Publications by authors named "Steve Seah"
Background/aims: This work aimed to study the effect of long-term intraocular pressure (IOP) fluctuation on visual field (VF) progression 8 years post-trabeculectomy in Asian eyes.
Methods: This was a retrospective analysis of 8-year post-trabeculectomy data from The Singapore 5-Fluorouracil (5-FU) Study. VFs were analysed using Progressor software (Medisoft, Leeds, UK).
Background/aims: To investigate longitudinal changes in anterior chamber depth (ACD) and axial length (AXL) over 5 years after trabeculectomy surgery in Asian patients with primary glaucoma, and to identify factors associated with these changes.
Methods: In this prospective cohort study, phakic subjects with primary glaucoma who underwent trabeculectomy had ACD and AXL measured over 5 years. The effect of intraocular pressure (IOP) on ACD and AXL was determined.
Objective: To report the 8-year outcomes of Asian subjects who underwent trabeculectomy augmented by intraoperative 5-fluorouracil (5-FU) or placebo.
Design: Retrospective review of a randomized controlled trial.
Participants: Subjects with primary open-angle or angle-closure glaucoma.
Background: To assess the efficacy and safety of collagen matrix implant (Ologen) in phacotrabeculectomy.
Design: Prospective, non-randomized, comparative study.
Participants: Sixty-six Asian patients.
Purpose: To compare the 2-year efficacy of phacoemulsification and intraocular lens implant (phaco/IOL) with laser peripheral iridotomy (LPI) in the early management of acute primary angle closure (APAC) and coexisting cataract.
Design: Randomized, controlled trial.
Participants: We included 37 subjects presenting with APAC who had responded to medical treatment such that intraocular pressure (IOP) was ≤30 mmHg within 24 hours, and had cataract with visual acuity of ≤6/15.
Objective: To determine whether the timing of cataract surgery after trabeculectomy has an effect on trabeculectomy function in terms of intraocular pressure control.
Methods: This was a cohort study nested within a randomized clinical trial. There were 235 participants with glaucoma who had a single previous trabeculectomy augmented with either intraoperative 5-fluorouracil or placebo.
Purpose: To examine the association between central corneal thickness (CCT) and glaucoma.
Methods: This was a nested case-control study using 1090 subjects from an eye disease population survey in Singapore and 243 participants from a hospital glaucoma surgery clinical trial in Singapore.
Results: Mean CCT in 938 community subjects was 539 μm ± 32 μm, and in 12 community subjects with primary open angle glaucoma (POAG) the mean CCT was 545 μm ± 38 μm.
Objective: To determine the prevalence of tilted and torted optic discs and associated risk factors among Chinese adults in Singapore.
Methods: As part of a population-based survey, optic disc stereophotographs of both eyes were obtained, and left eyes were analyzed using imaging software. A tilted optic disc was defined as an index of tilt (ratio of minimum to maximum optic disc diameter) less than 0.
Purpose: To report 3-year results of a randomized, controlled trial comparing the use of a single application of 5-fluorouracil (5-FU) with placebo in trabeculectomy surgery.
Design: Prospective, randomized, double-blinded treatment trial.
Participants: Two hundred forty-three Asian patients with primary open-angle or primary angle-closure glaucoma undergoing primary trabeculectomy.
Purpose: To assess the screening effectiveness of 3 new noncontact devices, the scanning peripheral anterior chamber depth analyzer (SPAC) (Takagi, Nagano, Japan), which measures peripheral anterior chamber depth (ACD); IOLMaster (Carl Zeiss Meditec, Jena, Germany), which measures central ACD; and Visante anterior segment optical coherence tomography (AS-OCT) (Visante, Carl Zeiss Meditec, Dublin, CA), which images the angles, and to compare these instruments with gonioscopy in identifying people with narrow angles (NAs).
Design: Cross-sectional, observational, community-based study.
Participants: Phakic subjects aged >or=50 years without ophthalmic symptoms who were recruited from a community polyclinic in Singapore.
Objectives: To investigate systemic and ocular risk factors for angle closure (AC) in older Singaporeans and to determine if these risk factors are different in men vs women and in Chinese vs non-Chinese persons.
Methods: A cross-sectional study of 2042 subjects with phakia 50 years or older recruited from a primary care clinic in Singapore. Subjects completed a detailed questionnaire and underwent refraction, biometry, and gonioscopy.
Background: Limited data are published on the ultrasound biomicroscope (UBM) findings of the anterior chamber angle. This work provides a population-based assessment of angle findings and compares 3 modalities for assessing angle dimensions.
Methods: A sample of 268 persons who had participated in a population-based study of glaucoma prevalence in Singapore were reexamined by UBM (nasal, temporal, and inferior angles only), Scheimpflug photography of angle width, and gonioscopy.
