Controversies in intraocular lens implantation in pediatric uveitis

Advances in cataract surgery with smaller incisions and reduced intraoperative manipulation have greatly contributed to reduced inflammation [6, 8, 19, 25]. In the late 1990s, Vasavada et al. advocated performing a primary posterior capsulorhexis with anterior vitrectomy in children with congenital cataract less than 5 years of age [26]. It had been found to reduce the incidence of postoperative retro-IOL membranes and posterior capsular opacification (PCO) and therefore lead to a better visual outcome. Since then, the procedure has been used effectively in surgeries for pediatric uveitic cataract as well [8, 15, 27, 28]. Some studies have reported postsurgical development of PCO and retro-IOL membranes despite this procedure [15, 28], indicating the aggressive nature of inflammation in uveitic eyes. Grajewski et al. [19] suggested performing a pars plana 25-gauge anterior vitrectomy and posterior capsulotomy after phacoemulsification and “in-the-bag” IOL, with reduced incidence of PCO and retrolental membranes.

In situations where the sequelae of inflammation like cystoid macular edema, ciliary membranes, and macular traction do not resolve with medical management, performing a complete vitrectomy with manual removal of the ciliary and intravitreal membranes may assist in relieving associated traction, provided the patient is well supported with good immunosuppression [29]. Palsson et al. [30] reported favorable visual results with combined phacoemulsification, IOL, and vitrectomy in pediatric uveitis but advocated the procedure only for eyes with vitreous pathologies.

Studies in non-uveitic pediatric cataracts reported less postoperative inflammation and complications such as glaucoma when the IOL was placed in the bag [31, 32]. This may be because the lens capsule protects the iris from persistent chafing by IOL haptics. It is seen to benefit uveitic eyes in reducing postoperative inflammation, maybe by decreasing physical contact with uveal structures [8, 16]. Nihalani et al. [31] have used manual separation of the two leaflets of the remaining capsule with a MVR blade for secondary in-the-bag IOL implantation in aphakic non-uveitic pediatric cataract. This may not always be possible in uveitic eyes where postoperative inflammation may lead to fibrosis of the capsule.

Magli et al. [33] suggested that delaying the placement of IOL by about 1 year after cataract extraction significantly reduced secondary glaucoma and retrolental membranes while maintaining similar visual acuity as primary IOL placement in JIA–uveitic cataracts. They suggested a reduced quantum of inflammation as the reason for the better outcome, but, significantly, visual acuities were found to be reduced in sulcus-placed IOLs compared to in-the-bag IOLs. We do not feel that this approach, requiring two interventions and resulting in a sulcus-fixated lens, should be recommended as it may potentially result in UGH syndrome postoperatively.

Calculating the IOL power is always a challenge in pediatric eyes due to the changing axial lengths and anterior chamber depths of growing eyes, especially in children less than 2 years of age [34]. Children with uveitis, especially JIA–uveitis, usually require cataract surgery around 9.8 years of age (range 4 to 10 years, mean 6 years) [6]. By this age, healthy eyes are sufficiently grown for appropriate IOL measurement. However, in uveitic eyes, there are a number of factors that interfere with surgery planning such as band-shaped keratopathy affecting keratometry readings, posterior synechiae affecting anterior chamber depth, and hypotony and epiretinal membranes affecting axial length measurements. To deal with proper measurement of anterior chamber depth and axial length, immersion A scan biometry seems to be more reliable [35]. Partial coherence interferometry is restricted by the age of the child and density of cataract, especially in uveitic eyes. Anterior segment optical coherence tomography has now become another tool that can help in the accurate determination of anterior chamber depth, but use is limited by a child’s age. All current IOL power calculation formulas have high predictive errors in the shortest eyes. Postoperative refraction target is still controversial, but low degrees of hyperopia do not seem to adversely impact long-term visual acuity in children [34].

Removing a cataractous lens results in a large refractive error that must be corrected for the best visual outcome. The resulting aniseikonia can result in deep amblyopia, especially in younger children, if not corrected in time. Contact lenses have been used to treat aniseikonia after unilateral cataract surgery. There are many problems that affect the use of contact lenses to correct vision. Eyes with JIA–uveitis are often on long-term topical steroid drops, increasing the chances of developing infective keratitis. Band keratopathy makes contact lens fitting difficult, leading to early intolerance. BenEzra and Cohen [15] found that contact lens was poorly tolerated in their group of patients.

