Health Library
The Health Library at Vista Center is an affiliate of Stanford Hospital Health Library.
The Health Library is designed to help address the needs of individuals with vision loss, with comprehensive information about:
- Eye conditions - Causes of vision loss
- Consumer and caregiver information
- General information about health and disease
The library is staffed by visually impaired volunteers 
trained in researching health-related questions. Our volunteers are equipped to provide information, not medical advice. Although they are happy to help clients by researching questions, we recommend that users contact their doctor or other health care professional when medical advice is needed.
The Health Library produces three e-mail research lists:
- AMD - Retina - monthly
- Glaucoma - Optic Neuropathy - monthly
- Diabetes - twice a month
These newsletters are compiled of research reports and excerpts from professional sources including Medline, Medscape, Nature and ophthalmology journals.
Individual health and medical information requests will be searched for and the results sent in large print, cd txt or MP3, braille or e-mail.
Yearly updated packets of information are available about macular degeneration, glaucoma, diabetic retinopathy and others. Some are available in Spanish. Our services are provided free to anyone in the blind and visually impaired community. E-mail or call the Health Library with your requests at 650-858-0202 Extension 132. thl@vistacenter.org
The Eye, a Verbal Description (MP3)
Braving the Low Vision Exam (MP3)
Medical News Articles
From The Health Library monthly research lists:
12/7/11 Scientists at UCSB have developed a greater understanding of how the nervous system [includes the retina] becomes wired during early development. They examined the connectivity of nerve cells, called neurons, in mice retinas. Neurons communicate with one another via synapses where the dendrites & axon terminals of different cells form contacts. This is where nerve signals are transmitted from one neuron to another. The retina is an outgrowth of the brain during embryonic development, and is a precisely layered structure in which the cells and terminals are restricted to particular layers. The team studied a type of cone bipolar cell which relay information from cone photoreceptors to the retinal ganglion cells. The latter are neurons that in turn project information to the brain where further visual processing of the retinal image takes place. The total number of connections made by a cone bipolar cell was remarkably plastic, defined solely by the number of cone contacts formed. Studies like these may prove relevant for re-establishing connectivity following nerve cell..replacement in degenerative diseases, particularly as advances in stem cell biology make this an increasing possibility, the team says. Medical News Today
2. 12/12 Retina implant up date -- Several technologies to restore sight to retina-damaged eyes are making headway--one seeks to begin human trials in the U.S. & another has already hit the market in Europe. There is no effective treatment for RP, but researchers such as those at Retina Implant, AG, are making great strides to remedy this through implants that stimulate still active nerves in the retina, the layer of tissue at the back of the inner eye. RP kills the retina's photoreceptors, rod and cone cells that convert light into electrical signals, which are transmitted via the optic nerve to the brain's visual cortex for processing. In November, Retina Implant, got approval to extend their phase II human clinical trial of its retinal implant outside its native Germany. Their implant is a 3- by 3-millimeter [mm] microelectronic chip (0.1-mm thick), containing about 1,500 light- sensitive photodiodes, amplifiers & electrodes surgically inserted beneath the fovea (which contains the cone cells) in the retina's macula region. The fovea enables the clarity of vision that people rely on to read, watch TV & drive. The chip helps generate at least partial vision by stimulating intact nerve cells in the retina. The nervous impulses from these cells are then led via the optic nerve to the visual cortex where they finally lead to impressions of sight. Thus far, some patients report having a narrow field of vision partially restored, providing them with enough acuity to locate light sources such as windows and lamps as well as detect lighted objects against dark backgrounds. The chip's power source is positioned under the skin behind the ear & connected via a thin cable. Retina Implant has successfully placed chips beneath the retina of 9 pts since May 2010. The company hopes to widen patients' field of vision further by arranging 3 chips in a row beneath the retina. The ability to produce accurate colors via retinal implants, however, is very complicated & may not be possible for years. Retina Implant has also developed an outpatient Rx for early-stage RP called Okuvision, which uses electric stimulation to help preserve retinal cells. The extension expands Retina Implant's trial to an additional 25 pts beginning early next year & follows a partnership the company struck made with the Wills Eye Institute in Philadelphia. Wills is looking to become the lead U.S. clinical trial investigator site for Retina Implant's technology & to help the company through the US(FDA) review process. SciAmerican
