Overview

Keratoconjunctivitis is a condition that affects both the cornea and the conjunctiva, occurring due to viral, bacterial, autoimmune, toxic, or allergic reactions. Keratoconjunctivitis due to viral infection can occur in anyone, irrespective of age. Viral keratoconjunctivitis affects around 75% of the population, followed by bacterial and fungal pathogens. Children are most commonly affected by bacterial conjunctivitis, which accounts for approximately 50% of the cases. Allergens present in the environment may cause allergic conjunctivitis, affecting approximately 40% of the population.¹

What is keratoconjunctivitis?

Keratoconjunctivitis is an inflammatory condition affecting both the superficial cornea and the conjunctiva of the eye. The word is derived from two words, “keratitis” and “ conjunctivitis”. It refers to the inflammation of the superficial cornea and conjunctiva, respectively.¹

Causes of keratoconjunctivitis¹

Infectious causes

Viral:

• The Adenovirus is responsible for the epidemic and highly contagious keratoconjunctivitis
• CMV(cytomegalovirus)- they cause keratoconjunctivitis in immunocompromised patients, those with HIV/AIDS, or a history of organ transplantation
• Herpes simplex virus(HSV) can cause recurrent keratitis and dendritic ulcerations

Bacterial:

• Staphylococcus aureus and Treponema pneumoniae are common bacterial pathogens causing keratoconjunctivitis. The disease may get complicated in contact lens wearers due to Pseudomonas aeruginosa, and lead to corneal perforation if left untreated

Fungi 

• Candida and Fusarium species are common causative agents of fungal keratoconjunctivitis

Allergic causes

Different types of allergic reactions leading to keratoconjunctivitis

• SAC- seasonal allergic conjunctivitis
• PAC- perennial allergic conjunctivitis
• VKC- vernal keratoconjunctivitis
• AKC- atopic keratoconjunctivitis

Autoimmune and systemic diseases

• Sjögren syndrome
• Rheumatoid arthritis
• Stevens-Johnson syndrome
• Toxic epidermal necrolysis

Keratoconjunctivitis may also be due to chemical injuries from industrial accidents, dry eye disease, direct trauma to the ocular surface, vitamin A deficiency, facial nerve palsy, trigeminal nerve dysfunction, congenital or genetic factors, and occupational hazards.

Complications of keratoconjunctivitis

1. Corneal ulcers-  keratoconjunctivitis account for 50.5% of corneal ulceration of the eye

It leads to a significant amount of visual loss and blindness in the developing world. It is a clinical diagnosis mainly detected by your caregiver or ophthalmologist (an eye specialist).²

In developed countries, most corneal ulcers are caused by viruses, though Acanthamoeba infections can also occur in individuals who wear contact lenses. In developing countries, bacteria, fungi, and Acanthamoeba are more common causes.²

• Scarring- A corneal scar may interfere with or distort the passage of light into the eye, which can lead to impaired vision. Minor corneal scratches and those caused by superficial injuries can heal on their own in one or two days with the help of oral antibiotics and topical steroid applications. A scar is formed when the deeper layer of the cornea is involved due to any infection or injury that can cause a loss of transparency, also called corneal opacity³
• Vision loss- Vision loss is a major complication of VKC (vernal keratoconjunctivitis). It is a chronic, severe form of allergic reaction to the ocular surface (cornea and conjunctiva) of the eye, mainly affecting children aged 5-10 years residing in hot climates. VKC is more prevalent in subtropical regions of Africa, Asia, the Middle East and Latin America and relatively uncommon in the United States and northern Europe

Close inspection of the eyes may show areas of gelatinous thickening of the conjunctiva by the edge of the cornea (Horner-Trantas dots, see figure) and sterile corneal lesions (shield ulcers). Boys may be affected more frequently than girls, and symptoms typically flare in the spring/ summer with a recurrence in the fall/ winter.⁵

Signs and symptoms⁶

• Redness of one or both of your eyes
• Itchy and gritty feeling in one or both of your eyes, leading to eye irritation
• Your eyes will be sensitive to light (photophobia)
• You will experience watery eyes or  unusual discharges that may ooze out 
• Your vision will be blurred
• You will have swollen eyelids (blepharitis)

Management and treatment⁶

Treatment of keratoconjunctivitis is mainly done on the basis of the cause of the condition

• Using lubricating ointment or artificial tears may help to lubricate your eyes when you are experiencing dry eyes (keratoconjunctivitis sicca)
• For treating allergy or infection, you will be provided with medicated eye drops, which may be an antibiotic or antihistamine, given by your healthcare provider
• You may need surgery in severe conditions of keratoconjunctivitis, such as corneal transplantation, photorefractive keratectomy(PRK), or vision correction surgeries

FAQs

When should you visit your healthcare provider?

As soon as you experience red, swollen eyes with an itchy, gritty feeling while rubbing the eyes, along with/without unusual discharge and changes in your vision, you must make haste to visit your health caregiver.

How do you prevent keratoconjunctivitis?

You may visit your healthcare provider for a regular eye check-up and follow a maintenance therapy for your eyes. At home, you should wash your hands before rubbing your eyes, disinfect your hands before wearing contact lenses, avoid your known allergens and take allergy medications as needed.

What is the prognosis(treatment outcome) of keratoconjunctivitis?

Timely intervention will likely lead to a good prognosis. Prognosis mainly depends on the type of keratoconjunctivitis that has affected you. Chronic infections will require lifelong maintenance therapy.

Summary

Keratoconjunctivitis is a complex condition that affects both the cornea and conjunctiva, requiring accurate diagnosis and thoughtful management. Applying current research and advanced treatment options can help healthcare providers improve patient outcomes. This activity will highlight the most common causes of keratoconjunctivitis.¹