Fiona O. J. Luk
The Chinese University of Hong Kong
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Featured researches published by Fiona O. J. Luk.
British Journal of Ophthalmology | 2008
Timothy Y. Y. Lai; Wai-Man Chan; David T.L. Liu; Fiona O. J. Luk; Dennis S.C. Lam
Aim: To evaluate the efficacy of intravitreal bevacizumab (Avastin) with or without verteporfin photodynamic therapy (PDT) in the treatment of polypoidal choroidal vasculopathy (PCV). Methods: Fifteen eyes of 15 patients with symptomatic PCV who received three monthly intravitreal bevacizumab were retrospectively reviewed. Subsequent retreatments with intravitreal bevacizumab and/or PDT were performed in patients with recurrent or persistent polypoidal lesions on indocyanine green angiography (ICGA), and persistent or recurrent subretinal fluid. Results: The mean follow-up duration was 12.8 months. At 3 months, the mean logMAR BCVA improved from 0.61 to 0.51 (p = 0.014), and the mean CFT reduced from 347 μm to 247 μm (p = 0.015). Despite the visual and anatomical improvements, persistent polyps were present in ICGA of all eyes at 3 months. At the last follow-up, mean BCVA remained at 0.51 after additional treatment with intravitreal bevacizumab and/or PDT (p = 0.022). Patients who had subsequent PDT were less likely to have persistent polypoidal lesions on ICGA at the last visit (p = 0.041). Conclusions: Intravitreal bevacizumab appeared to result in stabilisation of vision and reduction of exudative retinal detachment in PCV patients. However, intravitreal bevacizumab monotherapy had limited effectiveness in causing regression of the polypoidal lesions in ICGA, and additional PDT appeared to be useful for treating these lesions.
Retina-the Journal of Retinal and Vitreous Diseases | 2011
Timothy Y. Y. Lai; Gary K. Y. Lee; Fiona O. J. Luk; Dennis S.C. Lam
Purpose: To evaluate the efficacy of intravitreal ranibizumab with or without verteporfin photodynamic therapy (PDT) in the treatment of symptomatic polypoidal choroidal vasculopathy. Methods: Twenty-three eyes of 23 patients received 3 monthly intravitreal ranibizumab injections with or without indocyanine green angiography-guided PDT at baseline. All patients had follow-up of ≥12 months. Visual and anatomical outcomes were compared between the two groups and a PDT monotherapy group. Results: Seven eyes had ranibizumab monotherapy, 16 had combined ranibizumab injections and verteporfin PDT, and 12 had PDT monotherapy. At 3 months, the mean logarithm of minimal angle of resolution best-corrected visual acuity improved from 0.92 to 0.74 in the ranibizumab group (P = 0.18), from 0.70 to 0.59 in the combined group (P = 0.037), and from 0.74 to 0.57 in the PDT monotherapy group (P = 0.014). Complete regression of polypoidal lesions in indocyanine green angiography was found in 1 (14.3%) eye in the ranibizumab group, compared with 15 (93.8%) eyes in the combined group (P = 0.001). Additional PDT and ranibizumab injections in eyes with persistent polyps and fluorescein leakage resulted in regression of polyps in all eyes. At 12 months, no significant difference in logarithm of minimal angle of resolution best-corrected visual acuity and visual change was found between eyes initially treated with ranibizumab monotherapy, combined ranibizumab and PDT, or PDT monotherapy (P = 1.00 and P = 0.11, respectively). Conclusion: Intravitreal ranibizumab appeared to result in stabilization of vision in patients with symptomatic polypoidal choroidal vasculopathy. However, combined ranibizumab and PDT appeared to be more effective in causing complete regression of the polypoidal lesions in indocyanine green angiography compared with ranibizumab monotherapy.
