Corneal diseases continue to pose a significant threat to global eye health. Each year they contribute to 1.5 to 2 million new cases of corneal blindness worldwide.
This issue is particularly pervasive in developing nations. One specific concern is fungal keratitis, a condition that demands our attention. According to a study done in South India two types of fungi, Fusarium (47%) and Aspergillus (16%), are the primary culprits. However, the prevalence of fungal keratitis varies globally, with higher rates in regions such as South India, China and tropical climates. This article explores and provides a deeper understanding of various clinical presentations.
Factors for Development
Both local and systemic factors significantly influence the development of fungal keratitis. Among the most common local factors are traumatic incidents involving plant materials like thorns, leaves and sticks, as well as contact lens usage and the application of topical steroids. Additionally, conditions affecting the corneal surface, exposure to keratitis and certain ocular procedures, like photorefractive keratectomy and LASIK, can also contribute to fungal keratitis.
In contrast, systemic factors, specifically immunocompromised states, and diabetes are associated with a lower incidence but can still play a role in predisposing individuals to fungal keratitis. Understanding these factors and their interplay is crucial for effective clinical management and the development of preventive strategies.
Fungal keratitis, despite its often subtle initial presentation, exhibits distinct clinical features that set it apart from other corneal infections. The key characteristics include the presence of a dry-looking infiltrate with a raised surface on the cornea, feathery and irregular margins surrounding the ulcer, possible satellite lesions accompanying the primary ulcer and, in some cases, the development of a posterior corneal abscess or retro corneal plaque. These clinical indicators are crucial for ophthalmologists to differentiate fungal keratitis from other corneal conditions.
It's also important to note that the severity of symptoms may not always align with the size of the lesion and can be milder compared to bacterial keratitis with a similar-sized ulcer. Understanding these specific clinical presentations associated with fungal keratitis is essential for accurate diagnosis and timely intervention.
(See the slit-lamp slideshow of fungal keratitis below for a variety of presentations.)
Fungal keratitis is a challenging condition to manage, but with a keen eye for clinical features and prompt intervention, ophthalmologists can improve outcomes for their patients. Recognizing the distinct appearances associated with different fungal pathogens is a crucial step in diagnosing and treating fungal corneal ulcers effectively.
Fungal keratitis is a global concern with significant regional variations in prevalence. Ophthalmologists must remain vigilant, especially in regions where fungal keratitis is more common. By understanding the clinical presentations and risk factors associated with fungal keratitis, we can provide better care for our patients and work toward reducing the burden of corneal diseases worldwide.
||About the author: Tejaswi Prasad PV, MBBS, DO, DNB, is a fellow in cornea and refractive surgery. Having completed his fellowship at Aravind Eye Hospital in Madurai, India, he now serves as an assistant professor in the same institution. Dr. Prasad’s main areas of clinical interest are keratoplasty and keratoconus.