Genome-wide association study in a Chinese population with diabetic retinopathy.

Diabetic retinopathy (DR) is a leading cause of preventable blindness in adults. To identify genetic contributions in DR, we studied 2071 type 2 diabetics. We first conducted a genome-wide association study of 1007 individuals, comparing 570 subjects with ≥8 years duration without DR (controls) with 437 PDR (cases) in the Chinese discovery cohort. Cases and controls were similar for HbA1c, diabetes duration and body mass index. Association analysis with imputed data identified three novel loci: TBC1D4-COMMD6-UCHL3 (rs9565164, P = 1.3 × 10(-7)), LRP2-BBS5 (rs1399634, P = 2.0 × 10(-6)) and ARL4C-SH3BP4 (rs2380261, P = 2.1 × 10(-6)). Analysis of an independent cohort of 585 Hispanics diabetics with or without DR though did not confirm these signals. These genes are still of particular interest because they are involved in insulin regulation, inflammation, lipid signaling and apoptosis pathways, all of which are possibly involved with DR. Our finding nominates possible novel loci as potential DR susceptibility genes in the Chinese that are independent of the level of HbA1c and duration of diabetes and may provide insight into the pathophysiology of DR.

Polymorphism in the TNF-α(-863) locus associated with reduced risk of primary open angle glaucoma.

PURPOSE: Tumor necrosis factor-α (TNF-α), an important proinflammatory cytokine, exerts a variety of physiologic and pathogenic effects that lead to tissue destruction. Recent laboratory evidence indicates that TNF-α have either protective or adverse effects on primary open angle glaucoma (POAG). Inheritance of the TNF-α (-863) C allele has been associated with an elevated risk of Alzheimer disease. The neuronal injuries associated with Alzheimer disease have several similarities with the optic nerve changes often seen with POAG. In this study we investigated the possible association between the TNF-α (-863) polymorphism and the development of POAG. METHODS: A total of 234 patients with POAG were recruited and compared with 230 healthy controls in a Chinese population. Sequence-specific primers with 3' end mismatches were used to identify the presence of specific allelic variants by polymerase chain reaction (PCR) amplification. Patients and controls were genotyped for the A/C polymorphism at position -863 of the TNF-α gene promoter region. RESULTS: The frequency of the TNF-α (-863)A allele (22% versus 30%, respectively; p=0.007) and the carriers of the TNF-α (-863)A allele (37% versus 48%; p=0.017, OR 0.63, 95% CI 0.44-0.92) were lower in POAG patients compared with those in controls. There is a reduced risk of POAG associated with homozygosity for the TNF-α (-863)A allele (AA genotype) compared with that in the control population (AA genotype; 7% versus 11%, respectively, p=0.037; OR 0.5, 95% CI 0.26-0.98). CONCLUSIONS: The TNF-α (-863)A allele polymorphism may be a protective factor in the development of POAG.

Pharmacokinetics of intracameral voriconazole injection.

Elimination of voriconazole after intracameral injection exhibited an exponential decay with a half-life of 22 min. Voriconazole levels in the vitreous humor were below the detectable limit. The aqueous concentrations achieved with a 25-microg dose during the first 2 h were greater than the previously reported MICs of organisms most involved in fungal endophthalmitis. A rapid decline in intracameral concentration suggests that frequent supplementation of intracameral voriconazole may be required in clinical settings.

Clearance of intravitreal voriconazole.

