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The Lancet 05/2012; 380(9840):506. · 38.28 Impact Factor
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ABSTRACT: To study the safety and efficacy of treating early-stage Acanthamoeba keratitis (AK) with 20% alcohol-assisted epithelial debridement.
Four consecutive patients (2 wearing orthokeratology lenses and 2 wearing soft contact lenses) presented with pseudodendrites, radial keratoneuritis, and epithelial irregularities. Using a technique similar to laser-assisted subepithelial keratomileusis, we performed alcohol-assisted full-thickness debridement of the corneal epithelium and sent portions for smears, histopathologic and ultrastructural examinations, and culture for evidence of Acanthamoeba. Patients were then started on topical propamidine isethionate and 0.02% polyhexamethylene biguanide.
Immediately after debridement, minimal underlying anterior stromal infiltrate or haze was seen. Dosages of antiamoebic agents were tapered as corneal defects reepithelialized (in 1-3 weeks) with no evidence of post-debridement corneal infection. At the final follow-up, 1 cornea was transparent and the other 3 corneas had very faint subepithelial haze. Cultures of all epithelial debridement specimens yielded Acanthamoeba trophozoites and cysts, and histopathologic and electron microscopic examinations revealed Acanthamoeba organisms within corneal epithelial layers.
Alcohol-assisted epithelial debridement facilitates detachment of the full-thickness corneal epithelial layer in a controlled manner and seems to be effective in the treatment of early-stage AK. Unlike the fragile fragmented specimens obtained by mechanical scraping without alcohol soaking, epithelial sheets detached easily and the architectures were well preserved, permitting histopathologic and ultrastructural examinations. Most importantly, 20% alcohol-assisted epithelial debridement did not prevent culturing of Acanthamoeba from the removed epithelial specimens.
Cornea 01/2012; 31(4):442-6. · 1.73 Impact Factor
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Yi-Sheng Chang,
Chiou-Feng Lin,
Chao-Liang Wu,
Pao-Ying Kuo,
Fong-Sen Wu,
Chi-Chang Shieh,
Po-Wu Gean,
Shur-Tzu Chen,
Muh-Shy Chen,
Wen-Chuan Wu,
Ming-Hong Tai, Sung-Huei Tseng
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ABSTRACT: Benzyl alcohol (BA) is the preservative in triamcinolone acetonide (TA) suspensions, which are used in treating vitreoretinal diseases and during surgery. This paper investigates the molecular mechanisms and signaling pathways underlying BA toxicity in human retinal pigment epithelial (RPE) cells.
Cultured human RPE cells from the ARPE-19 cell line were exposed to culture medium alone (control) or with BA (0.0225, 0.225, 0.9, 3, or 9 mg/mL) for up to 6 hours. BA toxicity was assessed by TUNEL assay, propidium iodide/annexin V-FITC staining and flow cytometry, caspase activation assay, caspase and apoptosis inhibition assays, mitochondrial transmembrane potential by rhodamine staining and flow cytometry, reactive oxygen species by chemiluminescence, and apoptosis-inducing factor staining.
BA caused RPE cell death not only by necrosis but also by apoptosis, evidenced by exposure to 9 mg/mL BA for 6 hours leading to 19.0% early apoptotic cells and 64.2% apoptotic necrotic cells. Apoptotic signaling involved the immediate production of reactive oxygen species, activation of caspase-8, impairment of the mitochondrial transmembrane potential, and further activation of caspase-9 and -3. In addition, BA induced translocation of apoptosis-inducing factor into the nucleus, indicating caspase-independent apoptosis.
BA leads to necrosis of RPE cells and triggers mitochondrial apoptosis through both caspase-dependent and - independent pathways. Extreme caution is suggested in the intraocular use of TA suspensions and meticulous evaluation before adoption of BA as a preservative in the future development of ophthalmic formulations.
