AMD Update 15 Visualization of Living Rods and Cones

Back in February 2009, I first wrote about David Williams and his research group at the Institute of Optics at the University of Rochester, and their announcement that they had used adaptive optics to image RPE cells in vivo. That report, AMD Update 4: Does Visualizing RPE Cells Hold the Key to Understanding AMD? gave us a first look at how adaptive optics could image some of the retinal cells in the back of the eye in helping to understand how the effect of new drugs and treatments could be visualized in the living eye, providing a diagnostic mechanism to see changes in RPE cells, possibly when applying some of the new retinal treatment techniques.

Well, another group of researchers at  the same Institute of Optics at the University of Rochester, along with colleagues from several other research institutions have done it again. This time using their knowledge of applying adaptive optics to visualizing the much smaller photoreceptor rod cells present in the living eye.

This innovation, described in two papers in the Optical Society's (OSA) open access journal Biomedical Optics Express, will help doctors diagnose degenerative retinal eye disorders sooner, leading to quicker intervention and more effective treatments.

Here is the complete press release from the OSA, describing the two papers recently published:

Historic First Images Of Rod Photoreceptors In The Living Human Eye

Adaptive optics technology likely to spur sight-saving interventions, usher in new era of eye disease research, diagnosis and treatment

08 Jun 2011 

Scientists today reported that the tiny light-sensing cells known as rods have been clearly and directly imaged in the living eye for the first time. Using adaptive optics (AO), the same technology astronomers use to study distant stars and galaxies, scientists can see through the murky distortion of the outer eye, revealing the eye's cellular structure with unprecedented detail. This innovation, described in two papers in the Optical Society's (OSA) open access journal Biomedical Optics Express, will help doctors diagnose degenerative eye disorders sooner, leading to quicker intervention and more effective treatments.

"While therapies are only emerging, the ability to see the cells you are trying to rescue represents a critical first step in the process of restoring sight," says researcher Alfredo Dubra of the University of Rochester in New York, who led the team of researchers from Rochester, Marquette University, and the Medical College of Wisconsin (MCW), Milwaukee. "It's impossible to overemphasize how important early detection is to eye disease."

"One of the major hurdles in detecting retinal disease is that by the time it can be perceived by the patient or detected with clinical tools, significant cellular damage has often already occurred," adds team member Joseph Carroll of MCW.

The breakthrough that is ushering in a new era of eye disease research, diagnosis, and treatment is an improved design of a non-invasive adaptive optics imaging system. Dubra and his colleagues were able to push the device's resolution to its optical limits of nearly 2 microns (a micron is 1/1,000 of a millimeter), or the approximate diameter of a single rod in the human eye.

Rods are much more numerous than cones and are vastly more sensitive to light. With the optical design method successfully demonstrated by Dubra's team, even the smallest cone cells at the center of the retina, known as the foveal center, can be seen very clearly. Rods can be seen clearly in a less central retinal location.

"This is a really exciting breakthrough," says Steve Burns, a professor in the School of Optometry at Indiana University, who is not involved in the Biomedical Optics Express research. "Imaging contiguous rod mosaics will allow us to study the impact of a whole new class of blinding disorders on the retina. Since many of the eye diseases most amenable to intervention affect the rods, this should become a major tool for determining what treatments work best for those disorders."

De-twinkling Stars, Visualizing Rods

In astronomy, adaptive optics is able to correct for the blurring effect of Earth's atmosphere, effectively removing the "twinkling" from starlight and rendering cosmic objects as very sharp points of light. To achieve this correction, the AO system requires a reference point-either a bright, nearby star or an artificial "guide star" produced in the upper atmosphere by lasers mounted on a telescope. By monitoring that reference point, AO systems use a deformable mirror to create the exact but opposite distortion that is happening in the atmosphere. The result is a clearer image with much greater resolution.

Just as light passing through the atmosphere becomes bent and distorted, so too does light passing through the front part of the eye. This distortion is inconsequential on the scale of human vision, but poses a significant barrier in the microscopic realm of medical imaging.