3. 12/15 Needle-free, test being introduced to help Diabetics reduce their risk for serious complications – Young or old, any ethnic background, DM can hit anyone at anytime. Right now, 7 million diabetics are undiagnosed in the US. This new tool is a needle-free, test being introduced to help many pts reduce their risk for serious DM complications. Pediatric endocrinologist Dr. S.Chalews says the new tool uses light instead of an invasive skin biopsy to measure abnormal proteins in the skin associated with DM complications. This new machine could prove to be quicker & more effective than the presently used blood glucose testing machines. Two people with the same BS may have very different levels of glycated proteins. This new device is currently restricted to investigational use in the U.S. But it could get FDA approval by 2013. In other related news, USC neuroscientists have found the missing link on how the brain regulates blood sugar. They have identified the exact enzymes that lead to the release of glucose- controlling hormones. Understanding how the body naturally corrects for high or low blood sugar could change the way diabetes is treated. Eyewitness News LA (KABC)
3-31-11
From AMD-Retina Research List:
3/28/11 US scientists have taken an important step towards using stem cells to treat (AMD), The study demonstrates, for the first time, the ability to direct human iPS (induced pluripotent stem) cells to become the type of eye cells that die and cause loss of sight in sufferers of the disease. 'We have shown that we are able to generate retinal cells from cells originally taken from a small amount of biopsied skin, that are then induced to become stem cells', explained study leader at Georgetown U Med Centre Wash DC. .BioNews ..
'The retinal cells we have generated are really functional… they mimic the function of native retinal cells that play a key role in the eye for light absorption, nutrition & receptor function'. AMD affects the macula at the back of the eye, leading to death of retinal pigment epithelial (RPE) cells, a coloured layer which nourishes the light- receiving cells of the retina. Around 1 in 50 people more than 50 years of age, and up to one in 5 people over the age of 85, are affected by the disease, which results in the gradual loss of central vision needed for daily tasks such as reading and driving...
While existing treatments slow the progression of AMD, there is currently no cure. Human iPS cells offer the potential to use patient- specific stem cells to generate retinal cells for transplant. However, for transplantation to be possible, the iPS cells must first be programmed to possess the characteristics of native RPE cells The authors were careful to stress that their work is preliminary and much future research is needed before these cells can be used clinically. They pointed out that the cells they produced also displayed some structural abnormalities & chromosome damage, highlighting the need to focus on generating 'safe', as well as viable, iPS-derived cells. The study was published in the journal Stem Cells. BioNews 3/28/11
From the Diabetes Research List:
The 3 Stages of Diabetic Retinopathy - In people with T1, mild abnormalities in the retina begin to appear an average of 7 years after diabetes begins, but damage that threatens vision usually does not develop until much later. In T2-- retinopathy may be present at the time of diagnosis or relatively soon afterward. This is because the onset of T2 is gradual; changes in the retina may have already taken place before diabetes is even diagnosed. Here are the 3 progressive stages of Diabetic Retinopathy [DR]:..[link to more info]