Inserting an intraocular lens (IOL) has been widely accepted for adult uveitic eyes [36] but remains controversial for pediatric uveitic cataracts. In the early 1990s, the use of IOL in pediatric uveitic eyes was associated with significant inflammation, development of intractable glaucoma, cyclitic membrane, hypotony, and phthisis [37, 38]. In these eyes, the degree of fibrosis around the IOL led to cocooning of the IOL in the capsular bag [17, 38]. In 1993, Foster et al.[38] strongly advocated against intraocular lens implantation in children. In retrospect, we can see that these studies did not use systemic immunosuppression to control inflammation.

In the past, surgeons suggested keeping eyes aphakic for better visual outcomes and lensectomies and vitrectomies were procedures of preference in these eyes [38‐40], but all of these earlier reports failed to control ocular inflammation and systemic immunosuppressives were not used.

In 1996, Probst and Holland were the first to report on IOL implants in patients with JIA–uveitis. Seven patients (eight eyes) underwent phacoemulsification with intraocular lens insertion, and two were younger than 10 years. A final visual acuity of 20/40 or better was achieved in seven of the eight eyes. Postoperative complications were more common in the two youngest patients, suggesting that intraocular lens implants in younger patients may have more complications [17]. Notably, only corticosteroids were used for suppression of inflammation in their cases.

In 2000, Ben Ezra and Cohen [15] examined the outcomes postcataract surgery with posterior chamber IOL in five eyes of five children (aged 4–8 years) with JIA–uveitis. Three eyes had postoperative visual acuity of 6/240 or less, and complications included posterior synechiae, macular edema, persistent inflammation, and glaucoma. We need to highlight again that the authors had not waited for remission of uveitis before planning cataract surgery, as their focus was the treatment of amblyopia. Peri-operatively, all patients were given retro-orbital methyl prednisolone injections and an intravenous bolus hydrocortisone injection with no additional systemic steroids or immunosuppressives postoperatively. But despite the inflammation, the authors preferred the use of IOLs to contact lens in unilateral aphakia postuveitic cataract extraction [15].

Gradually changing attitudes and better postoperative results were reported in recently published studies and are attributed to improved medical control of inflammation, new surgical techniques, and more biocompatible IOLs [6, 8, 21, 25, 28, 41].

Nemet et al. [16] in a landmark study compared 10 patients with JIA–uveitis with 8 non-JIA–uveitis patients. They observed that eyes with JIA–uveitis had more severe manifestations of uveitis, an earlier presentation of cataract as well as a stormier postsurgical course. They concluded that if inflammation was well controlled, small incision surgery and foldable acrylic hydrophobic IOLs could be well tolerated by these eyes. They also concluded that with effective medical management of inflammation, final visual acuity in patients with JIA–uveitis and of those with other causes of uveitis was comparable. The authors concluded that IOL implantation should no longer be considered an absolute contraindication in pediatric uveitis. We need to note that poor visual outcomes and severe inflammatory sequelae were seen in eyes with poorly controlled inflammation.

Quinones et al. [8] studied the visual outcomes in aphakia and pseudophakia in 34 children (41 eyes) within the age group from 4 to 17 years, with 27 children having JIA-associated uveitis. They reported a 92 % improvement in visual outcome in eyes with polymethyl methacrylate (PMMA) posterior chamber IOLs (PCIOLs) placed in the bag. The authors noted no difference in postoperative inflammation between patients who received an IOL and those who did not. It is important to note that all eyes had been quiet for at least 3 months before surgery, and patients had been given perioperative immunomodulatory therapy. Four patients with JIA received an IOL implant—all four were using methotrexate and received intraocular steroid treatment intraoperatively. Twenty-three percent of children were less than 6 years of age. All of these patients were operated on by C. Stephen Foster who in 1993 recommended against lens implantation in children with JIA.

