Mohamad Rosman

Rationale and Methodology for a Population-Based Study of Eye Diseases in Malay People: The Singapore Malay Eye Study (SiMES)

Purpose: Although there are approximately 200 million people of Malay ethnicity living in Asia, the burden and risk factors of blinding eye diseases in this ethnic group are unknown. This study summarizes the rationale and study design of a population-based study of eye diseases among adult Malays in Singapore. Methods: A population-based cross-sectional study of Malays was designed in Singapore. The sampling frame consisted of all Malays aged 40–79 living in designated study areas in southwestern Singapore. From a list of 16,069 names provided by the Ministry of Home Affairs, age-stratified random sampling was used to select 5,600 names (1,400 people from each decade of 40–49, 50–59, 60–69, and 70–79 years). The target sample size for this study was 3,150 persons. Selected individuals were invited to a centralized clinic by letters, telephone calls, and home visits. Participants underwent standardized interview and assessment of blood pressure, anthropometry, presenting and best-corrected visual acuity, subjective refraction, ocular biometry, Goldmann tonometry, slit-lamp biomicroscopy, optic disc imaging, digital lens, and retinal photography. Blood and urine samples were collected for biochemical analyses and further stored for future studies. Selected participants also had gonioscopic examination, visual fields test, and assessment of ankle and brachial blood pressure to detect presence of peripheral vascular disease. Conclusions: This study provides population-based data on the prevalence of and risk factors for age-related eye diseases in people of Malay ethnicity in Singapore. Data from this study allow further understanding of the etiology and impact of eye diseases in this ethnic group.

The Prevalence and Types of Glaucoma in Malay People : The Singapore Malay Eye Study

PURPOSE To assess the prevalence and types of glaucoma in an Asian Malay population. METHODS The Singapore Malay Eye Study is a population-based, cross-sectional survey that examined 3280 (78.7% response) persons aged 40 to 80 years. Participants underwent a standardized clinical examination including slit-lamp biomicroscopy, Goldmann applanation tonometry, and dilated optic disc assessment. Participants who were suspected to have glaucoma also underwent visual field examination (24-2 SITA standard, Humphrey Visual Field Analyzer II), gonioscopy, and repeat applanation tonometry. Glaucoma was defined according to International Society for Geographical and Epidemiologic Ophthalmology criteria. RESULTS Of the 3280 participants, 150 (4.6%) had diagnosed glaucoma, giving an age- and sex-standardized prevalence of 3.4% (95% confidence interval [CI], 3.3%-3.5%). The age- and sex-standardized prevalence of primary open-angle glaucoma was 2.5% (95% CI, 2.4%-2.6%), primary angle-closure glaucoma 0.12% (95% CI, 0.10%-0.14%), and secondary glaucoma 0.61% (95% CI, 0.59%-0.63%). Of the 150 glaucoma cases, only 12 (8%) had a previous known history of glaucoma. Twenty-seven (18%) eyes had low vision (based on best corrected visual acuity logarithm of the minimal angle of resolution [logMAR] >0.30 to <1.00 in the eye with glaucoma for unilateral cases; and based on the better eye for bilateral cases) and 15 (10%) were blind (logMAR, >/=1.00). CONCLUSIONS The prevalence of glaucoma among Malay persons 40 years of age and older in Singapore is 3.4%, comparable to ethnic Chinese people in Singapore and other racial/ethnic groups in Asia. As in Chinese, Caucasians, and African people, primary open-angle glaucoma was the main form of glaucoma in this population. More than 90% of glaucoma cases were previously undetected.

Prevalence and Causes of Low Vision and Blindness in an Urban Malay Population: The Singapore Malay Eye Study

OBJECTIVE To describe the prevalence and causes of low vision and blindness in a Malay population. METHODS A population-based, cross-sectional study of 3280 participants of Malay ethnicity, aged 40 to 79 years, was conducted. Participants underwent standardized ophthalmic assessments to determine (1) presenting and best-corrected visual acuity according to US and modified World Health Organization definitions of blindness and low vision and (2) the primary causes of visual impairment. RESULTS Of 4168 eligible individuals, 3280 participated in the study (78.7%). The population-weighted prevalence of bilateral blindness was 0.3% and of bilateral low vision, 4.4% (US definition of presenting visual acuity). After best-corrected visual acuity, the population-weighted prevalence of bilateral blindness was reduced to 0.1% and bilateral low vision to 1.0%. Cataract was the main cause of presenting unilateral (38.9%) and bilateral (65.2%) blindness, whereas undercorrected refractive error was the main cause of presenting unilateral (68.8%) and bilateral (52.2%) low vision. Diabetic retinopathy, age-related macular degeneration, and glaucoma were the other leading causes of blindness and low vision. CONCLUSIONS The age-standardized prevalences of bilateral blindness and low vision in a Malay population were lower when compared with other Asian studies. Undercorrected refractive error and cataract are the leading causes of visual impairment among the Malay adult population in Singapore.

