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Analysis of bleb morphology after trabeculectomy with Visante anterior segment optical coherence tomography

Background: To describe the use of anterior segment optical coherence tomography (OCT) in imaging intrableb morphology after trabeculectomy. Methods: 14 post-trabeculectomy eyes from 11 primary open angle glaucoma and 3 primary angle closure glaucoma subjects were studied. The blebs were classified with reference to slit lamp morphology and bleb function. They included diffuse filtering (n = 7), cystic (n = 2), encapsulated (n = 2) and flattened (n = 3) bleb types. One eye in each patient was imaged with the Visante anterior segment OCT. A vertical scan line of 10 mm consisting of 512 A-scans was positioned at the centre of the bleb. The images were then analysed by built-in software. Intrableb morphologies and structures, including bleb wall thickness, subconjunctival fluid collections, suprascleral fluid space, scleral flap thickness, intrableb intensity (low, medium or high) and the route under the scleral flap were characterised and measured. Results: Diffuse filtering blebs were found by subconjunctival fluid collections. Suprascleral fluid space and the route under the scleral flap were identified in four of the seven cases. Cystic blebs were composed of a large hyporeflective space with multiloculated fluid collections covered by a thin layer of conjunctiva. Encapsulated blebs had a thick bleb wall with high reflectivity and an enclosed fluid filled space. Flattened blebs demonstrated high scleral reflectivity and no bleb elevation. Conclusions: Visante anterior segment OCT can be used for bleb imaging. The different patterns of intrableb morphology identified by OCT were related to slit lamp appearance and bleb function. This information may be useful to study the different surgical outcomes and the process of wound healing in trabeculectomised eyes.

Gene Expression Profiles of Human Trabecular Meshwork Cells Induced by Triamcinolone and Dexamethasone

PURPOSE Triamcinolone acetonide (TA) and dexamethasone (DEX) are corticosteroids commonly used for ocular inflammation, but both can cause ocular hypertension. In this study, the differential gene expression profile of human trabecular meshwork (TM) cells in response to treatment by TA in comparison with DEX was investigated. METHODS Total RNA was extracted from cultured human TM cells treated with TA or DEX and used for microarray gene expression analysis. The microarray experiments were repeated three times. Differentially expressed genes were identified by an empiric Bayes approach and confirmed by real-time quantitative PCR. RESULTS TA (0.1 mg/mL) treatment resulted in 15 genes upregulated and 12 genes downregulated, whereas 1 mg/mL TA resulted in 36 genes upregulated and 21 genes downregulated. These genes were mainly associated with acute-phase response, cell adhesion, cell cycle and growth, growth factor, ion binding, metabolism, proteolysis and transcription factor. Two genes, MYOC and GAS1, were upregulated, and three genes, SENP1, ZNF343, and SOX30, were downregulated by both TA and DEX treatment. Eight differentially expressed genes were located in known primary open-angle glaucoma (POAG) loci, including MYOC, SOAT1, CYP27A1, SPOCK, SEMA6A, EGR1, GAS1, and ATP10A. CONCLUSIONS Differential gene expression profiles of human TM cells treated by TA and DEX, and a dosage effect by TA, were revealed by microarray technology. TA and DEX treatment shared several differentially expressed genes, suggesting a common mechanism to cause ocular hypertension. Some differentially expressed genes located in the known POAG loci are potential candidates for glaucoma genes.

Association of apolipoprotein E polymorphisms with normal tension glaucoma in a Chinese population.