Investigative ophthalmology & visual science 02/2011; 52(7):4214-22. · 3.43 Impact Factor
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ABSTRACT: The authors describe an 11-year-old boy developing bilateral acute anterior uveitis, papillitis in one eye, and neuroretinitis in the other eye after an upper respiratory tract infection of influenza A virus, possibly H1N1. Steroid pulse therapy resolved these conditions. The authors recommend alertness for visual blurring and ocular inflammation after influenza A infection.
Journal of Pediatric Ophthalmology & Strabismus 01/2011; 48 Online:e30-3. · 0.63 Impact Factor
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Ophthalmology 01/2010; 117(1):190-190.e2. · 5.45 Impact Factor
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ABSTRACT: Pterygium is an ultraviolet (UV) related disease. UV radiation can produce DNA damage, which is repaired by the DNA repair systems. Among the DNA repair systems, the base excision repair (BER) and nucleotide excision repair (NER) systems are the major ones involved in repairing UV-induced DNA damage; X-ray repair cross complementary 1 (XRCC1) and human 8-oxoguanine DNA glycosylase 1 (hOGG1) are two BER genes, and xeroderma pigmentosum group A (XPA) and xeroderma pigmentosum group D (XPD) are two NER genes. Polymorphisms of these genes are associated with the differences in their repair DNA damage capacity, and they modulate the susceptibility to cancer. Because the polymorphism of hOGG1 was reported to be associated with pterygium, it is logical to assume the correlation between XRCC1, XPA, and XPD polymorphisms and pterygium formation.
One hundred and twenty-seven pterygium patients and 103 volunteers without pterygium were enrolled in this study. Polymerase chain reaction based analysis was used to resolve the XRCC1 codon 107, 194, 280, and 399; XPA A23G; XPA codon 228; and XPD codon 751 polymorphisms.
There were significant differences in the frequency of genotypes and alleles of XRCC1 codon 194 and 399 polymorphisms between the groups. In codon 194, individuals who carried at least 1 Trp allele had a decreased risk of developing pterygium compared to those who carried the Arg/Arg wild-type genotype (odds ratio [OR]=0.58; 95% CI: 0.34-0.98). In codon 399, individuals who carried at least 1 Gln allele had a threefold increased risk of developing pterygium compared to those who carried the Arg/Arg wild-type genotype (OR=3.06; 95% CI: 1.78-5.26). There were no significant differences in the frequency of the genotypes and alleles of XRCC1 codon 107 and 280, XPA A23G, and XPD codon 751 polymorphisms between the groups. The XPA codon 228 polymorphism was not detected in any of the cases or controls.
The XRCC1 codon 194 polymorphism causes a decreased risk of developing pterygium, but the codon 399 polymorphism increases the risk. There is no correlation between pterygium and XRCC1 codon 107 and 280, XPA A23G, and XPD codon 751 polymorphisms.
Molecular vision 01/2010; 16:698-704. · 2.20 Impact Factor
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ABSTRACT: To investigate the distribution of vimentin-expressing cells in human pterygium by immunocytochemical analysis of impression cytology specimens.
Using impression cytology, 3 samples of superficial conjunctival epithelial cells, including pterygium and adjacent conjunctiva were obtained from each of 24 eyes of 24 patients with unilateral primary pterygium, 16 eyes of 16 patients with unilateral recurrent pterygium, and the 40 unaffected fellow eyes. Specimens were processed in avidin-biotin complex immunostaining system with monoclonal anti-vimentin antibody and/or anti-CD1a antibody and counterstained with hematoxylin. Under light microscopy, the extent of vimentin-expressing cell infiltration beyond the pterygium margin was measured with a micrometer and the number of vimentin-expressing cells was counted in each of 6 randomly selected high-power fields in the specimens of pterygium and normal conjunctiva.
