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There is no known cure for this syndrome. Patients usually need ophthalmic surgery and may also need dental surgery
Genetic counseling and screening of the mother's relatives is recommended.
A 2008 study tested the effect of using gene therapy to help restore the sight of patients with a rare form of inherited blindness, known as Leber's congenital amaurosis or LCA. Leber's Congenital Amaurosis damages the light receptors in the retina and usually begins affecting sight in early childhood, with worsening vision until complete blindness around the age of 30.
The study used a common cold virus to deliver a normal version of the gene called RPE65 directly into the eyes of affected patients. Remarkably, all 3 patients, aged 19, 22 and 25, responded well to the treatment and reported improved vision following the procedure. Due to the age of the patients and the degenerative nature of LCA, the improvement of vision in gene therapy patients is encouraging for researchers. It is hoped that gene therapy may be even more effective in younger LCA patients who have experienced limited vision loss, as well as in other blind or partially blind individuals.
Two experimental treatments for retinal problems include a cybernetic replacement and transplant of fetal retinal cells.
In general, the younger the child, the greater the urgency in removing the cataract, because of the risk of amblyopia. For optimal visual development in newborns and young infants, a visually significant unilateral congenital cataract should be detected and removed before age 6 weeks, and visually significant bilateral congenital cataracts should be removed before age 10 weeks.
Some congenital cataracts are too small to affect vision, therefore no surgery or treatment will be done. If they are superficial and small, an ophthalmologist will continue to monitor them throughout a patient's life. Commonly, a patient with small congenital cataracts that do not affect vision will eventually be affected later in life; generally this will take decades to occur.
The World Health Organization estimates that 80% of visual loss is either preventable or curable with treatment. This includes cataracts, onchocerciasis, trachoma, glaucoma, diabetic retinopathy, uncorrected refractive errors, and some cases of childhood blindness. The Center for Disease Control and Prevention estimates that half of blindness in the United States is preventable.
Aniridia is the absence of the iris, usually involving both eyes. It can be congenital or caused by a penetrant injury. Isolated aniridia is a congenital disorder which is not limited to a defect in iris development, but is a panocular condition with macular and optic nerve hypoplasia, cataract, and corneal changes. Vision may be severely compromised and the disorder is frequently associated with a number of ocular complications: nystagmus, amblyopia, buphthalmos, and cataract. Aniridia in some individuals occurs as part of a syndrome, such as WAGR syndrome (kidney nephroblastoma (Wilms tumour), genitourinary anomalies and intellectual disability), or Gillespie syndrome (cerebellar ataxia).
The cataract-microcornea syndrome is the association of congenital cataract and microcornea.
Treatment for MSS is symptomatic and supportive including physical and occupational therapy, speech therapy, and special education. Cataracts must be removed when vision is impaired, generally in the first decade of life. Hormone replacement therapy is needed if hypogonadism is present.
It has been suggested that the disease follows a x-linked pattern of inheritance though studies done on this particular disease are few.
Nance–Horan syndrome is a rare X linked syndrome characterized by congenital cataract leading to profound vision loss, characteristic dysmorphic features and dental anomalies. Microcornea, microphthalmia and mild or moderate mental retardation may accompany these features. Heterozygous females often manifest similarly but with less severe features than affected males.
Treatment for Sturge–Weber syndrome is symptomatic. Laser treatment may be used to lighten or remove the birthmark. Anticonvulsant medications may be used to control seizures. Doctors recommend early monitoring for glaucoma, and surgery may be performed on more serious cases. When one side of the brain is affected and anticonvulsants prove ineffective, the standard treatment is neurosurgery to remove or disconnect the affected part of the brain (hemispherectomy). Physical therapy should be considered for infants and children with muscle weakness. Educational therapy is often prescribed for those with mental retardation or developmental delays, but there is no complete treatment for the delays.
Brain surgery involving removing the portion of the brain that is affected by the disorder can be successful in controlling the seizures so that the patient has only a few seizures that are much less intense than pre-surgery. Surgeons may also opt to "switch-off" the affected side of the brain.
Latanoprost (Xalatan), a prostaglandin, may significantly reduce IOP (intraocular pressure) in patients with glaucoma associated with Sturge–Weber syndrome. Latanoprost is commercially formulated as an aqueous solution in a concentration of 0.005% preserved with 0.02% benzalkonium chloride (BAC). The recommended dosage of latanoprost is one drop daily in the evening, which permits better diurnal IOP control than does morning instillation. Its effect is independent of race, gender or age, and it has few to no side effects. Contraindications include a history of CME, epiretinal membrane formation, vitreous loss during cataract surgery, history of macular edema associated with branch retinal vein occlusion, history of anterior uveitis, and diabetes mellitus. It is also wise to advise patients that unilateral treatment can result in heterochromia or hypertrichosis that may become cosmetically objectionable.
