Ching-Hsi Hsiao

Intrascleral dissemination of infectious scleritis following pterygium excision

AIMS To assess the clinical pictures, possible pathogenesis, management, and therapy of patients with infectious scleritis associated with multifocal scleral abscesses following pterygium excision. METHODS The records of patients with infectious scleritis after pterygium excision who developed multifocal scleral abscesses presenting from 1988 to the end of 1995 were reviewed. Early culture of abscesses was performed, and topical, systemic antimicrobials, or both were given to all patients. Fourteen eyes were operated on in addition to antimicrobial treatment. RESULTS The initial culture reports of scleral ulcers identified Pseudomonas species in 12 of these 18 patients, Aspergillus in one, Mycobacterium fortuitum in one, and mixed organisms in four. Subsequent abscess cultures were taken from 15 of the infected eyes, and revealed the same organism as the initial culture in 12. Associated complications included four serous retinal detachments, three choroidal detachments, two double detachments, five complicated cataracts, and four recurrences of the initial infection. Four eyes required eventual enucleation and 11 eyes regained useful vision. CONCLUSIONS With subsequent abscess cultures proving to be the same organism as found in the initial ulcer, the abscess formation appears to represent intrascleral dissemination. Early diagnosis and appropriate, prolonged topical plus systemic antimicrobial treatment are essential to halt the progression of such severe infections.

Methicillin-Resistant Staphylococcus aureus Ocular Infection: A 10-Year Hospital-Based Study

PURPOSE To characterize the patient demographics, clinical features, and antibiotic susceptibility of ocular infections caused by methicillin-resistant Staphylococcus aureus (MRSA), including community-associated (CA) and healthcare-associated (HA) isolates. DESIGN Retrospective, observational study. PARTICIPANTS Patients (n = 519) with culture-proven S. aureus ocular infections seen between January 1, 1999, and December 31, 2008, in Chang Gung Memorial Hospital. METHODS Data collected included patient demographics and clinical information. Antibiotic susceptibility was verified by disc diffusion method. MAIN OUTCOME MEASURES Proportion of MRSA in S. aureus ocular infections and the clinical characteristics, diagnoses, and antibiotic susceptibility patterns of CA-MRSA versus HA-MRSA ocular infections. RESULTS We identified 274 patients with MRSA ocular infections, which comprised 181 CA-MRSA and 93 HA-MRSA isolates. The average rate of MRSA in S. aureus infections was 52.8% with a stable trend, whereas the annual ratio of CA-MRSA in ocular MRSA infections averaged 66.1% and tended to increase over the 10-year interval. Patients with ocular CA-MRSA were younger. Lid and lacrimal system disorders were more common, but keratitis, endophthalmitis, and wound infection were less common among CA-MRSA cases than HA-MRSA cases. Both CA-MRSA and HA-MRSA isolates were resistant to clindamycin and erythromycin, but CA-MRSA was more susceptible to sulfamethoxazole/trimethoprim. CONCLUSIONS Community-associated MRSA is an important pathogen of ocular infections; CA-MRSA and HA-MRSA ocular infections differ demographically and clinically, but both strains were multi-resistant in Chang Gung Memorial Hospital, one of the biggest referral centers in Taiwan. In a country with a high prevalence of MRSA, ophthalmologists should be aware of such epidemiologic information.

Amniotic membrane transplantation for persistent corneal ulcers and perforations in acute fungal keratitis.

Purpose: To report the therapeutic effect and complications of amniotic membrane transplantation (AMT) in acute fungal keratitis. Methods: Diagnosis of fungal keratitis was confirmed by cultures in 23 eyes of 23 patients. The indications to perform AMT were to promote reepithelialization in non-healing ulcers or to prevent corneal perforation. Antifungal agents were administered throughout the whole course of hospitalization. Repeated cultures were performed immediately before AMT. The main outcome measurements were epithelial healing rate, necessity of therapeutic penetrating keratoplasty (TPK), and persistence of infection. Results: During a mean follow-up time of 20.6 months ± 23.22 (6-65 months) AMT was performed during the active phase of the keratitis (fungal culture was still positive) in 16 patients (69.6%), and during the inactive phase (fungal culture negative) in 7 patients (30.4%). Single-layer AMT was performed in 17 patients, and double-layer AMT was performed in 6 patients with corneal perforation and anterior chamber collapse. Complete epithelialization was observed in 12 patients (75%) in the active group and in 7 patients (100%) in the inactive group. Treatment failure requiring TPK was experienced in 4 patients (25%) in the active group. Persistent fungal keratitis was noted in 2 patients (8.7%) in that group. The final visual acuity improved in 17 cases, worsened in 2 cases, and remained unchanged in 4 cases. Twelve of the 23 eyes (52.2%) in this study preserved useful vision (20/400 and better) with or without subsequent surgeries. Conclusion: AMT is effective in promoting epithelialization and preventing corneal perforations in acute fungal keratitis, and there is no risk of rejection. However, the risk of persistent or recurrent infection necessitates continued antifungal treatment and patient monitoring.

