Blind as a bat– -Better than a poke in the eye—–
During the last one and one half centuries we’ve learned how to treat or correct most of the conditions that inhibit our ability to see.
One of them, Trachoma, has been a problem for mankind for thousands of years. Hippocrates thought it made eyelids, look like cut ripe figs. During the Napoleonic wars, it “raged” through the armies of Europe; and over the centuries it often occurred in clusters within villages or families.11 Caused by a Chlamydia, a type of bacteria that lives and reproduces inside the cell of the host, it leads to scarring of eyelids, and causes eyelashes to damage the cornea. Antibiotics kill the bug, but it tends to recur.9 The number of people who currently have “the late blinding stage of the disease dropped to 2.5 million in 2019.”
The prevention of river blindness remains another work in progress. Found chiefly in parts of Africa, the condition is caused by a tiny parasite and is spread by black flies that “breed in fast flowing streams.” In the 1990s The African Programme for Onchocerciasis Control (APOC) successfully treated more than a million at risk people with the anti parasitic drug Ivermectin, and it made a significant difference. Globally, it is estimated that 18 million people are infected and 270,000 have been blinded by the condition. It’s called onchocerciasis.6”
There’s little available data on infants who survive wars, droughts, suffer from malnutrition and develop a vitamin A deficiency. The resulting dryness and scarring of the conjunctiva, the mucous membrane that coats the inside of the eyelids, can cause them to lose their ability to see.1
The leading causes of blindness in this country are cataracts, glaucoma, macular degeneration, and diabetes.5
Cataracts: To create a sharp image the eye like the microscope and the telescope needs two lenses. Cataracts occur when the eye’s inner lens becomes cloudy and opaque. Most develop slowly as we age, though they are sometimes seen in children for a variety of reasons. Worldwide they diminished vision in many and are the leading cause of blindness.
A century ago when a person’s lens got so dense that they couldn’t see, the structure was surgically removed. Afterwards a person could see light and little more unless they wore thick glasses. No on liked wearing Mr. Magoo glasses, and everyone hated feeling helpless when they woke and couldn’t locate their spectacles. I remember the days when people didn’t have cataract surgery until they were literally no longer able to see. The lens removal operation is, apparently, still done in some countries.
Harold Ridley of England is the father of the implantable lens. The son of a physician he spent his early doctoring days working on cruise ships. During the Second World War he spent 18 months in Ghana. Later in Burma, he provided care for former British prisoners of war who had nutritional amblyopia, lazy eye. At some point he treated members of the RAF whose airplanes were damaged by enemy fire and whose cornea’s, the front lens of the eye, had been penetrated by pieces of the plane’s windshield. The acrylic plastic did not cause an inflammatory reaction. Years later, he was removing a cataract and he recalls one of his students remarked: “It’s a pity you can’t replace the cataract with a clear lens.” That got Ridley thinking. He started crafting implants from the material that was used to make airplane cockpits and he implanted them into eyes after he removed an opaque lens.” “Sterilization of the lenses was a major problem and he was afraid to tell anyone. Powerful colleagues had shown hostility to the idea of putting a foreign body in the eye.10There was a learning curve but Ridley and a pupil perfected the surgical technique and a company in East Sussex (Rayner) manufactured the implant. In 1981 the FDA approved the use of implantable lenses in the U.S. and American eye surgeons adopted the approach. It’s now part of the bread and butter of ophthalmology.
The last 50 plus years have witnessed the development and modification of many replacement lenses. By 2015, 9000 American ophthalmologists were replacing 3.6 million lenses a year. Worldwide 20 million cataract surgeries are performed annually.2
In the U.S. most surgeons numb the eye, insert a small ultrasound probe, and phacoemulsify (liquify) the dense lens. Then they suck out the debris, insert a small plastic or silicone lens, and if necessary, sew the incision shut. My ophthalmologist at Kaiser Oakland told me she doesn’t specialize in cataract surgery. The eyes she deals with often have additional problems. So on her surgical half days she only performs 9 operations. Each takes 6 to 14 minutes. The complication rate for Canadian surgeons who performed 50 to 250 operations a year was 8 in a thousand. It was one in a thousand for surgeons who replace a thousand cataracts a year. In poorer countries phacoemulsification is less common. Most Americans who need cataract surgery are of Medicare age and the government pays $2500 per eye. Special lenses can cost an extra $1500 to $2500.