Two types of cells expressed vimentin, epithelioid cells and dendritic cells, whereas cells that expressed CD1a showed only a dendritic pattern. Vimentin-expressing round epithelioid cells (presumed pterygial cells) were present over the entire surface of the pterygium and also on adjacent normal-appearing conjunctiva, up to an average of 3.01 +/- 0.83 mm beyond the superior margin and 3.14 +/- 0.99 mm beyond the inferior margin of primary pterygium and 3.72 +/- 0.85 mm and 3.58 +/- 0.98 mm beyond the superior and inferior margins of recurrent pterygium. For the superior margin but not the inferior margin, the clinically occult extension of vimentin-expressing epithelioid cells was statistically significantly greater for eyes with recurrent pterygium compared with those with primary pterygium (P = 0.016). The density of dendritic (Langerhans) cells, stained by anti-vimentin and anti-CD1a antibodies, was statistically significantly lower in normal fellow eyes than in eyes with either primary (P < 0.001) or recurrent (P = 0.024) pterygium.
The vimentin-expressing epithelioid cells were present not only over the ocular surface of the pterygium but also in the normal-appearing conjunctiva adjacent to primary and recurrent pterygium. The increased density of Langerhans cells in pterygium might reflect a higher level of antigenic and mitogenic exposure in the conjunctiva. However, the significance of these 2 phenomena in the recurrence and pathogenesis of pterygium remains undetermined and merits further studies.
Cornea 04/2009; 28(5):547-52. · 1.73 Impact Factor
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ABSTRACT: During phacoemulsification for advanced cataracts, particularly when complicated by anterior segment abnormalities, capsulorhexis is very difficult and carries a high risk of complications. This study investigated the efficacy and safety of indocyanine green (ICG)-assisted phacoemulsification in complicated or simple advanced cataracts.
Thirty-two patients (35 eyes) underwent phacoemulsification for complicated advanced cataracts (group 1) or simple advanced (mature/hypermature) cataracts (group 2). Anterior segment abnormalities (corneal opacity, small pupil, or glaucoma) in group 1 complicated phacoemulsification. In both groups, 0.5% ICG was used for capsulorhexis, and subsequent procedures were performed in the same routine manner.
Group 1 included 15 patients (17 eyes) with a mean age of 60.0 years. Group 2 included 17 patients (18 eyes) with a mean age of 69.4 years (p<0.05). Continuous curvilinear capsulorhexis was completed in all eyes in group 2, but radial tears occurred in four (23.5%) eyes in group 1 (p<0.05). Phacoemulsification was performed uneventfully in all eyes in both groups. Postoperative complications (corneal edema, vitreous prolapse, posterior capsule opacity, elevated intraocular pressure) were seen in five (27.8%) eyes in group 1 and four (23.5%) eyes in group 2 (p>0.05). None of these were attributed to the use of ICG. Visual acuity improved in all eyes in group 2, but in only 11 (64.7%) in group 1 (p<0.01).
ICG-assisted phacoemulsification is safe and helpful for complicated or simple advanced cataracts. Differences between the two groups in patient age, intraoperative complications, and visual outcome could be explained by differences in the cause(s) of advanced cataracts.
Journal of the Formosan Medical Association 10/2008; 107(9):710-9. · 1.13 Impact Factor
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ABSTRACT: To investigate whether a polymorphism in the complement factor H gene determines the risk for the development of early age-related macular degeneration (AMD).
In this retrospective case-control study, we enrolled 133 unrelated Taiwan Chinese patients with early AMD and 180 age- and sex-matched control subjects. Early AMD was defined as the presence of extensive intermediate drusen or any large, soft drusen (> or = 125 microm), possibly accompanied by drusenoid retinal pigment epithelial detachment, and the absence of signs of late AMD. Genomic DNA was extracted from peripheral blood obtained from all the AMD patients and control subjects. Polymerase chain reaction was performed to analyze the complement factor H polymorphism (Y402H, rs1061170).