PurposeTo evaluate the role of apolipoprotein E (APOE) polymorphisms in primary open angle glaucoma (POAG). MethodsA cohort of 400 unrelated Chinese POAG patients was examined, including 294 cases of high tension glaucoma (HTG) and 106 with normal tension glaucoma (NTG). Also studied were 300 unrelated Chinese control subjects. The genotypes of the APOE polymorphisms in exon 4 and in the promoter at positions −491, −427, and −219 were determined by polymerase chain reaction and restriction endonuclease analysis. Frequencies of the genotypes were compared between patients and controls by χ2 test or Fisher exact test. The association of APOE polymorphisms with POAG phenotypes including age at diagnosis, intraocular pressure (IOP) at diagnosis, highest IOP, cup–disc ratio, and visual field score was investigated by the Kruskal–Wallis test. ResultsNo significant difference was detected in the frequencies of APOE promoter polymorphisms between POAG patients and control subjects (P>0.0125). For the exon 4 polymorphism, when compared with control subjects, the frequency of ϵ4 carriers was significantly lower in patients with NTG (P=0.008; odds ratio=0.36, 95% confidence interval=0.17, 0.79) but not in HTG (P=0.07). Compared with −219TT, the −219G carriers had a significant higher age at diagnosis (P=0.0046). No significant association was found between other APOE polymorphisms and POAG phenotypes (P>0.07). ConclusionsOur findings suggest that the APOE ϵ4 allele confers a protective effect against NTG, whereas the APOE promoter polymorphisms do not contribute to POAG risk. However, the APOE −219G carriers tended to have later-onset POAG.

Intrableb triamcinolone acetonide injection after bleb-forming filtration surgery (trabeculectomy, phacotrabeculectomy, and trabeculectomy revision by needling): a pilot study

Intrableb triamcinolone acetonide injection after bleb-forming filtration surgery (trabeculectomy, phacotrabeculectomy, and trabeculectomy revision by needling): a pilot study

In vivo measurements of macular and nerve fibre layer thickness in retinal arterial occlusion.

AimTo investigate the structure–function relationship in patients with retinal arterial occlusion by measuring the macular and the peripapillary retinal nerve fibre layer (RNFL) thickness and the visual sensitivity.MethodsThis is an observational case series with three patients with central retinal arterial occlusion (CRAO) and two patients with branch retinal arterial occlusion (BRAO). The macular/peripapillary RNFL thickness and the visual field were measured with Stratus optical coherence tomography (OCT) and Humphrey visual field analyzer, respectively, at least 1 year after the diagnosis of CRAO or BRAO.ResultsThe macular thickness, in particular the inner retinal layer, and the peripapillary RNFL thickness were reduced in patients with retinal arterial occlusion. The decrease in the macular and the peripapillary RNFL thickness corresponded to the sites of retinal arterial occlusion with diffuse and segmental thinning found in CRAO and BRAO, respectively. Visual field defects were found in the corresponding locations of macular and RNFL thinning, and closely correlated with the degree of the structural damage.ConclusionsStructural damages in terms of reduction in the macular and peripapillary RNFL thickness were evident in patients with retinal arterial occlusion. A close structure–function correlation was found and a worse functional outcome is associated with a more extensive thinning of the macula and RNFL. OCT measurements of the macular/peripapillary RNFL thickness provide useful indicators to reflect the severity of the disease in retinal arterial occlusion and serve as a new paradigm to study and monitor the disease longitudinally.

Preoperative latanoprost to prevent ocular hypertension after phacoemulsification and intraocular lens implantation

Purpose: To evaluate the efficacy of latanoprost given 2 hours preoperatively to prevent ocular hypertension in the early period after phacoemulsification and posterior chamber intraocular lens (PC IOL) implantation. Setting: Departments of Ophthalmology, United Christian Hospital and Prince of Wales Hospital, Hong Kong, China. Methods: Sixty‐four eyes of 64 patients with uncomplicated cataract having phacoemulsification with PC IOL implantation were included in this prospective randomized double‐masked clinical trial. The eyes were randomly assigned to 1 of 2 groups: application of latanoprost 0.005% 2 hours before surgery or no latanoprost (control). Intraocular pressure (IOP) was measured 3 and 24 hours postoperatively. The anterior chamber was examined for the level of cells and flare using a slitlamp biomicroscope. The level of significance was 5%. Results: The decrease in the mean IOP was not statistically significantly different between eyes receiving latanoprost 2 hours preoperatively and control eyes 3 hours (P = .843) and 24 hours (P = .721) postoperatively. Conclusion: A single application of latanoprost given 2 hours before phacoemulsification and PC IOL implantation did not produce a statistically significant IOP‐lowering effect when compared with a control group in the first 24 hours after surgery.

