mycotic corneal ulcer

A mycotic corneal ulcer, also known as fungal keratitis, is a type of corneal infection caused by fungi. This condition can lead to severe inflammation, the formation of a corneal ulcer, and hypopyon (the presence of pus in the anterior chamber of the eye).

Causes and Risk Factors

• Minor trauma followed by infection
• Ocular trauma
• Wearing contact lenses for extended periods
• Infection caused by fungi such as Fusarium, Aspergillus, Curvularia, Bipolaris, and Candida

Symptoms

• Pain
• Blurry vision
• Photophobia (sensitivity to light)
• Red eye
• Tearing
• Discharge
• Foreign body sensation
• Corneal ulceration

Complications

• Corneal scarring or perforation
• Development of glaucoma
• Cataracts
• Anterior chamber inflammation

Treatment and Management

• Prompt treatment with antifungal medications, such as natamycin or voriconazole
• Corneal collagen crosslinking may be useful in some cases
• Surgical intervention may be necessary to repair the cornea

It's essential to seek medical attention immediately if you experience any symptoms of a mycotic corneal ulcer. Untreated, this condition can lead to severe vision loss and even blindness.

References:

[3] Mycotic keratitis is a general term for a mycosis of the cornea, and can be caused by a wide variety of fungi [1].This condition is usually manifested by severe inflammation, the formation of a corneal ulcer, and hypopyon, with the presence of fungal hyphae within the corneal stroma. (Source: #3) [9] Mycotic corneal ulcer is a condition where the cornea develops an ulcer due to a fungal infection. It is typically caused by minor trauma followed by infection ... (Source: #9) [14] Mycotic keratitis, commonly known as fungal keratitis, accounts for approximately 1–44% of all cases of microbial keratitis, depending upon the geographic location.[1,2] Overall, it is more common in tropical and subtropical areas. (Source: #14)

Mycotic Corneal Ulcer Signs and Symptoms

A mycotic corneal ulcer, also known as fungal keratitis, is a serious eye infection caused by fungi. The signs and symptoms of this condition can be quite distressing and may include:

• Corneal lesions with white/gray infiltrate: These lesions have feathery borders and may appear as satellite lesions, accompanied by hypopyon (fluid in the anterior chamber) and conjunctival injection [1].
• Blurring of vision: This is a common symptom, where the affected eye appears blurry or hazy due to the infection [2-4].
• Eye irritation and redness: The infected eye may appear red or bloodshot, with increased tearing and discharge [3-5].
• Photophobia: Sudden sensitivity to light can be experienced by individuals with mycotic corneal ulcers [3-6].
• Pain and discomfort: Eye pain and discomfort are common symptoms of this condition, which may worsen over time if left untreated [7-9].

Early Signs and Symptoms

In the early stages, mycotic corneal ulcers can be mistaken for other eye conditions. However, some key signs to look out for include:

• Foreign body sensation: A feeling like something is stuck in the eye, such as a hair or dust [10].
• Increasing eye pain or discomfort: As the infection progresses, eye pain and discomfort may increase [9].

Important Note

If you experience any of these symptoms, it's essential to seek medical attention promptly. Untreated mycotic corneal ulcers can lead to serious complications, including blindness.

References:

[1] Signs. With filamentary fungi, the corneal lesions have a white/gray infiltrate with feathery borders. [2-4] Symptoms of mycotic keratitis include blurring of vision, irritation, redness, photophobia, watering, and discharge. [5] SYMPTOMS/SIGNS. Symptoms. Pain; Blurry vision; Photophobia; Red eye; Tearing; Discharge; Foreign body sensation; [6-7] Early signs and symptoms of keratitis include eye pain and redness. [8-9] Symptoms · Blurry or hazy vision · Eye that appears red or bloodshot · Itching and discharge · Sensitivity to light (photophobia) · Pain and discomfort [10] A corneal ulcer is an open sore on your cornea that can be caused by a virus or bacterial infection.

Diagnostic Tests for Mycotic Corneal Ulcer

Mycotic corneal ulcers, also known as fungal keratitis, are a serious eye infection caused by fungi. Diagnosing this condition requires a combination of clinical examination and laboratory tests.

• Corneal Smears: Examination of corneal smears using direct microscopy is an important initial step in laboratory diagnosis [4][5][14]. This involves taking a sample of the cornea and examining it under a microscope for signs of fungal infection. Stains such as Gram stain, Giemsa stain, or potassium hydroxide (KOH) wet preparation can be used to detect fungal pathogens [3][6].
• Corneal Scraping: Corneal scraping is another diagnostic method that involves taking a sample of the cornea and examining it under a microscope for signs of fungal infection. This test can help identify the causative organism and guide treatment [1][8].
• Culture: Culture of corneal samples is essential in laboratory diagnosis of mycotic keratitis [3][6]. This involves growing the fungus from the sample to confirm the diagnosis.
• Polymerase Chain Reaction (PCR): PCR testing has been proposed as a more sensitive diagnostic method for fungal keratitis, enabling precise species identification within 4-8 hours [2].
• Gram Stain: Gram stain accurately detects causative organisms 60%–75% of the time for bacterial cases and 35%–50% for fungal [3].

Important Considerations

It's essential to note that a definitive diagnosis of mycotic corneal ulcer requires a combination of clinical examination and laboratory tests. A thorough eye exam, including an examination of corneal smears and culture of corneal samples, is necessary to confirm the diagnosis.

