Corneal infection occurs when pathogens (bacteria, fungi, parasites) are able to penetrate through the protective surface (epithelium) of the cornea and into the depths of the cornea.
Most commonly, the epithelium is damaged by minor injuries. In developed countries, the most common cause of minor damage and infection is the prolonged wearing of contact lenses, along with inadequate hygiene in storing the contact lenses. In developing countries, it is more of a minor accident, caused for example by leaves or plants, and is ideal for fungal infections. The infection can then progress rapidly and endanger the eyesight.
The numbers are alarming: in the US, around 60,000 corneal infections occur each year. In India, the estimated number is 800,000 new infections per year, and the WHO is talking about a silent epidemic. Corneal infections are one of the major global causes of blindness in the face of increasing antibiotic resistance and inadequate access to modern medicine in emerging markets.
In our cooler latitudes, the most common bacteria that cause the infection. After a first assessment with the ophthalmologist then usually a therapy with broad-spectrum antibiotic eye drops is initiated. In severe cases, we take a swab to accurately determine the nature of the pathogen. Things are very different in humid warm countries, for example in India. Here, the infection is often caused by a fungus, and these infections are much harder to treat.
For years antibiotic resistance has been increasing worldwide. This means that most bacteria have gotten used to our antibiotics in the past few decades and they are no longer acting properly. In addition, the last class of antibiotics was identified in 1980. Therefore, the World Health Organization warns in detail that in a few years already simple infections can no longer be treated and the number of people who will die from infections will increase drastically. The entire report can be found here.