Terrier breeds are predisposed to lens luxation, and it is probably inherited in the Sealyham Terrier, Jack Russell Terrier, Wirehaired Fox Terrier, Rat Terrier, Teddy Roosevelt Terrier, Tibetan Terrier, Miniature Bull Terrier, Shar Pei, and Border Collie. The mode of inheritance in the Tibetan Terrier and Shar Pei is likely autosomal recessive. Labrador Retrievers and Australian Cattle Dogs are also predisposed.

Lens subluxation is also seen in dogs and is characterized by a partial displacement of the lens. It can be recognized by trembling of the iris (iridodonesis) or lens (phacodonesis) and the presence of an aphakic crescent (an area of the pupil where the lens is absent). Other signs of lens subluxation include mild conjunctival redness, vitreous humour degeneration, prolapse of the vitreous into the anterior chamber, and an increase or decrease of anterior chamber depth. Removal of the lens before it completely luxates into the anterior chamber may prevent secondary glaucoma. A nonsurgical alternative involves the use of a miotic to constrict the pupil and prevent the lens from luxating into the anterior chamber.

Persistent tunica vasculosa lentis is a congenital ocular anomaly. It is a form of persistent hyperplastic primary vitreous (PHPV).

It is a developmental disorder of the vitreous. It is usually unilateral and first noticed in the neonatal period. It may be associated with micropthalmos, cataracts, and increased intraocular pressure. Elongated ciliary processes are visible through the dilated pupil. A USG B-scan confirms diagnosis in the presence of a cataract.

Persistent hyperplastic primary vitreous (PHPV), also known as Persistent Fetal Vasculature (PFV), is a rare congenital developmental anomaly of the eye that results

following failure of the embryological, primary vitreous and hyaloid vasculature to regress. It can be present in three forms: purely anterior (persistent tunica vasculosa lentis and persistent posterior fetal fibrovascular sheath of the lens), purely posterior (falciform retinal septum and ablatio falcicormis congenita) and a combination of both. Most examples of PHPV are unilateral and non-hereditary. When bilateral, PHPV may follow an autosomal recessive or autosomal dominant inheritance pattern.

Corectopia is the displacement of the eye's pupil from its normal, central position. It may be associated with high myopia or ectopia lentis, among other conditions. Medical or surgical intervention may be indicated for the treatment of corectopia in some cases.

Treatment is based

on the stage of the disease. Stage 1 does not

require treatment and

should be observed. 4

Neovascularization

(stage 2) responds well

to laser ablation or

cryotherapy.2,4 Eyes

with retinal detachments (stages

3 through 5) require surgery, with

earlier stages requiring scleral

buckles and later stages ultimately

needing vitrectomy. 2,4

More recently, the efficacy of

anti-VEGF intravitreal injections

has been studied. In one study,

these injections, as an in adjunct

with laser, helped early stages

achieve stabilization, but further

investigation is needed.6

Eye surgery has been documented to help those with ocular diseases, such as some forms of glaucoma.

However, long term medical management of glaucoma has not proven to be successful for patients with Weill–Marchesani syndrome. Physical therapy and orthopedic treatments are generally prescribed for problems stemming from mobility from this connective tissue disorder. However, this disorder has no cure, and generally, treatments are given to improve quality of life.

The primary vitreous used in formation of the eye during fetal development remains in the eye upon birth and is hazy and scarred. The symptoms are leukocoria, strabismus, nystagmus and blurred vision, blindness.

Photophobia may also affect patients' socioeconomic status by limiting their career choices, since many workplaces require bright lights for safety or to accommodate the work being done. Sufferers may be shut out of a wide range of both skilled and unskilled jobs, such as in warehouses, offices, workshops, classrooms, supermarkets and storage spaces. Some photophobes are only able to work night shifts, which reduces their prospects for finding work.

The best treatment for light sensitivity is to address the underlying cause. Once the triggering factor is treated, photophobia disappears in many but not all cases.

People with photophobia will avert their eyes from direct light, such as sunlight and room lights. They may seek the shelter of a dark room. They may wear sunglasses designed to filter peripheral light and wide-brimmed sun hats.