Chronic angle-closure with glaucomatous damage: Long-term clinical course in a north american population and comparison with an asian population☆

PURPOSE To study the long-term clinical course of North American chronic angle-closure glaucoma (CACG) patients with optic disc damage and visual field loss in the presence of an angle closed at least partially by peripheral anterior synechiae and to compare it with a similar group of Singaporean patients. DESIGN A retrospective, interventional case-control study series. PARTICIPANTS Fifty-one patients (80 eyes) diagnosed with CACG with glaucomatous optic nerve head and visual field damage at a New York hospital from January 1990 through December 1994. All study eyes underwent laser peripheral iridotomy (LPI). METHODS The presenting features, management, and subsequent long-term intraocular pressure (IOP) outcome were analyzed and compared with 65 Asian patients (83 eyes) from a Singapore hospital who were similarly diagnosed during the same period. MAIN OUTCOME MEASURES The long-term outcome after LPI was assessed in terms of IOP and the requirement for additional therapy. RESULTS The mean presenting IOP was higher in the Singapore eyes (40 +/- 15 mmHg) compared with the New York eyes (31 +/- 12.5 mmHg). All 80 New York eyes (100%) and 78 of 83 Singapore eyes (94%) required further treatment to control IOP during follow-up. Of the eyes with a subsequent rise in IOP, 33 of 80 eyes (41.3%) compared with 34 of 83 eyes (41.0%) of the Singapore patients were controlled with additional topical medication. Of the New York eyes, 25 of 80 (31.3%) eventually underwent filtering surgery, compared with 44 of 83 (53.0%) in the Singapore study. The other 22 eyes (27.5%) in the New York group went on to additional laser procedures, peripheral iridoplasty, laser trabeculoplasty, or a combination thereof, after which IOPs were controlled and no surgery was required. There was no similar comparison for the Singapore group, because these eyes went directly on to surgery. CONCLUSIONS Despite the presence of a patent LPI, most eyes with CACG presenting with elevated IOP and having both optic disc and visual field damage in both populations required further treatment to control IOP. Results in the American population are similar to that reported in Asian patients.

Impact of symptomatic dry eye on vision-related daily activities: the Singapore Malay Eye Study.

PurposeTo examine the impact of symptomatic dry eye on vision-related daily activities.MethodsA population-based survey of eye diseases was conducted on 3280 (78.7% response rate) Malay persons aged ⩾40 years, who were randomly selected from designated areas in southwestern Singapore. Participants were administered a standardized dry eye questionnaire consisting of six questions on symptoms, a questionnaire on vision-related daily activities, and underwent a comprehensive systemic and ocular examination. Symptomatic dry eye was defined as one or more self-reported symptoms that were frequently present (ranked as often or all the time). Logistic regression method was used to examine the relationship of symptomatic dry eye with difficulty in performing daily activities.ResultsIn adults without visual impairment, symptomatic dry eye after adjusting for age, gender, and presenting visual acuity was significantly associated with difficulty in vision-related activities such as navigating stairs (odds ratio (OR)=1.96, 95% confidence interval (CI): 1.28–3.00), recognizing friends (OR=1.99, 95% CI: 1.45–2.73), reading road signs (OR=1.87, 95% CI: 1.36–2.57), reading newspaper (OR=1.50, 95% CI: 1.11–2.04), watching television (OR=1.90, 95% CI: 1.26–2.87), cooking (OR=1.94, 95% CI: 1.02–3.71), and driving at night (OR=2.06, 95% CI: 1.32–3.21).ConclusionSymptomatic dry eye was associated with difficulty in performing vision-dependent tasks, independent of visual acuity and other factors. These findings have public health significance and suggest that the visual dysfunction in dry eye should be further characterized.

Prevalence and Risk Factors of Meibomian Gland Dysfunction: The Singapore Malay Eye Study

Purpose: To describe the prevalence and associations of meibomian gland dysfunction (MGD) in an urban Malay population in Singapore. Methods: Population-based cross-sectional study of 3280 (78.7% response rate) Malay persons aged 40 to 80 years, living in Singapore. MGD was defined by a slit-lamp clinical examination as either lid margin telangiectasia or meibomian gland orifice plugging in at least one eye. Participants underwent a standardized questionnaire and clinical examination, including laboratory investigations. Data were analyzed for 3271 persons. Results: The age-standardized prevalence of MGD was 56.3% [95% confidence interval (CI), 53.3–59.4]. A higher MGD prevalence was found in male participants across all age groups [odds ratio (OR), 1.30; 95% CI, 1.35–1.79], postmenopausal women (OR, 1.64; 95% CI, 1.19–2.33), and all participants with pinguecula (OR, 2.43; 95% CI, 2.08–2.85), high diastolic blood pressure (OR, 1.32; 95% CI, 1.08–1.62), and use of angiotensin II receptor blockers (OR, 4.02; 95% CI, 1.74–9.27). Conclusions: MGD was highly prevalent in this Asian population and associated with various systemic and ocular conditions.