Infectious keratitis related to overnight orthokeratology.

PURPOSE To report the microbial culture results, clinical course, and visual outcomes for infectious keratitis related to overnight orthokeratology. METHODS The records of patients with infectious keratitis related to overnight orthokeratology who presented to a tertiary referral center from April 2000 to March 2003 were retrospectively reviewed. RESULTS Twenty patients (21 eyes) were included; 1 patient had bilateral infections. The average age of the patients was 14 years. The average period between the time the patient started the overnight orthokeratology program and the onset of infectious keratitis was 23 months. Thirteen of the 21 eyes were culture positive. Organisms cultured were Pseudomonas aeruginosa (n = 9), coagulase-negative Staphylococcus species (n = 2), Serratia marcescens (n = 1), and Acathamoeba species (n = 1). All patients responded well to medical antimicrobial treatment. Final best spectacle-corrected visual acuity ranged from 20/20 to 20/100. CONCLUSIONS Infectious keratitis is a potential complication of overnight orthokeratology that may cause significant visual impairment. Parents of children who consider overnight orthokeratology should evaluate the benefit of temporary myopia reduction and the risk of infection.

Intraocular lens implantation after penetrating keratoplasty.

Purpose. We evaluated the clinical results of nonsimultaneous penetrating keratoplasty, cataract extraction, and intraocular lens (IOL) implantation (two-stage surgery) for combined corneal disease and cataract. Methods. Twenty-six eyes of 24 patients with an average age of 46 years who underwent two-stage surgery were studied retrospectively. Variables included visual acuity, refractive status, specular microscopy before and after IOL implantation (6 months), and the occurrence of graft failure. Astigmatism was corrected by suture removal and relaxing incision. The mean follow-up after IOL placement was 16 months. Results. Unaided visual acuity was 20/100 or better in 22 (83%) eyes after the second procedure. Twenty-one (81%) eyes had an aided visual acuity of at least 20/40. The mean refractive and absolute errors were −1.49 ± 1.39 diopters (D) and 1.55 ± 1.30 D, respectively. The mean keratometric and refractive cylinders were 3.50 D and 2.26 D, respectively. Nineteen (73%) eyes had a spherical equivalent refraction within 2 D of emmetropia. Anisometropia (≥3 D) occurred in four (15%) eyes. The endothelial cell density, the coefficient of variation, and the percentage of hexagonal cells documented by specular microscopy were not significantly different before and after IOL implantation. Complications included three rejections, two cases of herpetic recurrence, and one late decompensation. Two graft failures (8%) occurred after secondary surgery. Conclusion. The two-stage surgery is a safe and effective modality.

Staphylococcus aureus Ocular Infection: Methicillin-Resistance, Clinical Features, and Antibiotic Susceptibilities

Background Methicillin-resistant Staphylococcus aureus (MRSA) infection is an important public health issue. The study aimed to determine the prevalence of ocular infections caused by MRSA and to identify the clinical characteristics and antibiotic susceptibility of ocular MRSA infections by comparing those of ocular methicillin-sensitive S. aureus (MSSA) infections. Methodology/Principal Findings The medical records of the patients (n = 519) with culture-proven S. aureus ocular infections seen between January 1, 1999 and December 31, 2008 in Chang Gung Memorial Hospital were retrospectively reviewed. Two hundred and seventy-four patients with MRSA and 245 with MSSA ocular infections were identified. The average rate of MRSA in S. aureus infections was 52.8% and the trend was stable over the ten years (P value for trend  = 0.228). MRSA ocular infections were significantly more common among the patients with healthcare exposure (P = 0.024), but 66.1% (181/274) patients with MRSA ocular infections had no healthcare exposure. The most common clinical presentation for both MRSA and MSSA ocular infections was keratitis; MRSA and MSSA caused a similar disease spectrum except for lid infections. MRSA was significantly more resistant than MSSA to clindamycin, erythromycin and sulfamethoxazole/trimethoprim (all P<0.001). Conclusions/significance We demonstrated a paralleled trend of ocular MRSA infection in a highly prevalent MRSA country by hospital-based survey. Except for lid disorder, MRSA shared similar spectrum of ocular pathology with MSSA. Since S. aureus is a common ocular pathogen, our results raise clinician’s attention to the existence of highly prevalent MRSA.