UNLABELLED: Purpose To investigate the elimination rate of voriconazole after intravitreal injection in rabbits. METHODS: Intravitreal injections of 35 microg/0.1 mL voriconazole were administered to rabbits. Vitreous and aqueous humor levels of voriconazole were determined at selected time intervals (1, 2, 4, 8, 16, 24, and 48 hours), and the in vitreous half-life was calculated. Four to six eyes per time point after injection were enucleated and immediately stored at -80 degrees C. Aqueous humor samples were withdrawn before enucleation, and vitreous samples were obtained from ocular dissection and isolation at various time intervals. Voriconazole concentrations in vitreous and aqueous humor were assayed with high-performance liquid chromatography (HPLC). RESULTS: The concentration of intravitreal voriconazole at various time points exhibited exponential decay with a half-life of 2.5 hours. The mean vitreous concentration was 18.912 +/- 2.058 microg/mL 1 hour after intravitreal injection; this declined to 0.292 +/- 0.090 microg/mL at 16 hours. The mean aqueous concentration was much lower and showed a decline from 0.240 +/- 0.051 microg/mL at 1 hour to undetectable levels 8 hours after injection. CONCLUSIONS: Vitreous concentrations achieved during the first 8 hours were greater than the previously reported minimum inhibitory concentrations (MICs) of organisms most involved in fungal endophthalmitis. A rapid decline of intravitreal concentration suggests that supplementation of intraocular voriconazole to maintain therapeutic levels may therefore be required in clinical settings. Further studies are needed to determine the elimination rate of voriconazole after intravitreal injection in humans.

Investigation of the association between interleukin-1beta polymorphism and normal tension glaucoma.

PURPOSE: In normal tension glaucoma (NTG), factors other than elevated intraocular pressure are likely to have a role in the pathogenesis of optic neuropathy. The potential similarities in cellular apoptosis leading to neurodegeneration between Alzheimer's disease and NTG were shown in recent studies. The interleukin-1beta (IL-1beta; -511) and IL-1beta (+3953) polymorphisms were found to increase risk with Alzheimer's disease. The purpose of this study was to test the hypothesis that the IL-1beta polymorphism is associated with NTG in the Chinese population. METHODS: This is a cohort study in a Chinese population that involved 231 people with NTG and 245 healthy controls. Genomic DNA was amplified by a polymerase chain reaction, followed by the enzymatic restriction fragment length polymorphism technique. Patients and controls were genotyped for the C/T polymorphism at position -511 and +3953 of the IL-1beta gene. Genotypes for NTG and control groups were compared for statistically significant differences. RESULTS: There was no significant difference in genotype frequency or allele frequency distribution of the IL-1beta gene polymorphisms (position -511 and +3953) between NTG patients and the control group (p >0.3). CONCLUSIONS: Our study showed no evidence for an association between the IL-1beta (-511) and IL-1beta (+3953) polymorphisms and NTG. The IL-1beta gene polymorphisms (position -511 and +3953) may not play a key role in NTG pathogenesis in Chinese population.

Spontaneous resolution of partial donor disk dislocation after deep lamellar endothelial keratoplasty.

PURPOSE: We report a case of spontaneous resolution of donor disk partial dislocation after deep lamellar endothelial keratoplasty (DLEK). DESIGN: Case report. METHODS: A 70-year-old male with right pseudophakia bullous keratopathy underwent DLEK. Postoperatively, a partial dislocation of inferior donor disk was noted. Repositioning surgery with gas tamponade was performed. RESULTS: The interfacial separation remained after gas tamponade. Two weeks later, corneal edema subsided, and there was a reduction in interfacial separation. One month after DLEK, donor disk spontaneously attached to recipient corneal bed. At the six-month follow-up, astigmatism was 1.75 diopters. Specular microscopy showed endothelial counts of 1520 cells/mm(2). Spectacle-corrected visual acuity improved to 6/15. CONCLUSIONS: Partial dislocation of donor disk after DLEK has a possibility of spontaneous resolution, even after a failed attempt at gas tamponade.

Supratarsal triamcinolone injection in the treatment of superior limbic keratoconjunctivitis.

PURPOSE: To evaluate the efficacy of supratarsal triamcinolone injection in the treatment of superior limbic keratoconjunctivitis (SLK). METHODS: Forty eyes of 20 patients were diagnosed with SLK. All eyes with long-standing severe ocular irritation unresponsive to topical steroid and artificial tears were treated with supratarsal triamcinolone injection in addition to ongoing treatment of dry eye. Objective tarsal conjunctiva inflammation, bulbar conjunctiva, cornea staining, and subjective symptom gradings were performed before and after 2 weeks of therapy. All patients underwent laboratory evaluations of underlying systemic abnormalities. RESULTS: All 40 eyes responded well to treatment and had long-term (average, 7.8 months) improvement of irritation and dry sensation and improvement of inflammation and staining of conjunctiva and cornea. Fourteen patients (70%) had associated autoimmune diseases. There were no irreversible complications related to this therapy. CONCLUSIONS: Supratarsal triamcinolone injection effectively and rapidly resolved symptoms and signs associated with SLK. It is helpful as primary or adjunctive therapy for SLK.

