In this retrospective study on vitreoretinal lymphoma, there was significant change in diagnosis ... more In this retrospective study on vitreoretinal lymphoma, there was significant change in diagnosis and treatment trends over 17 years at a single institution. Fine needle aspiration biopsy had replaced vitrectomy to collect vitreous sample and external beam radiotherapy in combination with systemic chemotherapy was replaced by intravitreal methotrexate and rituximab, which regressed vitreoretinal lymphoma (VRL) with no relapses or major ocular complications. The purpose of this study was to report the changing trends in treatment (external beam radiotherapy [EBRT] and intravitreal chemotherapy) of VRL and treatment outcomes at a single institution. A retrospective chart review of vitreous biopsy proven patients was performed. The data analysis included demographics, systemic lymphoma status, ocular symptoms, clinical and immunocytological findings, treatment methods, and response (intravitreal methotrexate 300 μg/0.05 mL, 1000 μg/0.1 mL of rituximab and EBRT 36-45 Gy) and ocular and systemic lymphoma outcomes at last follow-up. Twelve eyes of 8 patients had intraocular B-cell lymphoma (median age, 61 years; range, 50-83). Central nervous system non-Hodgkin's lymphoma (CNS-NHL) was present in 7 of 8 patients. Most common ocular symptoms were diminution of vision in 4 and floaters in 3 patients. Iritis and uveitis were found in 6 eyes and vitritis in 11 eyes. Retinal infiltrates were present in 8 eyes. Immunocytology revealed elevated levels of interleukin (IL)-10 (12,783.5 pg/mL), IL-6 (26.7 pg/mL), and IgH gene rearrangement. Three patients were treated with EBRT, 6 eyes with intravitreal methotrexate (median, 9.5; range, 2-15), and 2 eyes with intravitreal rituximab injections (median, 4; range, 2-6). Two patients developed marked keratitis because of methotrexate toxicity. At median follow-up of 33.5 months (range, 4-96), VRL had resolved in 7 eyes and persistent in 5 eyes. One patient died because of advanced CNS-NHL. Intravitreal chemotherapy provided good control rates for VRL patients in our limited series. Patients with associated CNS-NHL had poorer outcomes.
Journal of Pediatric Endocrinology and Metabolism, 2000
The purpose of this study is to report clinical, optical coherence tomography (OCT), and fluoresc... more The purpose of this study is to report clinical, optical coherence tomography (OCT), and fluorescein angiogram/indocyanine green angiography (FA/ICG) findings in patients with long-chain 3-hydroxyacyl-coenzyme A dehydrogenase (LCHAD) enzyme deficiency in two siblings. A 13-year-old girl and her 14-year-old brother presented with progressive decrease in central vision. Clinically, there were blond-looking fundi, diffuse retinal pigment epithelial (RPE) disruption/atrophy in the macula and peripheral retina with choriocapillaris atrophy in both of them. OCT showed RPE irregularity and diffuse disruption of the RPE layer. FA/ICG imaging demonstrated transmitted choroidal fluorescence secondary to diffuse RPE atrophy with no evidence of leakage. Electroretinogram and electrooculogram findings were suggestive of primary abnormality of pigment epithelium. The boy died of cardiac/respiratory illness, whereas his sister is alive at the last follow-up. Abnormal chorioretinal findings in LCHAD patients should be carefully followed. Regular follow-up is recommended to monitor the ocular and systemic status.
To report laser pointer induced damage to retina and choroid and briefly review literature. A cas... more To report laser pointer induced damage to retina and choroid and briefly review literature. A case report of a 13-year old Caucasian boy developed blurry central vision and central scotoma in right eye (OD). He was exposed for one minute to class IIIA green laser pointer of 650 nm wavelength and 5 mW power. Clinical examination showed a grayish lesion in foveal region. Ancillary testing revealed disruption of the retinal pigment epithelial (RPE) layer in foveal region and indocyanine green angiography demonstrated evidence of choroidal hypofluorescence suggestive of choroidal infarction in OD. Visual acuity improved from 20/100 to 20/60 in one day and he was treated with tapering doses of oral prednisolone (40 mg) for 3 weeks. Laser pointer with a power of >5 mW caused damage to RPE in the macula. Children should not be given laser pointers as toys especially those with label of danger instructions.