In 1997, David Williams of the University of Rochester led the group that first demonstrated using AO technology to study the interior of the human eye. In this system, called an adaptive optics ophthalmoscope, a laser creates a reference point that is used to correct the blurring of the image obtained with a fundus camera. Today the fundus camera is commonly replaced by a second laser for imaging, which is known as an adaptive optics scanning laser ophthalmoscope. By moving the laser point across the retina and correcting the distortion along the way, line-by-line an accurate image emerges, in much the same way that a CRT monitor renders an image.

Though earlier AO systems could effectively image cones and have become a mainstay of high-resolution retinal imaging research, the smaller rods, which outnumber cones 20 to 1 in the retina, have eluded clear and contiguous observation in the living eye.

Breakthrough Design

The breakthrough in the design of the AO instrument that led to clearly visualizing rods was, according to Dubra, "embarrassingly simple, and relied on well-known equations and concepts." By simply folding the spherical mirrors that act as lenses in the instrument into a three-dimensional structure, the image quality of the retina was improved sufficiently to clearly resolve the contiguous rod mosaic, as well as the entire cone mosaic at the foveal center.

"By combining careful optical engineering, excellent adaptive optics control, and knowledge of the visual system the authors have made a major advancement in both biomedical imaging and vision science," says Burns.

Improving Patient Care

According to the researchers, their next step is to develop a clinical model that could be widely available. A related task is simplifying and teaching the art of interpreting AO images to guide clinical decisions about diagnosis and treatment.

When that occurs, hopefully in the next 5 to 10 years, doctors will likely be able to routinely peer into a living human eye with such precision and clarity that they will be able to see and evaluate individual rods-and do three things never before possible: accurately describe the physical presentation of specific rod disorders-the "phenotype" of a disease, intervene with early treatment at the first sign of disease, and even determine how individual cells are responding to a specific treatment.

"That's what's really exciting about this imaging device: it can really make a difference in a patient's life," says Carroll. "The ability to now resolve these cells opens up new possibilities for improving care that researchers have been anticipating for a long time-such as using the information in these retinal images to aid in targeting, delivering, and evaluating therapies."


Paper: "Non-invasive imaging of the human rod photoreceptor mosaic using a confocal adaptive optics scanning ophthalmoscope" Biomedical Optics Express, Volume 2, Issue 7, pp. 1864-1876.

Abstract:

The rod photoreceptors are implicated in a number of devastating retinal diseases. However, routine imaging of these cells has remained elusive, even with the advent of adaptive optics imaging. Here, we present the first in vivo images of the contiguous rod photoreceptor mosaic in nine healthy human subjects. The images were collected with three different confocal adaptive optics scanning ophthalmoscopes at two different institutions, using 680 and 775 nm superluminescent diodes for illumination. Estimates of photoreceptor density and rod:cone ratios in the 5°-15° retinal eccentricity range are consistent with histological findings, confirming our ability to resolve the rod mosaic by averaging multiple registered images, without the need for additional image processing. In one subject, we were able to identify the emergence of the first rods at approximately 190 μm from the foveal center, in agreement with previous histological studies. The rod and cone photoreceptor mosaics appear in focus at different retinal depths, with the rod mosaic best focus (i.e., brightest and sharpest) being at least 10 μm shallower than the cones at retinal eccentricities larger than 8°. This study represents an important step in bringing high-resolution imaging to bear on the study of rod disorders.


Paper: "Reflective afocal broadband adaptive optics scanning ophthalmoscope" Biomedical Optics Express, Volume 2, Issue 6, pp. 1757-1768.

Abstract:

A broadband adaptive optics scanning ophthalmoscope (BAOSO) consisting of four afocal telescopes, formed by pairs of off-axis spherical mirrors in a non-planar arrangement, is presented. The non-planar folding of the telescopes is used to simultaneously reduce pupil and image plane astigmatism. The former improves the adaptive optics performance by reducing the root-mean-square (RMS) of the wavefront and the beam wandering due to optical scanning. The latter provides diffraction limited performance over a 3 diopter (D) vergence range. This vergence range allows for the use of any broadband light source(s) in the 450-850 nm wavelength range to simultaneously image any combination of retinal layers. Imaging modalities that could benefit from such a large vergence range are optical coherence tomography (OCT), multi- and hyper-spectral imaging, single- and multi-photon fluorescence. The benefits of the non-planar telescopes in the BAOSO are illustrated by resolving the human foveal photoreceptor mosaic in reflectance using two different superluminescent diodes with 680 and 796 nm peak wavelengths, reaching the eye with a vergence of 0.76 D relative to each other.

