Hui-Chuan Kau

Increased oxidative DNA damage, 8-hydroxydeoxy- guanosine, in human pterygium.

PurposeChronic exposure to ultraviolet (UV) light is a widely accepted aetiological factor in the development of pterygium. UV radiation may induce production of reactive oxygen species via photosensitized oxidation, thus causing oxidative damage. This study was conducted to test the hypothesis that oxidative damage to DNA is increased in pterygium.MethodsImmunohistochemical analysis employing a monoclonal antibody specific for 8-hydroxy-2′-deoxyguanosine (8-OHdG), a ubiquitous maker of oxidative stress, was performed in three patients with primary pterygium. The levels of 8-OHdG in DNA isolated from the other 29 pterygium specimens and their adjacent normal conjunctival tissues were determined using enzyme-linked immunosorbent assay (ELISA).ResultsImmunohistochemistry of 8-OHdG showed a distinct pattern of more extensive and intense staining in the nuclei of pterygium tissue compared with that in their adjacent normal conjunctiva. ELISA also revealed that the average level of 8-OHdG in the pterygium tissues was 4.7-fold higher than that of the corresponding normal conjunctiva (P<0.001).ConclusionsThe increased levels of 8-OHdG in the pterygium tissues indicate that oxidative stress could play a role in the development of pterygium. These findings provide new information to better understand the pathogenesis of pterygium and are useful in the prevention and treatment of this disease.

Increased oxidative DNA damage, lipid peroxidation, and reactive oxygen species in cultured orbital fibroblasts from patients with Graves' ophthalmopathy: evidence that oxidative stress has a role in this disorder.

PurposeWe investigated the oxidative stress in orbital fibroadipose tissues and cultured orbital fibroblasts from patients with Graves’ ophthalmopathy (GO).MethodsThe content of 8-hydroxy 2′-deoxyguanosine (8-OHdG), an important biomarker of oxidative DNA damage, was measured in orbital fibroadipose tissues and cultured orbital fibroblasts from patients with GO and compared with age-matched normal controls. A product of lipid peroxidation, malondialdehyde (MDA), and intracellular reactive oxygen species (ROS) in cultured orbital fibroblasts was also determined.ResultsThere was no significant difference in the 8-OHdG content of orbital fibroadipose tissues between patients with GO and age-matched normal controls (P=0.074). However, the levels of 8-OHdG and MDA in GO orbital fibroblasts were significantly higher than those of normal controls (P=0.0026 and P<0.001, respectively). In addition, GO orbital fibroblasts had higher contents of superoxide anions and hydrogen peroxide compared with those of normal controls (P=0.0133 and 0.0025, respectively).ConclusionsOrbital fibroblasts represent the most abundant cell type among orbital connective tissues and exhibit great differences in their phenotypes. Increased oxidative DNA damage and lipid peroxidation, as well as higher intracellular ROS levels in GO orbital fibroblasts may have a role in the pathogenesis of GO.

Genetic polymorphism of hOGG1 and risk of pterygium in Chinese

AbstractPurpose Ultraviolet irradiation is known to cause oxidative DNA damage and is thought to be a major factor implicated in the pathogenesis of pterygium. The highly mutagenic 8-hydroxy-2′-deoxyguanosine, a marker for the evaluation of photo-oxidative DNA damage, can be repaired by human 8-oxoguanine glycosylase I (hOGG1). A transition of C to G at nucleotide position 1245 in exon 7 of the hOGG1 gene is associated with the substitution of cysteine for serine at codon 326. In this study, we investigated the association of the hOGG1 Ser326Cys polymorphism with pterygium in a Chinese population.Methods In all, 70 patients and 86 controls were enrolled in this study. The Ser326Cys polymorphism was determined by the polymerase chain reaction-restriction fragment-length polymorphism analysis. The association between this genetic polymorphism and risk of pterygium was examined by χ2-test and logistic regression.Results The allelic frequencies for the Ser and Cys variants of hOGG1 gene were not significantly different between the two groups. However, when compared with Ser/Ser and Ser/Cys genotypes combined, we found that the homozygous Cys/Cys genotype was more prevalent in pterygium patients than controls (P=0.024) with the odds ratio being 2.2 (95% CI: 1.1–4.5). In the pterygium group, the mean age of patients with the Cys/Cys genotype was younger than those with the other two genotypes (P=0.025).Conclusions Our findings suggest that the 1245C → G transition in exon 7 of the hOGG1 gene, which results in Ser326Cys substitution of the enzyme, might play a role in the susceptibility of humans to pterygium.