Normal tension glaucoma is not associated with the interleukin -1alpha (-889) genetic polymorphism.

BACKGROUND: Factors other than intraocular pressure are likely to play a role in the pathogenesis of glaucomatous optic neuropathy, particularly in individuals with normal tension glaucoma (NTG). Recent laboratory evidence has shown that there are potential similarities between Alzheimer disease and NTG in cellular apoptosis leading to neurodegeneration. IL-1alpha (-889) T allele polymorphism has been found to increase the risk of developing Alzheimer disease. The aim of this study was to test in a Chinese cohort the hypothesis that IL-1alpha (-889) polymorphism is associated with NTG. METHODS: One hundred sixty-two unrelated patients with NTG were recruited and compared with 167 controls in a Chinese population. Genomic DNA was amplified by polymerase chain reaction, followed by enzymatic restriction fragment length polymorphism technique. Patients and controls were genotyped for the C/T polymorphism at position -889 of the IL-1alpha gene promoter region. RESULTS: There was no significant difference in the frequency of IL-1alpha (-889) alleles or genotypes in the NTG population compared with that in the control group. CONCLUSIONS: We conclude that C/T polymorphism at position -889 of the IL-1alpha gene promoter region does not increase the risk of developing NTG. However, further studies on NTG are necessary to investigate the genetic basis and factors involved in the development of the neurodegenerative process.

Polymorphism in the IL-1alpha (-889) locus associated with elevated risk of primary open angle glaucoma.

PURPOSE: Recent laboratory evidence indicates that the inflammatory cytokine, interleukin-1 (IL-1), has either protective or adverse effects on primary open angle glaucoma (POAG). Inheritance of the IL-1alpha (-889) polymorphism (the T allele), previously shown to increase IL-1 production, has been associated with an elevated risk of Alzheimer's disease. The neuronal injuries associated with Alzheimer's disease have a number of similarities with the optic nerve changes often seen with POAG. In this report we have explored the possible association between the IL-1alpha (-889) polymorphism and the development of POAG. METHODS: Chinese patients with POAG (156) were recruited and compared with 167 healthy chinese controls. Genomic DNA was amplified by polymerase chain reaction, followed by enzymatic restriction fragment length polymorphism technique (PCR-RFLP). Patients and controls were genotyped for the C/T polymorphism at position -889 of the IL-1alpha gene promoter region. RESULTS: The frequency of the IL-1alpha (-889) T allele (21% versus 13%, respectively; p=0.007) and the carriers of the IL-1alpha (-889) T allele (37% versus 25%; p=0.019, OR 1.76, 95%CI 1.1-2.83) were greater in POAG patients compared with controls. There is a higher risk of POAG associated with homozygosity for the IL-1alpha (-889) T allele (TT genotype) compared with the control population (CC genotype; 5% versus 1%, respectively, p=0.04; OR 5.1, 95% CI 1.19-21.66). CONCLUSIONS: The IL-1alpha (-889) T allele polymorphism, previously shown to increase IL-1 gene expression, may be a risk factor in the development of POAG.

Diffuse lamellar keratitis induced by toxic chemicals after laser in situ keratomileusis.

