The corner of my eye is itchy, red and swollen with a small pimple

People nowadays live at a fast pace and overuse their eyes, which makes their eyes more susceptible to diseases. After working overtime and staying up late, the corners of my eyes will itch and have small bumps. At this time, many people think that they are getting angry, so they simply take some medicine to clear the heat. Sometimes it works and sometimes it doesn't. In fact, this situation may also be keratitis. Let's take a look at the causes and clinical manifestations of keratitis.

Causes

1. Infection

It is the most common cause of keratitis. Pathogenic microorganisms include bacteria (such as Pneumococcus, Staphylococcus aureus, hemolytic Streptococcus, Pseudomonas aeruginosa, gonococci, etc.), viruses (herpes simplex virus, adenovirus, etc.), fungi, Acanthamoeba, Mycoplasma, Chlamydia, Treponema pallidum, etc. It usually causes disease when combined with damage or shedding of corneal epithelial cells or decreased body resistance. Once the corneal epithelium is damaged, infectious inflammation is very likely to occur. Therefore, corneal foreign bodies, corneal abrasions, improper use of contact lenses, eye contact with contaminated medicines or water sources, etc. are common susceptibility factors for infectious keratitis. Patients with diabetes, malnutrition, and chronic wasting diseases are also susceptible to keratitis due to decreased resistance.

2. Internal factors

Refers to endogenous diseases that come from the whole body. For example, some autoimmune diseases or other systemic diseases (such as vitamin A deficiency, trigeminal nerve damage) affect the cornea.

The cornea has no blood vessels, so acute infectious diseases are less likely to invade the cornea. However, corneal tissue is involved in the systemic immune response. Although the degree of its immune response is lower than that of other tissues, it is precisely because it has no blood vessels and its metabolism is relatively slow that the changes in the immune response are prolonged. The cornea is in a sensitive state for a long time, making it easy to develop allergic diseases such as bullous keratitis.

Intrinsic keratitis often occurs in the corneal stroma and generally does not cause corneal ulcers.

3. Spread to adjacent tissues

Due to embryological homology and anatomical continuity, it spreads to the corneal epithelium. Most diseases originate from the conjunctiva. For example, severe conjunctivitis is often accompanied by superficial keratitis.

Clinical manifestations

Except for paralytic keratitis, most patients with keratitis have strong inflammatory symptoms, such as pain, photophobia, tearing and blepharospasm. Patients with keratitis not only have ciliary congestion, but also iris congestion. In severe cases, the conjunctiva and even the eyelids may become edematous.

The symptoms of keratitis caused by different causes are also different. Bacterial keratitis has the most rapid onset, the most severe symptoms, and increased and viscous secretions; viral keratitis is second, with less secretions, which are watery or mucous; fungal keratitis is the mildest, and sometimes the corneal lesions are already very serious, but the patient does not feel it obviously. Patients with herpes simplex keratitis may have decreased corneal sensation.

Corneal inflammation will inevitably affect vision to some extent, especially when the inflammation invades the pupil area, it is more serious. The corneal scar formed after the ulcer heals not only blocks the light from entering the eye, but also changes the curvature and refractive power of the corneal surface, making it impossible for objects to be focused on the retina to form a clear image, thereby reducing vision. The extent of vision loss depends entirely on the location of the scar. If it is located in the center of the cornea, even if the scar is small, it will have a great impact on vision.