Eye | 2012
Timothy Y. Y. Lai; Fiona O. J. Luk; Gary K. Y. Lee; Dennis S.C. Lam
PurposeTo evaluate the long-term efficacy of intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy as primary treatment for subfoveal myopic choroidal neovascularization (CNV).MethodsIn all, 37 treatment-naïve eyes of 37 patients with subfoveal myopic CNV who received intravitreal bevacizumab (n=22) or ranibizumab (n=15) injections with at least 2 years of follow-up were reviewed. All eyes received initial three loading doses of anti-VEGF at monthly intervals and retreatment was performed in persistent or recurrent CNV. Multivariate regression analyses were performed to determine the prognostic factors for visual outcome.ResultsThe mean age was 57.3 years and the mean refractive error was −11.7 D. For all eyes, the mean logMAR best-corrected visual acuity improved from 0.86 (20/145) at baseline to 0.48 (20/60) at 2 years (P<0.001). The mean visual improvement for the bevacizumab and ranibizumab groups at 2 years was 2.8 and 5.1 lines, respectively (P=0.073). There was no significant difference in the proportion of eyes having visual gain of three or more lines or visual loss of three or more lines between the two groups. The mean number of injections was 3.8 for both bevacizumab and ranibizumab groups. Multivariate analyses showed that eyes with higher myopic refractive error were less likely to have visual gain after treatment (P=0.043), while size of CNV was negatively correlated with mean change in vision (P=0.046).ConclusionsIntravitreal anti-VEGF therapy resulted in long-term visual improvement in myopic CNV. The treatment efficacy in terms of visual gain and number of retreatment appeared to be similar between bevacizumab and ranibizumab.
Retina-the Journal of Retinal and Vitreous Diseases | 2009
Fiona O. J. Luk; Alvin K H Kwok; Timothy Y. Y. Lai; Dennis S.C. Lam
Purpose: To evaluate the late development of open angle glaucoma (OAG) after vitrectomy and to compare the rate of postvitrectomy OAG development in phakic and pseudophakic eyes. Methods: Retrospective case series of 101 eyes of 101 patients who had vitrectomy for idiopathic epiretinal membrane or idiopathic macular hole with a follow-up duration of more than 6 months. Eligible patients were assessed for new development of OAG during the follow-up period. Patients were separated into two groups based on the lens status at the end of the vitrectomy for statistical analysis using Kaplan–Meier survival analysis with log-rank test and Cox regression analysis. Results: The mean follow-up duration was 51 months (range, 6–80 months). Of the 101 eyes, 8 (7.9%) eyes developed OAG during the follow-up period. Phakic eyes were less likely to develop OAG after vitrectomy compared with pseudophakic eyes, with 2% and 13%, respectively (log-rank test, P = 0.025). The result remained statistically significant after adjustment for age, refractive error and the use of gas tamponade (adjusted odds ratio = 0.09, P = 0.038). Conclusion: The presence of the crystalline lens may be protective against the late development of OAG after vitrectomy.
Clinical and Experimental Ophthalmology | 2011
Timothy Yy Lai; Raymond L. M. Wong; Fiona O. J. Luk; Vanissa Ws Chow; Carmen K. M. Chan; Dennis S.C. Lam
Background: To evaluate the ophthalmic manifestations and risk factors for mortality in HIV patients in the post‐highly active anti‐retrovirus therapy (HAART) era.
