Variety of surgical options may be successful in pediatric cataracts
Special consideration also needs to be given to IOL implantation.
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Congenital or pediatric cataracts, the leading cause of preventable blindness in children, can be challenging even for the experienced pediatric ophthalmologist. In addition to the cataract, both ocular growth and visual development add further complexity to such management. In dealing with pediatric cataracts, one has to consider preoperative, intraoperative and prolonged postoperative management for the overall success in obtaining and maintaining optimal vision without any significant amblyopia.
Pediatric cataracts can be congenital or acquired, unilateral or bilateral, with lenticular opacity ranging from tiny dots to dense, total clouding of the lens. Lens opacities may be central (sutural, coralliform, pulverulent, nuclear, cortical or lamellar) or polar, the latter being anterior (polar, pyramidal or subcapsular) or posterior (lenticonus, subcapsular or fetal vascular) in location. Congenital cataract represents lens opacity present at birth and is responsible for 10% to 30% of all vision loss in infants globally. The overall prevalence of congenital cataracts and childhood cataract has been reported in the range of 0.63 to 9.74 per 10,000 and 0.32 to 22.9 per 10,000, respectively.
Pediatric cataracts can be due to various etiologies including genetic causes, metabolic disorders such as diabetes and ocular trauma. Pediatric consultation for any associated systemic diseases or syndromes is needed.
Any vision-threatening lenticular opacity in children usually requires surgical intervention. The human eye growth phase ranges mostly up to age 2 years and is minimal thereafter. This plays a role in surgical intervention time. While IOL implantation is not usually recommended in infants younger than 1 year of age, in children older than 2 years, IOL implantation is usually preferred whenever possible. Various IOL choices are available to the surgeon, including multifocal IOLs. If considering multifocal IOLs in children, caution should be exercised, as such an IOL choice may be debatable. Hence, careful IOL selection in individual cases is warranted. After surgery, optical rehabilitation with contact lenses and/or glasses along with patch therapy, when needed, is important.
In this column, Drs. Vasavada and Agrawal provide a comprehensive overview and various surgical options in the management of pediatric cataracts.
Thomas “TJ” John, MD
OSN Surgical Maneuvers Editor
Cataract surgery in children is challenging because of increased sclera elasticity, underdeveloped ocular structures, poor compliance in postoperative care, and postoperative refractive error and deep amblyopia. Often these children have associated systemic illnesses. Therefore, it is important that these children are thoroughly assessed systemically, and ocular examination is done preoperatively under anesthesia. It is imperative that families are counseled at length about the need for long-term care postoperatively and the occasional necessity for examination under anesthesia to diagnose glaucoma as early as possible. It is important for the family to understand the challenges, both surgical and postoperative.
Anterior continuous curvilinear capsulorrhexis (ACCC) is the sheet anchor of pediatric cataract surgery, but it can be difficult to perform this predictably due to high elasticity of the pediatric lens capsule (Figure 1). With the advent of microincision forceps and high viscoelastic surgical devices, surgeons are winning over the difficulties of ACCC. Technologies such as femtosecond laser-assisted cataract surgery give precise and predictable ACCC (Figure 2). Using closed-chamber techniques and bimanual vitrectomy (Figure 3), surgeons are gradually gaining expertise in the performance of pediatric cataract surgery. Having said that, there are still a few question marks. The two most important ones involve the clarity of the central visual axis and the decision whether to implant an IOL or not.
Central visual axis clarity
Visual axis obscuration (VAO) is the most common complication after pediatric cataract surgery due to proliferation and epithelial mesenchymal transformation of lens epithelial cells (Figure 4). Hence, it is a standard practice to perform primary posterior capsulorrhexis or capsulectomy along with anterior vitrectomy through the limbal or pars plana route. However, despite this, obscuration of the central axis does occur at times. Also, we do not know the consequences of vitrectomy in a growing eye. Gimbel and colleagues first reported posterior optic capture of an IOL optic through a posterior capsulorrhexis with haptics placed inside the bag as a means to avoid vitrectomy and prevent VAO in children. In this technique, the anterior and posterior capsules fuse together and prevent progression of proliferating lens epithelial cells into the visual axis (Figure 5).
