Hello again, dear readers, and welcome to the late-summer edition of the letters column. Along with so many of you, we’re facing record-breaking heat, high humidity and a few natural disasters. All the more reason to seek refuge in our ongoing chat about health and medicine.

-- Many of you continue to have questions about the novel coronavirus.

“If a sneeze can spread the virus, can exhaling also spread the virus?” a reader asked. “So many times I see people with their mask under their nose and want to say something, but do not because I do not want to get into a fight.”

It’s important to remember that we’re still in the earliest stages of learning about the novel coronavirus. Emerging research suggests that, in addition to respiratory droplets from a cough or a sneeze, the virus may also be present in the microdroplets expelled during breathing and speech. What isn’t yet clear is whether or not these are a major source of infection. We will keep an eye on that research and update any new findings.

When it comes to wearing a mask, you’re correct on two points. First, the mask should indeed cover both the nose and the mouth. It should also have a snug fit around the perimeter. And we think you’re wise not to comment on how someone else wears his or her mask. Unfortunately, this practice, which we engage in to protect each other, has become a hot-button issue. Better to move at least 6 feet away from that individual and go about your day.

-- And speaking of transmission: “Why aren’t belching and expectorating mentioned as vehicles for spreading the coronavirus?” a reader asked. “If I can smell the belched air, surely it’s possible for the virus to be suspended in it.” The act of spitting or emitting a large and sustained belch can send respiratory droplets into the air. Although it’s possible that these can spread the virus, they are not known to be a major means of transmission.

-- A reader who recently survived COVID-19 wrote to ask about the likelihood of becoming infected again. “I contracted COVID-19 on July 1, became ill and tested negative on July 21,” he wrote. “My symptoms were coughing, muscle aches and fatigue. Pneumonia ensued for two weeks. I then tested positive for antibodies on July 23. How concerned should I be about contracting it again?”

Unfortunately, the answer isn’t clear yet. Researchers in Hong Kong recently identified what appears to be the first known case of reinfection 4 1/2 months after a patient’s initial illness. This reinfection, with a slightly different strain of the virus, occurred when the young man traveled to Spain. Genomic testing revealed differences in the two variants of the virus, which researchers say proves this is indeed a reinfection rather than prolonged viral shedding. The young man had no symptoms, and researchers believe existing antibodies helped his immune system fight off the second infection. Still, the wisest course is to continue practicing all precautions to protect yourself and those around you.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My eye doctor says I have something called “drusen” on top of my retina. I’ve read that this is connected to macular degeneration, and I’m worried. Can you please explain more about it?

Dear Reader: The term “drusen” is the plural of the German word “druse,” which means node. In a medical context, drusen refers to small deposits of debris within the retina. That’s the layer of tissue that lines the back of the eye and contains light-sensing cells known as photoreceptors. Drusen are found not on top of the retina, as you mention in your question, but in an area known as Bruch’s membrane. It’s a very thin layer of cells that separates the upper layers of the retina, including the photoreceptors, from an area known as the choroid. This is a network of blood vessels that deliver oxygen and nutrients to the macula, the functional center of the retina.

In order to diagnose the presence of drusen, your eye doctor performs a dilated eye exam. It involves the use of special eye drops that prevent the iris, which is the part of the eye that controls the size of the pupil, from contracting. With the iris wide open, the doctor can then use either a special instrument to see into the back of the eye or a special camera to photograph the interior structures. Drusen will appear as yellowish-white spots within the retina.

Drusen are described as either hard or soft. Hard drusen are small and round, have well-defined borders and are often spread out. They are common as people age. Soft drusen are larger, have indistinct borders and tend to cluster together. Although both types of drusen should be monitored, hard drusen don’t usually cause vision problems. Soft drusen, which can cause damage to the macula, are associated with dry age-related macular degeneration. That’s a condition in which the macula deteriorates and the center of the field of vision is compromised or even lost. Drusen can also be present on the optic nerve, which can result in a slight loss of peripheral vision. This is more common in children than adults.

There is no treatment available for drusen at this time. However, someone diagnosed with soft drusen may be asked to take a specialized combination of vitamins and minerals that have shown promise in slowing a certain type of age-related macular degeneration. Using data drawn from a large study known as AREDS 2 (Age-Related Eye Disease Study 2), researchers developed a nutritional supplement that has been shown to reduce one’s risk of developing advanced age-related macular degeneration by about 25%. The formulation includes vitamins C and E, copper, zinc and a pair of plant pigments called lutein and zeaxanthin, all in specific proportions.

Since you’re worried, it’s important to speak with your doctor and have all of your questions and concerns addressed. Be sure to ask if the drusen found in your eyes are hard or soft, as each type signals a different level of risk. And be vigilant about all follow-up visits to monitor your progress.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Would you please write about the risks of falls for the elderly, which can be fatal? The colonial houses in my area are dangerous and lead to many serious injuries and deaths. Now that so many of us are home alone more than ever, calling attention to this would be helpful.

Dear Reader: Thank you for bringing up a very important topic. Even before the coronavirus pandemic caused enforced isolation, falling had become the leading cause of injury-related death in people age 65 years and older. About 3 million older adults wind up in an emergency room each year due to a fall. More than 800,000 older adults are hospitalized each year due to serious injury. Even people who are lucky enough to get just a sprain or a bruise after falling can experience a marked decrease in their quality of life.

A common risk factor for falling is poor balance. This can be due to difficulty in walking, weakness in the lower body, foot pain, ill-fitting shoes, problems with vision and dizziness brought on by medications. Common hazards found inside the home include clutter, loose floor coverings, wobbly chairs or tables, extension cords, stairs, dim lighting, toilet seats that are too low, and slippery tubs or showers. Outside the house, sidewalk cracks, steep driveways and wet or icy pathways are all common trip hazards. Pets can also contribute to falling, both indoors and out.

To minimize risk, start with an inventory of potential hazards. Be honest about whether or not your balance is at all compromised. Signs of this include difficulty in rising from a chair or the need to steady yourself against a piece of furniture or a wall when walking from one place to another. If balance is an issue, it’s important to ask your health care provider about using a cane or a walker for added stability. If it’s determined this will be helpful, then be sure to use these aids consistently. When physical weakness is part of the problem, your health care provider can suggest strengthening exercises that are tailored to your specific needs and abilities. Keep up with vision appointments, and always wear your glasses. And be aware of the potential side effects of any medications. Sleep aids, pain meds with “P.M.” in the name and some prescription medications can cause dizziness.

Analyze each room in the house, and identify potential dangers. As we mentioned before, area rugs and throw rugs are a common trip hazard. Stairs should have secure handrails on both sides. The stairs themselves should be free of clutter and have slip-proof surfaces. Make sure all parts of your home, inside and out, have adequate lighting. Install grab bars in tubs and showers and near the toilet if needed. A shower chair, along with a hand-held shower head, are also helpful. People who live alone may consider medical alert buttons or a fall-detection device.

Excellent information is available from the National Institutes of Health, at nih.gov. Just enter the words “prevent falls” into the search box at the top right of the page.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)