Clinical aspects and prognosis of polymicrobial keratitis caused by different microbial combinations: a retrospective comparative case study

Herpes simplex keratitis: A brief clinical overview

The aim of our minireview is to provide a brief overview of the diagnosis, clinical aspects, treatment options, management, and current literature available regarding herpes simplex keratitis (HSK). This type of corneal viral infection is caused by the herpes simplex virus (HSV), which can affect several tissues, including the cornea. One significant aspect of HSK is its potential to cause recurrent episodes of inflammation and damage to the cornea. After the initial infection, the HSV can establish a latent infection in the trigeminal ganglion, a nerve cluster near the eye. The virus may remain dormant for extended periods. Periodic reactivation of the virus can occur, leading to recurrent episodes of HSK. Factors triggering reactivation include stress, illness, immunosuppression, or trauma. Recurrent episodes can manifest in different clinical patterns, ranging from mild epithelial involvement to more severe stromal or endothelial disease. The severity and frequency of recurrences vary among individuals. Severe cases of HSK, especially those involving the stroma and leading to scarring, can result in vision impairment or even blindness in extreme cases. The cornea's clarity is crucial for good vision, and scarring can compromise this, potentially leading to visual impairment. The management of HSK involves not only treating acute episodes but also implementing long-term strategies to prevent recurrences and attempt repairs of corneal nerve endings via neurotization. Antiviral medications, such as oral Acyclovir or topical Ganciclovir, may be prescribed for prophylaxis. The immune response to the virus can contribute to corneal damage. Inflammation, caused by the body's attempt to control the infection, may inadvertently harm the corneal tissues. Clinicians should be informed about triggers and advised on measures to minimize the risk of reactivation. In summary, the recurrent nature of HSK underscores the importance of both acute and long-term management strategies to preserve corneal health and maintain optimal visual function.

Clinical and Microbiological Spectra and Therapeutic Outcomes of Polymicrobial Keratitis

PURPOSE

The aim of this study was to evaluate the risk factors, microbiology, and treatment outcomes of polymicrobial keratitis (PMK).

METHODS

We retrospectively analyzed 65 patients diagnosed with PMK between 2016 and 2019. The clinical and microbiological characteristics and outcomes were evaluated. The primary outcome measure was clinical resolution of keratitis. Absolute success (group A) was defined as resolution of infection with medical treatment, qualified success (group B) was resolution with medical therapy and additional minor procedures, and failure (group C) was defined as worsening of infection and presence of corneal melting or perforation requiring therapeutic penetrating keratoplasty or evisceration.

RESULTS

Of 4764 cases of microbial keratitis, PMK was identified in 65 eyes of 65 patients (1.36%). Infiltrate was central in 60% (39 eyes). Predisposing factors were higher in group C and included uncontrolled diabetes mellitus in 25% (7/28), history of trauma/foreign body in 57.1% (16/28), and poor presenting visual acuity (0.9 for group A vs. 1.79 for group B vs. 3.00 logarithm of the minimum angle of resolution for group C; P = 0.02). Microbiological profiling revealed that a majority (95%: 62/65) had bacterial with fungal keratitis. High fluoroquinolone resistance was noted (57%; 34/59). Absolute success was achieved in 28.3% (17/60), qualified success in 16.6% (10/60), and treatment failure was noted in 55% (33/60). The final best corrected visual acuity in group A was significantly better than that in group B and C (0.44 vs. 3.00 vs. 2.78; P < 0.001).

CONCLUSIONS

PMK is extremely rare but responds poorly to medical therapy. Bacterial with fungal etiology is predominant. Early surgical intervention to improve overall outcome is advocated.

A Rare Case of Endophthalmitis with Rhizobium radiobacter, Soon after a Resolved Keratitis: Case Report

BACKGROUND

Rhizobium (Agrobacterium) species are plant aerobic bacteria, which in some cases can produce endophthalmitis in humans after corneal trauma.

CASE PRESENTATION

A 42-year-old female patient presented in the Emergency Department of the Emergency County Hospital of Craiova, Romania, reporting pain, epiphora, and blurry vision in her right eye for about five days. This initial infectious keratitis episode was successfully resolved, but after 20 days she presented again after trauma with a leaf with corneal abscess. In the conjunctival secretion, R. radiobacter was identified. Despite antibiotherapy, the patient's state did not improve, and ultimately the eye was eviscerated.

METHODS

A search was performed in the ProQuest, PubMed, and ScienceDirect databases for the terms Agrobacterium, Rhizobium, radiobacter, and eye. We eliminated non-human studies, editorials and commentaries, and non-relevant content, and excluded the duplicates.

RESULTS

In total, 138 studies were initially obtained, and then we selected 26 studies for retrieval. After the selection process, we ended up including 17 studies in our analysis. Most studies reported R. radiobacter endophthalmitis after ocular surgical procedures or outdoor activities that involve exposure to soil.

CONCLUSION

R. radiobacter is a rare cause of endophthalmitis after eye trauma that generally responds well to usual antibiotherapy, but occasionally can evolve to severe, leading to the loss of the eye.

Clinical and Mycological Features in Fungal Keratitis: Retrospective Single Center Study (2012-2018)

Objectives:

To present the demographic, etiological, clinical, and mycological characteristics and treatment results of fungal keratitis patients admitted to our clinic.

Materials and Methods:

The medical records of patients diagnosed with fungal keratitis between October 2012 and 2018 were reviewed. The diagnosis of fungal keratitis was confirmed mycologically and/or cytologically. Treatment response was defined as complete infiltrate resolution and re-epithelization with medical treatment and minor surgical interventions. Patients who underwent penetrating keratoplasty or evisceration due to clinical deterioration despite treatment were classified as treatment nonresponders and were compared with responders in terms of demographic, etiological, and clinical characteristics.

Results:

Seventy-two (12.8%) of 559 patients diagnosed with microbial keratitis in the 6-year period were fungal keratitis. Of these, 38 cases (38 eyes) without polymicrobial etiology were included in the study. The patients’ mean age was 44.9±19.0 years (range: 2-80) and males predominated (14 females [36.8%], 24 males [63.2%]). Trauma (63.6%) was the most common predisposing factor in patients younger than 40 years old, whereas pathologies impairing ocular surface immunity were the leading risk factor (48.1%) in patients older than 40 years. Filamentous fungi were detected in 34 (89.5%) cases, while yeasts were found in 4 (10.5%) cases. Among 26 cases with positive cultures, Aspergillus species were the most common pathogens (42.3%). Infiltrate size before treatment was larger in nonresponders (14/38, 36.8%) compared to treatment responders (19/38, 50%) (p=0.049). In addition, rates of treatment response were higher in cases in which the infiltrate was located paracentrally compared to other cases (p=0.036).

Conclusion:

Fungal keratitis is an important public health problem in our region. Ocular trauma is a leading etiology in men under the age of 40 years. In the 6-year period, we observed that the main causes of fungal keratitis were filamentous fungi, and most commonly Aspergillus species. In cases presenting with large and central lesions, aggressive treatment options should be considered and these patients should be followed up more closely.