A review of selective laser trabeculoplasty in the Hong Kong Chinese population.

INTRODUCTION: Selective laser trabeculoplasty was first introduced to Hong Kong in 2004 for intra-ocular pressure lowering in the treatment of primary glaucoma. Since then, it has gained popularity as an alternative to anti-glaucoma medications and as a bridging therapy prior to more invasive glaucoma surgeries because of the high safety profile of the laser. METHODS: An Ovid search was performed using "selective laser trabeculoplasty" as the key word, which identified 190 unique articles; 24 reviews and/or meta-analyses were excluded. All remaining abstracts of original articles were in English. This review particularly focuses on the local population by summarising the findings from peer-reviewed publications that involved a Hong Kong Chinese population. RESULTS AND CONCLUSION: This review addresses some of the clinically relevant questions relating to selective laser trabeculoplasty including laser application, optimal energy, efficacies and success rates among different glaucoma subtypes, predictors of success, adverse effects, and intra-ocular pressure fluctuation after selective laser trabeculoplasty.

Differences in corneal parameters between normal tension glaucoma and primary open-angle glaucoma.

The purpose of this study was to identify the differences in corneal parameters between medically treated normal tension glaucoma (NTG) and primary open-angle glaucoma (POAG) subjects. This cross-sectional study from September 2011 to September 2012 included consecutive subjects with POAG and NTG who were receiving topical anti-glaucoma medications at the time of the study. Subjects were excluded if they had pre-existing corneal pathology or scars and previous glaucoma lasers. The following parameters were compared between the NTG and POAG groups: endothelial cell count, central corneal thickness (CCT), spherical equivalent, presenting and current intraocular pressure (IOP), number and type of anti-glaucoma medication, retinal nerve fibre layer thickness, visual field index, visual acuity, and phakic status. Only the right eye was used for statistical analysis. The right eye of the 30 NTG and 28 POAG subjects had comparable baseline characteristics, post-treatment IOP, and glaucoma severity. The endothelial cell count was significantly lower in the NTG versus the POAG group (2,380.0 ± 315.4 vs. 2,530.0 ± 320.4 cells/mm(2), p = 0.04). There were no significant differences in the spherical equivalent or CCT between the NTG and POAG groups. A significantly lower corneal endothelial cell count was found in NTG compared to POAG.

Incidence and risk factors for retinopathy of prematurity in extreme low birth weight Chinese infants.

The objective of this study is to determine the incidence and risk factors of retinopathy of prematurity (ROP) in extremely low birth weight (ELBW) Chinese infants. A retrospective medical record review of all ELBW (≤1,000 g) neonates screened for ROP from 2007 to 2012 was performed in Hong Kong. ROP screening was conducted at 2 neonatal intensive care units by 3 pediatric ophthalmologists using the Royal College of Ophthalmologists ROP guideline and the International Classification of ROP. Maternal and neonatal covariates were analyzed using univariate and multivariate regression analyses for both ROP and Type 1 ROP. In 131 ELBW Chinese infants, the mean gestational age (GA) and birth weight (BW) were 27.3 ± 3.3 weeks and 806.9 ± 133.7 g, respectively. The incidence of ROP and Type 1 ROP was 53.4 and 14.5 %, respectively. For ROP, a lighter BW, smaller GA, vaginal delivery, postnatal hypotension, inotrope use, bronchopulmonary dysplasia, surfactant use, invasive mechanical ventilation, and supplementary oxygen were independent risk factors for ROP, while PET was protective (P ≤ 0.02). On multivariate analysis, a smaller GA was a risk factor, while PET and congenital heart disease were protective for ROP development (P ≤ 0.01). For Type 1 ROP, a lighter BW, smaller GA, surfactant use, and invasive mechanical ventilation were independent risk factors for ROP, while PET was protective (P ≤ 0.02). There were no significant covariates on multivariate analysis for Type 1 ROP. In ELBW, preterm Chinese infants, a smaller GA was a risk factor for ROP, while PET and congenital heart disease were protective for ROP development in multivariate analysis.