The genotype distribution differed significantly between the early AMD patients (TT 80%; TC 14%; and CC 6%) and controls (TT 91%; TC 9%; CC 0%; P = 9 x 10(-4)). The C allele frequency was significantly higher in the early AMD patients than in the controls (13% vs. 4%, P = 1 x 10(-4), odds ratios = 3.26, 95% confidence intervals = 1.76-6.02).
Our study demonstrated that the presence of the Y402H polymorphism in complement factor H is significantly associated with increased susceptibility to early AMD in Taiwan Chinese populations and that the C allele frequency is low in these populations.
Retina (Philadelphia, Pa.) 10/2008; 28(10):1416-20. · 2.93 Impact Factor
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ABSTRACT: To investigate vascular endothelial growth factor (VEGF) gene polymorphisms in unrelated Taiwan Chinese patients with late age-related macular degeneration (AMD) and controls.
Retrospective case-control study.
We enrolled 190 late AMD patients and 180 age-matched and gender-matched controls. Late AMD was classified as either dry (atrophic; grade 4) or wet (neovascular; grade 5) according to the International Age-Related Maculopathy Epidemiologic Study. Genomic deoxyribonucleic acid was prepared from peripheral blood obtained from all subjects. Polymerase chain reactions were used to analyze five candidate single-nucleotide polymorphisms (SNPs) in VEGF gene: +405C/G (rs2010963), -460 T/C (rs833061), +674 C/T (rs1413711), +936C/T (rs3025039), and -2578C/A (rs699947).
Of the 190 late AMD patients, dry AMD was diagnosed in 104 and wet AMD in 86. Among the five candidate SNPs studied, only the +936 C/T was significantly associated with wet AMD (T allele: 30% in wet AMD vs 14% in controls; P = 1.45 x 10(-5); odds ratio, 2.61; 95% confidence interval, 1.68 to 4.07). No single haplotype was significantly associated with either late AMD or controls. Based on genotypes at both VEGF +936 C/T and the complement factor H (CFH) Y402H (rs1061170), the association of VEGF +936 C/T to AMD was significant when analyzed conditional on the presence of the CFH C risk allele and vice versa (P < .0001). The VEGF +936 C/T was in strong linkage disequilibrium with CFH Y402H (D' = 0.99).
Both VEGF +936 C/T and CFH Y402H polymorphisms are dependently associated with wet AMD in the Taiwan Chinese population.
American Journal of Ophthalmology 07/2008; 145(6):1045-1051. · 4.22 Impact Factor
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ABSTRACT: The aim of the study was to investigate the toxicity of benzyl alcohol (BA), the preservative in commercial triamcinolone acetonide (TA) suspensions, on retinal pigment epithelial (RPE) cells. Cultured RPE cells from a human cell line (ARPE-19) and from rabbits were exposed to the balanced salt solution (control) or BA (0.0225, 0.225, 0.9, 3 or 9mg/mL) for 5, 30, 60, or 120min. Morphological changes of RPE cells were evaluated by the trypan blue in situ staining. The proportions of dead cells were quantitatively measured by the trypan blue exclusion assay, and those of functional cells were assessed by a mitochondrial dehydrogenase assay. The mechanism of cytotoxicity was determined by the acridine orange/ethidium bromide staining and DNA laddering technique. Furthermore, ultrastructural changes were observed by transmission electron microscopy. The results showed that RPE cell damage was dose- and time-dependent. BA 0.225mg/mL, the clinically relevant concentration in TA following intravitreal injection, caused ultrastructural damage and impaired human RPE cell function at 2h; but BA 0.0225mg/mL did not. BA 9.0mg/mL, the concentration in commercial TA suspensions, was toxic within 5min on each assay for both human and rabbit RPE cells. The major mechanism of cell death was necrosis. In conclusion, BA in commercial TA suspensions injected intravitreally (0.225-9mg/mL) can damage RPE cells. Our in vitro study on benzyl alcohol cytotoxicity has significant clinical implications for intravitreal use of TA. We suggest that, before a commercial TA solution is used intravitreally, the vehicle should be removed to prevent damaging the RPE layer, particularly during macular hole surgery. Commercial development of a preservative-free TA suspension for intraocular use is urged.