Wearing sunglasses indoors can make symptoms worse over time as it will dark-adapt the retina which aggravates sensitivity to light. Indoor photophobia symptoms may be relieved with the use of precision tinted lenses which block the green-to-blue end of the light spectrum without blurring or impeding vision.

A paper by Stringham and Hammond, published in the "Journal of Food Science", reviews studies of effects of consuming Lutein and Zeaxanthin on visual performance, and notes a decrease in sensitivity to glare.

Crossed dystopia (syn.unilateral fusion cross fused renal ectopia) is a rare form of renal ectopia where both kidneys are on the same side of the spine. In many cases, the two kidneys are fused together, yet retain their own vessels and ureters. The ureter of the lower kidney crosses the midline to enter the bladder on the contralateral side. Both renal pelvis can lie one above each other medial to the renal parenchyma (unilateral long kidney) or the pelvis of the crossed kidney faces laterally (unilateral "S" shaped kidney). Urogram is diagnostic.

The anomaly can be diagnosed through ultrasound of urography, but surgical intervention is only necessary if there are other complications, such as tumors or pyelonephritis.

Although surgery is the treatment of choice, it must be preceded by imaging studies to exclude an intracranial connection. Potential complications include meningitis and a cerebrospinal fluid leak. Recurrences or more correctly persistence may be seen in up to 30% of patients if not completely excised.

Stages 1 and 2 do not lead to blindness. However, they can progress to the more severe stages. Threshold disease is defined as disease that has a 50% likelihood of progressing to retinal detachment. Threshold disease is considered to be present when stage 3 ROP is present in either zone I or zone II, with at least 5 continuous or 8 total clock hours of disease, and the presence of "plus" disease. Progression to stage 4 (partial retinal detachment), or to stage 5 (total retinal detachment), will result in substantial or total loss of vision for the infant.

- Refractive errors (most common)

- Squint

- Amblyopia

- Retinal detachment and blindness

- Glaucoma

In order to allow timely intervention, a system of monitoring is undertaken for infants at risk of developing ROP. These monitoring protocols differ geographically because the definition of high-risk is not uniform or perfectly defined. In the USA the consensus statement of experts is informed by data derived by clinical trials and published in Pediatrics 2006. They included infants with birthweights under 1500 grams or under 30 weeks gestation in most cases. The first examination should take place within the first 4 weeks of life, and regular, weekly examination is required until it is clear that the eyes are not going to develop disease needing treatment, or one or both eyes develop disease requiring treatment. Treatment should be administered within a 48 hours, as the condition can progress rapidly.

Familial exudative vitreoretinopathy (FEVR) ( ) is a genetic disorder affecting the growth and development of blood vessels in the retina of the eye. This disease can lead to visual impairment and sometimes complete blindness in one or both eyes. FEVR is characterized by exudative leakage and hemorrhage of the blood vessels in the retina, along with incomplete vascularization of the peripheral retina. The disease process can lead to retinal folds, tears, and detachments.

Weill–Marchesani syndrome is a rare genetic disorder characterized by short stature; an unusually short, broad head (brachycephaly) and other facial abnormalities; hand defects, including unusually short fingers (brachydactyly); and distinctive eye (ocular) abnormalities. It was named after ophthalmologists Georges Weill (1866-1952) and Oswald Marchesani (1900-1952) who first described it in 1932 and 1939, respectively.

The eye manifestations typically include unusually small, round lenses of the eyes (spherophakia), which may be prone to dislocating (ectopia lentis), as well as other ocular defects. Due to such abnormalities, affected individuals may have varying degrees of visual impairment, ranging from nearsightedness myopia to blindness. Researchers suggest that Weill–Marchesani syndrome may have autosomal recessive or autosomal dominant inheritance.

Leukocoria (also leukokoria or white pupillary reflex) is an abnormal white reflection from the retina of the eye. Leukocoria resembles eyeshine, but leukocoria can occur in humans and other animals that lack eyeshine because their retina lacks a "tapetum lucidum".