Zonular cataract and nystagmus, also referred as Nystagmus with congenital zonular cataract is a rare congenital disease associated with Nystagmus and zonular cataract of the eye.
The cause of Primrose syndrome is currently unknown. This condition is extremely rare and seems to spontaneously occur, regardless of family history.
In the case studied by Dalai et al. in 2010, it was found that an abnormally high amount of calcitonin, a hormone secreted by the thyroid gland to stabilize blood calcium levels, was present in the blood serum. This suggests that the thyroid gland is releasing an abnormal amount of calcitonin, resulting in the disruption of calcium level homeostasis. No molecular cause was found, but an expanded microarray analysis of the patient found a 225.5 kb deletion on chromosome 11p between rs12275693 and rs1442927. Whether or not this deletion is related to the syndrome or is a harmless mutation is unknown. The deletion was not present in the patient's mother's DNA sample, but the father's DNA was unavailable.
Patients usually do not require treatment due to benign nature of the disease. In case cataract develops patients generally do well with cataract surgery.
Aniridia may be broadly divided into hereditary and sporadic forms. Hereditary aniridia is usually transmitted in an autosomal dominant manner (each offspring has a 50% chance of being affected), although rare autosomal recessive forms (such as Gillespie syndrome) have also been reported. Sporadic aniridia mutations may affect the WT1 region adjacent to the AN2 aniridia region, causing a kidney cancer called nephroblastoma (Wilms tumor). These patients often also have genitourinary abnormalities and intellectual disability (WAGR syndrome).
Several different mutations may affect the PAX6 gene. Some mutations appear to inhibit gene function more than others, with subsequent variability in the severity of the disease. Thus, some aniridic individuals are only missing a relatively small amount of iris, do not have foveal hypoplasia, and retain relatively normal vision. Presumably, the genetic defect in these individuals causes less "heterozygous insufficiency," meaning they retain enough gene function to yield a milder phenotype.
- AN
- Aniridia and absent patella
- Aniridia, microcornea, and spontaneously reabsorbed cataract
- Aniridia, cerebellar ataxia, and mental deficiency (Gillespie syndrome)
Although it is possible for the birthmark and atrophy in the cerebral cortex to be present without symptoms, most infants will develop convulsive seizures during their first year of life. There is a greater likelihood of intellectual impairment when seizures are resistant to treatment. Studies do not support the widely held belief that seizure frequency early in life in patients who have SWS is a prognostic indicator.
In general, approximately one-third of congenital cataracts are a component of a more extensive syndrome or disease (e.g., cataract resulting from congenital rubella syndrome), one-third occur as an isolated inherited trait, and one-third result from undetermined causes. Metabolic diseases tend to be more commonly associated with bilateral cataracts.
Galactosemic infants present clinical symptoms just days after the onset of a galactose diet. They include difficulty feeding, diarrhea, lethargy, hypotonia, jaundice, cataract, and hepatomegaly (enlarged liver). If not treated immediately, and many times even with treatment, severe mental retardation, verbal dyspraxia (difficulty), motor abnormalities, and reproductive complications may ensue. The most effective treatment for many of the initial symptoms is complete removal of galactose from the diet. Breast milk and cow's milk should be replaced with soy alternatives. Infant formula based on casein hydrolysates and dextrin maltose as a carbohydrate source can also be used for initial management, but are still high in galactose. The reason for long-term complications despite a discontinuation of the galactose diet is vaguely understood. However, it has been suggested that endogenous (internal) production of galactose may be the cause.
The treatment for galactosemic cataract is no different from general galactosemia treatment. In fact, galactosemic cataract is one of the few symptoms that is actually reversible. Infants should be immediately removed from a galactose diet when symptoms present, and the cataract should disappear and visibility should return to normal. Aldose reductase inhibitors, such as sorbinil, have also proven promising in preventing and reversing galactosemic cataracts. AR inhibitors hinder aldose reductase from synthesizing galactitol in the lens, and thus restricts the osmotic swelling of the lens fibers. Other AR inhibitors include the acetic acid compounds zopolrestat, tolrestat, alrestatin, and epalrestat. Many of these compounds have not been successful in clinical trials due to adverse pharmokinetic properties, inadequate efficacy and efficiency, and toxic side effects. Testing on such drug-treatments continues in order to determine potential long-term complications, and for a more detailed mechanism of how AR inhibitors prevent and reverse the galactosemic cataract.
N-Acetylcarnosine drops have been investigated as a medical treatment for cataracts. The drops are believed to work by reducing oxidation and glycation damage in the lens, particularly reducing crystallin crosslinking. Some benefit has been shown in small manufacturer sponsored randomized controlled trials but further independent corroboration is still required.
