Cataracts: Alport Syndrome and Fabry's Disease

Cataract and Systemic Diseases

• Several systemic diseases such as Alport Syndrome, Fabry's Disease, etc, can cause cataract

Alport Syndrome

• Alport Syndrome found in children, is X-linked dominant
• This condition is more prevalent in males
• Sufferers have altered lens geometry
• This is a disorder that causes defect in the BM (Basement Membrane) type IV collagen
• Those with Alport syndrome have progressive nephropathy that manifests as hematuria
• Can lead to sensorineural hearing loss
• Can lead to ocular abnormalities such as Leticonus
• Can lead to anterior capsule thinning, which allows the lens to bulge into the AC (anterior chamber) in the 2nd decade
• Posterior subcapsular cataracts can also be present in Alport Syndrome, but could be absent if Leticonus is absent
• Common symptoms are not being able to hear, see, or pee correctly

Fabry's Disease

• It comes with angiokeratose lesions that appear as red or purple
• Angiokeratoma corporis diffusum and Glycosphingolipid deposits (vascular and reticuloendothelial tissue) happen due to galactosidase enzyme deficiency
• Glycosphingolipid deposits show an abnormal breakdown of lipids in the basal membrane
• Symptoms include chronic diarrhea, Ischemic Heart Disease, and Proteinuria (foamy urine)
• Causes Angiokeratomatous rashes on the lower trunk and upper tights
• Also causes thick eyelids, Cornea Verticillata (wavy opacities in cornea)
• Leads to triangular anterior subcapsular cataract, posterior subcapsular cataract
• Can lead to Conjunctival and Retinal vascular tortuosity
• Ocular changes include increased vessel tortuosity and aneurysms in the bulbar conjunctiva, as well as faint spoke-like lines at the posterior lens capsule

Lowe Syndrome

• The system will be affected and will come with opacity and seeds
• Also known as Oculocerebrorenal Syndrome occurring more commonly in males
• It has an X-chromosome link inheritance related to the OCRL1 gene mutation
• OCRL1 gene mutation can present differently in different areas
• The person can have congenital bilateral cataracts that are Biconvex-shaped, posterior, polar, nuclear, and total
• Includes infantile glaucoma (first 3 years) and corneal opacity, miotic pupil, and enophthalmos
• Additional symptoms are metal retardation, epilepsy, seizures, and aminoaciduria

Leber's Congenital Amaurosis

• Amaurosis is the loss of vision for a moment in the AR inheritance
• Those affected will rub their eyes a lot to stimulate a light to see
• Additional symptoms are ptosis, strabismus, high hyperopia, and high myopia
• Severe vision loss at or near birth as well as cataracts with a main characteristic
• Features Keratoconus from rubbing, which increases the amount of rubbing
• This causes a small eye with coloboma; this can be a partial or incomplete coloboma
• Pigmentary retinopathy and maculopathy can be possible as well as disc edema
• Retinal vascular attenuation
• Mental retardation also comes with the syndrome
• Varies widely from retinitis pigmentosa-like appearance
• Thin vessels with attenuation of vessels, retinal pigment epithelium, and chorioretinal atrophy
• Includes Franceschetti’s oculodigital sign that consists of eye poking, pressing, and rubbing to mechanically stimulate the retina and produce a sensation of light

Congenital Cataract

• Happens due to prenatal infection in the central nuclei
• TORCH (intrauterine infection) like toxoplasmosis
• Other causes of intra-uterine infection is syphilis, varicella-zoster, parvovirus b19, rubella, cytomegalovirus, and Herpes infection
• Can be both uni or bilaterally asymmetric (mostly bilateral)
• Appears posterior, subcapsular, and anterior

Congenital Cataract Chromosomal Abnormalities

• Associated with specific chromosomal abnormalities like Down and Patau Syndrome

Down Syndrome

• Trisomy 21
• Mental retardation and cardiac defects (valve abnormalities and ischemie diseases) are common
• Ocular problems include Epicantal folds (extra skin on eyelid covering sup eyelid), Astigmatism, and Iris abnormalities (Brushfield spots hypopignented spots)
• Strabismus, Nystagmus, Amblyopia, Keratoconus (characteristic of down syndion) and Cataract
• Cataracts can appear either at birth (posterior polar) or in childhood with cortical riders