PURPOSE: To assess whether toxic chemicals produced during autoclaving sterilization were 1 of the main causes of diffuse lamellar keratitis (DLK) and to analyze the clinical outcomes of patients developing DLK after laser in situ keratomileusis (LASIK) treated with intensive topical corticosteroids. SETTING: Department of Ophthalmology, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China. METHODS: A total of 14 eyes of 7 patients received technically smooth LASIK and developed DLK, including 6 severe and 8 mild DLK cases. In all eyes the same microkeratome was used; it was contaminated with toxic chemical materials produced accidentally by coautoclaving instruments and a foam piece. RESULTS: Six eyes of 3 patients developed severe DLK on the same day, and 8 eyes of 4 patients developed mild DLK during the next LASIK surgery. After intensive topical corticosteroid treatment, lamellar infiltrates disappeared in 3 days in mild DLK eyes and 2 weeks in severe DLK eyes. No eye was treated with flap lifting and interface irrigation. For grade 4 DLK, the corneal opacity and flap folds disappeared in 4 weeks. There were no instances of permanent corneal scarring or loss of best spectacle-corrected visual acuity. CONCLUSIONS: Toxic chemicals produced during instrument autoclaving sterilization are a possible cause of DLK. Immediate diagnosis and treatment with intensive corticosteroid drops are critical and can resolve severe DLK.

Monitoring VEGF levels with low-volume sampling in major vision-threatening diseases: age-related macular degeneration and diabetic retinopathy.

The purpose of this article is to demonstrate the capacity of paper-based ELISA (P-ELISA) to monitor VEGF in patients requiring treatment for vision-threatening diseases. The most commonly encountered vision-threatening diseases are age-related macular degeneration (AMD) and diabetic retinopathy (DR), both of which may require short-term or life-long anti-VEGF injection treatment therapy. Accurate measurement of VEGF concentration in aqueous humor can provide significant and timely information to diagnose the disease state. Adequate and precise therapy may consequently be provided. At odds with conventional diagnostic approaches is the fact that a maximum of only 200 microliters of aqueous humor can be safely removed from the eye for testing. Fortunately, new diagnostic platforms, such as P-ELISA, require only minute volumes, i.e., approximately 2 microliters per test "well" and approximately 40 microliters total to quantify VEGF levels, and the testing process takes less than an hour. Thus, point-of-care (POC) diagnostics, such as P-ELISA, should be examined and improved upon as needed in order to develop an efficient tool for outpatient clinics and others to obtain semi-quantitative results that might facilitate accurate dosing of anti-VEGF treatment and delay or prevent the progression of AMD and DR.

Aniseikonia following pneumatic retinopexy for rhegmatogenous retinal detachment.

PURPOSE: To evaluate the characteristics of aniseikonia in patients with rhegmatogenous retinal detachment (RD) after pneumatic retinopexy. DESIGN: Prospective, interventional case series study. METHODS: Thirty patients who had undergone pneumatic retinopexy as the initial procedure for rhegmatogenous retinal detachment were selected for this study. The principal outcomes included visual acuity, postoperative aniseikonia measured by the New Aniseikonia Test, anatomical success, and measurement of central retinal thickness using optical coherence topography (OCT). These outcomes were measured postoperatively at 3, 6, and 12 months. RESULTS: The median patient age was 37 years (range, 13-57 years), with 17 cases of macula-off RD and 13 cases of macula-on RD. All of these patients achieved anatomical success, proven by OCT after surgical repair. Three months after pneumatic retinopexy, 18 patients (60.0%) developed micropsic aniseikonia and aniseikonia was diagnosed in 15 patients (88.2%) in the macula-off RD group, leaving 2 patients (11.8%) unaffected. In the macula-on RD group, 3 patients (23.1%) were found to have aniseikonia, while 10 patients (76.9%) were unaffected. The presence of aniseikonia was strongly linked to the difference in central retinal thickness, between the operated eye and the fellow eye, measured at 12 months postoperatively. CONCLUSION: Aniseikonia after pneumatic retinopexy for rhegmatogenous RD may be related to the preoperative macular status. Macula-off RD patients had a higher incidence of aniseikonia, compared to macula-on RD patients, following retina reattachment. There was a moderate to high correlation between the grading of aniseikonia and the difference in central retinal thickness.

Monitoring the VEGF level in aqueous humor of patients with ophthalmologically relevant diseases via ultrahigh sensitive paper-based ELISA.