In India, a land with over a billion inhabitants, cataract surgery took a giant step forward in 1983 when an American Doctor named David Green met a 58 year old eye surgeon named Govindappa Venkataswamy. When they reconnected 5 years later the Indian physician had mortgaged his home, built an 11 bed hospital and was performing 5000 eye operations a year, 70 percent of them at no charge. Given the need he was barely scratching the surface. In the late 1990s it was estimated that 9.5 million people in India were blind as a result of cataracts and 3.8 million were losing their vision annually. The cost of implantable lenses, $100 to $150 per eye was too high for the average Indian. Green and the doctor established a nonprofit manufacturing plant in India and were able to produce an inexpensive quality lenses. In 2016 the company they founded, Aurolab, manufactured 2.6 million intra ocular lenses, 10% of all produced in the world. The majority of the lenses are “distributed to NGOs in India and in developing countries.” The company is profitable.
In 1999 doctors in India performed 1.6 to 1.9 million surgeries in a single year and plans were made to increase the numbers of operations that would be carried out. By 2006 cataract surgery in India, Nepal, and Bangladesh was costing $20 and the lens sold for less than $5.3
Glaucoma: Often caused by elevated pressures in the eye, Glaucoma is a number of conditions that damage the nerve that transmits images from the eye to the brain. The dramatic, painful eye of angle closure glaucoma is a medical emergency and can lead to visual loss. It occurs relatively infrequently. Open angle glaucoma, on the other hand is relatively common. Experts have learned a lot about the more usual condition, but we don’t know what causes it, and it’s no longer defined merely as a condition where the pressures inside the eye are too high–though they commonly are. The middle of the eye produces a watery aqueous fluid. It flows through the pupil, enters the space in the front of the eye, and exits through the spongy tissue that surrounds the edge of the cornea. In people with the condition fluid is over produced or doesn’t drain normally. The retinal nerve layer thins. People lose peripheral vision and eventually can substantially lose much of their ability to see.
In the western world some ophthalmologists spend a year or more becoming glaucoma specialists. They learn how to carry out and interpret tests, and when and how to perform one of many operations. Sophisticated machines allow experts to photograph and follow the appearance of the layers of the retina, the nerve rich stratum that collects the focused light that our brain turns into images. Gadgets that detect early loss of peripheral vision and that measure the pressure in the eye have entered the digital era.
The drugs that control the pressure in the eye include beta blockers and prostaglandin inhibitors. Beta blockers cause the eye to produce less fluid and Prostaglandin inhibitors promote drainage. In 2004 when the FDA gave Pfizer the exclusive right to the prostaglandin inhibitor Xalatan, they sold $1.23 million worth of the drug. Before a generic competitor entered the U.S. market, a month’s worth was costing $80 a month. Pfizer manufactures and sells its products worldwide and has 43 manufacturing plants in: Ireland, Puerto Rico, the U.S., UK, Germany, Amboise, France; Ascoli, Italy; Belgium and Perth, Australia.
According to the World Bank, “almost half the world’s population — 3.4 billion people — live on less than $5.50 a day. For them eye drops aren’t an option. Laser surgery can increase the outflow of fluid. If that doesn’t work an older operation called a “trabeculectomy”, removing a bit of the mesh network the fluid pours through, can create “a new drainage path.” In 20 percent of the people who undergo surgery the openings stop working during the first year and two percent fail each year thereafter.15
Researchers checked the records of 113 Brits with open angle glaucoma who failed their last glaucoma appointment due to death. They had been followed for 7 to 25 years. During those years about half had undergone surgery for cataracts and 45% for glaucoma. “At final visit, vision was inadequate for driving in the UK in close to half. In 18%, this was due to glaucoma alone, while in 28.9%, other ocular pathologies contributed to poor vision.13”
AMD, age related macular degeneration, is a major cause of vision loss as we get older. Something goes wrong in the layer under the retina, and the macula, the part of the eye that provides sharp, central vision, is damaged or destroyed. The so called “dry” form of the disease mainly affects white people who are 80 or older and we have no effective treatment.
