OBJECTIVE

Despite being a preventable and treatable condition, central microbial keratitis (CMK) and its complications remain to be a significant cause of vision loss in our country. This study presents the demographic profile, risk factors, etiologies, treatments, and outcomes of CMK in the Philippines.

The study was a two-center, prospective, non-randomized clinical study involving the patients of the External Disease and Cornea Clinics of two tertiary eye referral centers in the Philippines. It was conducted as the Philippine leg of the Asia Cornea Society Infectious Keratitis Study (ASCIKS).1 Patients with a clinical diagnosis of CMK rendered by a cornea specialist, and who signed the consent form, were recruited into the study. They underwent uniform sample collection and culture techniques as described in the ACSIKS. All patients were followed-up for 6 months. Data collected included demographics, risk factors, culture results, management, and treatment outcomes. Descriptive statistics and frequency were used to analyze the data.

A total of 348 patients diagnosed with CMK were included. Trauma (65.5%) among the middle-aged (42.9 ± 17.9 years) male population was the most significant risk factor for development of CMK, followed by contact lens wear (12.9%), prior ocular surgery (6.0%), and ocular surface diseases (3.4%). Bacterial keratitis (53.2%) was still the most common etiology of CMK, followed by fungal keratitis (27.0%), Acanthamoeba keratitis (5.7%), and viral keratitis (2.0%). Aspergillus species (18.3%) were the most common microbial isolates. Pseudomonas species (13.9%) were the most common bacterial isolates. The median time from onset of symptoms to consultation with the study centers was 2 weeks. Medical treatment was enough to treat the infection in 34.8% of cases. Surgical intervention was necessitated in 22.6% with evisceration/enucleation done in 1 out of 3 patients who had surgery.

Bacterial infection remains the most common cause of CMK in the Philippines, followed by fungal infection. Significant risk factors include trauma and contact lens wear. Aspergillus species and Pseudomonas species were the most common fungal and bacterial isolates, respectively. Despite medical treatment, almost a quarter of the cases still required surgical intervention.

OBJECTIVES

Acanthamoeba spp. are free-living amoebae commonly found in aquatic environments, with pathogenic genotypes capable of causing severe diseases such as acanthamoeba keratitis and granulomatous amoebic encephalitis. Environmental factors, particularly pH, influence their survival and distribution. Tadlac Lake located at Los Baños, Laguna, Philippines is a Class C freshwater body used for aquaculture, recreation, and irrigation. To date, no study has specifically assessed Acanthamoeba colonization in Tadlac Lake.

In this study, detection of the presence of Acanthamoeba spp. and evaluation of pH as a potential factor influencing their persistence in Tadlac Lake was conducted. One-time sampling was conducted from nine sites of the lake. Surface water samples were collected at a depth of 10–20 cm, filtered through 1.2 μm glass microfiber filters, and cultured on non-nutrient agar plates lawned with live Escherichia coli. Plates were incubated at 30°C for 14 days and examined daily under light microscopy, while pH was measured in situ.

Cyst-like structures resembling amoebae were observed, but these did not exhibit definitive Acanthamoeba morphology under light microscopy. No Acanthamoeba spp. were confirmed and the recorded pH levels ranged from 8.72 to 10.51, exceeding the optimal growth range (7.0–9.0) reported for the organism.

Findings of this study suggest alkaline conditions may have inhibited the proliferation and persistence of Acanthamoeba spp. in the lake. These findings highlight pH as a potential limiting factor for Acanthamoeba survival in alkaline freshwater bodies and underscore the importance of integrating physicochemical monitoring into pathogen surveillance frameworks.

Aspergillus fumigatus ; Cytokines ; Humans ; Interleukin-1beta ; Keratitis ; Receptors, IgE ; Tumor Necrosis Factor-alpha ; Tumor Necrosis Factors

Acanthamoeba Keratitis/epidemiology* ; Hospitals ; Humans ; Referral and Consultation ; Retrospective Studies ; Singapore/epidemiology*

Keratoplasty, which is cornea transplant surgery, is one of the treatment methods for patients with turbidity or keratitis. Recently, keratoplasty using a surgical robot was studied to increase precision. In this study, the effect of surgical factors on the deformation and curvature of the cornea were analyzed in order to improve the accuracy of keratoplasty and derive the optimal surgical factors using finite element method (FEM). Suturing tension and depth were selected as surgical factors. An FEM model, a constitutive equation, and boundary conditions were determined using experiments and reference data. Suturing tension significantly impacted deformation and curvature change, and suturing depth affected the position of the thread-cornea contact point. Both factors have a significant impact on a focal point in the retina and the patient's visual acuity after keratoplasty.
Cornea ; Corneal Transplantation ; Finite Element Analysis ; Humans ; Keratitis ; Methods ; Retina ; Visual Acuity

