After the transplants, the researchers tested the patients' eyesight. Visual acuity improved in 10 of the patients' eyes, remained about the same in another seven patients and got worse in one patient's eye. The participants experienced no improvement in their untreated eyes. The results show that human embryonic stem cells can slow or reverse the vision loss in people with degenerative eye diseases, the researchers said.
In addition, the stem cells caused no medical problems for the patients up to three years after transplant, according to the study published today Oct. Stem cells, with their ability to develop into many different types of tissue, have long been touted for their promise in regenerative medicine, yet treatments have been slow to develop.
The new findings"mark an exciting step towards using [human embryonic] stem cells as a safe source of cells for the treatment of various medical disorders requiring tissue repair or replacement," study co-author Dr. What Can Animals See? Stem cell treatments have developed slowly in part due to concerns that the cells could be rejected by the immune system or grow into tumors.
But the eyes do not produce a strong immune response, so they're a good target for these treatments, the researchers said. Half of the patients in the study suffered from dry, atrophic age-related macular degeneration , which is the leading cause of blindness in adults in the developed world. The other half had Stargardt's macular dystrophy, the leading cause of blindness in young adults in the developed world. Roger Bacon, however, makes a notable contribution to ophthalmology with his work, Opus Majus.
This increased the level of precision that was possible in the diagnosis and treatment of ophthalmologic conditions. In particular, the operative treatment of glaucoma was refined at this time, and has helped greatly to improve patient outcomes. Several subspecialties were introduced to focus on particular areas or diseases of the eye. These include cataract, glaucoma, pediatrics, cornea and oncology subspecializations, among others. In the Ebers Papyrus , a section is devoted to eye diseases.
Indian surgeon Sushruta describes 76 ocular diseases, as well as several ophthalmological techniques and instruments. Sushruta is particularly interested in cataract surgery, and is referred to as the first cataract surgeon. Surgeons in ancient India already practice couching. Greek philosopher Celsus draws the lens in the center of the eye. Greek physician Rufus of Ephesus puts forward the concept of a fourth layer, the epithelial layer that covers the eye.
Rufus also notes that the eye has two chambers, one filled with water extending from the cornea to the lens, and one filled with viscous fluid occupying the space between the lens and the retina. Arab polymath Ibn al-Haytham writes his Book of Optics.
Arab Muslim ophthalmologist Ammar Al-Mawsili describes the suction of a cataract through the needle. Italian anatomist Hieronymus Fabricius illustrates the lens in its true anatomic position. French ophthalmologist Jacques Daviel publishes the first account of cataract extraction through an inferior corneal incision. English surgeon Samuel Sharp successfully performs intracapsular cataract extraction. The first hospital dedicated to the practice of ophthalmics opens in London.
Prussian ophthalmologist Albrecht von Graefe improves Jacques Daviel 's extracapsular cataract extraction technique using a superior corneal incision. English mathematician Charles Babbage invents the ophthalmoscope, which enables viewing of the interior of the eye. German physician Hermann von Helmholtz independently reinvents the ophthalmoscope. Dutch ophthalmologist Hermann Snellen develops his eponymous Snellen chart to measure visual acuity.
The chart would rapidly become a global standard. Archives of Ophthalmology and Otology is released. German physicist Ernst Abbe discovers the optical formula now called the Abbe sine condition, one of the requirements that a lens must satisfy if it is to form a sharp image, free from the blurring or distortion caused by coma and spherical aberration. The American Journal of Ophthalmology is established. Swedish ophthalmologist Allvar Gullstrand receives the Nobel Prize in Physiology or Medicine "for his work on the dioptrics of the eye.
The British Journal of Ophthalmology is established. Spanish ophthalmologist Ignacio Barraquer invents the first motorized vacuum instrument erisophake for intracapsular cataract extraction. The American Academy of Optometry is founded.
I really enjoyed reading Dr. Sheikh's book including the stories of his patients and the anecdotes of our forefathers who had poor vision and how this affected. Editorial Reviews. About the Author. Saad Shaikh, M.D. is a practicing physician and retinal Eyes on Ice & No Blind Mice: Visions of Science from the Science of Vision Kindle Edition. by.
Peer-reviewed medical journal Acta Ophthalmologica is established. The American Journal of Optometry is established. Japanese ophthalmologist Tsutomu Sato invents radial keratotomy treatment for myopia. English ophthalmologist Sir Harold Ridley becomes the first to create and implant intraocular lenses in a two-step procedure.
Strampelli starts to use anterior chamber intraocular lenses. The Indian Journal of Ophthalmology is first issued. Dutch ophthalmologist Cornelius Binkhorst introduces the first iris-clip lens. Polish ophthalmologist Tadeusz Krwawicz develops the first cryoprobe for intracapsular cataract extraction.
American ophthalmologist Charles Kelman develops phacoemulsification , a cataract surgery in which the eye's internal lens is emulsified with an ultrasonic handpiece and aspirated from the eye. Charles Kelman pioneers phacoemulsification.