Optic neuritis in Hong Kong: a 1-year follow-up study.

To investigate the etiology and prevalence of optic neuritis in a Chinese population. This was a single centre prospective cohort study. Consecutive patients with either a first or recurrent attack of optic neuritis from November 2010 to December 2011 were recruited from a district hospital in Hong Kong Special Administrative Region, China. All patients underwent serology testing for NMO (neuromyelitis optica) IgG; oligoclonal bands from lumbar puncture; computer tomography and contrast magnetic resonance imaging (MRI) of the brain and orbit as well as visual field; and optical coherence tomography testing. Patients were followed up for 1 year after the initial attack. 30 optic neuritis subjects were recruited. 73.3 % (22/30) remain as clinical isolated syndrome (CIS) after 1-year follow-up. 10 % (3/30) patients developed multiple sclerosis. 10 % (3/30) were diagnosed with NMO and 6.7 % (2/30) with NMO-spectrum disorder. The majority of acute unilateral optic neuritis in Chinese was CIS in origin although a fraction does progress to develop MS or NMO-related disorders. Clinicians should be aware of the associations and offer appropriate systemic workups.

Longitudinal Changes in Retinal Nerve Fibre Layer Thickness after an Isolated Unilateral Retrobulbar Optic Neuritis: 1-Year Results.

The objective of this study was to investigate the longitudinal changes in retinal nerve fibre layer (RNFL) thickness 1 year after an episode of unilateral acute optic neuritis. This prospective cohort study recruited consecutive patients with a first episode of isolated, unilateral acute optic neuritis from October 2010 to June 2013. RNFL thickness of the attack and normal fellow eyes was measured by optical coherence tomography on presentation and 3, 6, and 12 months post attack in both the treatment and non-treatment groups. The treatment group consisted of subjects that opted for systemic steroids to hasten recovery time. In 20 subjects, 11 received systemic steroids and 9 were treated conservatively. The baseline RNFL thickness was similar in the attack and fellow eyes (p ≥ 0.4). Progressive RNFL thinning was seen in the attack eye over the 12-month period, with significant differences for baseline versus 3 months; baseline versus 12 months; and 3 versus 12 months (all p < 0.0001). At 12 months, the attack eye had a thinner average RNFL than the fellow eye (100.9 ± 6.1 versus 107.3 ± 5.5 µm; p = 0.002). The 12-month RNFL was similar between the treatment and non-treatment groups (p ≥ 0.6). A single episode of optic neuritis triggered an accelerated, progressive RNFL thinning up to 6 months post attack. Initial treatment with systemic steroids did not seem to alter the degree of RNFL loss at 12 months.

A comparison of intralesional triamcinolone acetonide injection for primary chalazion in children and adults.

PURPOSE: To investigate outcome differences of intralesional triamcinolone acetonide (TA) injection for primary chalazia in children versus adults. METHODS: A retrospective review of consecutive subjects with primary chalazion who received intralesional TA injection was conducted. A single investigator injected 0.05-0.15 mL of TA (40 mg/mL) intralesionally. Patients were stratified into the pediatric (<18 years old) and adult (≥ 18 years old) group. In both groups, the correlation of resolution time with chalazion size and TA dose was performed. RESULTS: 17 children and 24 adults were enrolled, with a mean age of 7.4 ± 5.5 and 39.3 ± 16.7 years, respectively. Both groups had statistically similar baseline characteristics. There was no significant difference between the resolution time in the pediatric (18.2 ± 11.4 days) and adult (16.5 ± 11.0 days) group (P = 0.7). There were no significant complications from the TA injection. There was no significant correlation of resolution time to chalazion size (P = 0.7) nor TA dose (P = 0.3) in both groups. CONCLUSION: TA for the treatment of primary chalazion was equally effective in children and adults, without any significant complications, and the rate of clinical response did not appear to be dose-dependent.

The anterior chamber depth and retinal nerve fiber layer thickness in children.

