette [Figure 6]. A cataract is defined as total when no clear lens matter is observed between the capsule and nucleus, and as membranous when the capsule and organized matter are fused and form a membrane of varying density. Furthermore, a soft white cataract is defined as when loose cortical material is found in the anterior chamber together with a ruptured lens capsule. A lens with a rosette pattern of opacity is classified as a rosette-type cataract.

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Figure 3:

Total cataract.

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Figure 4:

Traumatic cataract with ruptured anterior capsule.

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Figure 5:

Traumatic cataract with fused anterior and posterior capsule.

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Figure 6:

Rossette cataract.

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One study proposed that all cataract cases can be assigned to these groups.²⁵

Controversies regarding the management of and surgical approaches to traumatic cataract

In adults in whom amblyopia is not an issue, the choice of surgery is governed by the surgeon’s own preferences and, to a certain extent, by the status of the cataractous lens. If the anterior capsule is significantly disrupted and there is free-floating lens matter in the anterior chamber, the surgeon may perform primary cataract extraction with or without IOL implantation [Figure 3].

The eyes with a vitreous lens admixture should be considered for combined cataract extraction with limited anterior vitrectomy. Care should be taken to judiciously use a vitrector and not an aspirator while removing the vitreous admixture in the ruptured lens matter [Figure 4]. Any traction on the vitreous can result in inadvertent retinal breaks.²⁶ When there is additional injury to the posterior segment, early pars plana lensectomy and vitrectomy by a posterior segment specialist are warranted.²⁶ In the eyes with an intact anterior capsule and total traumatic cataract, second cataract extraction with IOL implantation should be the best and safest approach for optimal visual outcomes [Figure 5].^27,28

Wherever possible, a multistep procedure after inflammation control with adequate corneal clarity and an appropriate IOL power calculation should be adopted.^28,29 A surgical approach of anterior versus posterior via the pars plana route is debatable.

The following types of surgical approaches may be used according to morphology:

• Unimanual or bimanual aspiration

• Lensectomy/membranectomy using the limbal or pars plana approach, with insertion of the lens in the sulcus

Challenges in children with traumatic cataracts include amblyopia, a tendency for inflammation, synechiae, and after-cataract.³⁰

In toddlers and adolescents, the surgical anatomy of the limbus and pars plana varies according to age.^31,32 Accordingly, different surgical techniques are required for treating traumatic cataracts in toddlers and adolescents.^33,34 IOL power calculation is also more complex in the unilateral eye.³⁴ The visual outcome is significantly better in children after the age of more than 5 years when the risk of amblyopia is low.³²

The timing of presentation can define the morphology and strategy for management.³⁴

The timing of intervention (i.e., early versus late surgery) is a matter of debate because if cataract surgery is deferred by 2–4 weeks, visual acuity is significantly better.³⁵ Tabatabaei reported that the visual outcome does not significantly differ between early and late cataract surgery.³⁶ A controversy exists regarding the timing of cataract extraction and IOL implantation. Arguments can be for both primary and secondary cataract extraction; however, we need to consider crucial facts before making the decision. Cataract extraction, along with primary wound repair, may have distinct advantages, such as inflammation control, and disadvantages, such as the possibility of increased intraocular pressure due to the presence of the soft lens matter in the anterior chamber.²⁶ Secondary advantages can be the direct visualization of the posterior segment and optic nerve.²⁶ Similarly, in pediatric patients, the removal of media opacity may be crucial to prevent vision-deprivation amblyopia. In patients with a lens vitreous admixture, further proliferative vitreoretinopathy can be a potent stimulator and can result in traction on the retina. Hence, the primary extraction of the lens and vitreous is imperative in such patients. The advantages of primary lens removal are the patient’s convenience and possibly cost effectiveness.^26,35,36

Studies supporting second cataract extraction recommend favorable intraocular inflammation control, satisfactory media clarity, and a stable wound before planning traumatic cataract extraction.²⁶ In addition, if inflammation is adequately controlled, IOL implantation at the second cataract extraction may be associated with better outcomes. The IOL power calculation is also appropriate if IOL implantation is planned for the second time.^26,33

A few factors should be considered before deciding on primary or delayed cataract extraction and IOL implantation. Factors such as the age of the patient, expertise of the surgeon and assisting staff, availability of the infrastructure facility, and status of the cataractous lens and lens vitreous admixture can guide the surgeon in planning the surgery.

An IOL should not be implanted in toddlers who are aged less than 1.5 years and have any eye with deficient zonules or any co-existing posterior segment pathology.^34,35,37

It may be difficult, if not impossible, to calculate the correct IOL power prior to surgery (often the other eye serves as a guide). The inflammatory debris can settle on the IOL surface, possibly requiring postoperative yttrium aluminum garnet (YAG) laser or even surgery to cleanse it. Furthermore, the edge of the IOL can interfere with the surgeon’s visualization of the peripheral retina, and the subsequent proliferative vitreoretinopathy development can necessitate vitrectomy.^32–34

The IOL power calculation is a complex problem for unilateral traumatic cataracts in children aged less than 5 years because it affects the final outcome owing to amblyopia and visual development.^33,35 In a unilateral case, making a child emmetropic is crucial for the development of binocular vision.³³ Few studies have compared the visual outcome between open and closed globe injuries and reported that the visual outcome is better in closed globe injuries.^31,38 The selection of single or multistep surgeries is under debate. A majority of studies have suggested multistep management.^39–41 Multistep management was also performed in a case with primary scleral repair and scleral buckle.⁴² Wherever possible, a multistep procedure after inflammation control, adequate corneal clarity, and appropriate IOL power calculation should be adopted.^30,31

The consideration of secondary lens implants in the case of aphakia, as unilateral aphakia is a common cause of deep amblyopia.^8,9 In planned aphakia, secondary implantation may be considered after the age of 1.5–2 years. If the sulcus-fixated lens is to be used, a three-piece lens is preferred to prevent secondary inflammation. In the absence of support, scleral-fixated lenses, either suture-fixated^41–43 or sclera-supported glued lenses,⁴³ may be used. In addition, specially designed endoscleral (scleral tuck lens) or iris-supported posterior chamber lenses may be used. The visual outcome does not significantly differ by the position of the lens.

