[Show abstract][Hide abstract] ABSTRACT: Purpose:
New femtosecond laser platforms may reduce ocular surface interference and LASIK-associated dry eye. This study investigated tear protein profiles in subjects who underwent LASIK using two femtosecond lasers to assess differences in protein expression.
This was a randomized interventional clinical trial involving 22 patients who underwent femtosecond laser refractive surgery with a contralateral paired eye design. Corneal flaps of 22 subjects were created by either Visumax or Intralase laser. Tear samples were collected preoperatively, and at 1 week and 3 months postoperatively using Schirmer's strips. Tear protein ratios were calculated relative to preoperative protein levels at baseline. The main outcome measures were the levels of a panel of dry eye protein markers analyzed using isobaric tagging for relative and absolute quantitation (iTRAQ) mass spectrometry.
A total of 824 unique proteins were quantifiable. Tear protein ratios were differentially regulated between the eyes treated with different lasers. The secretoglobulins Lipophilin A (1.80-fold) and Lipophilin C (1.77) were significantly upregulated (P < 0.05) at 1 week postoperatively in Visumax but not in Intralase-treated eyes. At 1 week, orosomucoid1 was upregulated (1.78) in Intralase but not Visumax-treated eyes. In the same eyes, lysozyme, cathepsin B, and lipo-oxygenase were downregulated at 0.44-, 0.64-, and 0.64-folds, respectively. Transglutaminase-2 was downregulated in both groups of eyes.
Different laser platforms induce distinct biological responses in the cornea and ocular surface, which manifests as different levels of tear proteins. This study has implications for surgical technology and modulation of wound healing responses. (ClinicalTrials.gov number, NCT01252654.).
[Show abstract][Hide abstract] ABSTRACT: To describe the subjective experience of patients and surgeons during laser in situ keratomileusis (LASIK) using the Intralase 60 kHz or the Visumax 500 kHz femtosecond laser.
Singapore National Eye Centre, Singapore.
Prospective randomized clinical study.
In myopic patients, LASIK was performed with the corneal flap created using the 60 kHz laser in 1 eye and the 500 kHz laser in the contralateral eye. Postoperatively, patients completed a standardized validated questionnaire about their subjective intraoperative experiences (eg, light perception, pain, fear). Surgeons reported their intraoperative experiences and preferences.
Loss of light perception occurred in 50.0% of 60 kHz laser cases and 0% of 500 kHz laser cases during docking and in 63.0% and 0% of cases, respectively, during laser flap creation (P < .0001). The mean pain score with the 60 kHz laser was significantly higher during docking (P < .0001) but not during laser flap cutting (P = .006). Subconjunctival hemorrhage occurred in 67.4% of eyes with the 60 kHz laser and in 2.2% of eyes with the 500 kHz laser (P < .0001). The 500 kHz laser was preferred by 78.3% of patients, while 21.7% preferred the 60 kHz laser (P < .0001). The surgeons preferred the 60 kHz laser in 50.0% of cases and the 500 kHz laser in 8.7% (P < .0001); 41.3% had no preference.
Patients preferred surgery with the 500 kHz laser with no loss of light perception, less pain, less fear, and less subconjunctival hemorrhage. Surgeons preferred the 60 kHz laser.
No author has a financial or proprietary interest in any material or method mentioned.
Journal of Cataract and Refractive Surgery 01/2014; 40(3). DOI:10.1016/j.jcrs.2013.08.056 · 2.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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.
Singapore National Eye Centre, Singapore.
Retrospective case review.
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.
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).
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.
No author has a financial or proprietary interest in any material or method mentioned.
Journal of Cataract and Refractive Surgery 09/2013; 39(11). DOI:10.1016/j.jcrs.2013.04.044 · 2.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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.
Journal of Cataract and Refractive Surgery 05/2013; 39(7). DOI:10.1016/j.jcrs.2013.02.038 · 2.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate longitudinal changes in corneal sensitivity, tear function, and corneal staining in patients who underwent laser in situ keratomileusis (LASIK) using two different femtosecond lasers.
In a prospective, randomized clinical trial, contralateral eyes of 45 patients underwent flap creation by either VisuMax or IntraLase™ femtosecond laser. Corneal sensitivity, tear break up time (TBUT), Schirmer's test, and corneal fluorescein staining were assessed preoperatively and at 1 week, 1 month, and 3 months postoperatively.
There were no statistical differences in any clinical outcome measure between the two femtosecond lasers (P > 0.05), although there was a trend towards slightly lower reductions for corneal sensitivity and TBUT in VisuMax-operated eyes. Overall, corneal sensitivity was significantly reduced at 1 week (P < 0.05), 1 month (P < 0 .001), and 3 months (P < 0.001) postoperatively. A significantly greater reduction of corneal sensitivity was noted in eyes with a myopic spherical equivalent of -6.00 diopters (D) to -11.25 D as compared with eyes that had a relatively lower level of myopia of less than -6.00 D (P < 0.001). TBUT and Schirmer's test values were significantly diminished at 1 week postoperatively (P < 0.04). Overall, corneal staining was significantly increased at 1 week postoperatively (P < 0.001). The level of myopia did not significantly affect postoperative changes in TBUT, Schirmer's test values, or corneal staining (P > 0.05).
This study showed that changes in corneal sensitivity, tear function, and corneal staining were statistically similar in LASIK using VisuMax and IntraLase femtosecond lasers for flap creation. However, the trend towards faster recovery of corneal sensitivity and TBUT observed in VisuMax-operated eyes may be attributable to improved technical specifications.
