Certified Ophthalmic Medical Technologist (COMT) Practice Exam

What type of white blood cells are typically present in a conjunctival smear of a patient with bacterial conjunctivitis?

1. Neutrophils and monocytes

2. Neutrophils and eosinophils

3. Lymphocytes and basophils

4. Macrophages and plasma cells

The correct answer is: Neutrophils and eosinophils

In a conjunctival smear of a patient with bacterial conjunctivitis, the white blood cells that are typically prominent are neutrophils. Bacterial infections elicit an acute inflammatory response, characterized by the rapid influx of neutrophils to the site of infection. These cells are part of the body's first line of defense against bacterial pathogens, as they are adept at phagocytosing bacteria and releasing enzymes that can destroy them. While eosinophils are also white blood cells, they are more commonly associated with allergic reactions and parasitic infections rather than bacterial infections. Therefore, in the context of bacterial conjunctivitis, the presence of neutrophils greatly outnumbers that of eosinophils. The increase in neutrophils in the conjunctival smear indicates the body's immune response to the bacterial invaders, which is helpful for diagnosis. Other types of white blood cells mentioned in the other options, such as lymphocytes, basophils, macrophages, and plasma cells, are associated with different immune responses. For instance, lymphocytes are more prevalent in viral infections or chronic inflammatory conditions. Thus, neutrophils' role in acute bacterial infections makes this the correct choice for the described condition.