Not only cataract surgery but also comorbidities affect outcomes.^31,32 Pre-existing pathologies, such as congenital anomalies, sensory nystagmus, microphthalmos, and colobomas, may affect the outcome.

In summary, the majority of ophthalmologists who encounter traumatic cataracts have sufficient experience in lens extraction (and IOL implantation) in a nontraumatic setting. Every ophthalmologist must accept that an injured lens requires many individualized, consciously made decisions regarding what to do when and how to achieve the best possible outcome.

Controversies related to the timing of intervention

Controversies exist regarding the timing of cataract extraction and IOL implantation. Arguments can support both primary and secondary cataract extractions; thus, many crucial factors should be considered before making a decision. Cataract extraction together with primary wound repair may have distinct advantages, such as inflammation control, but it might also increase intraocular pressure because of the presence of the soft lens matter in the anterior chamber.^34,44 Secondary advantages include the direct visualization of the posterior segment and optic nerve.²⁸ Similarly, in pediatric patients, the removal of media opacity may be crucial to prevent vision-deprivation amblyopia. In patients with a lens-vitreous admixture, further proliferative vitreoretinopathy can be a potent stimulator and result in traction on the retina; hence, primary extraction of the lens and vitreous is imperative in such patients.^35,44 Minor advantages of primary lens removal are the patient’s convenience and possibly cost-effectiveness.⁴⁵

Studies supporting second cataract extraction recommend favorable intraocular inflammation control, satisfactory media clarity, and a stable wound before planning for traumatic cataract extraction.³⁴ If there is adequate inflammation control, IOL implantation at the second cataract extraction may be associated with a better outcome.^34,44 An IOL power calculation is appropriate if IOL implantation is planned for the second time.^28,45

Studies have argued against performing multi-staged surgeries in children aged less than 5 years because of the risk of amblyopia; it is crucial to provide optical clarity to prevent amblyopia.

Current data suggest that improved visual outcomes result from intervention at 2–30 days.³⁵

Many factors must be known before performing primary or delayed cataract extraction with IOL implantation. These include the age of the patient, the expertise of the surgeon and assisting staff, the availability of the infrastructure facility, and the status of the cataractous lens and lens vitreous admixture. These factors can act as a guide for the surgeon in planning the surgery.

Controversies regarding predictive methods

Clinical conditions that might predict prognosis:

Controversies regarding primary posterior capsulotomy

Calculation of the correct IOL power prior to surgery may be difficult, if not impossible, due to various reasons. Often, the other eye serves as a guide, and inflammatory debris can settle on the IOL surface, cleansing of which may require postoperative YAG laser treatment or even surgery. In addition, the edge of the IOL can interfere with the surgeon’s visualization of the peripheral retina, and the subsequent proliferative vitreoretinopathy development can necessitate vitrectomy.⁴⁴ Considerable controversy exists regarding the use of primary posterior capsulotomy in all traumatic cases, particularly in children,⁵⁸ There are studies supporting that.

Controversy surrounding preoperative visual acuity of NLP and poor visual prognosis

Visual acuity can be profoundly impaired, even to the extent of NLP, in the presence of significant media opacity (e.g., corneal oedema, hyphema, cataract, and dense vitreous hemorrhage), retinal detachment, associated subretinal or subhyaloid hemorrhage, hemorrhagic choroidal, and even psychological factors (e.g., hysteria). The assessment of light perception is a subjective measurement and not a full-proof test in the presence of severe media opacity secondary to dense vitreous hemorrhage, traumatic cataract, dense hyphema, or corneal edema.¹⁶ Even with the bright light of an indirect ophthalmoscope, the assessment of light perception can give a false impression of NLP.⁴⁵ Ultrasonography is useful for assessing the posterior segment in eyes with media opacity and for differentiating between retinal detachment and vitreous haemorrhage.⁴⁵ However, using this methodology, it is sometimes difficult to differentiate a detached retina from blood clots in the vitreous cavity or membranes.⁴⁵ Before deciding on enucleation in patients with NLP, reversible causes of vision loss should be excluded, including psychological factors.^16,45 Even in situations where enucleation appears inevitable, the ophthalmologist should still discuss possible options with the patient before making a final decision. Primary enucleation for severely traumatized eyes with NLP is controversial because of the risk of sympathetic ophthalmia. Sympathetic ophthalmia with the potential for bilateral blindness is a relative indication for the enucleation of an injured eye.¹⁸ Therefore, primary surgical repair should not necessarily be abandoned because of the risk of sympathetic ophthalmia in eyes with NLP. Currently, most surgeons recommend a globe-salvaging procedure for eyes with severe trauma with NLP vision at the initial presentation.

Controversy remains regarding the age of children at which IOL insertion and aphakia rehabilitation can be undertaken.

Controversies regarding infection following OGI

Many studies have reported infection and endophthalmitis following OGI.^59,60 Intraocular infection is also common with a retained intraocular foreign body.^61–63

Absence of infection following wooden stick injuries due to the antimicrobial and antifungal properties of certain plants has been reported.^64–70