A 1987 study from Slovakia reports a Roma population with an extremely high incidence of PKU (one case in 40 births) due to extensive inbreeding. It is the most common amino acid metabolic problem in the United Kingdom. History
Before the causes of PKU were understood, PKU caused severe disability in most people who inherited the relevant mutations. Nobel and Pulitzer Prize winning author Pearl S. Buck had a daughter named Carol who lived with PKU before treatment was available, and wrote an account of its effects in a book called The Child Who Never Grew. Many untreated PKU patients born before widespread newborn screening are still alive, largely in dependent living homes/institutions.Phenylketonuria was discovered by the Norwegian physician Ivar Asbjørn Følling in 1934 when he noticed hyperphenylalaninemia (HPA) was associated with intellectual disability. In Norway, this disorder is known as Føllings disease, named after its discoverer. Følling was one of the first physicians to apply detailed chemical analysis to the study of disease. In 1934 at Rikshospitalet, Følling saw a young woman named Borgny Egeland. She had two children, Liv and Dag, who had been normal at birth but subsequently developed intellectual disability. When Dag was about a year old, the mother noticed a strong smell to his urine. Følling obtained urine samples from the children and, after many tests, he found that the substance causing the odor in the urine was phenylpyruvic acid.
With the discontinuation of the steroid drop the subretinal fluid resolved and did not show any sign of recurrence. Thus indicating the steroid was the probable cause of the CSR. A study of 60 persons with Cushings syndrome found CSR in 3 (5%). Cushings syndrome is characterized by very high cortisol levels. Certain sympathomimetic drugs have also been associated with causing the disease.Evidence has also implicated helicobacter pylori (see gastritis) as playing a role. It would appear that the presence of the bacteria is well correlated with visual acuity and other retinal findings following an attack. Evidence also shows that people with MPGN type II kidney disease can develop retinal abnormalities including CSR caused by deposits of the same material that originally damaged the glomerular basement membrane in the kidneys. Diagnosis
The diagnosis usually starts with a dilated examination of the retina, followed with confirmation by optical coherence tomography and fluorescein angiography. The angiography test will usually show one or more fluorescent spots with fluid leakage. In 10%-15% of the cases these will appear in a "classic" smokestack shape. Differential diagnosis should be immediately performed to rule out retinal detachment, which is a medical emergency. A clinical record should be taken to keep a timeline of the detachment. The affected eye will sometimes exhibit a refractive spectacle prescription that is more far-sighted than the fellow eye due to the decreased focal length caused by the raising of the retina.