Complications Following Congenital Cataract Surgery

Fig. 16.1
(a) the vitrector has come too close to the iris while in cutting mode and the iris has been aspirated into the tip. (b) At conclusion of case with defect in iris apparent

16.2.3 Hyphema

Hyphema is a rare complication, occurring in <5 % of the IATS patients [3]. A persistent hyaloid vessel is commonly found in cases of PFV, but is only very rarely a cause of intraocular bleeding.

16.2.4 Ruptured Posterior Capsule

Because the posterior capsule left intact in very young children will opacify quickly and completely, it is common practice to perform a primary posterior capsulectomy in young children. When done in a controlled fashion with vitreous cutting instruments, this procedure is safe and effective. If the capsule ruptures prematurely and vitreous is allowed to escape uncontrolled into the anterior chamber or left incarcerated into the corneal wound, complications including CME, retinal detachment, pupillary block glaucoma and corectopia can ensue [79].

16.2.5 IOL Malposition

All efforts should be made to ensure that the IOL is secured in the capsular bag whenever possible. Although some IOL’s can be placed in the ciliary sulcus, it is widely agreed that the safest long term resting place for an IOL is within the capsular bag (Fig. 16.2 and 16.3). Complications such as the UGH (uveitis-glaucoma-hyphema) syndrome are more likely in cases where the IOL is malpositioned.


Fig. 16.2
IOL has been injected through an opening in the posterior capsule. This is one type of IOL malposition and a reason some surgeons favor doing a primary posterior capsulotomy after the IOL has been securely implanted in the capsular bag


Fig. 16.3
A sulcus IOL that has become malpositioned over time

16.3 Immediate Postoperative Complications

16.3.1 Wound Leak/Dehiscence

The infant sclera is soft and collapsible – all but the tiniest unsutured wounds tend to gape and become a source of wound leak, iris prolapse and potentially endophthalmitis. Therefore it is highly recommended that most surgical wounds in young children be sutured closed. In addition to the challenging characteristics of the immature sclera, children cannot be relied on to keep their fingers away from the wounds during the early healing process. Using this philosophy, zero of 114 patients in the Infant Aphakia Treatment Study experienced a wound dehiscence (though one patient later developed a glaucoma-related wound dehiscence) [3].

16.3.2 Endophthalmitis

Endophthalmitis is perhaps the most feared complication of any intraocular surgery. Fortunately, the rate of endophthalmitis is very low in children – as it is in adults- but due to the relatively low number of patients involved, the rate in children is not as well established as it is in adult populations where it has ranged from 0.04–0.34 % in recent large studies [1013].

Most cases in adults are due to gram-positive organisms such as Staphylococcus epidermidis or Staph aureus, but gram negative enterococci have also been implicated. Other important organisms found particularly in pediatric cases are H influenza and pneumococci [14, 15].

Interventions that may be appropriate to help reduce the incidence of endophthalmitis have become a controversial topic in recent years. Specifically, some surgeons have adopted the practice of mixing antibiotics into the intracameral irrigating solution and/or injecting antibiotic directly into the eye at the end of the cataract surgery [16]. For others, the scientific evidence supporting these measures and the cost/benefit ratio makes the idea of instituting them less attractive. In vitro studies have questioned the validity of mixing antibiotics into the irrigating solution and no in vivo studies have shown a statistical advantage to this measure [17].

A European study of injection of antibiotic directly into the eye at the conclusion of surgery provides the only Level 1 evidence supporting its adoption [10]. This study showed that intraocular injection of cefuroxime reduced the incidence of endophthalmitis to .07 % compared to .34 % in the control group not receiving the antibiotic. But the conclusion has been criticized because the endophthalmitis rate in the control group was much higher than other published large scale studies. The choice of cefuroxime has also been questioned because of its relatively poor efficacy against MRSA and gram negative organisms [17]. Other studies have not supported this salutary effect [18]. In addition, because the solutions need to be mixed by hand on a case by case basis (at least in the US), there exists the possibility of dilution error causing more harm than good. In addition to dilution errors leading to vision threatening complications such as macular infarction, serous detachment and cystoid macular edema, non-dose dependent idiosyncratic reactions to the injected antibiotic have been reported [19]. Shows just such a devastating reaction following injection of vancomycin post cataract surgery. Because this reaction may be delayed for days or even weeks, the second eye may be operated and sustain the same fate before the damage to the first eye is diagnosed.