The papers appear as part of a special feature issue of Biomedical Optics Express on "Cellular Imaging of the Retina."

Food Nutrition A Look Assisted Living In San Diego County

By Rue Nichols

As we get older, they say that appetite and taste lessens, but "they" couldn't be more wrong. For the vast majority of older adults, the enjoyment of great food is something that never goes away. At assisted living communities, the food services generally offer great variety, and the residents also enjoy the social aspect of mealtimes.

At facilities for assisted living in San Diego County, most offer three meals each day as well as snacks. For a senior adult living at home alone, mealtimes can be lonely, not to mention that you have to prep, cook and clean yourself. In an assisted living community, all of this responsibility is gone and you don't have to eat alone.

This doesn't mean that you can't eat alone now and then, of course, and most communities for assisted living in Escondido or San Diego include a kitchenette space. This probably will include a small refrigerator and perhaps a coffee pot, a toaster or a microwave as well as some cupboards for storing snacks.

Because food is so important to one's happiness, don't forget to take a good look at the food offerings at every facility you visit. Obviously, you need to be concerned with other services and amenities, but it's smart to eat a meal at the facility and also take a look at some sample menus. These days, some facilities for assisted living in San Diego County offer some amazing selections and even some special themed dinners and events.

When you visit various facilities, you probably will note that larger communities tend to have more diverse menu selections. With so many residents to please, they will offer multiple entrees, several salads and a soup or two with each meal as well as a selection of side dishes and desserts. At a smaller board and care home, the menu might not be nearly as diverse, but it is important to know that with just five or six residents, it's easier to find options that suit the tastes of this smaller group.

For those of you with a loved one who is currently living in assisted living in San Diego or about to move into a facility, it's important that you come to dinner or lunch at the facility from time to time. Bring the grandkids and enjoy a weekend lunch or come for dinner once or twice each month. Not only will your loved one enjoy the company, you will get to know the new friends he or she has made. Plus you will truly get a better picture of how well your loved one is doing. Be sure to also plan some dining excursions off site, maybe a family party or a meal at their favorite steakhouse or whatever they enjoy.

About the Author:

Rue Nichols enjoys reading home health care blogs. To get more details about assisted living facilities in Escondido or for expert help searching board and care Dana Point homes for your loved ones, please check out the Care Placement site now.

Information Regarding Assisted Living Facilities Enumclaw

By Ruthie Livingston

As people get older or struggle with disabilities, they may lose their independence. The elderly may be sick or require help from people to carry out basic daily tasks. This may also be the case for people who are disabled. Close friends and family members may be tasked with finding an assisted living facility that fits the needs and desires of their loved ones. These places are available in many areas the world. Assisted living facilities Enumclaw may be of interest to people living in or nearby the Enumclaw, Washington area.

An ALF business is meant to provide for elderly and disabled individuals. The companies offer some supervision and assistance services to clients. They might provide assistance for activities of daily living, ADLs, coordinate services from health care providers, monitor the activities of residents, and strive to keep clients safe, happy and healthy.

It is important to understand that services will differ from place to place. This is why it is essential that people do their research to compare available services, fees, reviews and ratings, costs and similar details. It is important that people find a comfortable, affordable and efficient facility for their loved ones. The right place can make sure that all the needs of residents are met and their quality of life does not waiver because of their age, illnesses or disabilities.

Assistance at these places will range based on many factors. It is important that the staff are trained and prepared to give residents the care they need. There are usually additional services available that might involve fees being added to the total cost of staying at these facilities.