Experimental Eye Research 07/2008; 86(6):942-50. · 3.26 Impact Factor
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ABSTRACT: Pterygium is composed of proliferating fibrovascular tissue, and its formation and progression require neovascularization. Vascular endothelial growth factor (VEGF) is a specific mitogen for vascular endothelial cells and is essential for neovascularization. Recently, the VEGF-460 polymorphism was reported to be associated with increased VEGF basal promoter activity and with several fibrovascular diseases, such as proliferative diabetic retinopathy, endometriosis, and chronic renal disease. Therefore, this study evaluated the potential association between pterygium formation and VEGF-460 polymorphism.
One hundred twenty-seven pterygium patients and 102 volunteers without pterygium were enrolled in this study. Polymerase chain reaction-restriction fragment length polymorphism analysis was used to resolve the VEGF-460 genotypes of pterygium patients and normal controls.
There were no significant differences between pterygium and control groups in age, sex, and distribution of genotype and allelic frequency of VEGF-460 polymorphism. However, when results were stratified by sex, there were significant differences between female patients and controls in the distribution of genotype and allelic frequency of VEGF-460 polymorphism. Females who carried at least 1 C allele (C/C and C/T genotypes) had about a 2.5-fold increased risk of developing pterygium compared with those who carried the T/T genotype, and there was a significantly higher frequency of C/C and C/T genotypes in younger female patients than in older female patients. There were no differences between male patients and controls in the distribution of genotype and allelic frequency of the VEGF-460 polymorphism.
VEGF-460C polymorphism is associated with pterygium formation in female patients. Females who carried the C allele have increased risk of developing pterygium at a younger age.
Cornea 06/2008; 27(4):476-9. · 1.73 Impact Factor
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ABSTRACT: Subconjunctival injection of mitomycin C (MMC) before pterygium excision is a new adjunctive therapy to decrease pterygium recurrence. This study aimed to investigate the ultrastructural changes in pterygium after subconjunctival injection of MMC.
Four patients underwent subconjunctival injection of 0.1 mL of 0.15 mg/mL MMC 1 month before pterygium excision, and 2 patients served as controls without preoperative MMC injection. The excised specimens of pterygium were examined under transmission electron microscopy.
Epithelial cells of the treated pterygium remained unchanged. However, stromal fibroblasts were decreased in number, were oval rather than spindle-shaped, and had shrunken cytoplasmic processes; some were degenerating or apoptotic. Collagen and elastic fibers were decreased in density, disorganized, and degenerated. Capillary endothelial cells were thickened and swollen, with narrow or obliterated lumens. Axonal swelling and demyelination were observed.
Subconjunctival injection of MMC inhibits fibrovascular activity in the pterygial stroma, leading to degeneration of the extracellular matrix and nerve axons. These ultrastructural changes are consistent with the clinical observation of reduced vascularity in the pterygium after MMC injection and verify the effectiveness of subconjunctival MMC injection 1 month before pterygium excision in decreasing the risk of pterygium recurrence.
Cornea 06/2008; 27(4):471-5. · 1.73 Impact Factor
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ABSTRACT: To investigate the Met72Thr (T/C) polymorphism (rs1136287) of pigment epithelium-derived factor (PEDF) gene exon 3 in unrelated Taiwan Chinese patients with late age-related macular degeneration (AMD) and control subjects without AMD.
Retrospective case-control study.