Journal of Ophthalmology | 2012
Zenith H. Y. Wu; Rose P. S. Chan; Fiona O. J. Luk; David T.L. Liu; Carmen K. M. Chan; Dennis S.C. Lam; Timothy Y. Y. Lai
Purpose. To evaluate the clinical features, microbiological spectrum, and treatment outcomes of endogenous endophthalmitis. Methods. Retrospective review of consecutive cases with infective endogenous endophthalmitis presenting from 2000 to 2007. The main outcome measure was the visual outcome at the latest follow-up visit. Other outcome measures included microbiological investigations, anatomical and clinical outcomes. Results. 22 eyes of 21 patients were included, and the mean follow-up duration was 2.7 years. Eyes with fungal endogenous endophthalmitis were more likely to have visual acuity of finger counting or better at presentation compared with those with bacterial endogenous endophthalmitis (odds ratio = 15.0, P = 0.013). Gram-negative microorganisms accounted for 50% of infections, while fungal and gram-positive organisms accounted for 27.3% and 22.7%, respectively. Despite treatment, the visual outcome was poor in general as 10 (45.5%) eyes had no light perception at the latest follow-up visit and 6 (27.3%) eyes required enucleation or evisceration. Contrary to previous studies, fungal endogenous endophthalmitis did not appear to have better visual outcome compared with bacterial endogenous endophthalmitis. Conclusion. Gram-negative microorganisms were the main causative pathogens of endogenous endophthalmitis in Hong Kong. The visual prognosis of endogenous endophthalmitis is generally poor as almost 50% of eyes were blind despite treatment.
Retina-the Journal of Retinal and Vitreous Diseases | 2009
Timothy Y. Y. Lai; David T.L. Liu; Kwok Ping Chan; Fiona O. J. Luk; Chi Pui Pang; Dennis S.C. Lam
Purpose: To evaluate the visual and growth factor changes of two different intravitreal bevacizumab dosages for neovascular age-related macular degeneration. Methods: Fifty eyes of 50 patients with neovascular age-related macular degeneration were randomized to receive 3 monthly intravitreal injections of 1.25 mg (24 eyes) or 2.5 mg (26 eyes) bevacizumab. Patients were observed for 6 months, and the logarithm of minimal angle of resolution best-corrected visual acuity, central foveal thickness, aqueous vascular endothelial growth factor, and pigment epithelial derived factor levels were assessed. Results: Both groups had significant central foveal thickness reductions at 6 months (P < 0.001). Six (23.1%) eyes in the 2.5-mg group lost 3 or more lines compared with none in the 1.25-mg group (P = 0.023). No significant difference in logarithm of minimal angle of resolution best-corrected visual acuity, central foveal thickness, or growth factors levels was found between the two groups at all visits. Eyes with persistent angiographic leakage at 3 months had significantly higher baseline aqueous vascular endothelial growth factor levels compared with eyes without leakage (P = 0.013). Logistic regression analysis showed that high baseline aqueous vascular endothelial growth factor level was the only significant factor associated with persistent leakage at 3 months (P = 0.040). Conclusion: Three monthly intravitreal 1.25-mg bevacizumab injections seemed to result in better visual outcome than 2.5 mg bevacizumab. Baseline aqueous vascular endothelial growth factor level might have a role in predicting angiographic response after bevacizumab injections.
Journal of Ocular Pharmacology and Therapeutics | 2010
Timothy Y. Y. Lai; Carol P.S. Lam; Fiona O. J. Luk; Rose P. S. Chan; Wai-Man Chan; David T.L. Liu; Dennis S.C. Lam
PURPOSE To evaluate the outcome of verteporfin photodynamic therapy (PDT) with or without intravitreal triamcinolone acetonide (IVTA) for the treatment of symptomatic polypoidal choroidal vasculopathy (PCV). METHODS Retrospective analysis of PCV patients who underwent PDT with or without IVTA with follow-up of 2 or more years. Changes in best-corrected visual acuity (BCVA), proportion of eyes with moderate visual loss (3 or more lines), and complications were compared between patients with or without IVTA. RESULTS Twenty-seven eyes of 27 patients were analyzed, with 12 eyes treated by PDT monotherapy and 15 eyes treated by combined PDT with IVTA. The baseline characteristics of both groups were similar. At 1 year, the mean logMAR BCVA for the PDT monotherapy group improved from 0.74 to 0.58 (P = 0.011), whereas the combined PDT and IVTA group improved from 0.84 to 0.74 (P = 0.17). At 2 years, the mean logMAR BCVA for the monotherapy and combined treatment groups were 0.62 and 0.84, respectively, and the changes compared with baseline were not statistically significant. No significant difference was found in the mean logMAR BCVA, the mean line of visual changes, and the mean number of PDT treatments between the 2 groups at 1 and 2 years. One (8.3%) and 4 (26.7%) eyes in the monotherapy and the combined groups lost 3 or more lines at 2 years, respectively. Patients who had combined PDT with IVTA were more likely to develop cataract requiring surgery and ocular hypertension (P = 0.043 and 0.046, respectively). CONCLUSIONS PDT reduced the risks of visual loss in patients with symptomatic PCV in the short term but the effect might not be sustained after 1 year. The adjunctive use of IVTA during PDT did not appear to result in additional benefit for treating PCV.