In a randomized clinical trial, we included children from 0 to 4 years of age, and at 3 years’ follow-up, we found that VAO and complications such as glaucoma and inflammation were comparable in eyes that underwent in-the-bag IOL implantation of a three-piece hydrophobic acrylic IOL along with anterior vitrectomy vs. posterior optic capture without anterior vitrectomy. This technique has a learning curve, and its results in children younger than 6 months of age is not predictable, so the technique of conventional in-the-bag IOL and anterior vitrectomy combined with capsulectomy is preferred (Figure 6). The technique of posterior optic capture is of particular use in pediatric traumatic cataract surgery (Figure 7). Often there is an anterior capsular tear in which the surgeons have to implant the IOL in the ciliary sulcus, with the possible consequences of decentration and pupillary capture of the IOL. We studied our series of 38 patients with traumatic cataract with anterior capsular tear but intact posterior capsule. Posterior continuous curvilinear capsulorrhexis (PCCC) was performed on an intact posterior capsule, and a three-piece IOL was captured through it. At 2 years’ follow -up in these eyes with optic capture, the IOL remained stable and occurrence of posterior capsule opacification was as low as 22%.
To implant or not to implant an IOL
IOL implantation in pediatric cataract is recommended to facilitate early rehabilitation and amblyopia therapy. In unilateral cataracts, early implantation of an IOL should be considered. But the surgeon should also be aware that IOL implantation in children younger than 6 months of age is still controversial, as glaucoma and inflammation in this group are high. In such young eyes, surgeons can consider IOL implantation based on their surgical experience in pediatric cataract. The Infant Aphakia Treatment Study, a multicentric randomized clinical trial comparing IOL and contact lens correction for monocular aphakia in children younger than 6 months old, showed comparable visual outcomes in both groups.
Bilateral cataracts are a different disease from unilateral cataracts. In bilateral cataracts, IOL implantation in children older than 2 years has good outcomes. We published a randomized study comparing aphakia vs. pseudophakia with 5 years’ follow-up in children younger than 2 years with bilateral cataracts. The visual recovery was faster in the IOL group. The complication rate between the groups was comparable at 5 years of age.
In both unilateral and bilateral aphakia, secondary IOL implantation can be considered after 5 years of age, depending on the availability of capsule support and the presence of glaucoma. It should be kept in mind that secondary IOL implantation in children bears a high risk for glaucoma. Although IOL implantation in children younger than 2 years of age appears to be an acceptable modality, implantation in children younger than 6 months of age needs a lot of consideration and expertise.
Toric IOL
A significant number of children have corneal astigmatism contributing to amblyopia along with cataract. Corneal curvature stabilizes in children by 5 years of age with minimal change until adulthood. In adults, corneal astigmatism as low as 0.75 D is treated successfully with toric IOLs. Toric IOLs are being used more often to treat corneal astigmatism along with cataract in children older than 5 years of age and those who are cooperative enough to give accurate keratometric values on optical biometers. Studies have shown that toric implantation in children significantly reduces postoperative astigmatism and thereby improves visual outcomes. At our center, we implanted toric IOLs in 76 eyes of 38 children. Mean age at surgery was 7.41 ± 2.82 years of age, and mean preoperative keratometric astigmatism was 1.56 ± 2.13 D. At 3 years’ follow-up, mean postoperative uncorrected distance visual acuity was 0.32 ± 0.26 logMAR. Mean refractive astigmatism was 0.55 ± 0.40 D. We also found that toric IOL implantation reduces postoperative refractive astigmatism and gives excellent uncorrected distance visual acuity.
Multifocal IOL
In pediatric cataracts, there is an ongoing struggle to treat amblyopia and prevent complications such as posterior capsule opacification and glaucoma, which makes the use of multifocal IOLs controversial. Reduced contrast sensitivity and residual ametropia, both spherical and astigmatic, will defeat the purpose of treating amblyopia and make this modality out of favor in a growing eye.
- References:
- Infant Aphakia Treatment Study Group, et al. Arch Ophthalmol. 2010;doi:10.1001/archophthalmol.2009.350.
- Lambert SR, et al. J AAPOS. 2015;doi:10.1016/j.jaapos.2015.01.012.
- Li FF, et al. Mol Vis. 2008;14:750-755.
- Mohammadpour M, et al. J Curr Ophthalmol. 2018;doi:10.1016/j.joco.2018.11.005.
- Sheeladevi S, et al. Eye (Lond). 2016;doi:10.1038/eye.2016.156.
- Vasavada AR, et al. Am J Ophthalmol. 2018;doi:10.1016/j.ajo.2018.06.005.
- Vasavada AR, et al. J Cataract Refract Surg. 2017;doi:10.1016/j.jcrs.2017.07.022.
- For more information:
- Abhay R. Vasavada, MS, FRCS, and Deepa Agrawal, MS, can be reached at Raghudeep Eye Hospital, Gurukul Road, Memnagar, Ahmedabad – 380052, Gujarat, India; email: icirc@abhayvasavada.com.
- Edited by Thomas “TJ” John, MD, a clinical associate professor at Loyola University at Chicago and in private practice in Oak Brook, Tinley Park and Oak Lawn, Ill. He can be reached at email: tjcornea@gmail.com.
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