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*

PURPOSE: To investigate the effects of transplantation of a circumferentially-trephined autologous oral mucosal graft using a vacuum trephine on ocular surface reconstruction in patients with limbal stem cell deficiency. METHODS: Patients with a limbal stem cell deficiency who underwent transplantation of autologous oral mucosal graft performed by a particular surgeon in Seoul National University Hospital were included. The medical records of these five patients were retrospectively reviewed. The lower labial mucosal graft inside the inferior lip was trephined to a depth of 250 µm using a donor vacuum trephine with a 9-mm diameter. Outside markings were made using a 14-mm intraoperative keratometer. The oral mucosal graft was dissected under a microscope using a Beaver mini-blade as either a ring or a crescent-shaped strip with a 5-mm width. The mucosal graft was transplanted onto the limbus in the limbal-deficient eye. Best-corrected visual acuity and corneal status were measured during the follow-up period. RESULTS: Four patients were diagnosed with Stevens-Johnson syndrome and one was diagnosed with atopy-associated immune keratitis. The mean follow-up period was 10.4 ± 2.9 months. After 4 months, visual acuity improved in all patients, and the mean improvement in logarithm of the minimum angle of resolution visual acuity was 0.526 ± 0.470 (range, 0.15 to 1.10). Corneal surface erosion and neovascularization decreased in four patients, and stromal opacity decreased in two patients. The engraftments maintained ocular surface stabilization in four of the five patients at the last follow-up. CONCLUSIONS: Transplantation of circumferential autologous oral mucosal grafts may be effective for the treatment of limbal stem cell deficiency.
Follow-Up Studies ; Humans ; Keratitis ; Lip ; Medical Records ; Reconstructive Surgical Procedures ; Retrospective Studies ; Rodentia ; Seoul ; Stem Cells ; Stevens-Johnson Syndrome ; Tissue Donors ; Transplants ; Vacuum ; Visual Acuity

PURPOSE: To analyze clinical aspects in a cohort of patients with Staphylococcus keratitis according to coagulase positivity (coagulase negative Staphylococcus [CNS], coagulase positive Staphylococcus [CPS]). METHODS: Epidemiology, predisposing factors, clinical characteristics, treatment outcomes, and antibiotic susceptibility were comparatively analyzed in 138 cases of culture-proven Staphylococcus keratitis (94 eyes with CNS and 44 eyes with CPS) over 20 years (1998–2017) at Yeungnam University Hospital. Poor clinical outcomes were defined as a final corrected visual acuity <0.1, a decreased visual acuity after treatment, complications, or surgical treatment. Risk factors for poor clinical outcomes were evaluated in the total cohort and analyzed using multivariate logistic regression. RESULTS: The most common predisposing factors were corneal trauma in the CNS group (47.9%) and previous ocular surface disease in the CPS group (31.8%). No significant differences were observed in mean age, sex, previous ocular surface disease, epithelial defect size, and hypopyon between the two groups. Methicillin susceptibility (39.4% vs. 72.7%, p < 0.001) was significantly lower in the CNS group, and poor clinical outcomes (28.0% vs. 43.9%, p = 0.076) were more common in the CPS group. The significant risk factors for poor clinical outcomes were initial best-corrected visual acuity <0.1, epithelial defect size ≥ 5 mm², symptom duration ≥10 days, and hypopyon. CONCLUSIONS: No significant differences were observed in epidemiological factors and initial clinical characteristics between the two study groups, but predisposing factors and methicillin susceptibility differed between the two groups. Treatment outcomes were relatively worse in the CPS group than in the CNS group, but the difference was not statistically significant. Poor clinical outcomes were more associated with long symptom duration and poor initial clinical characteristics than with coagulase positivity.
Causality ; Coagulase ; Cohort Studies ; Corneal Injuries ; Epidemiology ; Humans ; Keratitis ; Logistic Models ; Methicillin ; Risk Factors ; Staphylococcus ; Visual Acuity

PURPOSE: The purpose of this study was to evaluate the clinical aspects of inpatients with bacterial keratitis according to culture positivity. METHODS: This was a retrospective review of 98 cases of inpatients with bacterial keratitis who were treated between January 2011 and December 2016 in Yeungnam University Hospital. Epidemiology, predisposing factors, clinical characteristics, and treatment outcomes were compared between culture positive (CP, 39 eyes) and culture negative (CN, 59 eyes) groups. Risk factors for poor clinical outcome were evaluated in the total cohort and analyzed using multivariate logistic regression. RESULTS: Pseudomonas spp. (31%) and Staphylococcus spp. (24%) were common in the CP group. There were no significant differences in previous ocular surface disease, contact lens wear, or hypopyon between the two groups. Epithelial defect size ≥5 mm² (51%:31%, p = 0.04) and initial visual acuity <0.1 (Snellen) (51%:31%, p = 0.04) were significantly higher in the CP group than in the CN group. Epithelial healing time ≥14 days (18%:5%, p = 0.08) and poor clinical outcome (28%:20%, p = 0.37) were more common in the CP group than in the CN group. Risk factors for poor clinical outcome were previous ocular surface disease (odds ratio [OR] = 11.29, 95% confidence interval [CI] = 2.01–63.41, p = 0.006) and previous ocular surgery (OR = 6.98, 95% CI = 1.51–32.20, p = 0.01). CONCLUSIONS: The CP group showed relatively worse initial clinical characteristics than the CN group. Treatment outcomes were slightly worse in the CP group than in the CN group; however, this difference was not statistically significant. Previous ocular surface disease and previous ocular surgery were associated with poor clinical outcome.
Bacterial Infections ; Causality ; Cohort Studies ; Corneal Ulcer ; Epidemiology ; Humans ; Inpatients ; Keratitis ; Logistic Models ; Pseudomonas ; Retrospective Studies ; Risk Factors ; Staphylococcus ; Visual Acuity

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