Congenital Cataract Treatment & Management

Medical therapy is directed at the prevention of amblyopia.

Cataract surgery is the treatment of choice and should be performed when patients are younger than 17 weeks to ensure minimal or no visual deprivation. Most ophthalmologists opt for surgery much earlier, ideally when patients are younger than 2 months, to prevent irreversible amblyopia and sensory nystagmus in the case of bilateral congenital cataracts. The delay in surgery is because of glaucoma. Since glaucoma occurs in 10% of congenital cataract surgery, many surgeons delay the cataract surgery.

Unfortunately, the improved surgical techniques of the 1990s have not lowered the incidence of glaucoma from the series published in the 1980s. The development of glaucoma (which occurs in later years) only occurs in cataract eyes that undergo surgery. This may be in part due to the immaturity of the angle at the time of surgery. A delay of a few weeks allows the angle of the immature eye to develop.

Koc et al concluded that early age at cataract extraction and microcornea are risk factors for delayed-onset glaucoma. ^[4]

Extracapsular cataract extraction with primary posterior capsulectomy and anterior vitrectomy is the procedure of choice (via limbal or pars plana approach). Intracapsular cataract extraction in children is contraindicated because of vitreous traction and loss at the Wieger capsulohyaloid ligament. Vitrectomy instrumentation is the preferred method since the lens material is very soft. The whole procedure can be performed using one intraocular instrument. Young eyes develop capsular opacification very quickly, necessitating primary capsulectomy at the time of cataract extraction.

A study is underway in the United States to determine if intraocular lens placement in children younger than 6 months is a viable option. (Several articles have already been published in British journals.)

A study by the Retina Foundation of the Southwest in Texas compared intraocular lens (IOL) implantation with aphakic contact lenses (CLs) after the extraction of a unilateral cataract. ^[5] Patients were as young as 6 months. They concluded that IOLs and aphakic CLs support similar visual acuity development after surgery for a unilateral cataract. IOLs may support better visual acuity development when compliance with CL wear is moderate to poor or when a cataract is extracted in a patient older than 1 year.

A study with promising preliminary results concerns the primary implantation of flexible IOLs in infants younger than 1 year. ^[6] The population studied includes infants aged 3-11 months who have different forms of unilateral congenital cataracts.

A 2008 study by Capozzi et al showed that, in the first 42 months of age, corneal power (Km) and axial length (AL) values are significantly different according to age. ^[7] These findings have implications for the calculation of IOL power. Km values were significantly greater, and AL readings were shorter, in younger children (p< 0.001). No differences according to gender were found. As a group, eyes from unilateral cataract cases had significantly longer AL readings than those from bilateral cataract cases (p=0.029). In a small subgroup of unilateral cataract cases, for which readings from the clear lens eye were available (n. 39), Km values of the affected eye were significantly greater than that of the fellow healthy eye (p=0.007).

In a study published in the British Journal ofOphthalmology, Hoevenaars et al found that in determining the level of myopic change in children who underwent cataract surgery with IOL, those younger than 12 months had a higher shift and greater mean rate of refractive change per year versus older children, thereby reflecting the importance that age at surgery and laterality rate have when deciding the power of IOL implants. ^[8]

The Infant Aphakia Treatment Study found that rates of intraoperative complications (ICs), adverse events (AEs), and additional intraocular surgeries (AISs) 1 year after infants had undergone cataract surgery with IOL implantation were numerically higher but their functional impact does not clearly favor either treatment group. ^[9]

The amount of endothelial cell loss after cataract surgery with IOL implantaion in children is within an acceptable range and should not affect corneal clarity in the long run. ^[10]

Goggin et al found in a publicly funded hospital study that the manufacturer seems to underestimate the corneal plane effective cylinder power of its toric IOLs. By estimating the effective corneal plane cylinder power of the IOL, as altered by the anterior chamber depth and pachymetry and by the IOL sphere power, a better outcome could be achieved; however, this is not currently addressed by the manufacturer. ^[11]

An ophthalmology consultation is essential to prevent visual loss as well as to make the appropriate diagnosis of the type of cataract.

A genetics evaluation is warranted if bilateral cataracts or any other anomalies are present.

Restriction of galactose, if galactosemia is present, may reverse the progression of the classic "oil droplet" cataract.

A red reflex is essential not only in the newborn nursery but also in all office visits.

Frequent eye examinations help in the prevention of amblyopia.

Frequent glaucoma screenings are needed throughout the patient’s lifetime.