Inherited muscle disorders and infections together cause the majority of rhabdomyolysis in children.The following hereditary disorders of the muscle energy supply may cause recurrent and usually exertional rhabdomyolysis:
Glycolysis and glycogenolysis defects: McArdles disease, phosphofructokinase deficiency, glycogen storage diseases VIII, IX, X and XI
Lipid metabolism defects: carnitine palmitoyltransferase I and II deficiency, deficiency of subtypes of acyl CoA dehydrogenase (LCAD, SCAD, MCAD, VLCAD, 3-hydroxyacyl-coenzyme A dehydrogenase deficiency), thiolase deficiency
Mitochondrial myopathies: deficiency of succinate dehydrogenase, cytochrome c oxidase and coenzyme Q10
Others: glucose-6-phosphate dehydrogenase deficiency, myoadenylate deaminase deficiency and muscular dystrophies

Mechanism
Damage to skeletal muscle may take various forms. Crush and other physical injuries cause damage to muscle cells directly or interfere with blood supply, while non-physical causes interfere with muscle cell metabolism. When damaged, muscle tissue rapidly fills with fluid from the bloodstream, including sodium ions. The swelling itself may lead to destruction of muscle cells, but those cells that survive are subject to various disruptions that lead to rise in intracellular calcium ions; the accumulation of calcium outside the sarcoplasmic reticulum leads to continuous muscle contraction and depletion of ATP, the main carrier of energy in the cell. ATP depletion can itself lead to uncontrolled calcium influx. The persistent contraction of the muscle cell leads to breakdown of intracellular proteins and disintegration of the cell.Neutrophil granulocytes—the most abundant type of white blood cell—enter the muscle tissue, producing an inflammatory reaction and releasing reactive oxygen species, particularly after crush injury.
Vitreous hemorrhage is the extravasation, or leakage, of blood into the areas in and around the vitreous humor of the eye. The vitreous humor is the clear gel that fills the space between the lens and the retina of the eye. A variety of conditions can result in blood leaking into the vitreous humor, which can cause impaired vision, floaters, and photopsia. Symptoms
Common symptoms of vitreous hemorrhage include:

Blurred vision
Floaters – faint cobweb-like apparitions floating through the field of vision
Reddish tint to vision
Photopsia – brief flashes of light in the peripheral visionSmall vitreous hemorrhage often manifests itself as "floaters." A moderate case will often result in dark streaks in the vision, while dense vitreous hemorrhage can significantly inhibit vision. Causes
There are many factors known to cause vitreous hemorrhage. Diabetic retinopathy
The most common cause found in adults is diabetic retinopathy. Abnormal blood vessels can form in the back of the eye of a person with diabetes. These new blood vessels are weaker and prone to breaking and causing hemorrhage. Diabetic retinopathy accounts for 31.5–54% of all cases of vitreous hemorrhage in adults in the United States. Trauma
Some injuries can cause blood vessels in the back of the eye to bleed. Trauma is the leading cause of vitreous hemorrhage in young people, and accounts for 12–18.8% of cases in adults. Retinal tear or detachment
A tear in the retina can allow fluids from the eye to leak in behind the retina, which causes retinal detachment. When this occurs, blood from the retinal blood vessels can bleed into the vitreous.