PURPOSE: To investigate the correlation of anterior chamber depth (ACD) with the peripapillary retinal nerve fiber layer (RNFL) thickness, age, axial length (AL), and spherical equivalent in children. SUBJECTS: Consecutive subjects aged 4 to 18 were recruited. Visually disabling eye conditions were excluded. Only the right eye was included for analysis. The ACD was correlated with RNFL thickness, age, spherical equivalent, and AL for all subjects. Subjects were then divided into 3 groups based on their postcycloplegic spherical equivalent: myopes (<-1.0 D), emmetropes (≥-1.0 to ≤+1.0 D), and hyperopes (>+1.0 D). The ACD was compared among the 3 groups before and after age adjustment. RESULTS: In 200 subjects (mean age 7.6 ± 3.3 years), a deeper ACD was correlated with thinner global RNFL (r = -0.2, r(2) = 0.06, P = 0.0007), older age (r = 0.4, r(2) = 0.1, P < 0.0001), myopic spherical equivalent (r = -0.3, r(2) = 0.09, P < 0.0001), and longer AL (r = 0.5, r(2) = 0.2, P < 0.0001). The ACD was deepest in myopes (3.5 ± 0.4 mm, n = 67), followed by emmetropes (3.4 ± 0.3, n = 60) and then hyperopes (3.3 ± 0.2, n = 73) (all P < 0.0001). After age adjustment, myopes had a deeper ACD than the other 2 groups (all P < 0.0001). CONCLUSIONS: In children, a deeper ACD was associated with thinner RNFL thickness, older age, more myopic spherical equivalent, and longer AL. Myopes had a deeper ACD than emmetropes and hyperopes.

Retrospective review on the use of topical cyclosporin a 0.05% for paediatric allergic conjunctivitis in Hong Kong Chinese.

PURPOSE: To evaluate the efficacy of using topical cyclosporin A 0.05% (Restasis) for the treatment of paediatric allergic conjunctivitis. METHODS: This retrospective study included consecutive cases of paediatric allergic conjunctivitis treated with Restasis between 2010 and 2013. Subjects with follow-up time less than 3 months after using Restasis were excluded. Itch severity score, symptom score, and sign score were compared before (baseline) and 3 months after using Restasis. RESULTS: In 27 eyes of 14 patients (mean age 10.8 ± 3.2 years), 44.4% had allergic conjunctivitis, 33.3% had vernal keratoconjunctivitis, and 22.2% had atopic keratoconjunctivitis. The mean duration of ocular symptoms was 20.4 ± 13.2 months. 92.6% of subjects were using steroid eye drop before Restasis. After 3 months of topical Restasis, there were statistically significant reductions in the symptom, sign, and itch severity scores compared with baseline (all P ≤ 0.001) and 78.6% of subjects were able to be tapered off steroid eye drops. CONCLUSION: Topical Restasis was effective and safe in significantly reducing ocular itchiness, sign, and symptom scores at 3 months after use in paediatric allergic ocular conditions.

Differences in risk factors for retinopathy of prematurity development in paired twins: a Chinese population study.

PURPOSE: To determine the differences in risk factors for retinopathy of prematurity (ROP) in paired twins. METHODS: A retrospective medical record review was performed for all paired twins screened for ROP between 2007 and 2012. Screening was offered to very low birth weight (≤ 1500 grams) and preterm (≤ 32 weeks) neonates. Twins 1 and 2 were categorized based on the order of delivery. Maternal and neonatal covariates were analyzed using univariate and multivariate regression analyses for both ROP and Type 1 ROP. RESULTS: In 34 pairs of Chinese twins, the mean gestational age (GA) was 30.2 ± 2.0 weeks. In Twin 1, smaller GA (OR = 0.44, P = 0.02), higher mean oxygen concentration (OR = 1.34, P = 0.03), presence of thrombocytopenia (OR = 1429.60, P < 0.0001), and intraventricular hemorrhage (OR = 18.67, P = 0.03) were significant risk factors for ROP. For Twin 2, a smaller GA (OR = 0.45, P = 0.03) was the only risk factor. There were no significant risk factors for ROP in Twin 1 or Twin 2 on multivariate analysis. CONCLUSION: In Chinese twin pairs, smaller GA was the only common risk factor for ROP while Twin 1 was more susceptible to the postnatal risks for ROP.

