Biomedical subjects

Raymond Kwok Kay Tse

Publications and source records attributed to Raymond Kwok Kay Tse.

3 recordsLinked to original sources

PubMed2006

Alignment artifacts in optical coherence tomography analyzed images.

PURPOSE: To compare retinal thickness and retinal height of the original scanned optical coherence tomography (OCT) images with those of the same images after automated retinal thickness analysis. DESIGN: Cross-sectional study. PARTICIPANTS: Thirty normal eyes, 20 eyes with neovascular age-related macular degeneration (AMD), 20 with central serous chorioretinopathy (CSC), 20 with macular holes, and 20 with non-AMD related macular edema from 110 subjects were selected randomly from an OCT database. One of the 6 macular scans in each eye was chosen randomly for analysis. METHODS: Two sets of OCT images--original images and analyzed images (after retinal thickness [single eye] analysis)--in each eye were exported for retinal thickness or retinal height measurement. Comparisons of retinal thickness or retinal height at selected locations were performed. MAIN OUTCOME MEASURES: Retinal thickness (defined as the distance between the anterior boundary of the retinal nerve fiber layer [RNFL] and posterior boundary of the photoreceptor layer) and retinal height (defined as the distance between the anterior boundary of the RNFL and baseline level of the anterior boundary of the retinal pigment epithelium [RPE]). Retinal height was measured when there was detachment of neurosensory retina or RPE. RESULTS: No significant difference in retinal thickness was observed between the original and the analyzed OCT images in normal eyes and in eyes with macular holes or non-AMD related macular edema. However, OCT-analyzed images demonstrated retinal thickness or retinal height measurements in eyes with CSC or neovascular AMD significantly lower than the corresponding measurements in the original images (all with Ps< or =0.001, Wilcoxon signed rank test). In the groups of neovascular AMD and CSC, Bland-Altman plots revealed mean differences of 124 mum (95% limits of agreement between -65.5 and 313.6) and 84.4 mum (95% limits of agreement between -178.0 and 346.8), respectively, between the original and analyzed retinal measurements. CONCLUSIONS: Retinal thickness and retinal height could be underestimated in patients with CSC or neovascular AMD after retinal thickness analysis in Stratus OCT when either automatic measurements or manual caliper-assisted measurements are performed on the analyzed images. We recommend exporting the original scanned OCT images for retinal thickness and retinal height measurement in patients with CSC or neovascular AMD.

Aged↗

PubMed2005

Visualization of anterior chamber angle dynamics using optical coherence tomography.

PURPOSE: To describe the technology of optical coherence tomography (OCT) in imaging the anterior chamber angles and its impact on understanding the pathophysiology of angle-closure glaucoma (ACG). DESIGN: Observational case series. PARTICIPANTS: Three subjects with, respectively, impending angle-closure attack, plateau iris syndrome, and phacomorphic glaucoma were recruited. METHODS: The anterior chamber angle in each patient was imaged with a commercially available OCT unit. The angle configurations were assessed and compared before and after laser peripheral iridotomy (LPI) and argon laser peripheral iridoplasty (ALPI). MAIN OUTCOME MEASURES: Visualization of the changes in the anterior chamber angle configurations and normalization of the intraocular pressure (IOP). RESULTS: A patient with impending angle-closure attack precipitated by a topical mydriatic agent was treated with LPI. Optical coherence tomography imaging of the anterior chamber angles was performed before and after the laser procedure. Conversion of anterior iris bowing and angle crowding to iris straightening and angle opening after LPI was demonstrated. Intraocular pressure became normalized with the change in angle configuration. The second patient presented with symptoms of intermittent angle-closure attacks and was initially diagnosed with primary ACG. Despite successful LPI, the angles remained occludable, and the IOP continued to be elevated. Optical coherence tomography was used to review the anterior chamber angle configuration and demonstrated a typical pattern compatible with the diagnosis of plateau iris syndrome. Subsequent ALPI converted the plateau configuration to open angle, with normalization of IOP and disappearance of symptoms. The third patient presented with an acute angle-closure attack and was diagnosed with phacomorphic glaucoma. Argon laser peripheral iridoplasty was performed successfully to open the angle, as evident by the OCT images, and the IOP was brought under control, together with relief of symptoms. CONCLUSIONS: The commercially available OCT unit can be practically employed for anterior chamber angle imaging. The different patterns of angle configurations are correlated with the underlying pathophysiology in different forms of ACG.

Aged↗

PubMed2005

Treatment of cystic epithelial downgrowth with intralesional administration of mitomycin C.

PURPOSE: To report a case of postoperative cystic epithelial downgrowth treated with needle aspiration and intralesional administration of mitomycin C. METHODS: Case report. A 60-year-old woman with a history of right cataract surgery 7 years ago presented with decreased vision of 1/60. The reduced vision was diagnosed secondary to a large acquired cystic epithelial downgrowth on the surface of the iris occluding the pupil. RESULTS: The cystic epithelial downgrowth was treated with aspiration and intralesional administration of mitomycin C solution. There was no evidence of recurrence on follow-up 1 year after the procedure. CONCLUSIONS: Treatment of acquired cystic epithelial downgrowth with needle aspiration and intralesional administration of mitomycin C resulted in a satisfactory outcome without undertaking more extensive and invasive surgical treatments.

Antibiotics, Antineoplastic↗