Moxifloxacin has become a popular alternative antibiotic for intracameral injection because of its safety profile and the fact that it comes in a preservative-free solution that does not require reconstitution. However resistance rates to this antibiotic are rising with its increased use and the cost effectiveness for prophylactic treatment of a very rare entity has been questioned [20]. At one outpatient hospital that this author is aware of, the charge for a single dose of moxifloxacin injection is higher than the surgeon’s Medicare fee for the cataract surgery.

16.3.3 Excessive Inflammation/Pupillary Membrane/Corectopia

Some degree of postoperative inflammation is expected after any cataract surgery, especially when an IOL is implanted, but the response is more intense in young children, particularly infants. If not controlled, this can lead to formation of inflammatory membranes causing pupil opacification and/or corectopia. Clearly aggressive use of steroids postoperatively is indicated in children. The route of administration- whether just topically or supplemented with intracameral or subconjunctival injection or orally- is not well settled [21, 22]. Interestingly, although the IATS was not designed to answer this question, the addition of subconjunctival steroid injection did not seem to reduce this complication- the number of babies that developed inflammatory pupillary membranes was 16 % in the eyes that had subconjunctival injection of steroid in addition to aggressive topical drops and only 13 % in the eyes that did not receive a subconjunctival injection in addition to the topical steroid [23].

16.3.4 Retinal Hemorrhages

Intraretinal hemorrhages are quite common after cataract surgery in infants, but these are invariably self-limited and non-sight threatening.

16.3.5 Vitreous Hemorrhage

Intraocular hemorrhage has been reported after surgery for congenital cataract especially in cases of PFV, but in this author’s experience it is very rare. Even in cases where the persistent hyaloid vessel appears to be intact, any bleeding after transection of the vessel is usually mild and can be controlled by raising the infusion pressure in the eye for a short time.

16.4 Later Postoperative Complications

16.4.1 Lens Reproliferation into the Visual Axis

The most common complication of cataract surgery with IOL implantation in infants <7 months of age is lens reproliferation into the visual axis (VAO). It must be emphasized that this complication is common only if an IOL is placed and only in the very young, e.g., in the first 6 months of life. In the IATS, this occurred in 24 of 57 (42 %) of infants when an IOL was placed, but only 1 of 57 when the child was left aphakic [3, 4]. Similarly, in a separate study comparing children with and without IOL implant at various ages, up to 80 % of infants <6 months with an IOL developed VAO but only 12 % of the same age group when no IOL was implanted. Notably no children >8 months of age developed VAO even when an IOL was implanted [24].

16.4.2 Why Does This Occur Only in Infants and Mostly When an IOL Is Implanted?

The lens cells are still undergoing rapid proliferation in the first six months of life. When a lensectomy is performed at this young age, even when all visible cortical lens material has been aspirated from the capsular bag, more lens epithelial cell proliferation is yet to come. In most cases these re-proliferating cells will be sequestered out of the visual axis by forming a Sommerring ring (Fig. 16.4). If an IOL is placed in the capsular bag, the anterior and posterior capsule leaflets are prevented from fusing to sequester the proliferating lens cells and they are free to grow across the visual axis (Fig. 16.5). This is usually across the posterior surface of the IOL, but can be anterior to it. In either case, when they obscure the visual axis, a second procedure to aspirate the offending lens material becomes necessary (Fig. 16.6).
Nov 21, 2017 | Posted by in OPHTHALMOLOGY | Comments Off on Complications Following Congenital Cataract Surgery

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