This kind of set up for living came about in the 1990s and was mostly an alternative for eldercare. It was meant to target people who were too young to live in retirement homes. These same people may have been incapable of living independently, but did not need the 24-hour attention seen in many nursing homes.

Many facilities that exist today are focused on promoting the independence among residents and maintaining their dignity. Still, services are available to clients as they need them. The objective is still to guarantee that they are well cared for. These places exist in many parts of the world and come in many varieties.

The buildings may range in size, from small houses available for one person to large facilities that offer services to hundreds of residents. These places fall between independent living communities and nursing homes in terms of care and services. Modern facilities even allow for residents to have their own private apartment.

Typically there is no intense monitoring equipment used to keep track of residents. However, the nursing staff and other professionals are easily available to offer support when needed. They are on-site at all times and can provide aid to those in need. There are also household chores that the staff will complete for patients, these include: laundry, changing sheets and cooking food. Depending on the needs of the resident, additional services may be available for added fees: dressing, escorts to activities and meals, insulin injections, medication management, assistance with bathing, transferring, toiling and more.

About the Author:

Read more about Information Regarding Assisted Living Facilities Enumclaw.

Healthy Living for Fall with Ayurveda and Yoga

by Ram

Fern Leaves by Melina Meza

As you may have noticed, summer is gradually winding down and making way for autumn to take over. The days become shorter, the rhythm shifts, and the light and heat of summer subside. Both yoga and ayurveda stress the fact that we are in sync with our environment so we need to be mindful of the change in seasons. Thus, as seasons change, our body and mind adapt to these changes. This requires us to be aware of the qualities associated with the seasonal changes.

Fall is marked by the domination of vata dosha (constitution). Vata is made of the ether and air elements. It represents the mobile force of the universe, and in our bodies is responsible for all activities that involve movement. Thus, locomotion, digestion, circulation, respiration, elimination, communication, sensory and motor function, cardiac function and nervous system impulses (among others) are all governed by vata. Vata in the mind is responsible for emotions that include enthusiasm, joy, clarity, creativity, fear, worry and anxiety.

The qualities (gunas in Sanskrit) of ether and air elements in turn constitute the vata qualities, and these include cold, dry, light, rough, subtle, mobile and clear. To understand the vata dosha, it is important to understand whether the above-mentioned qualities are dominating the body and mind at any given moment. When vata dosha is healthy, these qualities are in a balanced state and the individual experiences optimal health, stability, creativity enthusiasm and excitement for life. The movements of the body are graceful, unimpeded, and yet controlled. Individuals who possess a balanced state of vata tend to be imaginative, energetic, fun, light hearted and full of excitement. 

The fall season is characterized by a cold, windy and dry weather. Leaves change color and fall off the trees. During peak autumn, trees are devoid of leaves or flowers and look dry and barren. As our external environment changes, it increases vata in our own internal environment. If we are not aware of these changes, vata goes out of balance and so do the vata qualities and a totally different personality emerges.

In general, to balance vata, we learn to apply its opposite qualities to any given imbalance. Whether the tools used are lifestyle changes, dietary, herbal, colors, aromas, mantras or massage oils, the underlying principles used to return to balance are the same. It is necessary to increase the qualities opposed to the imbalance. Thus, we combat dryness by bringing in moisture. To counter an excess of lightness, we bring in heaviness, and if there is an excess of coldness, we increase heat. When vata dosha goes out of balance, the individual’s movements become erratic, the body becomes lighter and dryer and weight drops. The person may experience feeling of chillness/coldness throughout the day, the voice becomes too quick and out of context, there is an inability of the mind to focus, the eyes and mind may appear vacant and empty and there may be unexplained pain in the body. Irrespective of our doshic constitution, all individuals will experience these fall changes and need to pay attention to them. People of vata constitution, being more susceptible to the fall changes, should take every precaution to prevent vata from going out of balance. Some of the healthy living practices during the fall season include:

1. Stable Routines: One of the most important lifestyle tools for maintaining health and for supporting healing during the fall season is adopting stable routines. Stability is greatly improved through all activities performed at the same time every day. The routine should include time for self hygiene, massage, meditation, physical exercise and/or yoga asana practice in addition to other daily activities, including but not limited to eating, sleeping and waking up. Meals should be taken regularly throughout the day and at the same time each day. All activities done at the same time each day helps to counteract the vata qualities. For example, if a vata person is experiencing increased dry quality in their body, we will encourage them to utilize moistening, warming and nourishing foods, remedies and practices.

