Publications by authors named "Frank Hiu Ping Lai"

6 Publications

  • Page 1 of 1

Comparison of two-year treatment outcomes between subthreshold micropulse (577 nm) laser and aflibercept for diabetic macular edema.

Jpn J Ophthalmol 2021 Sep 14;65(5):680-688. Epub 2021 Jun 14.

Department of Ophthalmology, Caritas Medical Centre, 111 Wing Hong Street, Sham Shui Po, Hong Kong.

Purpose: To compare two-year treatment outcomes of subthreshold micropulse (577 nm) laser and aflibercept for diabetic macular edema (DME).

Study Design: Retrospective case-control study.

Methods: A total 164 eyes in 164 DME patients treated with either micropulse laser (86 eyes) or intravitreal aflibercept monotherapy (78 eyes) were recruited. Main outcome measures included at least five Early Treatment Diabetic Retinopathy Study (ETDRS) letters' improvement from baseline at 6, 12 and 24 months.

Results: Rescue aflibercept was initiated in 24% of eyes in micropulse laser group. At 6-month visit the aflibercept group achieved a higher percentage of eyes with at least 5-letter visual acuity improvement than micropulse laser group (56% vs 38%, P = 0.044), however, this was not the case at 12-month (45% vs 49%, P = 0.584) and 24-month visits (49% vs 57%, P = 0.227). At 6-month visit the aflibercept group achieved a higher percentage of eyes with at least 10% improvement of central macular thickness (73% vs 49%, P = 0.005), but this was not the case at 12-month (73% vs 70%, P = 0.995) and 24-month visits (85% vs 84%, P = 0.872).

Conclusion: Aflibercept achieved faster and higher rates of anatomical and functional improvement than micropulse laser in DME patients. Long term efficacy of treatment did not result in significant differences between aflibercept monotherapy and micropulse laser in DME patients. Primary treatment of micropulse laser with deferred rescue aflibercept might be the treatment option without reducing the chance of visual improvement in DME eyes.
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September 2021

Endoscopic vitreoretinal surgery: Review of current applications and future trends.

Surv Ophthalmol 2021 Mar-Apr;66(2):198-212. Epub 2020 Dec 3.

Department of Ophthalmology, Caritas Medical Centre, Hong Kong.

Endoscopy provides unique optical properties to circumvent anterior segment opacities and visualize difficult-to-access anatomical regions, including retroirideal, retrolental, ciliary body, and anterior retinal structures. We summarize the basic principles and utilization of endoscopic vitreoretinal surgery, along with recent technological advances in the field base on a structured literature search in Pubmed, Embase, and Google Scholar database up to February, 2020. Endoscopy has been used in the management of retinal detachment, ischemic retinopathies with neovascular glaucoma, severe ocular trauma, endophthalmitis, lens-related disorders in the posterior segment, pediatric vitreoretinal diseases, and implantation of retinal prostheses. Ongoing development of endoscopic technology aims to provide higher resolution images with endoscopes of smaller diameter. New surgical techniques supported by the adoption of endoscopy are available to manage challenging surgical scenarios. Endoscopy can be a useful adjunct to microscope wide-angle viewing systems in the management of complex vitreoretinal diseases.
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December 2020

Analysis of choriocapillaris perfusion and choroidal layer changes in patients with chronic central serous chorioretinopathy randomised to micropulse laser or photodynamic therapy.

Br J Ophthalmol 2021 04 12;105(4):555-560. Epub 2020 Jun 12.

Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China

Purpose: The purpose of this study was to investigate the signal changes in choriocapillaris flow deficits and choroidal thickness changes using swept-source optical coherence tomography angiography (OCTA) following different treatments.

Design: A double-blind, randomised controlled trial.

Methods: Patients with unilateral chronic central serous chorioretinopathy (CSC) were randomised to receive subthreshold micropulse laser therapy (MLT) or half-dose photodynamic therapy (PDT). Choroidal thickness and choriocapillaris flow deficit signals were investigated.

Results: Eighteen patients were randomised into the MLT group and 15 patients into the PDT group. Areas with flow deficit signals were identified in all baseline OCTA images of the choriocapillaris, with mean areas of 0.420 and 0.465 mm in the MLT and PDT groups, respectively. These flow deficit signal areas were significantly reduced at 6 months (p=0.011) in the MLT group and at 3 months (p=0.008) in the PDT group. Patients from the PDT group were shown to have smaller flow deficit areas than patients from the MLT group at all time points after treatment (p=0.001, analyses of variance). The mean choroidal volume of the fovea showed a significant reduction at 1 month (p=0.003), 3 months (p=0.199) and 6 months (p=0.006) in the PDT group.

Conclusion: The flow deficit areas identified in the choriocapillaris layer may suggest possible relative choroidal ischaemia. With measurement of choroidal volume reduction and faster rates of flow deficit area change, PDT has a stronger effect than MLT in promoting choriocapillaris recovery.
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April 2021

Lacrimal gland abscess in children: Two case reports and literature review.

