News and Views
Avastin as effective as Lucentis
Visual acuity show similar improvements with two vascular endothelial growth factor inhibitors used to treat age?related macular degeneration (AMD). In a study published in February issue of Ophthalmology about a fourth of patients treated with bevacizumab (Avastin) or ranibizumab (Lucentis) had ≥20/40 vision at 12 months. The frequency of adverse events did not differ between treatment groups, but bevacizumab patients received fewer injections over the course of a year.
Sleep apneas treatment improves golf performance
Twelve golfers with moderate to severe obstructive sleep apnea who started nasal positive airway pressure treatment saw a drop in their mean handicap from 12.4 to 11.0 (P=0.01), according to Marc Benton, MD, Atlantic Sleep & Pulmonary Associates in Madison, NJ (American College of Chest Physicians meeting). A control group of golfers who did not have obstructive sleep apnea had no change in their handicaps over the same time period.
Clopidrogel can be tapered abruptly
There is no evidence of a platelet aggregation rebound with abrupt discontinuation of clopidogrel in patients undergoing percutaneous coronary intervention. Values for adenosine diphosphate induced platelet aggregation did not differ significantly between patients whose clopidogrel therapy was withdrawn abruptly and those in whom clopidogrel was tapered before discontinuation.(Feb. 9 issue of the Journal of the American College of Cardiology)
Avoid femoral artery cannulization during cardiac surgery Avoiding femoral artery cannulization during cardiac surgery might eliminate some of the rare but potentially catastrophic aortic dissections that occur during the procedure. Doctors identified the femoral location as an increased risk factor in an analysis of records from the Society of Thoracic Surgeons’ national database of more than 2.2 million cardiac surgeries. The search yielded 1,294 incidents of aortic dissection. (Dr Matthew Williams, University of Louisville)
SSRI may delay post partum breast milk
Women taking SSRI antidepressants may experience delays in postpartum breast milk production. Delayed secretory activation occurred in 87.5% of a small group of women taking SSRIs, compared with 43.5% of those not taking the drugs (P=0.02), according to Aaron M. Marshall, PhD, of the University of Cincinnati in the Journal of Clinical Endocrinology and Metabolism.
Ablation for AF
If initial drug therapy fails to control paroxysmal atrial fibrillation, one should opt for radiofrequency catheter ablation. In a prospective randomized trial, catheter ablation succeeded in preventing fibrillation in 66% of patients. (Dr David J. Wilber, Loyola University Medical Center, Maywood) By comparison, only 16% of patients who got renewed drug therapy were free from treatment failure by the end of nine months of follow-up. (Jan. 27 issue, JAMA)
FDA warning for bortezomib
The FDA has revised dosage and safety information for bortezomib, the myeloma and mantle cell lymphoma drug, to reflect an increased toxicity risk. The new labeling includes a warning for patients with moderate?to?severe hepatic impairment and now recommends at?risk patients start at a lower dosage of 0.7 mg for the first cycle of treatment and escalate to 1.0 mg, or reduces further to 0.5 mg, in subsequent cycles.
Eye care snippets (Dr. Narendra Kumar (OptometryToday@gmail.com)
Optical Instrument and Tools
The optical dispenser makes use of an optician ruler for measuring the pupillary distance (PD), the nose bridge size, the size of the lens, palpebral aperture width, diameter of the cornea and the pupil, and the vertex distance of a lens from the wearer?s eye; a lens measure for surface curvature of the lens; a thickness gauge or caliper for measuring the centre or edge thickness of the lens; and a lensometer for ascertaining the power of the lens.
Optician ruler: It is one of the most commonly used tools. It is made of plastic. The scale is divided into 1mm increments and divisions are noted every 10mm or 1cm.
Thickness gauge: In our quest for ‘thinner’ lenses, we sometimes cross the limit. But from safety point of view, lenses must be of a certain minimum thickness. The thickness gauge or caliper is usually made of metal, has pointed jaws that open around a lens, and has a scale in mm and tenths of millimeters. It is used to measure the centre or edge thickness of lenses.
Lens measure: This is a device used to measure the front and back surface curvatures of lenses of 1.523 refractive index in dioptres of curvature. On placement against the surface of a lens, the central of the three pins of the lens measure is depressed and the needle on the dial turns to the appropriate dioptric value. The lens measure has a scale each for convex and concave measurements. Surface powers are recorded first at one position and then at 900 from it. If the surface is spherical, then the two readings will be the same. If these are different, the flattest and steepest curves are determined to find out the lowest and highest values. Nowadays, cylinders are usually made on the front surface of single vision lenses (and on the back surface of bifocal lenses). The lens measure for plastic lenses has rounded metal or nylon tip on the pin ends. The lens measure can also be used to verify the base curve of a lens. Even though wearing an identical prescription, the change from a front surface toric to a back surface toric lens can irritate some patients. The lens measure can be used in such cases to determine whether the front or the back surface of the lens has the cylinder. From time to time, it must be ascertained that there is no error present in the instrument. To check for an error, make sure that the surface registers plano as the lens measure legs are placed on the counter or a flat surface.
