Dense cataracts obscuring the visual axis produce deprivation amblyopia and require prompt surgical intervention and proper subsequent visual correction (Moore, 1994; Birch and Stager, 1988; Zetterstrom et al, 2005). If managed appropriately, infants who have partial or subclinical cataracts can obtain sufficient binocular stimulus to permit normal maturity of the visual system (Moore, 1994; Zetterstrom et al, 2005).
In newborns, dense bilateral cataracts are typically nuclear. The opacification is typically not progressive and is located in the embryonic and fetal nuclei between the anterior and posterior Y sutures (Zetterstrom et al, 2005). The axial lengths of eyes with this type of cataract are typically shorter than normal (Zetterstrom et al, 2005; Kugelberg et al, 1996).
Posterior cataracts in infants and children are commonly unilateral and associated with persistent fetal vasculature (PFV), posterior lenticonus, or posterior lentiglobus. Eyes with cataract from PFV are usually microphthalmic. Posterior lenticonus/lentiglobus creates a small defect in the posterior lens capsule, causing progressive bowing followed by eventual posterior bulging and disorganization of the subcapsular lamellae (Zetterstrom et al, 2005; Churchill and Graw, 2011).
Lamellar cataracts occur after fixation is established, are usually bilateral, and can remain subclinical for years. They are progressive, often requiring surgery before school age. This cataract involves the lamellae surrounding the fetal nucleus peripheral to the Y suture (Zetterstrom et al, 2005; Churchill and Graw, 2011). Eyes that have lamellar cataracts are usually normally sized (Zetterstrom et al, 2005).
Other types of congenital cataracts result from developmental lenticular defects present at birth. These cataracts are non-progressive and have little effect on vision. Examples include sutural and anterior polar cataracts (Zetterstrom et al, 2005; Churchill and Graw, 2011).
Contact Lens Management
Contact lenses are a good option for managing refractive error induced from congenital cataracts. Spectacles are a barrier to fusion in cases of unilateral cataract causing high refractive error. High-power spectacle optics are poor, causing decreased visual field and prismatic effects when the child looks off axis (Baradaran-Rafii et al, 2014). Surgical management is difficult because there is uncertainty in predicting intraocular lens (IOL) power in young, rapidly growing eyes (Taylor, 1998; VanderVeen et al, 2012). Contact lenses provide a wider field of view and clearer, more stable optics versus spectacles. Furthermore, unlike IOLs, contact lens power is readily changed (Chen et al, 2010).
Consider a two-month-old girl diagnosed with segmental medial posterior cataract of the left eye, causing severe myopia (–30.00D at the spectacle plane) and anisometropia. The visual axis was clear, and a contact lens provided good fixation and a bright retinoscopy retinal reflex. Thus, the girl was treated conservatively with occlusion therapy and myopia correction with a contact lens (Figure 1).
Left untreated, congenital cataracts cause amblyopia, preventing normal vision development. There are several cataract morphologies, and visual correction is best managed with contact lenses. In cases of congenital cataracts, contact lenses should be considered for effective management of refractive error. CLS
For references, please visit www.clspectrum.com/references and click on document #259.