DR. PRABHAT KIRAN DEVKOTA
MBBS(TU), MD(NAMS)
CONGENITAL CATARACT
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Added: Aug 14, 2024
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CONGENITAL CATARACT DR. PRABHAT DEVKOTA MBBS(TU), MD(NAMS)
Introduction Latin word cataracta : “waterfall” Cataract is defined as any opacity of the crystalline lens of the eye, which impedes the image clarity causing reduced visual acuity and impaired contrast sensitivity One of the most important causes of preventable blindness and is responsible for 5-20% of pediatric blindness worldwide May be congenital or acquired, unilateral or bilateral and in the majority of cases is treatable Gilbert C, Foster A. Childhood blindness in the context of VISION 2020—the right to sight. Bull World Health Organ 2001; 79 (3): 227–232 .
Embryology
Pediatric cataract Any opacification of the lens and its capsule in children less than 15 years of age is defined as pediatric cataract Can be : Isolated or associated with a systemic condition or other ocular anomalies Congenital or acquired Unilateral or bilateral Inherited or sporadic Partial or complete Stable or progressive
Epidemology An estimated 19 million children are visually impaired and 1.5 millions are blind with 1 million children living in Asia Prevalance of pediatric cataract range from 1.2 to 6 cases per 10,000 births In N epal (as in other developing countires ), cataract is a leading cause of blindness in children
Nepal blindness survey from 1978 to 1980, congenital cataract accounted for 16.3% of blindness detected in children under the age of 15 years (Brilliant et al, 1985) Epidemology of Blindness in Nepal 2012 survey has suggested that the prevalence of childhood blindness has reduced from 0.68% in 1981 to 0.4% in 2011 ( Sapkota , 2012)
Classification Based on :
According to AGE OF ONSET Congenital cataract Present since birth Developmental cataract Present during childhood before age of 15 years
According to LATERALITY Unilateral Bilateral 1/3 rd - Idiopathic- may be unilateral or bilateral 1/3 rd – Inherited – usually billateral 1/3 rd – associated with systemic disease – usually billateral
1. Anterior Polar cataract Opacities that involves anterior subcapsular cortex and capsule of anterior pole of lens Present as a small white dot Are thought to arise from Imperfect separation of lens vesicle from surface ectoderm Metaplasia of anterior epithelial cells Usually congenital, non progressive, small ,bilateral and symmetric
Does not impair vision significantly Associated with ocular abnormalities like Microphthalmos Aniridia Persistant pupillary membrane Anterior lenticonus
2. Anterior Pyramidal Cataract More severe form of anterior polar cataract Are conical opacities that project into anterior chamber from anterior lens capsule Tends to be larger, elevated and visually more significant Are usually congenital, bilateral, symmeterical
3. Anterior subcapsular cataract Usually developmental Associated with acquired diseases , trauma, uveitis, irradiation, Alport syndrome or atopic skin disease The opacities vary between very subtle to dense
4. Anterior lenticonus Associated with A lport syndrome, W aardenburg syndrome, L owe syndrome X linked dominant Progressive hereditary nephrtis , hearing impairment Anterior lenticonus < posterior lenticonus
Central cataract
1. Nuclear cataract These are opacities of embryonic and/or fetal nucleus, between the Y sutures Can be inherited or sporadic Usually billateral presents with a central white opacities approximately 3.5mm in diameter surrounded by clear cortex Density and size can vary
Are usually stable but can progress With time, the cortex may become diffusely opacified , or radial opacification (riders) of the cortex may occur
2. Lamellar cataract Zonular cataract Most common type It is opacification of specific layers or zones of the lens material Opacified layer is between adjacent clear lamella Are usually bilateral and may be aymmetric Does not tend to progress with time
Additional arcuate opacities spread from equator of lamellar cataract Riders