Patau Syndrome

• Trisomy 13
• Severe ocular malformation
• Associated with CNS with mental retardation and Microcephalia due to lack of exposure with Facal Cleft Lip
• Polydactyly with usually net complete (just extension)
• Can lead to cardiac defects and or ocular conditions like Microphthalmos, Anophthalmus, colobomas, RD, and or cataract in embryo nuclei

Atopic Dermatitis

• Common to SUN can appear everywhere
• Occurs most commonly in young males with thickened scaly skin and affects the anterior subscapular (20%)
• PSC (Posterior subcapsular cataract) can develop due to a complication of topical corticosteroids
• Increases the risk of RD because of eye rubbing
• The conditions that can lead down the atopic path are keratoconjunctivitis, corticosteroids, and longterm use of PSC

Neurofibromatosis Type 2

• AD Disorder (autosomal dominant)
• Related to Multiple central and peripheral nervous system tumors can be parocentral or polar
• Includes Bilateral Vestibular schwannomas with cataract 60-80%
• Posterior retrolental subcapsular, Plaque-like opacities, retinal hamartomas, ON sheath tumors, and Fibrotic maculopathies

Myotonic Dystrophy

• AD (autosomal dominant) disorder
• Contraction of muscle for a long period of time, leads to myotonia and atraphy of the muscles
• The muscles give weakness and cannot relax
• Include Myotony (delayed relaxation) and Distal Muscle Weakness, Arrhythmias and cardiomyopathy
• Characterized by Christmas Tree cataract in young adults
• Dust and flake like iridescent highly refractile multicolored "needles"
• Or Posterior Subcapsular stellate opacities which would appear much later on or after puberty

Diabetes Mellitus

• Displayed as Bilateral snowflake cataract with senile cataract and possible rapid progression
• Type 1 with young ages is more common
• snowflake cataract includes Fine, flaky, dot-like opacities subcapsularly

Wilson's Disease

• A Hepatolenticular degeneration liver problem
• Is an AR disorder of copper metabolism that causes Liver, Kidney, Eye complications
• Has an accuumlation of copper that can go anywhere and can be found in a corneal coinca
• Ocular includes
  • Kayser-Fleisher's corneal ring in the 1st or 2nd decade of life (most common 95%) that appears as golden brown line 1-3 mm wide adjacent to the limbus
• Green sunflower cataract 20-30% with a Disk-shaped central anterior lens capsule opacity

Galactosemia

• Due to a deficiency of galactose enzyme with a Most common AR GALT deficiency, also Increase of galactose oil-droplet cataract
• Presents in Brain damage, Cataracts, jaundice, enlarged liver, and kidney damage
• Causes Hepatosplenomegaly and liver failure with muscle hypotonia and Neurocognitive dysfunction
• Leads to hypogonadism, Catalacs 75% (Bilateral) with a Rapid progression after birth (Oil droplet appearance)
• Also creates Cortical vacuoles with a dense appearance

Glaucoma

• Acute Angle Closure glaucoma episodes and glaukomfleken
• Presents at Center as well an anterior subcapsular Opacity
• Milk splash becomes an incute cluation of 100

Posterior Subcapsular Cataract

• buildup and clumping of protein fibers in the back of the lens
• Common cause is due to Chronic Anterior Uveitis, High Myopia, Retinal dystrophies and Corticosteroids

Marfan Syndrome

• AD Inheritance, in which Zonular fibers can elongate easily or breade
• Musculoskeletal abnormalities with Increase length of extremities, Arachnodactyly, and Loose joints
• The 3. shape vertebra or "excavasion" or Scoliosis pectum excavatum
• Zonular fibers are fragmented and stretched 50-80%

Homocystinuria

• Autosomal recessive condition involving liver metabolism, with an error in aminoacidic phenylalanine
• Phenylketonuria comes as a side effect, caused by buildup of ketones
• This leads to Mental retardation and Osteoporosis
• Can lead to Pupillary Block Glaucoma and Ectopia lentis inferior

Weil-Marchesani Syndrome

• Can result in both the AR and AD inheritance
• Can cause Cardiac abnormalities
• Musculoskeletal abnormalities include Short stature, shortened fingers (Brachydactyly), and Joint stiffness
• Ocular includes
  • Microspherophakia, Severe Myopia, and Glaucoma
  • the smaller lens body is still connected via small fibres

Ehlers Danlos Syndrome

• Related to elongation of skin with joints
• Includes Connective tissue disorder, Hyperextensibility of the skin,
• Causes Hypermobility of joints and affects Ocular with Keratoconus, blue sclera, and Ectopia lentis