The vascular endothelial growth factor (VEGF) level in aqueous humor has been used as an indicator to monitor specific diseases in the retinal ischemic condition. For clinical diagnosis, only about 200 µL of aqueous humor can be collected from the anterior chamber before the threat of anterior chamber collapse. It is necessary to develop an inexpensive diagnostic approach with the characteristics of highly sensitive, short operation duration, and requires small clinical sample quantities. To achieve the main objective of this study, we first prepared bevacizumab to be conjugated with HRP. We then deposited 2 µL aqueous humor from patients with different diseases onto each test zone of paper-based 96-well plates. After the colorimetric results were performed via ELISA protocol, the output signals were recorded using a commercial desktop scanner for analysis. In this study, only 2 µL from the aqueous humor of each patient was required for paper-based ELISA. The mean aqueous VEGF level was 14.4 pg/mL from thirteen patients (N = 13) with senile cataract as the control. However, the mean aqueous VEGF level from other patients with proliferative diabetic retinopathy (N = 14), age-related macular degeneration (N = 17), and retinal vein occlusion (N = 10) showed VEGF increases to 740.1 pg/mL, 383 pg/mL, and 219.4 pg/mL, respectively.

Intracameral voriconazole injection in the treatment of fungal endophthalmitis resulting from keratitis.

PURPOSE: To report the therapeutic efficacy of intracameral voriconazole injection in the treatment of fungal endophthalmitis resulting from keratitis. DESIGN: Retrospective, single-institution, consecutive case series. METHODS: Microbiologic and medical records were reviewed for patients with positive intraocular culture results or proven pathologic features for fungal organisms and clinically diagnosed fungal endophthalmitis resulting from keratitis. Ten eyes were treated with an intracameral injection of 100 microg voriconazole. Clinical characteristics, treatment, and causative organisms were analyzed. RESULTS: Fusarium and Aspergillus were the most common causative organisms. Voriconazole was injected intracamerally from 1 to 8 times. Of the 7 patients who received 5 or more repeat injections, 6 were caused by Fusarium and 1 by Acremonium. In the remaining 3 patients who were administered 4 or fewer voriconazole injections, the causative organisms were Aspergillus and Alternaria. CONCLUSIONS: Intracameral voriconazole injection may be an effective treatment for fungal endophthalmitis contiguously spreading from keratitis.

Comparison of voriconazole concentration in the aqueous humor and vitreous between non-scraped and scraped corneal epithelium groups after topical 1% voriconazole application.

PURPOSE: To investigate the penetration of topical 1% voriconazole through the cornea into the aqueous humor in New Zealand white rabbits and to determine the effect of mechanical scraping of the corneal epithelium. MATERIALS AND METHODS: The right eyes of 29 New Zealand white rabbits were maintained with the epithelium intact, and the left eyes underwent mechanical epithelium debridement of the central 7.5 mm of the cornea. A loading dose consisted of a drop of 1% voriconazole applied every 5 min for the initial half hour and followed by a maintenance dose consisting of a drop every 20 min, which was applied for about 2 hr. Then, the first sample was obtained 5 min after the first seven doses (loading dose) were given, and then four more samples were taken 5 min after four more subsequent drops (maintenance dose). The samples were analyzed by high performance liquid chromatography. RESULTS: The mean aqueous concentration of voriconazole was 33.44 +/- 5.77 microg/mL 5 min after the loading dose in the non-scraped group and 57.67 +/- 6.77 microg/mL in the scraped group, respectively. The mean aqueous concentration of voriconazole was maintained in a range from 19.97 to 23.70 microg/mL 5 min after the maintenance doses in the non-scraped group and from 44.44 to 49.02 microg/ mL in the scraped group. The mean vitreous concentration of voriconazole ranged from 0.38 to 0.49 microg/mL in the non-scraped group and ranged from 0.72 to 0.94 microg/mL in the scraped group. These levels were statistically significant (P < 0.05) between the scraped and non-scraped groups. CONCLUSIONS: Topically administered voriconazole achieved minimum inhibitory concentrations in the aqueous for all the organisms most commonly involved in fungal endophthalmitis and achieved minimum inhibitory concentrations in the vitreous for some pathogenic fungi. The concentrations of voriconazole were higher in the scraped group than in the non-scraped group.