3. Central Pulverulent cataract Powdery disc-like opacity involving the embryonal and f etal nucleus with many tiny white dots in the lamellar portion of the lens Is usually bilateral, nonprogressive and only rarely affects vision May also occur in transient metabolic changes such as Galactosemia Hypolycemia Hypocalcemia
4. Sutural Cataract Opacification of Y-sutures of the fetal nucleus May be unilateral or bilateral Are often stationary and are usually not visually significant May be X-linked recessive or autosomal dominant Has radiating spoke-like branches or knobs
5. Cortical cataract are usually in children Nucleus is not involved and the opacity is limited to the cortex
6. Cerulean cataract Also known as Blue dot cataract Blue and white opacification scattered in the nucleus and cortex Developmental cataract Usually asymptomatic until 18-24 months of age Slowly progressive
Cerulean cataract that are elongated or club-shaped and concentrated in a ring around the equator of the lens are referred to as coronary cataracts
Posterior cataract
1. Posterior subcapsular cataract Less common in children than in adults Usually acquired and are often bilateral PSCs tends to progress, visually significant
Often have a frosted glass appearance, which occurs immediately anterior to the posterior capsule Causes includes Corticosteriod use Uveitis Retinal abnormalities Radiation exposure And trauma
2. Posterior Polar C ataract Are usually a small, dense, white, central opacity of the posterior lens More profound decrease in vision as compared to anterior polar cataract May be bilateral or unilateral May be familial or sporadic
3. Mittendorf’s Dot Remnant of anterior part of the hyloid artery Is a small, dense and white round plaque attached to the posterior lens capsule Is a clinical variant of Persisternt Fetal vasculature Visually insignificant
4. Posterior Lenticonus Is a thinning of the posterior capsule that results in the adjacent lens material buldging posteriorly More common than anterior lenticonus Vision may be significantly affected Most cases are unilateral and sporadic Has been associated with lowe syndrome, Alport syndrome
Total cataract General opacity of all lens fibers Lamellar and nuclear cataracts progress to total cataract Suspect posterior lenticonus if minimal opacity progress in short time to total cataract or suspect persistent fetal vasculature Electrolyte imbalance in severe dehydration and diarrhea Rubella and Downs syndrome
1. Congenital morgagnian cataract Special type of cataract Lens fibers liquify but nucleus remains intact Nucleus moves within lens capsule depending on gravity Rarely if present late, fluid gets absorbed leading to fusion of anterior and posterior capsule
2. Membranous cataract Is thin fibrotic lens resulting from absorption of lens materials Anterior and posterior capsule fuses forming dense white membrane
Has been assosciated with trauma, posterior or anterior capsule defects, congenital rubella, Hallermann-Streiff syndrome, persistent fetal casculature , Lowe’s syndrome and aniridia
Miscellaneous Cataracts
Coralliform cataracts Needle or coral like projections from nucleus into cortex Bilateral Usually non progressive and may be visually significant
Floriform Cataract Uncommon morphological form Autosomal dominant Resemble the petal of a flower
Sectoral Cataract Wedge shaped cataract May be specific to Stickler Syndrome and Conradi-Hunermann Syndrome
Persistent fetal Vasculature Common cause of unilateral cataract Associated with microphthalmos , elongated ciliary process, shallow AC, retrolental plauqe , cataract, retinal detachment Suspect Norrie’s disease in B/L persistent vasulature
Steroid induced Cataract Children are more susceptible than adults Mechanism: Increase glucose levels Inhibition of Na+- k+ ATPase pump Loss of ATP Increased cation permeability Have little effect on vision and do not usually require surgery
Radiation Induced Cataracts Radiation used to treat ocular and periocular tumors Dose of 15GY shown to be associated with 50% risk Posterior subcapsular cataracts – 1-2 years after therapy Late effects of radiation on the eye and ocular adnexa K B Gordon 1 , D H Char , R H Sagerman
Late effects of radiation on the eye and ocular adnexa K B Gordon 1 , D H Char , R H Sagerman