We enrolled 190 unrelated Taiwan Chinese patients with late AMD and 90 age- and gender-matched control subjects. Grading of late AMD was classified based on a standardized set of diagnostic criteria established by the International Age-Related Maculopathy Epidemiologic Study. Late AMD was classified as either atrophic (dry, grade 4) or neovascular (wet, grade 5). Atrophic AMD refers to dry late-stage AMD without neovascularization, and wet AMD refers to neovascular AMD. Genomic deoxyribonucleic acid was prepared from peripheral blood obtained from all AMD patients and control subjects. Polymerase chain reaction analysis was used to analyze this polymorphism.
Of the 190 participants with late AMD, atrophic AMD was diagnosed in 104 patients and wet AMD was diagnosed in 86 patients. The genotype distribution of the Met72Thr (T/C) variant of PEDF was TT (homozygous T), TC (heterozygous), and CC (homozygous C). The T allele was found significantly more frequently in wet AMD patients than in controls (50% vs 31%; P =.0005). The allele frequencies in atrophic AMD (30%) and controls (31%) did not differ significantly (all P = .87). The homozygous T genotype was more prevalent in wet AMD than in controls (26/86 [30%] vs nine/90 [10%]; odds ratio, 3.9; all P = .0015). The homozygous T genotype in atrophic AMD patients (8%) and controls (10%) did not differ significantly (all P = .75).
Our data suggest that the PEDF Met72Thr T allele may be a risk factor for wet AMD in the Taiwan Chinese population. PEDF may play a role in the pathogenesis of wet AMD.
American Journal of Ophthalmology 05/2008; 145(4):716-721. · 4.22 Impact Factor
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ABSTRACT: To investigate HTRA1 polymorphisms in unrelated Taiwan Chinese patients with age-related macular degeneration (AMD) and control subjects without AMD.
A total of 95 unrelated Taiwan Chinese patients with AMD and 90 age- and sex-matched control subjects were enrolled in the study. Genomic DNA was prepared from peripheral blood obtained from all patients with AMD and control subjects. Polymerase chain reactions were used to analyze two HTRA1 single-nucleotide polymorphisms (rs11200638 [G/A] and rs10490924 [G/T]).
Of the 95 participants with AMD, dry AMD was diagnosed in 52 patients and wet AMD in 43 patients. Both rs11200638 (G/A) and rs10490924 (G/T) were significantly associated with all AMD (rs11200638: P = 6.7 x 10(-7) for an additive allele-dosage model, OR(het) = 1.97 [0.81, 4.81], OR(hom) = 8.59 [3.28, 22.49], A allele: 73% in all AMD versus 47% in controls; rs10490924: P = 9.2 x 10(-6), OR(het) = 1.86 [0.79, 4.35], OR(hom) = 5.08 [2.21, 11.70], T allele: 73% in all AMD versus 50% in controls). In terms of significance of association, rs11200638 was the most significantly associated variant. Subtype analysis including dry and wet AMD also revealed similar results. Haplotype analysis demonstrated that AT was significantly associated with wet and all AMD (P = 0.011 and 0.004, respectively), whereas GG was significantly associated with the control group when compared with all AMD (P = 0.035).
The study demonstrated that both single-nucleotide polymorphisms were significantly associated with dry and wet AMD and rs11200638 was the most significantly associated variant in a Taiwan Chinese population.
Retina 03/2008; 28(2):309-13. · 2.81 Impact Factor
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ABSTRACT: To investigate polymorphisms in a candidate gene of interleukin (IL) in unrelated Taiwan Chinese patients with late age-related macular degeneration (AMD) and control subjects without AMD.
In this retrospective, case-control study, 312 unrelated Taiwan Chinese patients with late AMD and 180 age- and sex-matched control subjects were enrolled. Late AMD was classified as either atrophic (dry) or neovascular (wet) according to the International ARM Epidemiologic Study. Genomic DNA was prepared from peripheral blood obtained from all patients with AMD and control subjects. Polymerase chain reactions were used to analyze 14 single-nucleotide polymorphisms (SNPs) in candidate genes of 5 ILs: IL-1beta(2q14): -511 T/C; IL-6 (7p21): -572 C/G and -596 G/A; IL-8 (4q13-q21): -251 A/T, +781 C/T, +1633 T/C, and +2767 A/T; IL-10 (1q31-q32): -592 A/C, -819 C/T, and -1082 G/A; and IL-18 (11q22.2-q22.3): +105 A/C, -137 C/G, -607 A/C, and -656 T/G.