The association between clinical parameters and glaucoma-specific quality of life in Chinese primary open-angle glaucoma patients.

OBJECTIVE. To investigate the association between clinical measurements and glaucoma-specific quality of life in Chinese glaucoma patients. DESIGN. Cross-sectional study. SETTING. An academic hospital in Hong Kong. PATIENTS. A Chinese translation of the Glaucoma Quality of Life-15 questionnaire was completed by 51 consecutive patients with bilateral primary open-angle glaucoma. The binocular means of several clinical measurements were correlated with Glaucoma Quality of Life-15 findings using Pearson's correlation coefficient and linear regression. The measurements were the visual field index and pattern standard deviation from the Humphrey Field Analyzer, Snellen best-corrected visual acuity, presenting intra-ocular pressure, current intra-ocular pressure, average retinal nerve fibre layer thickness via optical coherence tomography, and the number of topical anti-glaucoma medications being used. RESULTS. In these patients, there was a significant correlation and linear relationship between a poorer Glaucoma Quality of Life-15 score and a lower visual field index (r=0.3, r(2)=0.1, P=0.01) and visual acuity (r=0.3, r(2)=0.1, P=0.03). A thinner retinal nerve fibre layer also correlated with a poorer Glaucoma Quality of Life-15 score, but did not attain statistical significance (r=0.3, P=0.07). There were no statistically significant correlations for the other clinical parameters with the Glaucoma Quality of Life-15 scores (all P values being >0.7). The three most problematic activities affecting quality of life were "adjusting to bright lights", "going from a light to a dark room or vice versa", and "seeing at night". CONCLUSION. For Chinese primary open-angle glaucoma patients, binocular visual field index and visual acuity correlated linearly with glaucoma-specific quality of life, and activities involving dark adaptation were the most problematic.

Intralesional triamcinolone acetonide injection for the treatment of primary chalazions.

The aim of this study was to investigate the safety and efficacy of intralesional triamcinolone acetonide (TA) injection in the treatment of primary chalazions not responding to conservative treatment. Patient medical records were retrospectively reviewed for all consecutive patients that received intralesional TA injection by a single surgeon between January 2012 and March 2013 for the treatment of unresolved primary chalazions despite 1 month of conservative treatment. The dose of TA injection ranged from 2 to 6 mg (40 mg/mL) depending on the size of the chalazion. The main outcome measures included time to resolution, time to 50 % size reduction, and complications from the treatment. During the study period, 48 chalazions from 38 patients were treated by intralesional TA injection. A 50 % reduction in size was achieved in 81.3 % of chalazions in 4 weeks and 83 % achieved complete resolution in 6 weeks. The mean time to complete resolution was 15.7 ± 10.0 days. There were no complications noted from the injections; 14.6 % required subsequent incision and curettage and 2.1 % required a second TA injection for complete resolution. Intralesional TA injection is a safe, simple, and effective procedure for the management of primary chalazions and may be considered as an alternative to incision and curettage in cases not responding to conservative treatment.

Primary acute angle closure: long-term clinical outcomes over a 10-year period in the Chinese population.

To investigate long-term clinical outcomes after acute angle closure in the Chinese population. A 10-year retrospective review of primary acute angle closure in Hong Kong Chinese to document patient demographics, treatment, and pre- and post-acute angle closure intraocular pressure (IOP) and visual acuity (VA). The year of attack was correlated with the timing of laser, last VA and IOP, and the number of anti-glaucoma eye drops. In 210 eyes (200 patients), 10 % had a simultaneous bilateral acute angle closure. VA improvement was noted in 68.6 % of eyes whilst 11.4 % were blinded. At 3.7 ± 2.4 years of follow-up, 49.5 % had IOP <21 mmHg with medication or surgery, 41.9 % needed anti-glaucoma eye drops, and 13.8 % had undergone trabeculectomy. The older the year of attack, the poorer the VA (r = 0.2, p = 0.03) and the longer the laser wait time (r = 0.3, p < 0.0001). VA outcome and laser promptness in acute angle closure has improved over the years. At 4 years after the attack, 50 % had normal IOP, 69 % had improved VA but 11 % were blinded.