Scientific Reports | 2017
Fang Yao Tang; Danny Siu-Chun Ng; Alexander Lam; Fiona O. J. Luk; Raymond Chi-Wing Wong; Carmen W.H. Chan; Shaheeda Mohamed; Angie Fong; Jerry Lok; Tiffany Tso; Frank Lai; Marten E. Brelen; Tien Yin Wong; Clement C. C. Tham; Carol Y. Cheung
Early microvascular damage in diabetes (e.g. capillary nonperfusion and ischemia) can now be assessed and quantified with optical coherence tomography-angiography (OCT-A). The morphology of vascular tissue is indeed affected by different factors; however, there is a paucity of data examining whether OCT-A metrics are influenced by ocular, systemic and demographic variables in subjects with diabetes. We conducted an observational cross-sectional study and included 434 eyes from 286 patients with diabetes. Foveal avascular zone (FAZ) area, FAZ circularity, total and parafoveal vessel density (VD), fractal dimension (FD), and vessel diameter index (VDI) from the superficial capillary plexus OCT-angiogram were measured by a customized automated image analysis program. We found that diabetic retinopathy (DR) severity was associated with increased FAZ area, decreased FAZ circularity, lower VD, lower FD, and increased VDI. Enlarged FAZ area was correlated with shorter axial length and thinner central subfield macular thickness. Decreased FAZ circularity was correlated with a reduction in visual function. Decreased VD was correlated with thinner macular ganglion-cell inner plexiform layer. Increased VDI was correlated with higher fasting glucose level. We concluded that the effects of ocular and systemic factors in diabetics should be taken into consideration when assessing microvascular alterations via OCT-A.
Eye | 2016
Danny Siu-Chun Ng; Carol Y. Cheung; Fiona O. J. Luk; Shaheeda Mohamed; Marten E. Brelen; J C S Yam; Chi Wai Tsang; Timothy Yy Lai
The natural course of high-axial myopia is variable and the development of pathologic myopia is not fully understood. Advancements in optical coherence tomography (OCT) technology have revealed peculiar intraocular structures in highly myopic eyes and unprecedented pathologies that cause visual impairment. New OCT findings include posterior precortical vitreous pocket and precursor stages of posterior vitreous detachment; peripapillary intrachoroidal cavitation; morphological patterns of scleral inner curvature and dome-shaped macula. Swept source OCT is capable of imaging deeper layers in the posterior pole for investigation of optic nerve pits, stretched and thinned lamina cribrosa, elongated dural attachment at posterior scleral canal, and enlargement of retrobulbar subarachnoid spaces. This has therefore enabled further evaluation of various visual field defects in high myopia and the pathogenesis of glaucomatous optic neuropathy. OCT has many potential clinical uses in managing visual impairing conditions in pathologic myopia. Understanding how retinal nerve fibers are redistributed in axial elongation will allow the development of auto-segmentation software for diagnosis and monitoring progression of glaucoma. OCT is indispensable in the diagnosis of various conditions associated with myopic traction maculopathy and monitoring of post-surgical outcomes. In addition, OCT is commonly used in the multimodal imaging assessment of myopic choroidal neovascularization. Biometry and topography of the retinal layers and choroid will soon be validated for the classification of myopic maculopathy for utilization in epidemiological studies as well as clinical trials.