Lensmeter: Lensmeter, lensometer or focimeter, is an instrument to verify or determine the power of a lens, and to mark the axis of a cylinder. It will reveal the spherical power, cylindrical power, its axis, presence of prism, and the direction of its base. It incorporates a device to mark the optical centre of the lens. The lensmeter, with the use of an additional holder, can also be used to measure the power of a contact lens. Its major parts include the eyepiece (which is a part of the telescopic focusing system), power drum (a rotating wheel calibrated in 0.25D units), axis drum (a rotating wheel calibrated in 10 increments), lens/frame table (a horizontal reference for lenses/frames parallel to the 0–1800 line), and marking device (to place three ink dots on the lens for subsequent processing). The lensmeter does neutralization, which is the process of defining the prescription of lenses, i.e. the sphere, cylinder and axis of a lens. And, Rxs may be written either in minus or plus cylinder forms by way of transposition.
Prior to use, the eye–piece of the instrument needs to be adjusted. The lens, to be checked, should be placed in the holder with the front surface facing yourself. The adjustment should be such that the position of cross–lines observed in the instrument are centrally located. In case of a spherical lens, the small lines become as sharp as the large lines at the same time. In case of a cylindrical lens, the small lines do not become sharp at the same time with the large lines. To find the power of a cylindrical lens, first find the more plus power (e.g. –2.50 D is more plus than –3.50 D). Then sharpen the small lines. Record this as the sphere power and axis. Next find out the more minus power. The difference between the spherical power and the cylinder power is called the minus cylinder power at the axis determined by the more plus power.
The lensmeter can be placed in the following basic categories:
Manual: A design in which the operator adjusts measuring scales with control knobs, and views the results on an internal/external screen and graticule.
Semi–automatic: A design in which some operations are automated, e.g., centering the lens in the beam path of the instrument.
Automatic: In this design, the majority of the operations, e.g., lens centering and add determination are automatically carried out. Some sophisticated instruments even determine the refractive index of the lens material or the UV and visual transmission.
Hand tools: The optical dispenser also needs a variety of hand tools to fit and adjust frames. The optical screwdriver has a handle and a rotating head, and comes in several blade sizes. Pliers come in variety of jaws for varied jobs of adjusting frames. Lathes and polishing buff are used to restore the finish on metal or shell frames. And, files are used to remove irregularities from the surface of frames.
International Conference on Reproductive Health and the 20th Annual Meetings of the Indian Society for the Study of Reproduction and Fertility
Time: February 8–10, 2010
Venue: Bhagwat Singh Mehta Auditorium, Nehru Bhawan, Jaipur, Rajasthan
Be on the Alert for Symptom of Heart Attack
If you aren’t sure whether you are having heartburn or something more serious––like a heart attack––you should get yourself checked out, said Dr K K Aggarwal President, Heart Care Foundation of India and Editor eMedinewS.
The most common symptom of coronary heart disease is chest pain (angina) or discomfort, which can also occur in the shoulders, arms, neck, jaw or back. People may mistake this pain for indigestion, which can be dangerous.
Sometimes, it’s impossible to tell the difference between the symptoms of heartburn, angina and heart attack, said Dr. Aggarwal. A heart attack occurs when the blood supply to part of the heart muscle is severely reduced or stopped. This can result in death or disability, depending on how much of the heart muscle is damaged. Unfortunately, many people may not be aware they are having a heart attack.
There are some useful pointers that might help a person know whether they're having a heart attack or not, but when in doubt, check it out, said Dr Aggarwal. Symptoms of a heart attack include the sudden onset of tightness, pressure, squeezing, burning or discomfort in the chest, throat, neck or either arm. When these symptoms are accompanied by nausea, vomiting, sweating, shortness of breath or a fainting sensation, Dr. Aggarwal says one should be especially suspicious that you might be having a heart attack. People who have any risk factors that may predispose them to a heart attack should be particularly cautious.
1. Heart attack pain is never pinpointed
2. Heart attack pain never lasts less than 30 seconds.
3. If you smoke, have diabetes, high cholesterol, high blood pressure, are overweight or have a strong family history of heart disease and have any symptom related to the chest or heart, you should be alert.
Question of the Day
What is the management of coma in malaria?
ABC of coma management
1. Maintain the airway by keeping airway clean, i.e., free from saliva, vomitus, etc.
2. Unconscious patients should be nursed on side, preferably left lateral position, on a flat surface without a pillow. This reduces incidence of aspiration of gastric contents.
3. Keep changing the side every 2 hours.
4. Insert a nasogastric tube to prevent aspiration pneumonia and aspirate stomach contents.
5. Oral or oropharyngeal airway should be used to prevent the tongue from falling back and to keep the airway clean.
6. If facilities exist, endotracheal intubation should be done in a coma patient if needed.
Breathing: If tachypnea, labored respiration, acidotic breathing is present or develops in the course of the management, patient may need oxygen inhalation and ventilatory support. Hence, it should be referred to centers with facilities for intensive care.
1. Check for dehydration by examining the pulse rate, blood pressure, skin elasticity, jugular venous pressure, moisture of the tongue, urinary volume and color.
2. If dehydration is present, infuse IV fluids.
3. Frequently check the rate of infusion to prevent overhydration.
4. If patient has overhydration, stop or restrict IV fluids and give IV diuretics (furosemide).
5. Suspected infection must be treated with antibiotics. Keep an accurate record of fluid intake and output. Strict intake and output chart should be maintained. Normal urine output is approximately 1 ml/min.
(Suggested reading: World Health Organization. Guidelines for the treatment of malaria. Geneva, 2006)
Quote: You are what your deep rooted desires are.