Scleral perforation following diode laser trans-scleral cyclophotocoagulation

acid-fast stain. Polymerase chain reaction (PCR) for microsporidia was performed using primers capable of identifying several Enterocytozoon and Encephalitozoon species of microsporidia. A single B270 base pair fragment was observed on agarose gel electrophoresis and ethidium bromide staining of the PCR amplified patient sample (Figure 2b). Topical steroids were discontinued and he was treated with topical 0.3% ciprofloxacin eight times daily along with topical lubricants. After 10 days, all his lesions had disappeared (Figure 1b). The patient was seronegative for HIV by ELISA test. Bilateral punctate epithelial keratopathy and conjunctivitis has been described in immunocompromised and more recently in immunocompetent patients as well. Previously described risk factors like trauma, contact lens wear, prior refractive surgery or exposure to contaminated water were absent in our patient. The only possible associated risk in this case was the use of topical steroids, leading to a localized immunosuppressed state, resulting in secondary infection by microsporidia. In our patient, diagnostic debridement probably debulked the epithelium of the load of organisms and hastened resolution. Contrary to belief that debridement worsens the infection by driving the organisms into the stroma; we found that debridement actually hastens resolution.

Correlation of previous acute angle-closure attack with extent of synechial angle closure in chronic primary angle-closure glaucoma patients

AimTo document any correlation between previous acute angle-closure attack and the extent of synechial angle closure in chronic primary angle-closure glaucoma (PACG) patients.MethodsConsecutive cases of chronic PACG with patent peripheral iridotomy had gonioscopy performed. The extents of synechial angle closure of those chronic PACG eyes with previous documented acute angle-closure attack were compared to those eyes without such a history.ResultsA total of 102 chronic PACG eyes of 102 patients were recruited. Twenty-seven eyes (26.5%) had a previous documented acute angle closure, while 75 eyes (73.5%) did not. The mean extent of synechial angle closure ±1 SD was 307±68 degrees (range, 150–360 degrees) in those chronic PACG eyes with a history of previous acute angle closure, compared to 266±89 degrees (range, 90–360 degrees) in those chronic PACG eyes without such a history (P=0.03, Students t-test). There were no statistically significant differences between the two groups in age, LogMAR visual acuity, intraocular pressure (IOP), number of glaucoma eye drops, vertical cup-to-disk ratio, mean deviation or pattern SD in Humphrey automated perimetry, and anterior chamber depth (P>0.05).ConclusionPrevious acute angle-closure attack correlated with more extensive synechial angle closure in chronic PACG patients in this study.

Ophthalmology in Hong Kong

A catalyst for ophthalmic developments in China Hong Kong is unique in China: she is where the virtues of the East meet the values of the West. Her sovereignty returned from the British to the Chinese Government in 1997, but Hong Kong has continued to flourish, under the “one country, two systems” model, and remains international, dynamic, innovative, and prosperous. Western style rule of law and freedom of speech and thought have persisted here. Against this unique historical and political background, ophthalmology has made important strides in Hong Kong over the past decade, both in academic research and in the provision of quality care of international standard to the local population. Hong Kong has also increasingly become a catalyst for ophthalmic developments in China. One of our earliest projects to bring quality ophthalmic care to remote and poverty stricken regions of China was the “Lifeline Express.”1 (DSCL is a founding executive committee member and an ambassador of sight of the Lifeline Express, and the honorary director of the Shantou University/The Chinese University of Hong Kong Joint Shantou International Eye Center.) The Lifeline Express is a tailor built train to help eliminate cataract blindness in China (Fig 1). It is a charity project with most of its funding raised in Hong Kong. Ophthalmologists on the Lifeline Express are either volunteer …