Surgical outcome of involutional lower eyelid entropion correction using transcutaneous everting sutures in Chinese patients.

To evaluate the clinical efficacy of transcutaneous everting sutures for lower eyelid involutional entropion in Chinese patients. A retrospective, non-comparative, interventional case series. This retrospective study consecutively reviewed the medical records of all patients with involutional lower eyelid entropion who underwent transcutaneous everting suture for entropion correction at the Department of Ophthalmology, Caritas Medical Centre, from 1st January 2010 to 31st October 2013. Exclusion criteria included concurrent eyelid pathologies such as malignant tumor, infection, cicatricial entropion, post-operative follow-up period of <3 months, significant horizontal lid laxity, and aged <60 years at the time of surgery. The primary outcome measures were recurrence rate and complications. Secondary outcome measures included patient demographic data, type and number of everting sutures, duration of operation, timing of stitch removal, duration of follow-up, as well as each patient's medical history and current medications. Thirty-four eyelids of 28 patients were included. The average age was 78.2 ± 7.3 years and the male to female ratio was 4:3. In this series, 26.5 and 2.9 % of eyelids underwent entropion correction whilst receiving aspirin and warfarin, respectively. The mean duration of post-operative follow-up was 13.2 ± 10.5 months. The recurrence rate was 11.8 % at a mean of 9.0 ± 6.0 months. There were no peri-operative or post-operative complications observed. A transcutaneous everting suture was found to be a quick and effective means to correct senile involutional lower lid entropion in Chinese patients with no complications despite the continued use of anti-coagulation therapy in >25 % of our cases.

Neuromyelitis Optica Spectrum Disorder in a Chinese Woman with Ocular Myasthenia Gravis: First Reported Case in the Chinese Population.

Coexisting myasthenia gravis and neuromyelitis optica spectrum disorder was reported as a rare association, with only 26 reported cases in the literature. The authors report the case of a middle-aged Chinese woman with bilateral recurrent optic neuritis and seropositive ocular myasthenia gravis who was subsequently diagnosed with neuromyelitis optica spectrum. She was tested seropositive for the neuromyelitis optica immunoglobulin G (NMO-IgG) and had elevated antinuclear antibody titres, but workup for other autoimmune disorders were negative. She was subsequently prescribed with azathioprine and pyridostigmine, and showed good control of both autoimmune disorders. To the best of the authors' knowledge, this is the first reported case in the literature of a Chinese patient with seropositivity for both anti-acetylcholine receptor and NMO-IgG without a thymic disorder. Testing of NMO-IgG may be considered in patients with optic neuritis with underlying autoimmune disorders even in the absence of transverse myelitis for the detection of associated neuromyelitis optica spectrum disorders.

Prospective study on retinal nerve fibre layer thickness changes in isolated unilateral retrobulbar optic neuritis.

PURPOSE: To investigate the retinal nerve fibre layer (RNFL) thickness after unilateral acute optic neuritis using optical coherence tomography (OCT). PATIENTS AND METHODS: This prospective cohort study recruited consecutive patients with a first episode of isolated, unilateral acute optic neuritis. RNFL thickness and visual acuity (VA) of the attack and normal fellow eye were measured at presentation and 3 months in both the treatment and nontreatment groups. RESULTS: 11 subjects received systemic steroids and 9 were treated conservatively. The baseline RNFL thickness was similar in the attack and fellow eye (P ≥ 0.4). At 3 months, the attack eye had a thinner temporal (P = 0.02) and average (P = 0.05) RNFL compared to the fellow eye. At 3 months, the attack eye had significant RNFL thinning in the 4 quadrants and average thickness (P ≤ 0.0002) compared to baseline. The RNFL thickness between the treatment and nontreatment groups was similar at baseline and 3 months (P ≥ 0.1). Treatment offered better VA at 3 months (0.1 ± 0.2 versus 0.3 ± 0.2 LogMAR, P = 0.04). CONCLUSION: Generalized RNFL thinning occurred at 3 months after a first episode of acute optic neuritis most significantly in the temporal quadrant and average thickness. Visual improvement with treatment was independent of RNFL thickness.