2. Diet to Counteract the Fall/Vata Season: Cold sandwiches, cold salads, and dry cereals with cold milk should preferably be avoided during this season. Such foods can aggravate vata qualities during fall and create a vata imbalance. The food should be preferably cooked (warm), oily (moist) and moderately spiced (warm). Since vata is cold, dry and rough, warm cooked foods made with a little olive oil or ghee have a wonderful soothing effect that immediately calms down the restless vata. Warm drinks such as hot milk or ginger/cinnamon/basil tea also have an immediate balancing effect. Suggested snacks include vata tea with a wheat bread, dates, fresh fruit, or warm milk. Coffee and other caffeinated drinks can be vata aggravating and should be avoided. Sipping warm water and herbal teas throughout the day enhances warmth and hydration. Dinner could be a warm hearty soup and bread. Before bed a cup of warm milk with a pinch of ginger/cardamom and some sugar or honey is recommended for sound sleep.

3. Massage (Abhyanaga): Fall brings dryness and lightness not only to plants but also to the body. To prevent excessive dryness it is a good idea to use oil both in food and on the body. Daily oil massage will not only treat dry skin but it will moisten the joints and tissues of the body as well keeping the body lubricated and healthy throughout the fall season. Warm sesame or almond oil with 1-2 drops of rosemary, lavender or jasmine essential oil is used for the body massage. Apply the oil all over and gently massage the body. If possible, keep the oil on the body as long as possible and do not wash it off. If you take a shower afterwards, do not use soap and pat yourself dry. 

4. Yoga Asanas: The emphasis throughout the fall season is to incorporate an asana practice that softens your lower abdominal cavity, and builds strength and stability in the body and mind. Practice at a slow, smooth and steady pace. Pay attention to detail and use gentle movements. Asanas that aid in pelvic compression and flexion of the hips (iliopsoas, rectus femoris, and adductors) are recommended. Hold each posture for a short amount of time, but do multiple repetitions. Draw into and move from your power center (core). This is the area below the navel and above the pubic bone. Focus on the foundation of the pose to create stability and focus on lengthening your inhalation. Stay connected to the earth. Ground down through your big toes. Engage your entire body by hugging your muscles to the bones. Do not overextend or deplete yourself. Your practice should be strengthening, not draining. If the vata imbalance is severe, a restorative practice is best. Stay warm and conclude your practice with a long relaxation.

5. Pranayama: In India, pranayama is generally taught in the two seasons of transition, fall and spring. During the fall season, start the day with Nadi Shodana (alternate nostril breathing) to help to purify the bodily channels. A regular practice of pranayama during the fall season helps to tune our breath, body and mind (see Yoga and the Mind-Body Connection). Pranayma practices could include Alternate Nostril breathing, Ujjayi pranayama and Surya Bhedana (Sun-Piercing), which create balance by providing warmth and stability to the body and mind. (Timothy has already introduced us to the concept of Pranayama with his article on Bhramari Pranayama and he will be addressing other Pranayama practices as well.)

6. Meditation: Follow your pranayama practice with several minutes of mindfulness meditation. During the fall season and for the overactive vata mind, meditation is one of the best ways to be grounded and to find calm and stillness.

7. Other Activities: Always stay warm. Wear clothing made with soft fabrics and earth colors (grounding energy). Get enough sleep. Enjoy regular, relaxing and peaceful walks in nature to calm the mobile body. Other great activities during this season include gardening, culinary activities, and creating art and music. Make sure all activities are followed with a sufficient rest period. Pay attention to the influences that you allow into your life—from the foods you eat to the amount of time you spend in front of a computer, cell phone or TV. As we get ready to welcome fall, let us experience perfect health, bliss and freedom every moment and throughout the season.

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