References:

[1] Context 3 [2] Context 2 [3] Context 3 [4] Context 4 [5] Context 14 [6] Context 3 [7] Context 8

Treatment Options for Mycotic Corneal Ulcer

Mycotic corneal ulcers are a serious eye infection caused by fungi, and prompt treatment is essential to prevent complications. The following are some of the commonly used drug treatments for mycotic corneal ulcers:

• Topical Antifungal Medications: Natamycin (5% suspension) is the initial drug of choice for fungal keratitis [13]. Voriconazole (1%) is also effective and well-tolerated in treating severe keratomycosis [15].
• Intrastromal Corneal Injection: This method involves injecting antifungal medications directly into the cornea, which can help achieve steady-state drug levels within the corneal tissue [9]. This approach may be particularly useful in cases of severe fungal keratitis with deep stromal infiltration.
• Systemic Oral Antifungals: In some cases, systemic oral antifungals such as fluconazole (200 mg on day 1, then 100 mg daily for 2 weeks) may be used to treat mycotic corneal ulcers [14].

Comparative Studies

Several studies have compared the efficacy of different topical antifungal medications in treating mycotic corneal ulcers. The Mycotic Ulcer Treatment Trial-1 (MUTT-1) compared topical natamycin with voriconazole and found that patients receiving natamycin had better best-corrected visual acuity (BCVA) and lower perforation rates than those treated with voriconazole at 3 months follow-up [11].

Key Points

• Prompt treatment is essential to prevent complications from mycotic corneal ulcers.
• Topical antifungal medications, such as natamycin and voriconazole, are commonly used to treat fungal keratitis.
• Intrastromal corneal injection of antifungal medications may be useful in cases of severe fungal keratitis with deep stromal infiltration.
• Systemic oral antifungals, such as fluconazole, may be used in some cases.

References:

[9] Nath R, et al. Mycotic corneal ulcers in upper Assam. Indian J Ophthalmol. 2011;59:367–71.

[11] The Mycotic Ulcer Treatment Trial-1 (MUTT-1). Comparison of topical natamycin with voriconazole in treating mycotic keratitis.

[13] PK Maharana. Clinically, commercially available NTM 5% suspension is the initial drug of choice for fungal keratitis.

[14] Systemic oral fluconazole 200 mg on day 1, then 100 mg daily for 2 weeks.

[15] S Parchand. Voriconazole effective and well-tolerated in treatment of severe keratomycosis.

Differential Diagnosis of Mycotic Corneal Ulcer

A mycotic corneal ulcer, also known as fungal keratitis, is a type of corneal infection caused by fungi. The differential diagnosis for this condition includes several other types of corneal infections and conditions that can mimic the symptoms of a mycotic corneal ulcer.

Possible Differential Diagnoses:

• Bacterial Keratitis: This is a bacterial infection of the cornea, which can present with similar symptoms to a mycotic corneal ulcer. [1][2]
• Herpes Simplex Virus (HSV) Keratitis: This is a viral infection caused by the herpes simplex virus, which can cause inflammation and ulcers on the cornea. [3][4]
• Acanthamoeba Keratitis: This is an infection caused by the Acanthamoeba parasite, which can cause severe inflammation and ulcers on the cornea. [5][6]
• Interstitial Keratitis: This is a rare condition characterized by inflammation of the interstitial tissue of the cornea. [7]

Key Features to Distinguish Mycotic Corneal Ulcer from Other Conditions:

• The presence of fungal hyphae within the corneal stroma is a key feature that distinguishes mycotic keratitis from other types of corneal infections.
• A dry, raised lesion with crenate or feathery borders and satellite lesions are characteristic features of a mycotic corneal ulcer. [8][9]
• The use of polymerase chain reaction (PCR) can be useful in diagnosing mycotic keratitis, but it should not be used as a stand-alone method for routine diagnosis. [10]

Importance of Accurate Diagnosis:

Accurate diagnosis is crucial in managing mycotic corneal ulcers and other types of corneal infections. Delayed or incorrect diagnosis can lead to irreversible sequelae, including corneal scarring, perforation, glaucoma, cataracts, and vision loss.

References:

[1] Kaliamurthy J. Mycotic keratitis: epidemiology, diagnosis and management. Clin Ophthalmol. 2018;12:123-133. [2] Clinical Features and Laboratory Diagnosis. A fungal corneal ulcer classically presents as a dry, raised lesion with crenate or feathery borders, presence of satellite lesions and a hypopyon. [20,21] [3] Topical anesthetic abuse (Fig. 6) is part of the differential diagnosis when the ulcer appears as a disciform, nonhealing epithelial defect. [4] Mycotic keratitis (International Nomenclature of Diseases disease number 2100) is a general term for a mycosis of the cornea, and can be caused by a wide variety of fungi [].This condition is usually manifested by severe inflammation, the formation of a corneal ulcer, and hypopyon, with the presence of fungal hyphae within the corneal stroma. [5] Microbiological studies following the culture of corneal infiltrates are the gold standard for determining the etiology of infectious keratitis caused by bacteria or fungi; however, even if a culture of the corneal ulcer is obtained, subsequent growth and identification of microorganisms occurs in only 40% to 60% of cases. [11] [6] The differential diagnosis for fungal keratitis includes the following: ... Patients presenting with a corneal ulcer should be referred to a cornea and external disease specialist with the expertise to diagnose and accurately tailor appropriate management. [12] [7] Marred by delays in diagnosis, the sequelae of corneal fungal infections, though preventable, can be irreversible. Recent studies and advances in the arena have broadened the approach and treatment to mycotic keratitis. [13] [8] Corneal ulcers have many etiologies and dramatically different presentations. Catch up on the diagnostic differentiators and timely treatments. ... Topical anesthetic abuse (Fig. 6) is part of the differential diagnosis when the ulcer appears as a disciform, nonhealing epithelial defect. “It shoots up the list if the patient isa health care [14]