Similarly, Sijssens et al. [41] compared the outcomes of aphakia versus pseudophakia in a group of 29 children (48 eyes) of JIA-associated uveitis. They noted that though the major risk factors for visual outcome were duration of disease, severity at onset, and age at development of cataract, there was no difference in development of ocular complications in PCIOL and aphakia. They also suggested that with maximum control of inflammation, IOL implantation was associated with better visual outcomes and reduced risk of postoperative CME and glaucoma. They suggested that before surgery, risk of IOL implantation should be evaluated for individual eyes. Shallow anterior chamber, hypotonic eyes, age less than 4 years, and bad outcomes with IOL in fellow eye were considered a contraindication for IOL use.

As the IOL seems to be the major trigger of the intraocular inflammation in uveitic eyes, various materials have been tried in the search for the least immunogenic one. Studies document the use of different IOL materials like silicone, PMMA, heparin surface-modified PMMA (HSM-PMMA), and hydrophilic and hydrophobic acrylic lenses [6, 28, 40, 42, 43].

In 2004, Ganesh et al. [44] reported a higher incidence of PCO development and inflammatory deposits on PMMA than acrylic lenses. Terrada et al. [6] reported good visual results with HSM-PMMA coated IOLs in children with well-controlled uveitis, within an age group of 4 to 16 years, followed up for a median of 6 years. They went on to suggest that the new generation of foldable acrylic hydrophobic lenses are biocompatible and may reduce inflammatory response because of small incision surgery. Lundvall and Zetterstrom [28] followed up seven children (10 eyes, age range 3.5 to 10 years) postcataract surgery with HSM-PMMA lenses for 5 years. While ensuring uveitis remained under control, they noted that visual acuity improved in nine eyes. They recommended the use of HSM-PMMA lens to correct aphakia, provided the uveitis was well controlled. Similarly, Lam et al. in 2003 studied five patients (six eyes) with well-controlled JIA-associated uveitis who underwent phacoemulsification with IOL (PMMA and acrylic). They advocated the use of IOL in eyes with very good inflammation control, as IOL reduces the risk of amblyopia, while avoiding compliance issues with contact lenses and risk of corneal infections. Though the follow-up period was a median of 43.5 months, the age range was of slightly older children from 7 to 12 years [21].

Alio et al., in their study in adult uveitic cataract, found acrylic IOLs to be associated with least amount of immediate and delayed inflammation, and HSM-PMMA and acrylic IOLs had the least incidence of uveitis relapse. Silicone IOLs had the highest rates of opacification of the posterior capsule [42]. Papaliodis et al., in their study comparing four types of IOL materials, reported acrylic IOLs to be superior to HSM-PMMA, PMMA, and silicone lenses in adult uveitic eyes, when they evaluated inflammation, posterior capsular opacification, visual acuity, and macular oedema [43]. The Perry review concluded that acrylic and HSM lenses performed better in uveitic eyes. They suggested that a lens with a sharp optic edge had better visual outcomes in uveitic eyes because of reduced incidence of PCO [45]. A Cochrane review by Leung et al. on types of intraocular lenses for cataract surgery in uveitis included four studies with a patient profile of adult uveitic eyes [42, 46‐49]. They concluded that there was uncertainty as to which type of IOL gave best visual and clinical outcomes in uveitic cataract surgery based on existing studies and advocated a multicenter international study. Abela-Formanek [50], while comparing IOL biocompatibility in 72 uveitic eyes versus 68 control eyes, suggested that though design and biomaterial of the IOL was important, meticulously performed surgery and perioperative management of inflammation could not be overlooked. They compared foldable hydrophilic acrylic, hydrophobic acrylic, and silicone lenses and found hydrophilic acrylic lenses to have good uveal but worse capsular biocompatibility. Hydrophobic acrylic had low uveal but better capsular biocompatibility, and silicone lenses showed more severe anterior capsular contraction. They suggested avoiding round edged hydrophilic acrylic lenses in uveitic eyes because of accelerated rate of PCO formation seen. As all their uveitic patients benefited from the surgery despite the different foldable IOLs, they suggested a longer follow-up to have more conclusive results. Van Gelder et al. [14] in their review for adult uveitis also suggested optimum management of uveitis, including scrupulous attention to preoperative and postoperative inflammation and intraoperative technique for excellent visual outcomes.