Pediatric herpes simplex virus keratitis.

Purpose: To report the clinical characteristics and visual outcomes of pediatric herpes simplex virus (HSV) keratitis. Methods: The medical records of 29 patients younger than 16 years with HSV keratitis who were diagnosed and treated at Chang Gung Memorial Hospital, Taoyuan, Taiwan, between 1996 and 2004 were retrospectively reviewed. The diagnosis of HSV keratitis was proven by a positive viral culture and/or real-time quantitative polymerase chain reaction or by a clear history of dendritic keratitis or herpetic kerato-uveitis. Type of HSV keratitis, recurrence rate, and visual outcome were analyzed. Results: The average age at the entry into the study was 5.7 years (range: 7 months to 15 years). Mean follow-up time was 35.3 months (range: 2-69 months). Epithelial keratitis including dendritic and geographic ulcers was noted in 14 eyes, stromal keratitis in 2 eyes, stromal keratitis concurrent with epithelial keratitis in 8 eyes, and endotheliitis in 6 eyes. One patient had sequential involvement of both eyes. Thirteen patients (45%) developed recurrent HSV keratitis after the first documented episode. Female gender (but not age or the type of keratitis) was significantly associated with recurrences. Five patients who were maintained on oral valacyclovir prophylaxis up to 1 year had no recurrence during the period. Fifteen of 21 patients younger than 8 years of age had best-corrected visual acuity available at last follow-up, and 10 patients developed amblyopia. Conclusions: Children with HSV keratitis are at risk for recurrent keratitis and amblyopia. Prolonged systemic antiviral prophylaxis may help to prevent such consequences.

The successful medical treatment of a case of Paecilomyces lilacinus keratitis.

Purpose: To report the successful medical treatment of Paecilomyces lilacinus keratitis case with topical voriconazole. Methods: A 72-year-old male farmer developed a corneal infection in the left eye and corneal culture revealed Paecilomyces lilacinus. Infection was progressive despite initial treatment with hourly topical amphotericin B (1.5 mg/mL) and topical 5% natamycin. Treatment was switched to hourly topical voriconazole (10 mg/mL). Results: The infection responded well to topical voriconazole and resolved within 1 month without any surgical intervention. The patients best-corrected visual acuity was 20/200 secondary to central corneal scarring and a cataract in the left eye at the 10-month follow-up. Conclusion: Voriconazole may be effective in the treatment of Paecilomyces lilacinus keratitis refractory to standard antifungal agents. Early organism detection and appropriate treatment are necessary to eradicate such an infection.

Expression of Tissue Inhibitor of Metalloproteinase-4 in Normal Human Corneal Cells and Experimental Corneal Neovascularization

Purpose: To study the expression of TIMP-4 in cultured corneal cells and in corneal neovascularization. Methods: Human limbo-corneal epithelial cells, fibroblasts, and endothelial cells were cultured in serum-free, PMA- or basic fibroblast growth factor (bFGF)-treated condition. Neovascularization in rat cornea was induced by suturing. The expression of TIMP-4 was examined by immunohistochemistry, Western blot and RT-PCR. Results: TIMP-4 was constitutively expressed in cultured human corneal cells. The expression was only mildly enhanced after mitogen treatment. TIMP-4 immunoreactivity was predominantly expressed in normal rat corneal epithelium, and also in ingrowing blood vessels following suturing, which persisted up to day 28. Increased staining in corneal epithelium and blood vessels were also noted in vascularized human corneas. Conclusions: TIMP-4 is expressed in the cornea, which may play a role in modulating extracellular matrix remodeling associated with corneal wound healing and angiogenesis.

Retained Descemet's membrane after penetrating keratoplasty

Retained Descemets membrane is a rare complication of penetrating keratoplasty (PKP). The membrane can become progressively opaque and threaten the health of the corneal graft. We report such a case involving a 53-year-old man. Simultaneous surgical removal of the membrane and phacoemulsification with intraocular lens implantation were performed 3 months after PKP. The graft remained clear and best corrected visual acuity was 20/20 2 years after secondary surgery.