In the 312 patients with late AMD, dry AMD was diagnosed in 136 and wet AMD in 176. Among the 14 SNPs in the 5 IL genes studied, only the IL-8 +781 C/T SNP was significantly associated with wet AMD (T allele: 46% in wet AMD versus 28% in the control subjects, P = 1.03 x 10(-6), OR = 2.16, 95% CI = 1.58-2.94). The association analysis based on genotypes at both IL-8 +781 C/T and the CFH Y402H demonstrated that the IL-8 +781 C/T to AMD was not significant when analyzed conditional on the presence of the CFH Y402H C risk allele and vice versa. The IL-8 +781 C/T was in low linkage disequilibrium with CFH Y402H (D' = 0.02).
The data suggest that Taiwan Chinese carriers of the IL-8 +781 T allele, independent of the CFH Y402H polymorphism, are at increased risk of developing wet AMD.
Investigative Ophthalmology & Visual Science 03/2008; 49(2):693-8. · 3.60 Impact Factor
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ABSTRACT: To assess the incidence, risk factors, management, and sequelae of intraoperative epithelial damage during LASIK using a linearly advancing microkeratome.
Chart review of 1873 eyes (956 patients) that underwent primary LASIK using the Automated Corneal Shaper microkeratome and the VISX Star S2 excimer laser. The main outcome measure was the incidence of intraoperative epithelial damage (patch of loosened epithelium with or without any frank epithelial defect). Univariate and multivariate logistic regression were performed to identify risk factors for intraoperative epithelial damage.
Intraoperative epithelial damage occurred in 31 (1.66%) of 1873 eyes. The incidence of intraoperative epithelial damage increased with increasing patient age (odds ratio [OR] 1.095/decade; 95% confidence interval [CI] 1.002 to 1.197, P=.045) and increasing years of contact lens wear (OR 1.136, 95% CI 1.024 to 1.261, P=.016). No correlation was found for gender, corneal curvature, central corneal thickness, microkeratome plate depth, or preoperative or postoperative refraction. The risk of intraoperative epithelial damage was significantly higher in the second eye if damage occurred in the first eye (66.7% versus 0.67%, OR 298.7, CI 78.2 to 1141.2, P<.001). Epithelial damage was managed successfully intraoperatively in all 31 eyes; recurrent corneal erosion was noted 4 months postoperatively in 1 eye but resolved after anterior stromal puncture.
The risk for intraoperative epithelial damage during LASIK increases with patient age, years of contact lens wear, and intraoperative epithelial damage in the first eye during simultaneous bilateral LASIK, but with proper intraoperative management, postoperative sequelae are rare.
Journal of refractive surgery (Thorofare, N.J.: 1995) 11/2007; 23(9):916-23. · 2.54 Impact Factor
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ABSTRACT: To investigate the toxic effects of triamcinolone acetonide (TA) suspensions on human retinal pigment epithelial (RPE) cells.
Cultured human RPE cells were exposed for up to 2 hours to one of seven solutions: control (balanced salt solution, BSS; Alcon Laboratories, Ft. Worth TX), commercial TA suspension (cTA), cTA from which the vehicle (which contains the preservative benzyl alcohol) had been removed (vehicle-removed TA, -vTA), vehicle of the cTA (V), or a 1:10 dilution (in BSS; Alcon) of cTA, -vTA or V. Solution effects were evaluated by phase-contrast microscopy of cells stained in situ with trypan blue and in vitro by trypan blue exclusion assay. RPE cell function was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The mechanism of TA toxicity was studied by acridine orange-ethidium bromide staining and epifluorescence microscopy, and ultrastructural changes were examined by transmission electron microscopy (TEM).