on Beam Analysis Of Silicon Based Surfaces And Correlation With Surface Energy Measurements, 2011
"The water affinity of Si-based surfaces is quantified by contact angle measurement and surface f... more "The water affinity of Si-based surfaces is quantified by contact angle measurement and surface free energy to explain hydrophobic or hydrophilic behavior of silicone, silicates, and silicon surfaces. Surface defects such as dangling bonds, surface free energy including Lewis acid-base and Lifshitz-van der Waals components are discussed. Water nucleation and condensation is further explained by surface topography. Tapping mode atomic force microscopy (TMAFM) provides statistical analysis of the topography of these Si-based surfaces. The correlation of the above two characteristics describes the behavior of water condensation at Si-based surfaces. Surface root mean square roughness increasing from several Å to several nm is found to provide nucleation sites that expedite water condensation visibly for silica and silicone. Hydrophilic surfaces have a condensation pattern that forms puddles of water while hydrophobic surfaces form water beads. Polymer adsorption on these surfaces alters the water affinity as well as the surface topography, and therefore controls condensation on Si-based surfaces including silicone intraocular lens (IOL). The polymer film is characterized by Rutherford backscattering spectrometry (RBS) in conjunction with 4.265 MeV 12C(α, α)12C, 3.045 MeV 16O(α, α)16O nuclear resonance scattering (NRS), and 2.8 MeV elastic recoil detection (ERD) of hydrogen for high resolution composition and areal density measurements. The areal density of hydroxypropyl methylcellulose (HPMC) film ranges from 1018 atom/cm2 to 1019 atom/cm2 gives the silica or silicone surface a roughness of several Å and a wavelength of 0.16 ± 0.02 μm, and prevents fogging by forming a complete wetting layer during water condensation.
Keywords: ERD, NRS, RBS, AFM, polymer film, silicone, silica, Si(100), contact angle, surface free energy, surface topography, intraocular implant."
In this retrospective study on vitreoretinal lymphoma, there was significant change in diagnosis ... more In this retrospective study on vitreoretinal lymphoma, there was significant change in diagnosis and treatment trends over 17 years at a single institution. Fine needle aspiration biopsy had replaced vitrectomy to collect vitreous sample and external beam radiotherapy in combination with systemic chemotherapy was replaced by intravitreal methotrexate and rituximab, which regressed vitreoretinal lymphoma (VRL) with no relapses or major ocular complications. The purpose of this study was to report the changing trends in treatment (external beam radiotherapy [EBRT] and intravitreal chemotherapy) of VRL and treatment outcomes at a single institution. A retrospective chart review of vitreous biopsy proven patients was performed. The data analysis included demographics, systemic lymphoma status, ocular symptoms, clinical and immunocytological findings, treatment methods, and response (intravitreal methotrexate 300 μg/0.05 mL, 1000 μg/0.1 mL of rituximab and EBRT 36-45 Gy) and ocular and systemic lymphoma outcomes at last follow-up. Twelve eyes of 8 patients had intraocular B-cell lymphoma (median age, 61 years; range, 50-83). Central nervous system non-Hodgkin's lymphoma (CNS-NHL) was present in 7 of 8 patients. Most common ocular symptoms were diminution of vision in 4 and floaters in 3 patients. Iritis and uveitis were found in 6 eyes and vitritis in 11 eyes. Retinal infiltrates were present in 8 eyes. Immunocytology revealed elevated levels of interleukin (IL)-10 (12,783.5 pg/mL), IL-6 (26.7 pg/mL), and IgH gene rearrangement. Three patients were treated with EBRT, 6 eyes with intravitreal methotrexate (median, 9.5; range, 2-15), and 2 eyes with intravitreal rituximab injections (median, 4; range, 2-6). Two patients developed marked keratitis because of methotrexate toxicity. At median follow-up of 33.5 months (range, 4-96), VRL had resolved in 7 eyes and persistent in 5 eyes. One patient died because of advanced CNS-NHL. Intravitreal chemotherapy provided good control rates for VRL patients in our limited series. Patients with associated CNS-NHL had poorer outcomes.
