The Gist of Science Reporter: November 2016
- Study on Cartilage and Bone Formation shows Promising Results (Free Available)
- Seeing the World of Eye (Free Available)
- ISRO Conducts Successful In-flight Test of Scram Jet Engines
(Only For The Subscribed Members)
Study on Cartilage and Bone Formation shows Promising Results
For patients of bone-related ailments, good news might be in
the offing. Research undertaken by Professor Amitabha Bandyopadhyay at Indian
Institute ofTechnology, Kanpur studying the mechanisms of cartilage and bone
formation in fetuses and the maintenance of joint cartilage and bone in adults
could have ground-breaking applications in the treatment of osteoarthritis and
In early fetuses the elements of hand and leg skeleton are
made of pure unsegmented cartilage. As the fetus grows, this cartilage element
is branched and segmented, during which the majority of the. cartilage gets
converted to bone. Thus, only afflicted of cartilage remains, capping the Dones
at joint sites.
Bandyopadhyay and his team pose that osteoarthritis is
nothing but conversion of permanent cartilage to transient cartilage to bone in
adults. He is now trying to study whether the gene that promotes formation of
bones in fetuses can lead to development of osteoarthritis in adults. If true,
he hopes to find means to block this gene which will be a huge leap forward in
anti-osteoarthritis drug development research.
His research also shows a way forward in osteoporosis
treatments. Osteoporosis is a result of failure to maintain bone mass in adults
and post- menopausal women are particularly susceptible to this condition. Until
very recently, its treatment was exclusively focused on preventing deterioration
of bones post diagnosis but it is only in the last few years that drugs helping
in bone regeneration have been used as treatments, though there are adverse
effects related to them as well.
Seeing the World of Eye
October 13 is the World Sight Day and the theme this year is
‘Stronger Together’. The theme aptly signifies how different components -
researchers in optics, patients, opticians, optometrists, orthoptists,
ophthalmologists and allied workers - work together to appreciate, utilize, and
advance the world of eye and eye care.
The eye is an interesting organ - a marvel of biological
adaptation. Along with the brain it makes a complete processing system
consisting of a camera, a filter, an aperture controller and an image sensor.
The eye-brain system performs the acts of seeing by first forming the image of
the object being seen and then by interpreting this image.
An eye sees just as a camera does a highly sophisticated
video camera. The eyelids act as the camera shutter. The compound lens formed by
the cornea, a transparent structure in the front portion of the eye, and the
crystalline eye lens, form the focusing system of the camera. Iris, the coloured,
ring-shaped membrane behind the cornea, acts like a diaphragm. The choroid helps
in forming the darkened interior of the camera and the retina acts as a
A fluid called the aqueous humour, which fills the space
between cornea and iris, helps to maintain the cornea’s optical shape by gentle
internal pressure. A fluid called vitreous humour that fills the space between
the lens and the retina helps to keep the retina in place.
Limitations of eye also arise due to age or other factors
that inhibit its normal functioning. One of the most common limitations is the
inability to focus light properly on the retina, known as refractive error or
An autorefractometer is a computers machine that facilitates an objective
measurement of refractive error and prescription for glasses. The patient is
asked to look at the picture inside the machine with one eye and the picture is
moved in and out of focus and readings are taken by the machine to determine
when the image is on the retina. The machine takes several readings and averages
them to form a prescription. This method is particularly useful for examining
patients who cannot communicate like young children and those with disabilities.
A Retinoscope provides a more accurate estimation of
refractive error than autorefraction. It shines a beam of light into the
patient's eye and the reflection (reflex) off the patient's retina is observed.
Retinoscopy is particularly useful for . patients who are unable to undergo a
subjective refraction test.
Ophthalmoscopy and fundus photography are also used for
examination of the fundus - the interior surface of the eye opposite the lens.
In fundus photography a photograph of the fundus is captured using a fundus
camera that generally consists of a microscope attached to a flash enabled
Examinations through equipments are followed by subjective
examinations in which the examiner asks the patient about their vision by using
lenses of progressively higher or weaker powers from a trial set. Generally, the
term 'visual acuity' (VA), which means acuteness or clearness of vision, is used
in this type of examination.
Overcoming Eye Limitations
Eye limitations can be overcome either with the help of
glasses or contact lenses or surgical procedures. While myopia can be easily
corrected with the use of a concave lens, both hyperopia and presbyopia can be
corrected with the help of appropriate convex lenses. Astigmatism can be
corrected by refracting light more in one meridian than the other using a
A lensmeter is generally used to verify whether the lenses
are made as per the prescription of the specialist. It is also used to properly
orient and mark uncut lenses, and to confirm the correct mounting of lenses in
spectacle frames. Single vision lenses have a single power and can correct for
only one distance. A bifocal lens has two optical powers; the upper part of the
lens is generally used for distance vision, while the lower one for near vision.
Bifocals allow people with presbyopia to see clearly at distance and near
without the need to remove the glasses, which would be required with single
vision lenses. Progressive or varifocal lenses having variable optical powers
provide a smooth transition from distance correction to near correction allowing
clear vision at all distances.
Cataract can be corrected by a surgical procedure in which
the natural lens is removed and an artificial lens is implanted in its place. If
treated early it is possible to slow or stop the progression of glaucoma with
medication, laser treatment, or surgery. These treatments work towards
decreasing the eye pressure.?