On 1 May, the hospital director reported to the local public health office the discovery of an "epidemic of an unknown disease of the central nervous system", marking the official discovery of Minamata disease.To investigate the epidemic, the city government and various medical practitioners formed the Strange Disease Countermeasures Committee at the end of May 1956. Owing to the localised nature of the disease, it was suspected to be contagious and as a precaution patients were isolated and their homes disinfected. Although contagion was later disproved, this initial response contributed to the stigmatisation and discrimination experienced by Minamata survivors from the local community. During its investigations, the committee uncovered surprising anecdotal evidence of the strange behaviour of cats and other wildlife in the areas surrounding patients homes. From around 1950 onward, cats had been seen to have convulsions, go mad, and die. Locals called it the "cat dancing disease", owing to their erratic movement. Crows had fallen from the sky, seaweed no longer grew on the sea bed, and fish floated dead on the surface of the sea. As the extent of the outbreak was understood, the committee invited researchers from Kumamoto University (or Kumadai) to help in the research effort.The Kumamoto University Research Group was formed on 24 August 1956. Researchers from the School of Medicine began visiting Minamata regularly and admitted patients to the university hospital for detailed examinations. A more complete picture of the symptoms exhibited by patients was gradually uncovered.
Valsalva retinopathy is a form of retinopathy due to retinal bleeding secondary to rupture of retinal vessels caused by intrathoracic or intra-abdominal pressure due to physical activities. It can occur in any person irrespective of age, gender, race or health status. Pathophysiology
Valsalva retinopathy is a form of sub-retinal, sub-hyaloid or sub-internal limiting membrane hemorrhage occur due to rupture of retinal vessels caused by a strenuous physical activity. Physical exertion like weight lifting and aerobic exercise, coughing, sneezing, straining at stool, vomiting, sexual intercourse, pregnancy, asthma, blowing up balloons, blowing musical instruments, cardiopulmonary resuscitation or compression injuries may cause sudden increase in intrathoracic or intra-abdominal pressure may lead to rupture of superficial retinal blood vessels. A sudden increase in venous pressure due to intrathoracic or intra-abdominal pressure cause the small perifoveal capillaries of retina to rupture, leading to premacular hemorrhage of varying intensity. Signs and symptoms
The main symptom of valsalva retinopathy is painless sudden loss of vision. Sudden-onset floaters and central or paracentral visual field defects and nausea resulting from increased intraocular pressure are other symptoms. Diagnosis
Patients may have a history of sudden vision loss after a strenuous physical activity. Physical examination and eye examination is needed for diagnosis of valsalava retinopathy. OCT scanning can be used to identify the location of the bleeding. Complications
One of the main complications of valsalva retinopathy is vitreous hemorrhage. Epidemiology
As of 2022, there is currently no specific age, gender or racial preference noted for this retinopathy in the medical literature.