Femtosecond laser mode-locking, used during cataract surgery, was originally used to cut accurate and predictable flaps in LASIK surgery, and has been introduced to cataract surgery. The incision at the junction of the sclera and cornea and the hole in capsule during capsulorhexis, traditionally made with a handheld blade, needle, and forceps, are dependent on skill and experience of the surgeon. Sophisticated three-dimensional images of the eyes can be used to guide lasers to make these incisions. can also then break up the cataract as in phacoemulsification.
Stem cells have been used in a clinical trial for lens regeneration in twelve children under the age of two with cataracts present at birth. The children were followed for six months, so it is unknown what the long-term results will be, and it is unknown if this procedure would work in adults.
Norrie disease is a genetic disorder that primarily affects the eye and almost always leads to blindness. In addition to the congenital ocular symptoms, some patients suffer from a progressive hearing loss starting mostly in their 2nd decade of life, and some may have learning difficulties.
Patients with Norrie disease may develop cataracts, leukocoria (a condition where the pupils appear white when light is shone on them), along with other developmental issues in the eye, such as shrinking of the globe and the wasting away of the iris. Around 30 to 50% of them will also have developmental delay/learning difficulties, psychotic-like features, incoordination of movements or behavioral abnormalities. Most patients are born with normal hearing; however, the onset of hearing loss is very common in early adolescence. About 15% of patients are estimated to develop all the features of the disease.
The disease affects almost only male infants, because the disease is inherited X-linked recessive. Only in very rare cases, females have been diagnosed with Norrie disease as well. The exact incidence number is unknown; only a few hundred cases have been reported. It is a very rare disorder that is not associated with any specific ethnic or racial groups.
Treatments are usually based on the individuals symptoms that are displayed. The seizures are controlled with anticonvulsant medication. For the behavior problems, the doctors proscribe to a few medications and behavioral modification routines that involve therapists and other types of therapy. Even if mental retardation is severe, it does not seem to shorten the lifespan of the patient or to get worse with age.
Risk factors such as UVB exposure and smoking can be addressed. Although no means of preventing cataracts has been scientifically proven, wearing sunglasses that counteract ultraviolet light may slow their development. While adequate intake of antioxidants (such as vitamins A, C, and E) has been thought to protect against the risk of cataracts, clinical trials have shown no benefit from supplements; though evidence is mixed, but weakly positive, for a potential protective effect of the nutrients lutein and zeaxanthin. Statin use is somewhat associated with a lower risk of nuclear sclerotic cataracts.
Cell based therapies using bone marrow stem cells as well as retinal pigment epithelial transplantation are being studied. A number of trials have occurred in humans with encouraging results.
Although advancement has been slow to come during the decades of research dedicated to the galactosemic cataract, some notable additions have been made. In 2006, Michael L. Mulhern and colleagues further investigated the effects of the osmotic swelling on galactosemic cataract development. Experiments were based on systematic observation of rats fed a 50% galactose diet. According to Mulhern, 7 to 9 days after the onset of the galactose diet, lenses appeared hydrated and highly vacuolated. Lens fibers became liquefied after nine days of the diet, and nuclear cataract formation appeared after 15 days of the diet.
The experiment concluded that
Apoptosis in lens epithelial cells (LEC) is linked to cataract formation. Essentially, the study suggested that the mechanism outlined by Friedenwald and Kinoshita, which centers on osmotic swelling of the lens fibers, is just the beginning in a cascade of events that causes and progresses the galactosemic cataract. Mulhern determined that osmotic swelling is actually a cataractogenic stressor that leads to LEC apoptosis. This is because osmotic swelling of lens fibers considerably strains LEC endoplasmic reticula. As the endoplasmic reticulum is the principal site of protein synthesis, stressors on the ER can cause proteins to become misfolded. The subsequent accumulation of misfolded proteins in the ER activates the unfolded protein response (UPR) in LECs. In agreement, it was later observed on galactosemic yeast models, the activation of UPR upon galactose treatment. UPR initiates apoptosis, or cell death, by various mechanisms, one of which is the release of reactive oxygen species (ROS). Thus, according to recent findings, osmotic swelling, UPR, oxidative damage, and the resultant LEC apoptosis all play key roles in the onset and progression of the galactosemic cataract. Other studies claim that the oxidative damage in LECs is less a result of the release of ROS and more because of the competition between aldose reductase and glutathione reductase for nicotinamide adenine dinucleotide phosphate (NADPH). Aldose reductase requires NADPH for the reduction of galactose to galactitol, while glutathione reductase utilizes NADPH to reduce glutathione disulfide (GSSG) to its sulfhydryl form, GSH. GSH is an important cellular antioxidant. Therefore, what exactly the key roles are for these cataractogenic factors is not yet fully understood or agreed upon by researchers.
A practical application of AMD-associated genetic markers is in the prediction of progression of AMD from early stages of the disease to neovascularization.
Childhood cataract is cataract that occurs at birth or in childhood. It may be congenital or acquired.