Orbit 2017 Dec 18;36(6):468-472. Epub 2017 Aug 18.

e Department of Ophthalmology and Visual Sciences , The Chinese University of Hong Kong.

Acute suppurative bacterial dacryoadenitis (ASBD) with abscess formation is rarely seen in clinical practice. A retrospective review of medical records in the past 8 years identified two unilateral cases in children, one developed presumably after methicillin-sensitive Staphylococcus aureus (MSSA) conjunctivitis and the other due to community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection. Computerized tomography scans showed globe indentation by the enlarged lacrimal glands with rim-enhancing lesions. After failing to respond to intravenous antibiotics, both abscesses resolved promptly with surgical drainage without any long-term sequelae.
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December 2017

Classification of Exudative Age-Related Macular Degeneration With Pachyvessels on En Face Swept-Source Optical Coherence Tomography.

Invest Ophthalmol Vis Sci 2017 02;58(2):1054-1062

Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong 5Department of Ophthalmology, Prince of Wales Hospital, Hong Kong.

Purpose: The purpose of this study was to classify exudative maculopathy by the presence of pachyvessels on en face swept-source optical coherence tomography (SSOCT).

Methods: Consecutive patients with signs of exudative maculopathy underwent SSOCT, fluorescein and indocyanine green angiography (ICGA), ultra-widefield fundus color photography, and autofluorescence examinations. Images were analyzed in a masked fashion by two sets of four examiners in different sessions: (1) the presence of pachyvessels in en face OCT and (2) features of exudative maculopathy in conventional imaging modalities. Quantitative data obtained were subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI), which was the ratio of choroidal vessels lumen area to a specified choroidal area from binarized cross-sectional OCT scans.

Results: Pachyvessels was observed in 38 (52.1%) of 73 eyes. The pachyvessels group was associated with younger age (69.1 ± 9.4 years, odds ratio [OR] = 0.95, 95% confidence interval [95% CI] = 0.90-0.97, P = 0.04), presence of polypoidal lesions (OR = 3.27, 95% CI = 1.24-8.62, P = 0.01), increased SFCT (OR = 1.08, 95% CI = 1.02-1.14, P < 0.01), and increased CVI (65.4 ± 5.3, OR = 1.12, 95% CI = 1.02-1.23, P = 0.01). In multivariate regression, CVI significantly correlated with pachyvessels (OR = 1.24, 95% CI = 1.03-1.55, P = 0.04).

Conclusions: Exudative maculopathy could be classified based on differences in choroidal vasculature morphology. Current results implied that choroidal hemodynamics may be relevant to variable natural history and treatment response in neovascular AMD and polypoidal choroidal vasculopathy.
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February 2017

Choroidal structures in polypoidal choroidal vasculopathy, neovascular age-related maculopathy, and healthy eyes determined by binarization of swept source optical coherence tomographic images.

Graefes Arch Clin Exp Ophthalmol 2017 May 1;255(5):935-943. Epub 2017 Feb 1.

Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, 4/F Hong Kong Eye Hospital, 147K Argyle Street, Mongkok, Hong Kong, SAR, China.

Purpose: To evaluate quantitatively the choroidal vascularity in polypoidal choroidal vasculopathy (PCV) and neovascular age-related macular degeneration (AMD) patients compared to healthy controls.

Methods: All eyes underwent swept source optical coherence tomography (OCT), and choroidal images were binarized into blood vessels lumen and stroma. The choroidal vascular index (CVI) was defined as the ratio of luminal area (LA) over total choroidal area of the subfoveal region with a width of 1500 μm.

Results: The study included 73 patients with neovascular AMD or PCV with mean ± standard deviation (SD) age of 71.8 ± 9.3 years, which was older than the mean age of 65.1 ± 10.8 years of 72 healthy eyes from control group (p < 0.01). The 44 PCV eyes had significantly higher mean SFCT of 214.23 ± 95.21 μm than neovascular AMD eyes (172.74 ± 96.48 μm, p = 0.03) and greater luminal area (0.23 ± 0.09 mm vs. 0.19 ± 0.08 mm, p = 0.05). After adjusting for age, axial length, and gender in multivariate regression analysis, the SFCT of PCV and neovascular AMD eyes were not significantly different from healthy eyes (195.55 ± 93.11 μm), but the CVI of both PCV (64.94 ± 5.43%, p = 0.01) and neovascular AMD (62.54 ± 5.57%, p = <0.01) were significantly lower than control (68.53 ± 5.91%).

Conclusion: Despite physiological changes of choroidal vasculature due to aging, the choroidal morphology is different in PCV, neovascular AMD and healthy eyes, which has implication on disease pathogenesis.
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May 2017