Corneal ulcer of the side port after phacoemulsification induced by Acinetobacter baumannii

A 75-year-old man had clear corneal phacoemulsification using a temporal approach in the left eye. Two months after surgery, a focal corneal epithelial defect developed with infiltration near the lower limbus on the site of the side-port incision. The culture of corneal scrapping grew Acinetobacter baumannii, which is resistant to most ordinary antibiotics in sensitivity tests. After appropriate antibiotic treatment, the ulcer healed gradually with vessel ingrowth. Acinetobacter baumannii is usually found in nosocomial infection of immune-compromised patients in the intensive care unit. It is a rare pathogen of infectious keratitis. Our case, with its unusual infection site, may point to potential risk factors for this pathogen.

Lymphoepithelial carcinoma of the lacrimal sac

This case illustrates two non-infectious forms of endophthalmitis associated with IVTA in the same eye. First, a rapid sterile endophthalmitis resulted from an acute reaction to either triamcinolone or its vehicle components. This inflammatory reaction may be similar to that of toxic anterior shock syndrome (TASS). Our patient with chronic uveitis developed this when the IVTA was combined with a cataract surgery. Previous intraocular surgery and uveitis have been reported to be risk factors for sterile endophthalmitis. Subsequently, he developed pseudoendophthalmitis, which results from the anterior migration of triamcinolone crystals. In our patient, loose zonules may have contributed to the anterior migration. The patient’s findings were not typical of infectious endophthalmitis, given the rapidity of the hypopyon and lack of pain. However, the dramatic rise in IOP is uncommon in non-infectious endophthalmitis. Given the atypical presentation, aspirates were taken for culture. To the best of our knowledge, this is the first report of sterile endophthalmitis and pseudoendophthalmitis in the same eye.

Adenoid cystic carcinoma arising in the inferior orbit without evidence of lacrimal gland involvement.

A 60-year-old woman sought treatment for right orbital fullness and intermittent headache. CT revealed an inferior orbital mass along the inferior rectus muscle. Incisional biopsy revealed an adenoid cystic carcinoma. Orbital exenteration followed by concurrent radiotherapy and chemotherapy was performed. The lacrimal gland was uninvolved by tumor microscopically. Although rare, adenoid cystic carcinoma must be considered in the differential diagnosis of an orbital tumor, because the unusual location of an orbital adenoid cystic carcinoma may make its early detection difficult.

Clinical features, microbiological profiles and treatment outcome of lacrimal plug-related canaliculitis compared with those of primary canaliculitis