Purpose: Approximately 10% of Chinese people older than 50 years in Singapore have asymptomatic narrow angles [also termed primary angle closure suspects (PACS)]. The aim of this study was to determine the attitudes and practices of ophthalmologists in Singapore regarding the management of these patients.
Methods: A nation wide questionnaire-based survey was conducted on all registered, practicing ophthalmologists in Singapore by electronic mail and post.
Objective: To assess visibility of the scleral spur in anterior segment optical coherence tomography (AS-OCT) images.
Methods: This cross-sectional observational study included 502 participants aged 50 years or older who had no previous ophthalmic problems and were recruited from a community clinic in Singapore. All participants underwent gonioscopy and AS-OCT (Visante; Carl Zeiss Meditec, Dublin, California).
[Effects of lens opacity on AccuMap multifocal objective perimetry in glaucoma].
Zhonghua Yan Ke Za Zhi
November 2006
Objective: To investigate the effect of lens opacity on the performance of the multi-focal visual evoked potential (mfVEP) test in patients with glaucoma and its relationship with the Humphrey's automated static perimetry.
Methods: This is a prospective, non-randomized study. Twenty-two patients were enrolled with moderate cataract and primary glaucoma scheduled for cataract surgery with or without glaucoma surgery.
Aim: To determine the changes in peripapillary atrophy after episodes of acute primary angle closure (APAC).
Methods: Prospective observational study of 40 eyes in 38 patients of predominantly Chinese ethnicity. The mean (SD) intraocular pressure at the time of presentation was 51.
Aim: To compare anterior chamber depth measurements by three non-contact devices-the IOLMaster, scanning peripheral anterior chamber depth analyser (SPAC), and Visante anterior segment optical coherence tomography (AS-OCT) METHODS: Prospective, cross sectional study of 497 phakic subjects over 50 years of age attending a community clinic in Singapore. Anterior chamber depth of the right eye was measured using all three techniques by the same investigator. Depth measurements were made from the corneal epithelium to the anterior lens surface.
View Article and Find Full Text PDFPurpose: To determine the long-term outcome of the contralateral eye in Asian persons with a unilateral attack of acute primary angle closure (APAC).
Design: Cross-sectional observational case series.
Participants: Seventy-nine individuals who were examined from 4 to 10 years after a unilateral episode of APAC at 2 Singapore hospitals.
Purpose: To compare lens thickness (LT), lens position (LP), relative lens position (RLP), and degree and type of lens opacity between affected and fellow eyes of subjects with acute primary angle closure (APAC) to identify any differences in lens characteristics that may be contributory to the acute episode. In addition, axial length (AL) and anterior chamber depth (ACD) measurements were evaluated.
Methods: Seventy-three study subjects with unilateral APAC were treated with sequential laser iridotomy (LI) in both eyes.
Objective: To examine the progression of lens opacity in Asian people after trabeculectomy and determine associated risk factors.
Methods: This was an observational case series of 243 people aged 36 to 82 years. Trabeculectomy was performed on 1 eye of each subject.
Purpose: To evaluate the changes in optic disc morphology in the first 4 months after an episode of acute primary angle closure (APAC) using stereoscopic optic disc photography and computer-assisted planimetry.
Design: Prospective observational case series.
Participants: Forty-seven Asian subjects with unilateral APAC who were successfully treated with laser peripheral iridotomy (LPI).
Purpose: To determine the relationship between peripapillary retinal nerve fiber layer (RNFL) thickness and myopia using optical coherence tomography (OCT).
Design: Prospective observational case series.
Methods: One hundred thirty-two young males with myopia (spherical equivalent [SE], -0.
Purpose: To assess the performance of peripheral and central anterior chamber depth (ACD) measurements, and autorefraction, in identifying Chinese people with occludable drainage angles or established primary angle closure.
Design: Population-based cross-sectional analysis.
Methods: Subjects aged 40 years and older were drawn from a representative sample of Chinese Singaporean residents.
Purpose: To evaluate utility values in Chinese glaucoma patients.
Patient And Methods: Singapore Chinese residents (n = 213) with primary open-angle glaucoma or primary angle-closure glaucoma were recruited from a single tertiary ophthalmic center. Standard face-to-face interviews were conducted to ask about utility values (time trade-off and standard gamble for both death and blindness).
Background: Ischaemic changes in the iris occur frequently after an episode of acute primary angle closure (APAC). The aim of this study was to investigate the significance of such changes with regards to visual outcome.
Methods: Acute primary angle closure cases were treated with medical therapy followed by laser peripheral iridotomy after resolution of the acute episode.