الفهرس 
Anatomy of the lensOnly 14 pages are availabe for public view
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Abstract
Congenital, infantile, and juvenile onset cataracts represent important causes of visual impairment in childhood. A thorough ocular and systemic examination will often be needed to uncover valuable information needed to assign the appropriate etiology and develop the best treatment plan for the child.
Ocular examination should include assessment of visual acuity, and evaluation of the size, density, and location of the cataract so as to plan the surgical procedure and to determine the anticipated visual outcome. Fundus examination should be carried out after pupillary dilatation. “A”-scan ultrasound helps to measure the axial length for calculating the intraocular lens power and monitoring the globe elongation. For an eye with a total cataract, a B-scan ultrasound evaluation is useful for detection of vitreoretinal pathology.
A history from the parents is useful to exclude maternal drug use, infection, or exposure to radiation during pregnancy to determine whether the cataract is congenital, developmental, or traumatic in origin. Each child should be thoroughly examined by a pediatrician to rule out systemic associations, anomalies, or congenital rubella syndrome. The morphological features of childhood cataracts are varied. A classification system based on categories commonly used by surgeons and in clinics is presented and recommended. Segregating childhood cataracts in this way may also help predict the prognosis and the risk for later complications.
The growth of a child’s eye causes a myopic shift that is substantial and predictable. This refractive growth is one of the factors to consider in achieving the ultimate goal; a child who grows up to have good visual acuity and emmetropia in adulthood. The empiric, logarithmic model of refractive growth has been found to be useful in clinical practice and research. This simple model can be used to predict future refractions of any patient and at any age.
The anterior capsule is highly elastic in the pediatric patient and poses challenges in the creation of the capsulotomy. While a manual CCC is ideal for adults, it is more difficult to perform in infantile eyes with cataracts. Although appealing, these techniques are not without added risk when applied to pediatric eyes, which are more elastic than adult eyes. As a result, inadvertent extensions out to the lens equator (known as the “runaway” rhexis) are common in children. Posterior capsulectomy and vitrectomy are an essential surgical step in the management of pediatric cataract surgery. Treatment of the posterior capsule determines the ultimate outcome of pediatric cataract surgery.
Attention to postoperative inflammation and its control are of utmost importance. Periodic reassessment of the operated eye is necessary to detect media opacification, glaucoma, or any other complication. One should always bear in mind that performing an uncomplicated pediatric cataract extraction with or without IOL implantation is only the first step toward visual rehabilitation. Timely correction of refractive errors and amblyopia therapy and early recognition of other complications are critical for a successful outcome.
Amblyopia management should be carried out within the first few years of life, when the visual system is sufficiently plastic to respond to modifications in visual input.
Pediatric cataract surgery remains a challenge to ophthalmologists. Surgical management is however evolving with the advance of microsurgical techniques in adult cataract surgery and these will no doubt be modified and translated to pediatric cataract management. Surgery is only one part of the entire management of the pediatric cataract patient. Participation in the visual rehabilitation of the child involving parents, ophthalmologists, pediatricians and optometrists cannot be overemphasized.