The term used to describe corneal inflammations is keratitis. In some impoverished countries, particularly in the tropics, corneal infections are recognised to be the second most significant cause of monocular blindness, ranking after unoperated cataract.A frequent eye illness that could endanger your vision is called microbial keratitis. It can be brought on by bacteria, fungus, viruses, or parasites. Numerous studies in India and overseas have recorded the frequency of microbial infections and identified the risk factors predisposing a population to corneal infection, highlighting the significance of corneal ulceration as a significant cause of sight loss.[2]We must address a contentious issue about the early treatment of nonviral infective keratitis in our population. I believe that by slavishly following the western protocol, which holds that 90% of corneal ulcers are brought on by germs, we actually inflict more injury. Numerous research indicate that our community has a relatively high incidence of fungal keratitis (up to 63 percent).[3]

2.1.1. Bacterial Keratitis

Contact lens use, particularly overnight usage, and ocular damage, including refractive surgery, are risk factors for bacterial keratitis. Staphylococci, including MRSA, streptococci, Pseudomonas aeruginosa, Moraxella species, and other gram-negative bacilli are the pathogens that are most frequently isolated. The cornea has an underlying opacity as well as an epithelial deficiency. During the first 48 hours of treatment, compounded, high-concentration topical antibiotic drops may be used hourly day and night.[3]

Herpes Simplex Keratitis

Symptoms of a primary ocular herpes simplex virus infection include ulceration of the cornea, conjunctiva, or lids. Recurrences are brought on by the virus' capacity to colonise the trigeminal ganglia and may be brought on by fever, severe sun exposure, or immunosuppression. Herpetic corneal disease is normally unilateral, although in cases of atopy or immunocompromise, it may manifest bilaterally. The most recognisable symptom of herpetic corneal illness is the dendritic (branching) corneal ulcer. Additionally, larger ("geographic") ulcers might develop, especially after topical corticosteroid treatment.[4]

Herpes Zoster Opthalmicus

The trigeminal nerve's ophthalmic division is frequently affected by herpes zoster. Malaise, fever, headache, and periorbital burning and itching are its initial symptoms. These signs could appear a day or more before the eruption. The rash starts off vesicular before swiftly turning pustular and crusting. It is predicted that the eye will be involved if the nose tip or lid margin are affected. Conjunctivitis, keratitis, episcleritis, and anterior uveitis are ocular symptoms, frequently accompanied by increased intraocular pressure. Long-term complications include posterior subcapsular cataract, neurotrophic keratitis, and recurrent anterior segment inflammation. Rare conditions include optic neuropathy, cranial nerve palsies, acute retinal necrosis, and cerebral angiitis. HIV infection is a significant risk factor for developing complications from herpes zoster ophthalmicus.[5]

Fungal Keratitis

Fungal keratitis commonly affects eyes with chronic ocular surface diseases, contact lens users, and agricultural settings after corneal damage involving plant material. It can be a slow procedure. The corneal infiltration may contain several "satellite" lesions and feathery borders. Possible hypopyons are present. In contrast to bacterial keratitis, an epithelial defect might or could not exist. Every time a patient's history or the look of their cornea is indicative of a fungal condition, corneal scrapings should be cultured on media suited for fungi. Treatment is challenging and frequently takes six months or longer for severe disease, with diagnosis frequently delayed.[6]

Ocular morbidity is largely caused by infectious keratitis. Risk factors in a major portion of instances may be addressed. Poorer visual results were linked, in particular, to topical corticosteroid use and prior ocular surgery. By providing patients and ophthalmologists with the right information, many cases of severe keratitis could be avoided or have their severity decreased.[7]

It can take several decades to reduce infective keratitis-related corneal blindness. The only issue at this point is how to help the one million people who are already corneally blind. To do this, we must utilize cutting-edge keratoplasty technology and state-of-the-art eye banking facilities to the fullest extent possible.[8]

In closing, we would like to express our gratitude to the readers for their interest in this topic and express our sincere hope that soon, we will all be working together to lessen the incidence of corneal blindness in our nation.

The authors declare that they have no conflict of interest

No funding sources

The study was approved by the Government of Himachal Pradesh.

1. Srinivasan, M. "Infective Keratitis: A Challenge to India." Indian Journal of Ophthalmology 55.1 

2. Tewari, A., et al. "Epidemiological and Microbiological Profile of Infective Keratitis in Ahmedabad." Indian Journal of Ophthalmology 60.4 (2012): 267–272. https://doi.org/10.4103/0301-4738.102177.

3. Lin, A., et al. "Bacterial Keratitis Preferred Practice Pattern®." Ophthalmology 126.1 (2019): P1–P55. https://doi.org/10.1016/j.ophtha.2018.08.034.

4. Azher, T. N., et al. "Herpes Simplex Keratitis: Challenges in Diagnosis and Clinical Management." Clinical Ophthalmology 11 (2017): 185–191. https://doi.org/10.2147/OPTH.S128902.

5. Vrcek, I., et al. "Herpes Zoster Ophthalmicus: A Review for the Internist." American Journal of Medicine 130.1 (2017): 21–26. https://doi.org/10.1016/j.amjmed.2016.09.004.

6. Prajna, N. V., et al. "Effect of Oral Voriconazole on Fungal Keratitis in the Mycotic Ulcer Treatment Trial II (MUTT II): A Randomized Clinical Trial." JAMA Ophthalmology 134.12 (2016): 1365–1372. https://doi.org/10.1001/jamaophthalmol.2016.4212.

7. Wong, T., et al. "Severe Infective Keratitis Leading to Hospital Admission in New Zealand." British Journal of Ophthalmology 87.9 (2003): 1103–1108. https://doi.org/10.1136/bjo.87.9.1103.

Carrijo-Carvalho, L. C., et al. "Therapeutic Agents and Biocides for Ocular Infections by Free-Living Amoebae of Acanthamoeba Genus." Survey of Ophthalmology 62.2 (2017): 203–218. https://doi.org/10.1016/j.survophthal.2016.10.004