• Microaneurysms- In the early, or nonproliferative, stages of DR, blood vessels in the retina develop weak spots that bulge outward (microaneurysms) & may leak fluid and blood into the surrounding retinal tissue. These initial abnormalities usually cause no visual symptoms & in many people the disease progresses no further. However, microaneurysms can lead to macular edema. • Macular Edema -- Swelling around the macula caused by the leakage & accumulation of fluid can occur in people with diabetes. The swelling alters the position of the retina & causes blurred vision. • Proliferative Retinopathy -- This is the most dangerous form of DR characterized by neovascularization -- the growth of new blood vessels onto the back surface of the vitreous humor. Acute loss of vision can occur when new blood vessels rupture & bleed into the vitreous humor or when these blood vessels lead to traction on the retina, causing it to detach from the back of the eye (retinal detachment). [Experts don't yet know exactly how high blood glucose levels cause DR. One possibility involves a protein known as vascular endothelial growth factor (VEGF), which promotes the growth of new blood vessels in the eye and is secreted into the eye in response to damage caused by diabetes. Studies suggest that elevated levels of cholesterol & triglycerides as well as high BP can increase the risk of diabetic retinopathy. These conditions are more common in people with DR than in the general population. Johns Hopkins 3/10/11
From Glaucoma- Optic Neuropathy Research List:
Eye Development Error Found To Be The Cause Of Cataracts, Glaucoma. Research teams, working with juvenile cataracts in humans & with mice show that RNA granules can affect eye development & find a connection with glaucoma, They identified a malfunctioning gene (Tdrd7) in a mouse strain that develops both cataracts & glaucoma. Tdrd7, fails to build an essential protein & disrupts the development of the mouse eye lens. Mice missing the protein developed high IOP & optic nerve damage--the hallmarks of glaucoma--as well as cataracts... The missing protein belongs to a type of structure known as RNA granules which regulate mRNAs in the cell. mRNA serves as a template to carry DNA- encoded information from the nucleus into the body of the cell, providing the blueprints for protein production. Furthermore, the human patients developed glaucoma following cataract extraction. ..Tdrd7 deficiency greatly reduces the number of stress granules that are produced in lens cells in response to oxidative stress. Stress granules are important to protect the cell in stressful conditions. Oxidative stress has been previously suggested to contribute to glaucoma by damaging the ocular drainage structures. The new findings imply that mice & patients with these mutations may not have adequate protection from oxidative stress in the drainage structures of the eye. With increasing age, their tissues may be more susceptible to oxidative damage resulting in high intraocular pressure and glaucoma. "There is a growing body of literature indicating that if you disturb oxygen levels in the eye– including after cataract surgery--the risk of developing glaucoma increases." One author says that mutations in the Tdrd7 gene could cause a double jeopardy for childhood glaucoma.."This is a good example of a 21st century collaboration, with major contributions by multiple groups, including basic and clinical researchers across multiple continents." Funding included NEI.. Medical News Today 3/25/11
thl 3/31/11
From AMD-Retina : ADA 2/11/11 Omega-3 fatty acids may help prevent retinopathy, which can lead to blindness. Previous research has indicated that eye diseases may be slower to develop in people who eat a lot of fish. Now new research [Harvard] suggests that an enzyme (5-LOX) may convert omega-3 into an acid called 4-HDHA, which slows abnormal blood vessel growth. The team is working with the NEI to conduct a trial of omega-3 supplements in pts with advanced macular degeneration.
From the Diabetic Research List: Diabetic Retinopathy [DR]- vasoregression [vessel deterioration] 3/2/11 Diabetes. 2011;60(1) DR is a sight-threatening, chronic microvascular [smallest blood vessels that bring oxygen & glucose to cells] a complication that eventually affects virtually all patients with diabetes.. The sight-threatening proliferative DR is not the primary response of the retina to chronic hyperglycemia [high blood sugar] Rather, it is an attempted compensation for retinal hypoxia [lack of oxygen] caused by loss of capillary pericytes [normal cells in capillaries] & by formation of [abnormal non functional] capillaries ] Further understanding these mechanisms will provide new targets for drug intervention before irreversible retinal ischemia & proliferative retinopathy require damaging treatments such as panretinal laser ..
From the Glaucoma list: M Long-term perimetric fluctuation in patients with different stages of glaucoma. Pub 2/2011 AIM: To evaluate the long-term perimetric fluctuation (LF) in pts with different stages of glaucoma according to the Glaucoma Staging System 2. [161 eyes of 161 stable glauc pts; 4 Humphrey visual field tests] Conclusions - the lower the visual- field defect, the lower was LF, except at stage 5 . As test- retest changes exceeding LF could represent a sign of progression, the authors suggest that clinicians using this classification system calculate LF, in order to better differentiate true progression from variability.
compiled 3/11/11 D.Wilcox RN BSN Coordinator Health Library