The less common “wet” form of the disease is sometimes helped by laser coagulation or photodynamic therapy and is commonly treated with Avastin, an antibody that “blocks” the growth of the new blood vessels. When an ophthalmologist injects the medication into the eye of someone with wet macular degeneration, the disease process slows or turns off. “Blindness is prevented in most patients, and the majority of treated patients go on to have some improvement in vision.”
Before using it the doctor evaluates the patient. He or she discusses the risks of injecting the drug, and explains downsides like bleeding and retinal detachment. On the appointed day the patient is brought to the procedure room and checked. The edge of the eye is injected with a numbing agent. A second needle is then passed into the inner cavity of the eye, a chamber full of a gelatinous material known as the vitreous. The medication is injected and the pressure in the eye is raised for a brief period of time. Vision is temporarily blurry. After a period of observation the patient can go home.
A law caps the amount a U.S. doctor can charge for an Avastin injection. It can’t be more than 6% of the drug’s price. The small amount needed to treat an eye had a cost of $50, so the fee Medicare paid for the injection and observation was capped at $3.
Avastin was FDA approved as a drug that slows the growth of cancer. When the FDA approves a medication for one indication (cancer), the company that produces and markets it is not allowed to talk about other possible ways the drug can make a difference. Doctors who read the medical literature and learn a drug helps an additional–different condition, do have the legal right to use it for that condition. The doctor does not have to wait for the drug company or the FDA to act. In spite of the economics eye doctors were injecting Avastin into the eyes of people with wet macular degeneration. In 2006 the FDA approved a biosimilar, Lucentis.17 It was an almost identical antibody that blocked the growth of blood vessels, was made by the same company as Avastin, and it worked as well. In 2014 the company was selling it for over $2000 a month, and doctors who used it in their office were able to charge $180 for the visit and the injection.16
Refractory problem: At some point in most of our lives we can’t see well because our eyes are unable to focus light on the layer of cells at the back of our eyeballs, the retina. Some people are born with refractory errors. Others find it increasingly difficult to read small print after they turn 40. Wearable eye glasses have been used for many centuries.
In the 1950s people started correcting their vision by placing a thin lens on the surface of their eye. Contact lenses were initially small and had to be removed at night.
In 1965 Bausch and Lomb, bought the rights to contact lenses that were soft and were created in the kitchen of a Czech chemist. Once they owned the product’s license the once American, currently Canadian company started a billion dollar industry.14
The man who developed the lens, Otto Wichterle, was a Czech dissident who was jailed by the Nazis in 1942. In 1958 he lost his University job because he criticized the country’s Communist government. Continuing his work on the kitchen table of his Prague apartment, he used an instrument made from a child’s building kit (similar to an erector set) and a phonograph motor, and he produced four hydrogel contact lenses.17 When he put them in his own eyes they were comfortable. Ever a protester, Otto was expelled from the nation’s chemistry institute in 1970 because he supported Czechoslovakia’s attempt to become independent of Russia—the Prague Spring of 1968. When the cold war ended Otto resumed his scientific activities. In 1962 he patented his invention and produced an additional 5500 lenses. At one point he met and learned to trust an American optometrist named Robert Morrison. When he was harassed by patent attorneys Otto asked Morrison to come to Prague. “Wichterle said, “Robert, I have decided that I must give patent rights to the gel to someone who can use them in the Western Hemisphere and, perhaps, in some other areas as well.18” Ulitmately the US National Patent Development Corporation (NPDC) bought the American rights to the lenses from the Czechoslovak government for $330,000. Then they sublicensed the patent to the Bausch and Lomb Corporation. Wichterle was paid less than 1/10 of 1 % of the money, but he was now free to speak and travel and he had no regrets.