Aims To compare the clinical features and treatment outcome between lacrimal plug-related canaliculitis and primary canaliculitis. Methods Patients with plug-related canaliculitis and primary canaliculitis between 2007 and 2014 in a medical centre were collected. Charts were reviewed for clinical features, microbiological profiles, time lapse between plug insertion and symptom onset, type of plug and outcomes. Results Of 76 eligible cases collected, 13 were plug-related canaliculitis and 63 were primary canaliculitis. The most common presenting symptom was discharge in both groups (85% and 79%, respectively). The average time interval from plug insertion to symptoms onset was 5.5 years. Most canaliculitis developed in women, especially for plug-related canaliculitis, when compared with primary canaliculitis (100% vs 65.1%; p=0.015). The most common isolated microorganism was Pseudomonas aeruginosa in plug-related canaliculitis (46%) and Streptococcus in primary canaliculitis (28%), respectively. Isolation of Pseudomonas was significantly higher in plug-related canaliculitis than in primary canaliculitis (46% vs 12%; p=0.029). Most plug-related canaliculitis resolved after removal of plugs by canaliculotomy (12 cases, 93%). Most identified plug was SmartPlug (seven cases), followed by EaglePlug (two cases) and Herrick Lacrimal Plug (two cases). There was no recurrence in patients with plug-related canaliculitis, however, recurrence developed in seven patients (11%) with primary canaliculitis. Conclusions In comparison with primary canaliculitis, plug-related canaliculitis appear to be more prevalent in women and show a different microbiological profile. Retrieval of infected plug by canaliculotomy and adequate antibiotics can achieve a good outcome. Long-term follow-up is required because canaliculitis may develop several years after plug insertion.

Comparison of the Clinical Characteristics and Outcome of Benign and Malignant Eyelid Tumors: An Analysis of 4521 Eyelid Tumors in a Tertiary Medical Center

We retrospectively reviewed the clinical features and outcome of benign and malignant eyelid tumors from 1995 to 2015 in a tertiary medical center. Among 4,521 histologically confirmed eyelid tumors, 4,294 (95.0%) were benign tumors and 227 (5.0%) were malignant tumors. The mean age at diagnosis was significantly higher in patients with malignant lid tumors than those with benign lid tumors (72.5 and 55.4 years, resp., p < 0.001). The most common benign eyelid tumors were intradermal nevus (21.1%), followed by seborrheic keratosis (12.6%) and xanthelasma (11.2%). The most common malignant eyelid tumors were basal cell carcinomas (57.8%), followed by sebaceous gland carcinomas (21.1%) and squamous cell carcinomas (10.1%). There was a relative male predominance (63.4% and 49.2%, resp., p < 0.001) and higher recurrence rate (11.9% and 4.4%, resp., p < 0.001) in malignant lid tumors as compared with those of benign lid tumors. Twenty-two patients (9.7%) received orbital exenteration/enucleation. Eight patients (3.5%) with malignant lid tumors died of disease. Patients with eyelid melanoma were associated with a high mortality rate (25.0%). It is important to differentiate between benign and malignant eyelid tumors, because they may cause cosmetic disfigurement and severe morbidity, especially in those with malignant eyelid tumors.

Needle decompression in a patient with vision-threatening orbital emphysema

Orbital emphysema is a condition resulting from trapping of air in loose subcutaneous or orbital tissues from the paranasal sinuses. This condition commonly seen in patients with a history of periorbital trauma or surgery, especially following sneezing or nose blowing. It usually has a benign and self-limited course. However, the entrapped orbital air can cause a substantial increase in pressure with restricted ocular motility or vascular compromise and become severe enough to cause visual impairment. We herein present the case of a patient who developed severe orbital emphysema after blunt trauma followed by sneezing and was successfully treated with needle decompression of intraorbital air. Emergency needle decompression resulted in an improvement in vision and intraocular pressure.

Lacrimal Gland Pleomorphic Adenoma Masquerading as Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy is the most common cause of proptosis in adult female, especially those with positive thyroid antibody. Sometimes, other diagnoses should be considered. A 45-year-old female presented with progressive right proptosis and mild diplopia for 2 years. One year earlier, she had been diagnosed with thyroid-associated ophthalmopathy because of abnormal thyroid autoantibody. Computed tomography scan showed a 2.4- × 1.9- × 1.6-mm heterogeneous soft-tissue density lying above the left eye. Excisional biopsy of this mass revealed the histopathologic diagnosis of pleomorphic adenoma. This case highlights the need for including other diagnoses such as pleomorphic adenoma in the differential diagnosis of patients with proptosis, diplopia and abnormal thyroid antibody.