Singapore Malay Eye Study: rationale and methodology of 6‐year follow‐up study (SiMES‐2)

Background:  To describe the rationale and study design of a follow‐up epidemiological eye study among Singaporean Malay adults.

Visual outcomes comparison of 2 femtosecond laser platforms for laser in situ keratomileusis

Purpose To compare the efficacy, predictability, and safety outcomes of 2 femtosecond laser platforms for flap creation during laser in situ keratomileusis (LASIK) for myopia and myopic astigmatism. Setting Singapore National Eye Centre, Singapore. Design Retrospective case review. Methods In this single‐center multisurgeon study, patients had LASIK with flaps created using a Visumax 500 kHz or Intralase 60 kHz femtosecond laser system. Ablation was performed with the Wavelight Allegretto Eye‐Q 400 Hz excimer laser in all patients. Preoperative and 3‐month postoperative manifest refraction, attempted treatment spherical equivalent (SE), visual acuity, and complications were compared. Results The 500 kHz femtosecond laser group comprised 381 patients (381 eyes) and the 60 kHz femtosecond laser group, 362 patients (362 eyes). Three months postoperatively, the uncorrected distance visual acuity was 20/40 or better in 99.1% of eyes in the 60 kHz laser group and 99.4% of eyes in the 500 kHz laser group (P=.678). Regarding predictability, 98.6% of eyes and 97.4% of eyes, respectively, were within ±1.0 diopter of the attempted SE correction postoperatively (P=.228). The safety index was similar in the 60 kHz laser group and the 500 kHz laser group (mean 1.06 ± 0.16 [SD] versus 1.05 ± 0.14) (P=.321). Conclusion The safety, predictability, and efficacy profiles of the 500 kHz femtosecond platform for LASIK were excellent and comparable to those of the 60 kHz platform. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

A questionnaire-based assessment of symptoms associated with tear film dysfunction and lid margin disease in an Asian population.

Purpose: To study the prevalence, associated factors and impact of symptomatic dry eye in an Asian population. Methods: A population based survey of eye diseases in 3,280 (78.7% response rate) Malay persons aged 40–80 selected from designated areas in southwestern Singapore. Participants were administered a standardized dry eye questionnaire consisting of 6 questions on symptoms, and had a comprehensive systemic and ocular examination. Symptoms of tear film dysfunction (STFD) was defined as one or more self-reported symptoms that were frequently present (ranked often or all the time). Results: The prevalence rate of STFD was 6.5% (95% confidence interval [CI]: 5.7, 7.4). The prevalence was significantly higher in men compared to women (8.2% and 4.9%, respectively; p < 0.001) and decreased with age in men (p = 0.002) but not in women (p = 0.101). After adjusting for age, gender, nature of work (outdoor/indoor), and housing type, factors significantly associated with STFD were cigarette smoking (odds ratio [OR] 1.77, 95% CI: 1.17–2.66), thyroid disease (OR 2.58; 95% CI: 1.29–5.18) and higher income (OR 1.74; 95% CI: 1.13–2.68). STFD were associated with self-reported difficulty in performing daily activities (work, family and leisure related) (p = 0.006). Conclusion: STFD are present in 6.5% of Singapore Malay adults and is associated with cigarette smoking, presence of thyroid disease and a reduced visual function-related quality of life.

Comparison of efficacy and safety of laser in situ keratomileusis using 2 femtosecond laser platforms in contralateral eyes

Purpose To compare the efficacy, predictability, and refractive outcomes of laser in situ keratomileusis (LASIK) using 2 femtosecond platforms for flap creation. Setting Multisurgeon single center. Design Clinical trial. Methods Bilateral femtosecond LASIK was performed using the Wavelight Allegretto Eye‐Q 400 Hz excimer laser system. The Visumax femtosecond platform (Group 1) was used to create the LASIK flap in 1 eye, while the Intralase femtosecond platform (Group 2) was used to create the LASIK flap in the contralateral eye. The preoperative, 1‐month, and 3‐month postoperative visual acuities, refraction, and contrast sensitivity in the 2 groups were compared. Results The study enrolled 45 patients. Three months after femtosecond LASIK, 79.5% of eyes in Group 1 and 82.1% in Group 2 achieved an uncorrected distance visual acuity of 20/20 (P=.808). The mean efficacy index was 0.97 in Group 1 and 0.98 in Group 2 at 3 months (P=.735); 89.7% of eyes in Group 1 and 84.6% of eyes in Group 2 were within ±0.50 diopter of emmetropia at 3 months (P=.498). No eye in either group lost more than 2 lines of corrected distance visual acuity. The mean safety index at 3 months was 1.11 in Group 1 and 1.10 in Group 2 (P=.570). Conclusion The results of LASIK with both femtosecond lasers were similar, and both platforms produced efficacious and predictable LASIK outcomes. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.