In 1989 Gholam A. Peyman, an ophthalmologist and inventor patented Lasik, a laser and computer assisted device that allowed doctors to peel back a flap of the outer skin of the cornea, the front lens of the eye. The inner corneal layer could then be altered with the beam of a laser, and eyes could focus better. At the end of the procedure the flap was replaced. The inventor, Dr. Peyman, was born in Shiraz Iran and went to medical school in Germany. He’s a constant innovator and has held more than 100 patents. In 2010 it was estimated that 8 million Americans have undergone the Lasik procedure at a cost of about $2000 per year.
Finally, no sooner is one problem solved than a new one develops. In a country where the incidence of obesity is increasing as a result of our high caloric diets and diminished activity, more and more individuals become diabetic. People with longstanding diabetes develop a number of eye problems and can go blind.
By 2010 close to 7 billion people lived on earth and about 32 million, one in 200 were blind. An additional 191 million, one in 40, were visually impaired.
Blood sugars usually have to be elevated for ten to 15 years before blood vessels on the surface of the retina become permeable and weepy and the amount of oxygen that reaches the cells of the eye decreases. New vessels, signaled by VEGF, grow and impair eyesight. “Left untreated, nearly half of eyes that develop proliferative diabetic retinopathy will have profound vision loss.”
Lasers are used to destroy the blood vessels that are overgrowing, and the antibodies that block VEGF, the hormone that encourages new blood vessel growth, are injected into eyes. In 2020, the Medicare paid $1000 to $1800 a session for the VEGF inhibitors that were FDA approved for use in the eye.
REFERENCES:
In 2019, according to the NIH, the most common causes of blindness are: Cataracts (51%); Glaucoma (8%);Age-related macular degeneration (5%);Corneal opacification (4%); Childhood blindness (4%; Refractive errors (3%); Trachoma (3%); Diabetic retinopathy (1%) https://www.ncbi.nlm.nih.gov/books/NBK448182/
https://www.who.int/news-room/fact-sheets/detail/trachoma
Trachoma, is it history by H.R. Taylor https://www.nature.com/articles/eye2008432https://www.who.int/news-room/detail/27-06-2019-eliminating-trachoma-who-announces-sustained-progress-with-hundreds-of-millions-of-people-no-longer-at-risk-of-infection
https://www.who.int/apoc/onchocerciasis/en/ http://sped.wikidot.com/malnutrition-a-cause-for-visual-impairment
CATARACTS: Harold Ridley and the intraocular lens https://rayner.com/wp-content/uploads/2019/02/Invention_of_the_IOL.pdf https://www.reviewofophthalmology.com/article/thoughts-on–cataract-surgery-2015
https://www.seva.org/site/SPageServer/;jsessionid=00000000.app272a?NONCE_TOKEN=D331A52171C42E9234E1E43A336A29B0&pagename=25_Years_of_Aurolab https://www.mitpressjournals.org/doi/pdf/10.1162/itgg.2006.1.3.25
RIVER BLINDNESS (PAHO-Pan American Health Organization.) (see: setting the price–Ivermectin)
MACULAR DEGENERATION https://www.jci.org/articles/view/77540 A Conversation with Napoleone Ferrara
diabetic retinopathy NEJM 2011;365:1520-6
https://www.nejm.org/doi/exam/10.1056/NEJMcme1909637?ef=article
phttps://www.cbsnews.com/news/nearly-half-the-planets-population-lives-on-less-than-5-50-a-day-worlf-bank-reports/ (half the planets population lives on $5.50 or less a day)
Glaucoma https://www.nature.com/articles/6702284
https://www.hopkinsmedicine.org/wilmer/services/glaucoma/book/ch17s01.html
Soft contact lenses phttps://b-c-ing-u.com/celebrities/hard-life-of-otto-wichterle/
Lucentis wet macular degeneration https://www.businessinsider.com/price-difference-lucentis-and-avastin-2014-6
soft lenses https://www.mayoclinicproceedings.org/article/S0025-6196(16)00071-9/fulltext