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.

Efficacy of selective laser trabeculoplasty for normal tension glaucoma: 1 year results.

BACKGROUND: Normal tension glaucoma (NTG) is commonly treated with anti-glaucoma medications. Recently, selective laser trabeculoplasty (SLT) has been demonstrated to lower the intraocular pressure (IOP) and medication use in NTG. The purpose of this study was to investigate the efficacy of a single session of SLT for NTG at 1 year. METHODS: This prospective cohort study recruited NTG patients taking anti-glaucoma medication. Potential subjects were excluded if they had had previous glaucoma surgery or laser and also if intraocular surgery or additional SLT procedures were performed after the first treatment. All subjects underwent a 1-month washout. A 30% IOP reduction was set as the target IOP. A single session of SLT was performed to 360 degrees of the trabecular meshwork. At 1-month after SLT, medication was resumed to achieve the target IOP. The IOP was measured every 3 months, and the number of medications was recorded at 3, 6, and 12 months. Only the right eye was used for statistical analysis. RESULTS: In 41 right eyes, the mean pre-study IOP was 14.3 ± 3.4 mmHg while on 1.5 ± 0.8 eye drops. The post-washout IOP was 16.2 ± 2.2 mmHg. A mean of 191.1 ± 26.3 SLT shots at 1.0 ± 0.07 mJ were applied. There was significant IOP reduction at all time intervals following SLT when compared to the post-washout IOP (P < 0.0001). The number of medications was significantly reduced at all time intervals following SLT when compared to the pre-study level (P < 0.0001). At 12 months, the mean IOP was 12.2 ± 2.2 mmHg while on 1.1 ± 0.9 eye drops. CONCLUSIONS: A single session of SLT for NTG achieved an additional 15% IOP reduction while using 27% less medication at 1 year compared to pre-study levels. TRIAL REGISTRATION: The Clinical Trials Register of the University of Hong Kong HKCTR1847 The European Clinical Trials Database 2014-003305-15 (August 11, 2014) ( https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-003305-15 ).

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.

Effect of groundwater--lake interactions on arsenic enrichment in freshwater beach aquifers.

Field measurements combined with numerical simulations provide insight into the water exchange, groundwater flow, and geochemical processes controlling the mobility of arsenic (As) in freshwater beach aquifers. Elevated dissolved As (up to 56 µg/L) was observed 1-2 m below the shoreline at two sandy beaches on Lake Erie, Ontario, Canada. Water and solid-phase analyses suggest that Fe (hydr)oxides present below the shoreline accumulate As, creating a risk of high As in the beach aquifer. Groundwater flow simulations combined with vertical hydraulic gradient measurements indicate that wave-induced flow recirculations across the groundwater-lake interface are significant. These recirculations, which vary with wave intensity and lake water level fluctuations, set up redox and pH gradients, where Fe precipitates and subsequently sequesters As. The elevated As concentrations observed at both beaches, combined with the distribution of other dissolved species, suggest that the As enrichment may be naturally occurring. Regardless of the As source, the interacting hydrologic and geochemical processes revealed may have important implications for the flux of As and also other oxyanions, such as phosphate, across the groundwater-lake interface in nearshore areas of the Great Lakes.

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.

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.

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.

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.

Dynamic Changes in Long-Standing Multiple Sclerosis Revealed by Longitudinal Structural Network Analysis Using Diffusion Tensor Imaging.

BACKGROUND AND PURPOSE: DTI can be used to derive conventional diffusion measurements, which can measure WM abnormalities in multiple sclerosis. DTI can also be used to construct structural brain networks and derive network measurements. However, few studies have compared their sensitivity in detecting brain alterations, especially in longitudinal studies. Therefore, in this study, we aimed to determine which type of measurement is more sensitive in tracking the dynamic changes over time in MS. MATERIALS AND METHODS: Eighteen patients with MS were recruited at baseline and followed up at 6 and 12 months. All patients underwent MR imaging and clinical evaluation at 3 time points. Diffusion and network measurements were derived, and their brain changes were evaluated. RESULTS: None of the conventional DTI measurements displayed statistically significant changes during the follow-up period; however, the nodal degree, nodal efficiency, and nodal path length of the left middle frontal gyrus and bilateral inferior frontal gyrus, opercular part showed significant longitudinal changes between baseline and at 12 months, respectively. CONCLUSIONS: The nodal degree, nodal efficiency, and nodal path length of the left middle frontal gyrus and bilateral inferior frontal gyrus, opercular part may be used to monitor brain changes over time in MS.

Harnessing Next-Generation Sequencing as a Timely and Accurate Second-Tier Screening Test for Newborn Screening of Inborn Errors of Metabolism.

In this study, we evaluated the implementation of a second-tier genetic screening test using an amplicon-based next-generation sequencing (NGS) panel in our laboratory during the period of 1 September 2021 to 31 August 2022 for the newborn screening (NBS) of six conditions for inborn errors of metabolism: citrullinemia type II (MIM #605814), systemic primary carnitine deficiency (MIM #212140), glutaric acidemia type I (MIM #231670), beta-ketothiolase deficiency (#203750), holocarboxylase synthetase deficiency (MIM #253270) and 3-hydroxy-3-methylglutaryl-CoA lyase deficiency (MIM # 246450). The custom-designed NGS panel can detect sequence variants in the relevant genes and also specifically screen for the presence of the hotspot variant IVS16ins3kb of SLC25A13 by the copy number variant calling algorithm. Genetic second-tier tests were performed for 1.8% of a total of 22,883 NBS samples. The false positive rate for these six conditions after the NGS second-tier test was only 0.017%, and two cases of citrullinemia type II would have been missed as false negatives if only biochemical first-tier testing was performed. The confirmed true positive cases were citrullinemia type II (n = 2) and systemic primary carnitine deficiency (n = 1). The false positives were later confirmed to be carrier of citrullinemia type II (n = 2), carrier of glutaric acidemia type I (n = 1) and carrier of systemic primary carnitine deficiency (n = 1). There were no false negatives reported. The incorporation of a second-tier genetic screening test by NGS greatly enhanced our program's performance with 5-working days turn-around time maintained as before. In addition, early genetic information is available at the time of recall to facilitate better clinical management and genetic counseling.

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.