Hermann Jakob Knapp was a German-American ophthalmologist who was born in Dauborn, Nassau

Nassau (state)

Nassau was a German state within the Holy Roman Empire and later in the German Confederation. Its ruling dynasty, now extinct in male line, was the House of Nassau.-Origins:...

. He earned his medical degree from the University of Giessen

University of Giessen

The University of Giessen is officially called the Justus Liebig University Giessen after its most famous faculty member, Justus von Liebig, the founder of modern agricultural chemistry and inventor of artificial fertiliser.-History:The University of Gießen is among the oldest institutions of...

 in 1854. As a young physician he studied with Franciscus Cornelis Donders in Utrecht

Utrecht University

Utrecht University is a university in Utrecht, Netherlands. It is one of the oldest universities in the Netherlands and one of the largest in Europe. Established March 26, 1636, it had an enrollment of 29,082 students in 2008, and employed 8,614 faculty and staff, 570 of which are full professors....

, William Bowman in London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

, Albrecht von Graefe in Berlin

Humboldt University of Berlin

The Humboldt University of Berlin is Berlin's oldest university, founded in 1810 as the University of Berlin by the liberal Prussian educational reformer and linguist Wilhelm von Humboldt, whose university model has strongly influenced other European and Western universities...

 and Hermann von Helmholtz

Hermann von Helmholtz

Hermann Ludwig Ferdinand von Helmholtz was a German physician and physicist who made significant contributions to several widely varied areas of modern science...

 in Heidelberg. From 1860 until 1868 he was a professor of ophthalmology

Ophthalmology

Ophthalmology is the branch of medicine that deals with the anatomy, physiology and diseases of the eye. An ophthalmologist is a specialist in medical and surgical eye problems...

 at Heidelberg. Afterwards he emigrated to New York City

New York City

New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

, where he worked as a surgeon

Surgeon

In medicine, a surgeon is a specialist in surgery. Surgery is a broad category of invasive medical treatment that involves the cutting of a body, whether human or animal, for a specific reason such as the removal of diseased tissue or to repair a tear or breakage...

 and college professor. In 1869 he founded the New York Ophthalmic and Aural Institute, which from 1913 to 1939 was called the Herman Knapp Memorial Hospital. His son, Arnold Knapp (1869-1956) was also a noted ophthalmologist.

In 1869, Knapp along with Salomon Moos

Salomon Moos

Salomon Moos was a German otologist born in Randegg, a village in the Grand Duchy of Baden.He studied medicine at the University of Heidelberg, and following graduation worked as an assistant at the medical clinic of Karl Ewald Hasse. Afterwards he continued his education in Prague and Vienna, and...

 (1831-1895) founded the "Archives of Ophthalmology and Otology

Otology

Otology is a branch of biomedicine which studies normal and pathological anatomy and physiology of the ear as well as its diseases, diagnosis and treatment....

" (Archiv für Augen- und Ohrenheilkunde), which was an international scientific monthly journal that was published in Wiesbaden

Wiesbaden

Wiesbaden is a city in southwest Germany and the capital of the federal state of Hesse. It has about 275,400 inhabitants, plus approximately 10,000 United States citizens...

 and New York. In 1878 the archives split into two independent entities; as the "Archives of Ophthalmology" (Archiv für Augenheilkunde) and the "Journal of Otology" (Zeitschrift für Ohrenheilkunde).

His name is lent to the eponymous "Knapp streaks"; also known as angioid streaks

Angioid streaks

Angioid streaks, also called Knapp streaks or Knapp striae are small breaks in Bruch's membrane, an elastic tissue containing membrane of the retina that can become calcified and crack....

, which are tiny breaks in the elastin

Elastin

Elastin is a protein in connective tissue that is elastic and allows many tissues in the body to resume their shape after stretching or contracting. Elastin helps skin to return to its original position when it is poked or pinched. Elastin is also an important load-bearing tissue in the bodies of...

-filled tissue

Tissue (biology)

Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...

 in the back of the eye

Human eye

The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...

. He also created his own version of an ophthalmotrope, a device used in physiological

Physiology

Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...

 optics

Optics

Optics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...

 to demonstrate the action of ocular muscles individually or in various combinations. Several instruments used in eye surgery

Eye surgery

Eye surgery, also known as orogolomistician surgery or ocular surgery, is surgery performed on the eye or its adnexa, typically by an ophthalmologist.-Preparation and precautions:...

 bear his name, including the Knapp trachoma

Trachoma

Trachoma is an infectious disease causing a characteristic roughening of the inner surface of the eyelids. Also called granular conjunctivitis and Egyptian ophthalmia, it is the leading cause of infectious blindness in the world...

 forceps

Forceps

Forceps or forcipes are a handheld, hinged instrument used for grasping and holding objects. Forceps are used when fingers are too large to grasp small objects or when many objects need to be held at one time while the hands are used to perform a task. The term 'forceps' is used almost exclusively...

.

Selected writings

• "Curvature of the Cornea of the Human Eye" (Heidelberg, 1859):
• "Intraocular Tumors" (Carlsruhe, 1868; New York", 1869)
• "Cocaine and its Use in Ophthalmic and General Surgery" (New York, 1885)
• "Investigations on Fermentation, Putrefaction, and Suppuration" (1886)
• "Cataract Extraction without Iridectomy" (1887)
• "A Series of One Thousand Successive Cases of Cataract Extraction without Iridectomy" (1887).