Leukocoria is a medical sign for a number of conditions, including Coats disease, congenital cataract, corneal scarring, melanoma of the ciliary body, Norrie disease, ocular toxocariasis, persistence of the tunica vasculosa lentis (PFV/PHPV), retinoblastoma, and retrolental fibroplasia.

Because of the potentially life-threatening nature of retinoblastoma, a cancer, that condition is usually considered in the evaluation of leukocoria. In some rare cases (1%) the leukocoria is caused by Coats' disease (leaking retinal vessels).

Nasal glial heterotopia is rare, while an encephalocele is uncommon. NGH usually presents in infancy, while encephalocele may present in older children and adults. It is seen in both genders equally.

The prevalence of congenital Chiari I malformation, defined as tonsilar herniations of 3 to 5 mm or greater, was previously believed to be in the range of one per 1000 births, but is likely much higher. Women are three times more likely than men to have a congenital Chiari malformation. Type II malformations are more prevalent in people of Celtic descent. A study using upright MRI found cerebellar tonsillar ectopia in 23% of adults with headache from motor-vehicle-accident head trauma. Upright MRI was more than twice as sensitive as standard MRI, likely because gravity affects cerebellar position.

Cases of congenital Chiari malformation may be explained by evolutionary and genetic factors. Typically, an infant's brain weighs around 400g at birth and triples to 1100-1400g by age 11. At the same time the cranium triples in volume from 500 cm to 1500 cm to accommodate the growing brain. During human evolution, the skull underwent numerous changes to accommodate the growing brain. The evolutionary changes included increased size and shape of the skull, decreased basal angle and basicranial length. These modifications resulted in significant reduction of the size of the posterior fossa in modern humans. In normal adults, the posterior fossa comprises 27% of the total intracranial space, while in adults with Chiari Type I, it is only 21%. If a modern brain is paired with a less modern skull, the posterior fossa may be too small, so that the only place where the cerebellum can expand is the foramen magnum, leading to development of Chiari Type I. H. neanderthalensis had platycephalic (flattened) skull. Some cases of Chiari are associated with platybasia (flattening of the skull base).

While there is no current cure, the treatments for Chiari malformation are surgery and management of symptoms, based on the occurrence of clinical symptoms rather than the radiological findings. The presence of a syrinx is known to give specific signs and symptoms that vary from dysesthetic sensations to algothermal dissociation to spasticity and paresis. These are important indications that decompressive surgery is needed for patients with Chiari Malformation Type II. Type II patients have severe brain stem damage and rapidly diminishing neurological response.

Decompressive surgery involves removing the lamina of the first and sometimes the second or third cervical vertebrae and part of the occipital bone of the skull to relieve pressure. The flow of spinal fluid may be augmented by a shunt. Since this surgery usually involves the opening of the dura mater and the expansion of the space beneath, a dural graft is usually applied to cover the expanded posterior fossa.

A small number of neurological surgeons believe that detethering the spinal cord as an alternate approach relieves the compression of the brain against the skull opening (foramen magnum), obviating the need for decompression surgery and associated trauma. However, this approach is significantly less documented in the medical literature, with reports on only a handful of patients. It should be noted that the alternative spinal surgery is also not without risk.

Complications of decompression surgery can arise. They include bleeding, damage to structures in the brain and spinal canal, meningitis, CSF fistulas, occipito-cervical instability and pseudomeningeocele. Rare post-operative complications include hydrocephalus and brain stem compression by retroflexion of odontoid. Also, an extended CVD created by a wide opening and big duroplasty can cause a cerebellar "slump". This complication needs to be corrected by cranioplasty.

In certain cases, irreducible compression of the brainstem occurs from in front (anteriorly or ventral) resulting in a smaller posterior fossa and associated Chiari malformation. In these cases, an anterior decompression is required. The most commonly used approach is to operate through the mouth (transoral) to remove the bone compressing the brainstem, typically the odontoid. This results in decompressing the brainstem and therefore gives more room for the cerebellum, thus decompressing the Chiari malformation. Arnold Menzes, MD, is the neurosurgeon who pioneered this approach in the 1970s at the University of Iowa. Between 1984 and 2008 (the MR imaging era), 298 patients with irreducible ventral compression of the brainstem and Chiari type 1 malformation underwent a transoral approach for ventral cervicomedullary decompression at the University of Iowa. The results have been excellent resulting in improved brainstem function and resolution of the Chiari malformation in the majority of patients.

