In the current study, we reported four cases of long-term endophthalmitis that developed after IOL implantation in children and retrospectively evaluated their surgical management and outcomes. Endophthalmitis is a severe complication that may develop days to years after lens aspiration and IOL implantation, causing irreversible blindness, eye pain, and the need for eye enucleation. The risk factors for endophthalmitis after lensectomy and IOL implantation include lacrimal duct obstruction, blepharitis, use of contact lenses, long surgical time, posterior capsular rupture, scleral suture fixation, corneal suturing, and the polypropylene loop of the IOL(3). However, studies on endophthalmitis that develops after IOL implantation in children are rare. Asadi et al.(4) reported long-term surgical complications in 25 eyes of 23 children who underwent implantation of transscleral fixated posterior chamber IOLs, including six eyes of four patients with lens dislocation caused by MFS. Endophthalmitis developed in one patient with MFS approximately 3 years after IOL implantation. Kristianslund et al.(5) reported 132 eyes (92 patients) that underwent MCTR implantation with scleral suturing. One eye (0.8%) developed late endophthalmitis, possibly related to suture exposure. Kanigowska et al.(6) reported that the endophthalmitis rate after lensectomy, vitrectomy, and IOL implantation with scleral fixation was 0.8% (1/116) in children exhibiting lens dislocation. Recently, Chen et al.(7) reported the surgical outcomes of MCTR and IOL implantation in patients with MFS and ectopia lentis. A total of 174 eyes with MFS underwent surgery. One eye of a patient (0.57%) in their cohort developed endophthalmitis 19 months after the corneal suture was removed. Although the above studies reported sporadic cases of endophthalmitis after IOL implantation in children, study focusing on the surgical treatment of long-term endophthalmitis after IOL implantation in children is rare. No consensus has been reached regarding the management of vitreous surgery for long-term endophthalmitis following IOL implantation in children. Therefore, we reviewed relevant cases and surgical outcomes to share our experience.
In the current study, all four children had a history of lens dislocation caused by MFS, an uncommon autosomal-dominant pleiotropic connective tissue disease, known to affect many systems, including the ophthalmological, musculoskeletal, and pulmonary systems. Ocular conditions may be the initial presenting symptoms in patients in whom cardiovascular symptoms have not yet developed. These symptoms include lens dislocation, myopia, glaucoma, cataracts, and retinal detachment(8). Lensectomy followed by IOL implantation effectively treats lens dislocation that characterizes MFS. However, MFS appears to be an independent risk factor for long-term endophthalmitis. The possible causes of long-term infection are the existence of corneal or scleral sutures, which can also be seen in other lens surgeries in children, such as surgeries for congenital cataract or ocular trauma. Further case-control studies are necessary to confirm the role of MFS in long-term endophthalmitis development after lens aspiration and IOL implantation in children.
Corneal sutures were an important possible cause of long-term endophthalmitis in our study. Two of the four patients had a history of corneal suture exposure, which may cause microorganisms on the surface to penetrate the cornea, causing endophthalmitis even several years after the previous surgery. This reveals the importance of removing corneal sutures appropriately after cataract surgery or IOL implantation, although general anesthesia must be induced prior to suture removal in children. The direction of removal is also important. The suture should not contact the surface of the cornea as this may introduce microorganisms into the interior of the eye.
Another reason for the long-term onset of endophthalmitis is the scleral suture. The exposure of suture knots has been reported as a long-term complication of scleral IOL fixation(9); however, in our cases of endophthalmitis developing after IOL fixation, the sutures were not exposed on the surface of the cornea or conjunctiva. However, microorganisms may access the internal eye via scleral sutures associated with the near-invisible gaps on the eye surface. Although scleral flap placement reduces the risk of suture exposure, suture ends can penetrate partial-thickness scleral flaps and conjunctiva in the long term(4). Therefore, suture ends should not be exposed. This can be prevented by leaving the suture ends long, rotating the knots into the sclera, or tying the knots at the depth of the partial-thickness scleral incision(10). In 2007, Scharioth introduced transscleral fixation of a three-piece IOL using intrascleral tunnels(11). Recently, Yamane et al.(12) reported a new flanged IOL fixation technique to achieve good IOL fixation with firm haptic fixation. These suture-free techniques prevent suture-related complications.
In our study, all patients underwent complete vitrectomy, although three of the four patients required two vitrectomies prior to complete control of the infections. The utility of complete and core vitrectomy as treatments for post cataract endophthalmitis remains controversial. In the Endophthalmitis Vitrectomy Study (EVS) conducted in the 1990s, the question was raised whether pars plana vitrectomy (PPV) was superior to vitreous tap/biopsy (VTB) in conjunction with broad-spectrum intravitreal antibiotics. It was found that the three-port PPV and VTB were equivalent in eyes with vision better than LP. In LP eyes, vitrectomy provided significantly better visual results(13). However, given the advances in vitrectomy techniques in recent decades, experts have questioned whether the EVS findings remain applicable. The principal limitation of the EVS was that all vitrectomies were of the core type, and removal of cortical vitreous purulence on the retinal surface was explicitly discouraged to avoid iatrogenic retinal tears. Dib et al.(2) recommended complete vitrectomy for all eyes with infections that obscured the fundus, including posterior vitreous detachment if required. The main advantage of complete vitrectomy compared with core vitrectomy is the removal of purulence from the cortical vitreous and retinal surface, which limits retinal injury caused by endophthalmitis. In our clinical practice, the type of vitrectomy used depends on many factors, including the extent of infection, transparency of the refractive medium, presence/absence of a ciliary membrane, and the surgeon’s ability. In patient #1, a ciliary membrane was formed prior to vitrectomy; thus, we performed an initial CEVE and IOL removal. The outcome 7 days after vitrectomy was satisfactory; however, the patient was lost to follow-up. The three other patients underwent initial incomplete vitrectomies; however, the extent was wider than that of core vitrectomy and VTB. Unfortunately, the infections were not controlled, and all three patients underwent a second (complete) vitrectomy.
The IOL was removed from three of the four patients. Capsulectomy was performed in patient #4 (whose IOL was retained). These factors promote intraocular fluid circulation and control infection and inflammation. The need for IOL removal remains controversial because of increased surgical difficulty and possible complications, including retinal detachment, hypotony, corneal edema, endothelial decompensation, macular edema, and vitreous or subretinal hemorrhage(14). Zhang et al.(15) retrospectively evaluated surgical efficacy and determined when IOL removal was indicated during vitrectomy to treat endophthalmitis. It was concluded that IOLs should not be removed. However, it remains unclear whether IOL removal is necessary when endophthalmitis develops long after IOL implantation in children with MFS, and further research is needed. We removed IOLs that were opaque and associated with severe anterior vitreous symptoms, such as ciliary membrane formation.