Laser Photo coagulation Used to ablate avascular retina of infants with threshold retinopathy of prematurity Occurs after few weeks after laser treatment Visually insignificant o pacities to total opacification of lens Anterior/ Posterior subcapsular cataract, nuclear cataract
Traumatic Cataract Birth trauma Child Abuse – Battered Baby Syndrome Closed globe or Open globe injury Rosette cataract
Galactosemia Oil droplet central opacity Fabry’s Disease
Myotonic Dystrophy Christmas Tree opacity Cart wheel cataract: mannosidosis
Hypoglycemia and hypocalcemia Lamellar cataracts develop in hypoglycemic or hypocalcemic condition Hypoglycemia common in Low Birth Weight Babies Hypocalcemia – hypoparathyroidism or pseudohypoparathyroidism
Cataract associated with infections Congenital cataract occurs in intra uterine with Rubella Cytomegalovirus Toxoplasmosis HSV Varicella Syphillis
Congenital Rubella Syndrome Infection occurs in 1 st trimester of pregnancy Traid of congenital heart disease, hearing loss and congenital cataract Pearly white nuclear cataract -> complete cataract and the cortex may liquify Other ocular manifestation Microphthalmia Cloudy cornea Iris atrophy Congenital glaucoma Pigmentary maculopathy Optic neuritis
Complicated Cataract Result of the chornic ocular inflammation or secondary to the chronic use of steroids Juvenile idiopathic arthritis (IJA) Chronic anterior uveitis
Inherited with systemic abnormalities Assosciated with number of syndrome – systemic disorders as well as other ocular anomalies Chromosomal abnormalities Trisomy 21 (Down’s syndrome) Trisomy 13 ( Patau’s syndrome) Trisomy 18 (Edward’s syndrome) XO (Turner’s syndrome)
Skeletal disease Conradi-Hunermann syndrome Stickler syndrome Bardet-biedl syndrome Weil marchesani syndrome Central nervous system abnormalities Norrie’s disease Cerebro - oculo -facial-skeletal syndrome Myotonic dystrophy Renel disease Lowe’s syndrome Alport syndrome
Diagnosis and pre-operative work up by careful history taking, examinations and investigation History Detailed history of ocular complaints Duration of symptoms Previous ocular surgery/treatment Systemic complaints History of drug intake/radiation exposure/trauma Presence of nystagmus , squint
Maternal history – antenatal history, history of drug intake/ radiation exposure, fever Birth history Developmental history Similar family history (siblings/parents)
Examination General physical and systemic examinations : for metabolic and associated congenital ocular and systemic anomalies Ocular examinations: Assessment of visual function: VA, retinoscopy /refraction, alignment, nystagmus , EOM Fixation behavious Pupillary reaction Anterior segment biomicroscopy Posterior segment evaluation : FEUM, USG B-scan Tonometry, corneal diameter, keratometry Axial length measurement
Signs and symptoms Symptoms : Informant – usually parents History of white spot in pupillary area Child is usually brought with history of dimunition of vision/ does not recognize objects and parents Unsteady eyes Deviation of eye Associated symptoms of systemic disease, if rpesent
Signs : Dimunished vision (at times it is difficult to establish in very young children) Lenticular opacity Nystagmus Deviation of eye There may be other ocular and systemic abnormalities in cases of rubella nuclear cataract
Laboratory Investigations For all non-hereditary, idiopathic, bilateral cases TORCH VDRL Urine for reducing substance Serum glucose, calcium, phosphorus, alkaline phosphatase Thyroid function tests Karyotyping
Summary Pediatric cataract is one of the important causes of blindness Represents a diverse spectrum of morphologies, etiologies and clinical presentations Determination of the visual significance of congenital cataracts depends upon measurements of the size, location and density of opacity, duration of visual deprivation and assessment of the red reflex Early detection and intervention to prevent irreversible amblyopia and permanent blindness
Reference Clinical Ophthalmology-Myron Yanoff American Academy of ophthalmolog (lens and cataract,Pediatic opthalmology and strabismus) Albert and Jakobiec Clinical Ophthalmology -Jack J. Kanski