Prospective study on retinal nerve fibre layer changes after an acute episode of phacomorphic angle closure.

To investigate the retinal nerve fibre layer (RNFL) changes after an acute attack of phacomorphic angle closure. This prospective study involved ten cases of phacomorphic angle closure that underwent cataract extraction and intraocular lens insertion after intraocular pressure lowering. Apart from visual acuity and intraocular pressure (IOP), RNFL thickness and vertical cup disc ratio (VCDR) were measured by optical coherence tomography (OCT) at 3-9 months post attack. Humphrey visual field assessment was performed at 9 months post attack. All cases had mean phacomorphic duration of <5 days. Postoperatively, best correct Snellen visual acuity was 0.4 ± 0.2 and IOP at 9 months was 11.0 ± 3.1 mmHg. There was no difference in VCDR and RNFL between the attack and contralateral eye at 3 months post attack (both p = 0.4). At 9 months post attack, there was significant thinning in the average (p = 0.01), superior (p = 0.01), and inferior (p = 0.006) RNFL. There was no significant difference in the pattern standard deviation (PSD) between the two eyes on the Humphrey visual field nor was there any correlation between PSD severity and RNFL thinning (all p > 0.2. Patients with <5 days duration of phacomorphic angle closure are likely to have reasonable postoperative vision. An acute episode of phacomorphic angle closure can trigger an accelerated RNFL thinning despite normal IOP and open angles, most noticeable in the superior and inferior quadrants, occurring between 3 and 9 months post attack. Glaucomatous optic neuropathy in the attack eye was evident by OCT but not by visual field assessment at the same time interval.

Minimally Invasive Glaucoma Surgery in Primary Angle-Closure Glaucoma.

Primary angle-closure glaucoma (PACG) is responsible for half of the glaucoma-related blindness worldwide. Cataract surgery with or without trabeculectomy has been considered to be the first-line treatment in eyes with medically uncontrolled PACG. While minimally invasive glaucoma surgery has become an important surgical approach for primary open-angle glaucoma, its indications and benefits in PACG are less clear. This review summarizes the efficacy and safety profile of minimally invasive glaucoma surgery in PACG to unfold new insights into the surgical management of PACG.

Latest Developments in Normal-Pressure Glaucoma: Diagnosis, Epidemiology, Genetics, Etiology, Causes and Mechanisms to Management.

Normal-pressure glaucoma (NPG) is part of the spectrum of the open-angle glaucomas and morphologically characterized, as any glaucoma, by a loss of neuroretinal rim parallel to an enlargement and deepening of the optic cup, and development or enlargement of parapapillary beta zone. These morphological characteristics, in addition to the therapeutic benefit of lowering the intraocular pressure (IOP), make NPG differ from vascular-induced optic neuropathy. Based on the anatomy of the optic nerve as a cerebral fascicle, the physiological counter-pressure against the IOP is the orbital cerebrospinal fluid pressure (CSFP), with both pressures forming the trans-lamina cribrosa pressure difference (TLCPD). In contrast to the IOP, the TLCPD is the true pressure exerting force on the optic nerve fibers when passing through the lamina cribrosa. As a theoretical notion, an abnormally high TLCPD due to a low CSFP, in association with a low arterial blood pressure, could therefore be involved in the pathogenesis of NPG. It fits with the finding that the reduction of the IOP (and thus indirectly of the TLCPD) is (the only proven) procedure for NPG therapy. This review additionally highlights the genetic background, diagnostic methods, and therapeutic modalities of NPG.