On photographs taken using a flash, instead of the familiar red-eye effect, leukocoria can cause a bright white reflection in an affected eye. Leukocoria may appear also in low indirect light, similar to eyeshine.

Leukocoria can be detected by a routine eye exam (see Ophthalmoscopy). For screening purposes, the red reflex test is used. In this test, when a light is shone briefly through the pupil, an orange red reflection is normal. A white reflection is leukocoria.

The treatment of pentalogy of Cantrell is directed toward the specific symptoms that are apparent in each individual. Surgical intervention for cardiac, diaphragmatic and other associated defects is necessary. Affected infants will require complex medical care and may require surgical intervention. In most cases, pentalogy of Cantrell is fatal without surgical intervention. However, in some cases, the defects are so severe that the individual dies regardless of the medical or surgical interventions received.

The specific treatment strategy will vary from one infant to another based upon various factors, including the size and type of abdominal wall defect, the specific cardiac anomalies that are present, and the particular type of ectopia cordis. Surgical procedures that may be required shortly after birth include repair of an omphalocele. At this time, physicians may also attempt to repair certain other defects including defects of the sternum, diaphragm and the pericardium.

In severe cases, some physicians advocate for a staged repair of the defects associated with pentalogy of Cantrell. The initial operation immediately after birth provides separation of the peritoneal and pericardial cavities, coverage of the midline defect and repair of the omphalocele. After appropriate growth of the thoracic cavity and lungs, the second stage consists of the repair of cardiac defects and return of the heart to the chest. Eventually, usually by age 2 or 3, reconstruction of the lower sternum or epigastrium may be necessary.

Other treatment of pentalogy of Cantrell is symptomatic and supportive.

Zamzam–Sheriff–Phillips syndrome is a rare autosomal recessive congenital disorder. It is characterized by aniridia, ectopia lentis, abnormal upper incisors and intellectual disability. Not a lot of research has been undertaken of this particular disease so thus far there is no known gene that affects this condition. However it has been hypothesised that the symptoms described are found at a particular gene, though intellectual disability is believed to be due to a different genetic cause.

Consanguinuity (intermarrying among relatives such as cousins), often associated with autosomal recessive inheritance, has been attributed to the inheritance of this disease.

The American Heart Association made the following recommendations for Marfan's patients with no or mild aortic dilation:

- Probably permissible activities: bowling, golf, skating (but not ice hockey), snorkeling, brisk walking, treadmill, stationary biking, modest hiking, and doubles tennis.

- Intermediate risk: basketball (both full- and half-court), racquetball, squash, running (sprinting and jogging), skiing (downhill and cross-country), soccer, singles tennis, touch (flag) football, baseball, softball, biking, lap swimming, motorcycling, and horseback riding.

- High risk: bodybuilding, weightlifting (non-free and free weights), ice hockey, rock climbing, windsurfing, surfing, and scuba diving.

Lipomatosis is believed to be an autosomal dominant condition in which multiple lipomas are present on the body. Many discrete, encapsulated lipomas form on the trunk and extremities, with relatively few on the head and shoulders. In 1993, a genetic polymorphism within lipomas was localized to chromosome 12q15, where the HMGIC gene encodes the high-mobility-group protein isoform I-C. This is one of the most commonly found mutations in solitary lipomatous tumors but lipomas often have multiple mutations. Reciprocal translocations involving chromosomes 12q13 and 12q14 have also been observed within.

Although this condition is benign, it can sometimes be very painful depending on location of the lipomas. Some patients who are concerned with cosmetics seek removal of individual lipomas. Removal can include simple excision, endoscopic removal, or liposuction.

Other entities which are accompanied by multiple lipomas include Proteus syndrome, Cowden syndrome and related disorders due to PTEN gene mutations, benign symmetric lipomatosis (Madelung disease),Dercum's Disease, familial lipodystrophy, hibernomas, epidural steroid injections with epidural lipomatosis, and familial angiolipomatosis.