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: We report a case of herpes simplex keratitis after Descemet membrane endothelial keratoplasty (DMEK). CASE SUMMARY: A 67-year-old male underwent DMEK in his left eye due to pseudophakic bullous keratopathy. One week after DMEK, re-bubbling was performed due to partial detachment of Descemet's membrane at the corneal periphery. After re-bubbling, the cornea remained clear and the patient's visual acuity gradually improved. Two months after DMEK, the patient presented with mild discomfort and decreased visual acuity. The cornea showed an irregular, narrow dendrite with an epithelial defect and surrounding opacity. After confirming that Descemet's membrane was attached, the patient was started on oral valacyclovir for suspected herpes keratitis. Herpes simplex virus type 1 was eventually identified by polymerase chain reaction. The corneal lesion resolved after three weeks of antiviral treatment. CONCLUSIONS: Similar to penetrating keratoplasty, DMEK can trigger outbreaks of herpes simplex keratitis. Herpes simplex keratitis should remain on the clinician's differential diagnosis for patients who present with a corneal epithelial irregularity and decreased visual acuity following DMEK.
Aged ; Cornea ; Corneal Transplantation ; Dendrites ; Descemet Membrane ; Diagnosis, Differential ; Disease Outbreaks ; Herpes Simplex ; Herpesvirus 1, Human ; Humans ; Keratitis ; Keratitis, Herpetic ; Keratoplasty, Penetrating ; Male ; Polymerase Chain Reaction ; Visual Acuity

PURPOSE: To report polymicrobial keratitis involving Pseudomonas aeruginosa, Acinetobacter baumannii, and Ochrobactrum anthropi. CASE SUMMARY: A 53-year-old female complained of pain and secretion in her right eye, which started 6 weeks before her visit. She applied steroid ointment, which was received from the dermatologist, to her eyelid 7 days prior to her visit but this treatment worsened her symptoms. At the initial visit, the visual acuity of the right eye was light perception, and purulent secretions were observed. Using a slit lamp, severe conjunctival hyperemia, hypopyon, and a ring-shaped central corneal ulcer were observed. The anterior chamber and fundus were not observed due to corneal lesions but ultrasonography showed no intraocular inflammation. Infectious keratitis was suspected and cultured by corneal scraping. During the incubation period, 0.5% moxifloxacin, 2% voriconazole, and 1% cyclopentolate were administered. A total of 400 mg of moxifloxacin and 100 mg of doxycycline were given orally. In the primary culture, Pseudomonas aeruginosa and Acinetobacter baumannii were identified so 5% ceftazidime, which was sensitive for the antibiotic susceptibility results was further instilled. Thereafter, the keratitis improved but the keratitis again worsened while maintaining the topical treatment. A secondary culture was positive for Ochrobactrum anthropi. Treatment with 1.4% gentamicin, which was sensitive for the antibiotic susceptibility test was added and the keratitis improved. A conjunctival flap was performed because of the increased risk of perforation. CONCLUSIONS: We report polymicrobial keratitis involving Pseudomonas aeruginosa, Acinetobacter baumannii, and Ochrobactrum anthropi for the first time in the Republic of Korea.
Acinetobacter baumannii ; Acinetobacter ; Anterior Chamber ; Ceftazidime ; Corneal Ulcer ; Cyclopentolate ; Doxycycline ; Eyelids ; Female ; Gentamicins ; Humans ; Hyperemia ; Inflammation ; Keratitis ; Middle Aged ; Ochrobactrum anthropi ; Ochrobactrum ; Pseudomonas aeruginosa ; Pseudomonas ; Republic of Korea ; Slit Lamp ; Ultrasonography ; Visual Acuity ; Voriconazole