Journal of Pediatric Endocrinology and Metabolism, 2000
The purpose of this study is to report clinical, optical coherence tomography (OCT), and fluoresc... more The purpose of this study is to report clinical, optical coherence tomography (OCT), and fluorescein angiogram/indocyanine green angiography (FA/ICG) findings in patients with long-chain 3-hydroxyacyl-coenzyme A dehydrogenase (LCHAD) enzyme deficiency in two siblings. A 13-year-old girl and her 14-year-old brother presented with progressive decrease in central vision. Clinically, there were blond-looking fundi, diffuse retinal pigment epithelial (RPE) disruption/atrophy in the macula and peripheral retina with choriocapillaris atrophy in both of them. OCT showed RPE irregularity and diffuse disruption of the RPE layer. FA/ICG imaging demonstrated transmitted choroidal fluorescence secondary to diffuse RPE atrophy with no evidence of leakage. Electroretinogram and electrooculogram findings were suggestive of primary abnormality of pigment epithelium. The boy died of cardiac/respiratory illness, whereas his sister is alive at the last follow-up. Abnormal chorioretinal findings in LCHAD patients should be carefully followed. Regular follow-up is recommended to monitor the ocular and systemic status.
To report laser pointer induced damage to retina and choroid and briefly review literature. A cas... more To report laser pointer induced damage to retina and choroid and briefly review literature. A case report of a 13-year old Caucasian boy developed blurry central vision and central scotoma in right eye (OD). He was exposed for one minute to class IIIA green laser pointer of 650 nm wavelength and 5 mW power. Clinical examination showed a grayish lesion in foveal region. Ancillary testing revealed disruption of the retinal pigment epithelial (RPE) layer in foveal region and indocyanine green angiography demonstrated evidence of choroidal hypofluorescence suggestive of choroidal infarction in OD. Visual acuity improved from 20/100 to 20/60 in one day and he was treated with tapering doses of oral prednisolone (40 mg) for 3 weeks. Laser pointer with a power of >5 mW caused damage to RPE in the macula. Children should not be given laser pointers as toys especially those with label of danger instructions.
on Beam Analysis Of Silicon Based Surfaces And Correlation With Surface Energy Measurements, 2011
"The water affinity of Si-based surfaces is quantified by contact angle measurement and surface f... more "The water affinity of Si-based surfaces is quantified by contact angle measurement and surface free energy to explain hydrophobic or hydrophilic behavior of silicone, silicates, and silicon surfaces. Surface defects such as dangling bonds, surface free energy including Lewis acid-base and Lifshitz-van der Waals components are discussed. Water nucleation and condensation is further explained by surface topography. Tapping mode atomic force microscopy (TMAFM) provides statistical analysis of the topography of these Si-based surfaces. The correlation of the above two characteristics describes the behavior of water condensation at Si-based surfaces. Surface root mean square roughness increasing from several Å to several nm is found to provide nucleation sites that expedite water condensation visibly for silica and silicone. Hydrophilic surfaces have a condensation pattern that forms puddles of water while hydrophobic surfaces form water beads. Polymer adsorption on these surfaces alters the water affinity as well as the surface topography, and therefore controls condensation on Si-based surfaces including silicone intraocular lens (IOL). The polymer film is characterized by Rutherford backscattering spectrometry (RBS) in conjunction with 4.265 MeV 12C(α, α)12C, 3.045 MeV 16O(α, α)16O nuclear resonance scattering (NRS), and 2.8 MeV elastic recoil detection (ERD) of hydrogen for high resolution composition and areal density measurements. The areal density of hydroxypropyl methylcellulose (HPMC) film ranges from 1018 atom/cm2 to 1019 atom/cm2 gives the silica or silicone surface a roughness of several Å and a wavelength of 0.16 ± 0.02 μm, and prevents fogging by forming a complete wetting layer during water condensation.
Keywords: ERD, NRS, RBS, AFM, polymer film, silicone, silica, Si(100), contact angle, surface free energy, surface topography, intraocular implant."
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Papers by Henry Kwong
Keywords: ERD, NRS, RBS, AFM, polymer film, silicone, silica, Si(100), contact angle, surface free energy, surface topography, intraocular implant."
Keywords: ERD, NRS, RBS, AFM, polymer film, silicone, silica, Si(100), contact angle, surface free energy, surface topography, intraocular implant."