No abstract available.
Keratitis

PURPOSE: To report a case of a Corynebacterium macginleyi-infected corneal ulcer of a patient who had been treated for conjunctivitis for more than 3 months. CASE SUMMARY: A 72-year-old female was transferred from a private ophthalmic clinic for evaluation of herpetic keratitis with progressive corneal edema and infiltration in the left eye. She had a history of conjunctival hyperemia and eyeball pain in her left eye 3 months prior to her visit. She was treated with levofloxacin eye drops and acyclovir ointment (Herpesid®, Samil, Co., Ltd. Seoul, Korea). On slit lamp examination, 5.4 × 4.0 mm corneal epithelial defects and stromal infiltrations were observed in the upper to central cornea, and endothelial keratic precipitates were found. Gram positive bacteria were detected on Gram staining and Corynebacterium macginleyi was identified on bacterial cultures from the conjunctiva and cornea. She was treated with topical vancomycin eye drops. After 3 months of treatment, the corneal ulcer was completely resolved, leaving mild superficial opacity on the cornea. CONCLUSIONS: While Corynebacterium macginleyi, normal flora of the conjunctiva, is considered a major causative agent for conjunctivitis and blepharitis, Corynebacterium macginleyi should also be considered a possible cause of slowly progressive keratitis in patients with chronic conjunctivitis.
Acyclovir ; Aged ; Blepharitis ; Conjunctiva ; Conjunctivitis ; Cornea ; Corneal Edema ; Corneal Ulcer ; Corynebacterium ; Female ; Gram-Positive Bacteria ; Humans ; Hyperemia ; Keratitis ; Keratitis, Herpetic ; Levofloxacin ; Ophthalmic Solutions ; Seoul ; Slit Lamp ; Vancomycin

PURPOSE: We report a case of Aeromonas keratitis presenting as radial keratoneuritis. CASE SUMMARY: A 33-year-old woman with a history of cleaning her contact lenses with tap water presented with decreased visual acuity for 1 day in the left eye. The patient showed diffuse corneal edema, stromal infiltration, and radial keratoneuritis, which were thought to be pathognomonic for Aeromonas keratitis. Based on the patient's clinical findings and past history, a diagnosis of Aeromonas keratitis was made and she was prescribed topical fortified cefazolin (50 mg/mL, 5%), tobramycin (3 mg/mL), and 0.02% chlorhexidine per hour. Culture results from the contact lens and contact lens solution confirmed infection by Aeromonas hydrophilia. Polymerase chain reaction results for Aeromonas were negative. After 8 days of treatment, the uncorrected visual acuity was 0.7/0.3 with improvement in her corneal findings. CONCLUSIONS: Radial keratoneuritis is not always pathognomic for Aeromonas keratitis and can be present in Aeromonas keratitis. Therefore, ophthalmologists should be cautious when interpreting this clinical sign.
Adult ; Aeromonas ; Cefazolin ; Chlorhexidine ; Contact Lens Solutions ; Contact Lenses ; Cornea ; Corneal Edema ; Diagnosis ; Female ; Humans ; Keratitis ; Polymerase Chain Reaction ; Tobramycin ; Visual Acuity ; Water

PURPOSE: We report a case of infectious keratitis caused by Shewanella putrefaciens in a patient after fishing. CASE SUMMARY: A 75-year-old male with no underlying disease other than hypertension was admitted to our hospital because of decreased visual acuity and congestion in his left eye for 2 weeks. At the first ophthalmic examination, the best-corrected visual acuity (BCVA) of the left eye was counting fingers. Slit lamp examination showed stromal infiltrates with 2.0 × 2.0 mm corneal epithelial defects, endothelial inflammatory plaques and 1 mm height hypopyon with severe inflammation in the anterior chamber. Bacterial culture tests were performed by corneal scraping, which were positive for Shewanella putrefaciens, followed by treatment with moxifloxacin and ceftazidime topical antibiotics. After 2 months of treatment, the BCVA of the left eye improved to 0.4 and the corneal lesion clinically improved with residual mild stromal opacity. CONCLUSIONS: Shewanella putrefaciens should be considered as a causal pathogen of infectious keratitis in patients after fishing. We report a case of infectious keratitis caused by Shewanella putrefaciens, which has never previously been reported in the Republic of Korea.
Aged ; Anterior Chamber ; Anti-Bacterial Agents ; Ceftazidime ; Corneal Ulcer ; Estrogens, Conjugated (USP) ; Fingers ; Humans ; Hypertension ; Inflammation ; Keratitis ; Male ; Republic of Korea ; Shewanella putrefaciens ; Shewanella ; Slit Lamp ; Visual Acuity

PURPOSE: We investigated the regional characteristics and trends in causative agents, clinical features, and antibiotic susceptibility in infectious keratitis in western Gyeongnam province. METHODS: This retrospective chart review included 551 eyes of 551 patients with infectious keratitis, who were referred to our center from January 2004 to December 2017. The period of this study was divided into two terms of 7 years before and after 2011 to analyze the changes in causative organisms and antibiotic susceptibilities and to investigate the clinical features and regional characteristics in western Gyeongnam province. RESULTS: The most common occupation among patients was farming; the mean time taken for initial treatment was 8.6 days. The culture positivity rate was 35.8%, the most commonly isolated microorganisms were Staphylococcus epidermidis (14.5%) for Gram-positive bacteria and Pseudomona aeruginosa (13.5%) for Gram-negative bacteria. The distribution of culture-positive organisms before and after 2011 did not show any significant difference, but the increase in resistance to second and third generation quinolones was significantly greater in Gram-positive bacteria after 2011. There was no significant difference in clinical characteristics before and after 2011, but the hospital stay duration and treatment needs were significantly reduced. CONCLUSIONS: This was a large-scale study analyzing the clinical features of infectious keratitis in western Gyeognam province over a 14-year period. The results will help us understand the characteristics, microbiology, and community in infectious keratitis by analyzing patients referred to tertiary centers.
Agriculture ; Gram-Negative Bacteria ; Gram-Positive Bacteria ; Gyeongsangnam-do ; Humans ; Keratitis ; Length of Stay ; Occupations ; Quinolones ; Republic of Korea ; Retrospective Studies ; Staphylococcus epidermidis