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 compare the efficacy and safety of Botox and Neuronox in the management of benign essential blepharospasm (BEB). METHODS: We performed a triple-masked, randomized control study to compare Botox and Neuronox in 48 eyes of 24 patients with BEB. All 24 patients randomly received Botox or Neuronox in the periorbital region in a masked, randomized split-face manner, keeping the injection sites and doses uniform. The toxin preparation, injection, and clinical evaluations were done by three independent observers. Objective outcome measures included improvement in the severity of spasm, grading of the functional visual status, changes in palpebral fissure height, lagophthalmos, superficial punctate keratitis and Schirmer's test at 2 weeks, 6 weeks, and upon conclusion of the effect of the toxin. Subjective outcome measures included duration of the effect and a forced choice stating which half of the face was better. Evaluations were performed through clinical measurements, external digital photography, and high-definition videography. RESULTS: The mean duration of relief from spasms was 3.78 months (standard deviation, 1.58 months; range, 1 to 6 months). The improvement in the objective parameters like severity of spasm and functional visual status was statistically significant at the 2-week and 6-week follow-up visits (p < 0.001). The changes in palpebral fissure height, lagophthalmos, and superficial punctate keratitis were equally observed in both groups. At 2 and 6 weeks, three of 24 (12.5%) and one of 24 (4%) patients, respectively, reported an unequal effect between the two sides of the face, but this difference was not statistically significant. At final follow-up (conclusion of the toxin effect), patients reported equal effect with no preference for either hemiface. No statistically significant differences were found in the comparative analysis between the Neuronox and Botox groups. CONCLUSIONS: Neuronox and Botox are comparable in terms of their safety and efficacy in the management of BEB.
Blepharospasm ; Botulinum Toxins ; Botulinum Toxins, Type A ; Clothing ; Follow-Up Studies ; Humans ; Keratitis ; Masks ; Outcome Assessment (Health Care) ; Photography ; Spasm

Acanthamoeba castellanii has ubiquitous distribution and causes primary acanthamoebic keratitis (AK). AK is a common disease in contact lens wearers and results in permanent visual impairment or blindness. In this study, we observed the cytopathic effect, in vitro cytotoxicity, and secretion pattern of cytokines in human corneal epithelial cells (HCECs) induced by A. castellanii trophozoites and/or cysts. Morphological observation revealed that panked dendritic HCECs co-cultured with amoeba cysts had changed into round shape and gradually died. Such changes were more severe in co-culture with cyst than those of co-cultivation with trophozoites. In vitro cytotoxicity assay revealed the highest cytotoxicity to HCECs in the co-culture system with amoeba cysts. A. castellanii induced the expression of IL-1α, IL-6, IL-8, and CXCL1 in HCECs. Secreted levels of IL-1α, IL-6, and IL-8 in HCECs co-cultured with both trophozoites and cysts were increased at an early incubation time (3 and 6 hr). These results suggested that cytopathic changes and pro-inflammatory cytokines release of HCECs in response to A. castellanii, especially amoebic cysts, are an important mechanism for AK development.
Acanthamoeba castellanii ; Acanthamoeba ; Amoeba ; Blindness ; Coculture Techniques ; Cytokines ; Epithelial Cells ; Humans ; In Vitro Techniques ; Interleukin-6 ; Interleukin-8 ; Keratitis ; Trophozoites ; Vision Disorders

Acanthamoeba, one of free-living amoebae (FLA), remains a high risk of direct contact with this protozoan parasite which is ubiquitous in nature and man-made environment. This pathogenic FLA can cause sight-threatening amoebic keratitis (AK) and fatal granulomatous amoebic encephalitis (GAE) though these cases may not commonly be reported in our clinical settings. Acanthamoeba has been detected from different environmental sources namely; soil, water, hot-spring, swimming pool, air-conditioner, or contact lens storage cases. The identification of Acanthamoeba is based on morphological appearance and molecular techniques using PCR and DNA sequencing for clinico-epidemiological purposes. Recent treatments have long been ineffective against Acanthamoeba cyst, novel anti-Acanthamoeba agents have therefore been extensively investigated. There are efforts to utilize synthetic chemicals, lead compounds from medicinal plant extracts, and animal products to combat Acanthamoeba infection. Applied nanotechnology, an advanced technology, has shown to enhance the anti-Acanthamoeba activity in the encapsulated nanoparticles leading to new therapeutic options. This review attempts to provide an overview of the available data and studies on the occurrence of pathogenic Acanthamoeba among the Association of Southeast Asian Nations (ASEAN) members with the aim of identifying some potential contributing factors such as distribution, demographic profile of the patients, possible source of the parasite, mode of transmission and treatment. Further, this review attempts to provide future direction for prevention and control of the Acanthamoeba infection.
Acanthamoeba ; Amoeba ; Animals ; Asia, Southeastern ; Asian Continental Ancestry Group ; Encephalitis ; Humans ; Keratitis ; Nanoparticles ; Nanotechnology ; Parasites ; Plants, Medicinal ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Soil ; Swimming Pools ; Water