Overview
Definition:
Congenital cataract is an opacity of the crystalline lens present at birth, which can impair vision and lead to amblyopia if left untreated.
Epidemiology:
Incidence varies globally, estimated between 1 to 4 per 10,000 live births in developed countries
Higher prevalence reported in some developing nations
Genetic factors account for about one-third of cases, while infections, metabolic disorders, and chromosomal abnormalities contribute to the rest
Bilateral involvement is common, affecting approximately 50-75% of cases.
Clinical Significance:
Early detection and intervention are critical
Untreated congenital cataracts in infants and young children can lead to irreversible visual impairment (amblyopia) due to the lack of proper visual stimulation to the developing visual cortex
Prompt surgical correction followed by appropriate visual rehabilitation significantly improves visual outcomes and prevents lifelong vision loss.
Clinical Presentation
Symptoms:
Parental observation of a white reflex or cloudy pupil
Difficulty focusing on faces or objects
Nystagmus (involuntary eye movements)
Strabismus (misaligned eyes)
Poor visual tracking
Rubbing of eyes
Apparent poor vision in one or both eyes.
Signs:
Leukocoria (white pupillary reflex) on red reflex testing
Visible opacity within the lens on slit-lamp examination
Reduced visual acuity
Presence of nystagmus or strabismus
Fundus examination may reveal optic nerve hypoplasia or other retinal abnormalities if associated with syndromes.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on the presence of a lens opacity in an infant or child younger than one year of age
A significant opacity is typically defined as one that obstructs at least 50% of the visual axis, or any opacity causing reduced visual acuity or other visual dysfunction
Classification includes total, partial, nuclear, cortical, and posterior subcapsular cataracts.
Diagnostic Approach
History Taking:
Detailed family history of eye conditions or syndromes
Maternal history of infections (rubella, toxoplasmosis) during pregnancy
Perinatal history, including prematurity or birth trauma
Age of onset of noticed symptoms
Progression of visual symptoms
Any associated systemic symptoms suggesting a syndrome.
Physical Examination:
Full ophthalmic examination is crucial
This includes visual acuity assessment (preferential looking, Cardiff cards, E-chart depending on age)
Red reflex testing using a direct ophthalmoscope to detect leukocoria
Slit-lamp biomicroscopy to precisely characterize the cataract (type, density, location)
Dilated fundus examination to assess the retina and optic nerve
Cycloplegic refraction to detect refractive errors
Assessment for nystagmus and strabismus.
Investigations:
Genetic testing may be indicated if a specific syndrome is suspected or in cases of familial cataracts
Metabolic screening (serum calcium, glucose, amino acids) may be performed if metabolic disorders are suspected
TORCH titers if intrauterine infection is a concern
Echocardiography may be considered if syndromes like Down syndrome or Lowe syndrome are suspected
Imaging (e.g., cranial MRI) is rarely needed unless there are neurological concerns.
Differential Diagnosis:
Retinoblastoma (may present with leukocoria)
Persistent hyperplastic primary vitreous (PHPV)
Coats' disease
Retinal detachment
Uveitis
Posterior segment tumors
Medulloepithelioma
Vitreous hemorrhage
Ocular inflammation.
Management
Initial Management:
Early diagnosis is paramount
Timely referral to a pediatric ophthalmologist is essential for definitive assessment and management planning
If surgical intervention is indicated, it should be performed as soon as possible, ideally within the first few weeks to months of life, to maximize visual potential.
Surgical Management:
The primary treatment is surgical removal of the cataract
Indications for surgery in congenital cataracts are based on the density of the opacity and its impact on visual development
Total or dense partial cataracts requiring surgery within the first few months
Partial cataracts causing significant amblyopia or nystagmus may also warrant surgery
Standard procedures include lensectomy (removal of the lens) via pars plana or anterior capsulorhexis with phacoemulsification if technically feasible
The goal is to clear the visual axis.
Postoperative Care:
Postoperative management is critical and involves intensive management of aphakia and visual rehabilitation
This includes: 1
Spectacle correction (high plus lenses) or contact lens wear to correct aphakia
2
Frequent instillation of topical antibiotics and steroids to prevent infection and inflammation
3
Diligent occlusion therapy (patching) to treat amblyopia and promote visual development in the non-operated or less-affected eye
Regular follow-up is essential to monitor intraocular pressure, refractive error, and visual acuity, and to adjust amblyopia treatment as needed.
Visual Rehabilitation:
Aggressive and consistent amblyopia management is as crucial as the surgery itself
This involves appropriate refractive correction and targeted patching or atropine penalization
Early and prolonged patching is often required
The duration and intensity of patching are guided by visual progress and depend on the age of the child and the severity of pre-existing amblyopia.
Complications
Early Complications:
Intraocular infection (endophthalmitis)
Significant postoperative inflammation
Corneal edema
Wound dehiscence
Persistent pupillary membrane
Vitreous prolapse
Retinal detachment (rare).
Late Complications:
Glaucoma (secondary to inflammation, retained lens fragments, or abnormal anterior chamber angle)
Posterior capsular opacification (PCO) requiring YAG laser capsulotomy or surgical revision
Residual amblyopia despite treatment
Nystagmus progression
Strabismus
Retinal detachment
Visual field defects.
Prevention Strategies:
Strict aseptic surgical techniques
Judicious use of prophylactic antibiotics
Careful intraoperative manipulation to minimize trauma
Early recognition and prompt treatment of postoperative inflammation
Diligent follow-up for early detection of complications like glaucoma or retinal detachment
Aggressive amblyopia therapy and regular monitoring of refractive error and visual acuity.
Prognosis
Factors Affecting Prognosis:
Age at surgery (earlier is better)
Density and type of cataract
Presence of associated ocular anomalies (e.g., nystagmus, strabismus, retinal abnormalities)
Presence of systemic syndromes
Quality and adherence to postoperative care, especially amblyopia treatment
Surgeon's expertise.
Outcomes:
With timely surgery (before 3-6 months of age) and aggressive visual rehabilitation, good visual outcomes (e.g., visual acuity > 6/60) can be achieved in a significant proportion of cases
However, some degree of residual amblyopia or visual impairment may persist, especially in cases with dense cataracts, late presentation, or associated ocular anomalies
Successful management requires lifelong follow-up.
Follow Up:
Lifelong ophthalmological follow-up is mandatory
This includes regular checks for refractive errors, amblyopia, strabismus, intraocular pressure (to monitor for glaucoma), and the health of the retina and cornea
The frequency of follow-up decreases with age but remains crucial for managing long-term complications and optimizing visual function.
Key Points
Exam Focus:
The primary goal of congenital cataract surgery is to prevent amblyopia by providing clear visual input to the developing retina and visual cortex
Early surgical intervention (within weeks to months of birth) is critical
Postoperative management, including refractive correction and aggressive amblyopia therapy (patching), is as important as the surgery itself
Glaucoma is a significant long-term complication to monitor.
Clinical Pearls:
Always perform a red reflex test on all newborns and infants
Do not dismiss nystagmus as a sole finding
always look for an underlying cause like cataract
Remember that congenital cataracts can be part of broader systemic syndromes, so a thorough medical history is essential
In dense bilateral cataracts, consider surgery in both eyes staged appropriately, with aggressive patching to the fellow eye for amblyopia management.
Common Mistakes:
Delaying surgery in dense congenital cataracts, leading to irreversible amblyopia
Underestimating the importance of postoperative amblyopia management and refractive correction
Neglecting to monitor for secondary glaucoma
Failing to adequately investigate for associated ocular or systemic anomalies
Inadequate follow-up, missing late complications.