The effects of vehicle-removed solutions (-vTA and 1:10 -vTA) were similar to those of the control solution. Exposure for 1 hour or longer to a vehicle-containing solution (cTA and V) resulted in similar and significant degrees of cell damage that were dose and time dependent. The major mechanism of cell death was necrosis, and the early ultrastructural change was swelling of organelles in the cytoplasm.
Preserved commercial TA suspensions damaged human RPE cells, but vehicle-free solutions did not. The authors suggest removing the vehicle as completely as possible from TA solutions before they are administered intravitreally. Furthermore, they recommend that a commercial formulation of preservative-free TA suspension be made available for intraocular use.
Investigative Ophthalmology & Visual Science 07/2007; 48(6):2792-8. · 3.60 Impact Factor
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ABSTRACT: To study the acute ocular/cutaneous manifestations, causes, and management of the erythema multiforme (EM)/Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) disease spectrum.
We retrospectively reviewed the medical records of all EM/SJS/TEN patients hospitalized at National Cheng Kung University Hospital in Taiwan between 1988 and 2004. Demographic data, medical/medication histories, ocular/mucocutaneous manifestations, management, sequelae, and recurrence were analyzed.
A total of 207 patients 2 months to 95 years of age were hospitalized with 213 episodes/attacks of EM/SJS/TEN. Medications were the most common cause of any condition: for SJS, carbamazepine was most common; for EM or TEN, allopurinol was most common. In 128 of the 213 attacks (60.1%; 126 patients), ocular manifestations were documented during hospitalization, occurring more often in those with SJS (81.3%) or TEN (66.7%) compared with those with EM (22.7%; P < 0.01). The most frequent ocular treatments were topical steroids, topical antibiotics, and lubricants. Overall, 24 (18.8%) of 128 acute attacks in 126 patients were followed by ocular sequelae, mostly dry eye. Five (2.4%) of the 207 patients sustained a total of 6 recurrent attacks, in 3 cases because of the same medication.
Ocular manifestations occur in a high proportion of patients with EM/SJS/TEN. The most frequent causes were carbamazepine and allopurinol. A careful medication history should be obtained from these patients. Ophthalmic consultation, evaluation, and management are mandatory.
Cornea 03/2007; 26(2):123-9. · 1.73 Impact Factor
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ABSTRACT: Following the recent discovery of an abnormal expression of the p53 gene in the epithelium in pterygium, some researchers felt that pterygium is a tumor rather than a degenerative disease. Ultraviolet (UV) radiation has been reported to be associated with pterygium formation, however the mechanism whereby UV induces uncontrolled proliferation in pterygial cells is unclear. Because cyclooxygenase 2 (COX 2) was reported to exist and play an important role in UV-related cutaneous carcinogenesis, it is logical to suspect that COX 2 existed in pterygium. This study was designed to investigate the expression of COX 2 in pterygium.
Immunohistochemical staining using a monoclonal antibody to COX 2 was performed on 90 pterygial specimens, 40 normal conjunctiva, and 5 normal limbus.
In the pterygium group, 75 (83.3%) specimens stained positive for COX 2. The staining was limited to the cytoplasm of the epithelial layer and predominantly over the basal epithelial layer. No substantial staining was visible in the subepithelial fibrovascular layers. All specimens were negative in the normal conjunctiva and limbus group.
The present study showed COX 2 existed in pterygium. Given the role of COX 2 in cutaneous tumor carcinogenesis, we suggest COX 2 may also play a role in pterygium formation. This study could be used as the basis for future surveys of the causal relationship between COX 2 and pterygium as well as the effect of COX 2 inhibitor in preventing primary or recurrent pterygium.
Molecular vision 02/2007; 13:635-8. · 2.20 Impact Factor