[Show abstract][Hide abstract] ABSTRACT: Purpose: To evaluate longitudinal changes in corneal sensitivity, tear function, and corneal staining in patients who underwent laser in situ keratomileusis (LASIK) using two different femtosecond lasers.
Methods: In a prospective, randomized clinical trial, contralateral eyes of 45 patients underwent flap creation by either VisuMax or IntraLase™ femtosecond laser. Corneal sensitivity, tear break up time (TBUT), Schirmer’s test, and corneal fluorescein staining were assessed preoperatively and at 1 week, 1 month, and 3 months postoperatively.
Results: There were no statistical differences in any clinical outcome measure between the two femtosecond lasers (P . 0.05), although there was a trend towards slightly lower reductions for corneal sensitivity and TBUT in VisuMax-operated eyes. Overall, corneal sensitivity was significantly reduced at 1 week (P , 0.05), 1 month (P , 0 .001), and 3 months (P , 0.001) postoperatively. A significantly greater reduction of corneal sensitivity was noted in eyes with a myopic spherical equivalent of −6.00 diopters (D) to −11.25 D as compared with eyes that had a relatively lower level of myopia of less than −6.00 D (P , 0.001). TBUT and Schirmer’s test values were significantly diminished at 1 week postoperatively (P , 0.04). Overall, corneal staining was significantly increased at 1 week postoperatively (P , 0.001). The level of myopia did not significantly affect postoperative changes in TBUT, Schirmer’s test values, or corneal staining (P . 0.05).
Conclusion: This study showed that changes in corneal sensitivity, tear function, and corneal staining were statistically similar in LASIK using VisuMax and IntraLase femtosecond lasers for flap creation. However, the trend towards faster recovery of corneal sensitivity and TBUT observed in VisuMax-operated eyes may be attributable to improved technical specifications.
[Show abstract][Hide abstract] ABSTRACT: To describe the rationale and study design of a follow-up epidemiological eye study among Singaporean Malay adults.
Follow-up prospective population-based study.
Participants of the Singapore Malay Eye Study (SiMES-1), which was conducted from August 2004 to June 2006.
This is a follow-up study of the 3280 participants who participated in the SiMES-1 and are residing in Singapore. All participants of this follow-up study will undergo various standardized validated questionnaires on socio-demographics, quality of life and impact of visual impairment. Participants will undergo assessment of blood pressure, anthropometry, presenting and best corrected visual acuity, subjective refraction, ocular biometry, slit lamp and dilated eye examination, Goldmann tonometry, optic disc imaging, digital lens and retinal photography. Retinal tomography, retinal optical coherence topography and fundus autofluorescence will also be performed. Gonioscopy and visual fields examination will be performed on selected individuals.
Incidence, risk factors and impact of visual impairment and major eye diseases.
A total of 3280 people who participated in the SiMES-1 will be contacted and invited to participate in this follow-up study. It is estimated that 12.8% of the participants will be deceased and there will be an 80% participation rate for the survivors of SiMES-1 (approximately 2288 participants).
SiMES-2 will be one of the few follow-up epidemiological eye studies among Asians and will determine the cumulative 6-year incidence, progression, risk factors and impact of major eye diseases in Singaporean Malay adults.
[Show abstract][Hide abstract] ABSTRACT: This study highlights the key epidemiological findings from the Singapore Malay Eye Study (SiMES-1).
SiMES-1 was a cross-sectional, population-based epidemiological study on eye diseases. It was performed on 3,280 randomly selected Malay adults living in the south-western part of Singapore. All study participants underwent various validated questionnaires and detailed eye examinations. A review of all papers published from SiMES-1 was performed.
A total of 24.6% of the study population had myopia, while 35.3% had hyperopia and 39.4% had astigmatism. 20.4% of the population had under-corrected refractive error. 1,338 (45.7%) participants were diagnosed to have cataracts in at least one eye. 8.6% of the study population had undergone cataract surgery in either eye, while 4.7% had bilateral cataract surgery. 150 (4.6%) participants were diagnosed to have glaucoma, of which primary open angle glaucoma was the most common type (3.2% of the study population), followed by secondary glaucoma (0.8%) and primary angle closure glaucoma (0.2%). Pterygium was diagnosed in 508 out of 3,266 study participants, giving a prevalence rate of 15.6%. The presence of diabetic retinopathy was observed in 421 (12.9%) out of 3,265 study participants. 183 (5.6%) study participants had some degree of age-related macular degeneration (AMD), of which 23 (0.7%) were classified as having late AMD.
This paper provides a summary of the prevalence of common eye diseases among the Singaporean adult Malay population and provides data useful for public health education and disease prevention.
Singapore medical journal 02/2012; 53(2):82-7. · 0.60 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: : To describe the prevalence and associations of meibomian gland dysfunction (MGD) in an urban Malay population in Singapore.
: 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.
: 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).
: MGD was highly prevalent in this Asian population and associated with various systemic and ocular conditions.
[Show abstract][Hide abstract] ABSTRACT: To examine the association of corneal arcus with central corneal thickness (CCT), intraocular pressure (IOP), and the prevalence of primary open-angle glaucoma.
This was a population-based cross-sectional study of Malay participants aged 40 to 80 years living in Singapore. Participants underwent a standardized interview and systemic and ocular examinations, including CCT, IOP, and corneal curvature radius measurements. Corneal arcus, assessed using a slitlamp, was defined as gray-white or yellow opacity located near the periphery of the cornea but separated from the limbus by a clear zone.
Corneal arcus was found in right eyes among 1747 (57.9%) of 3015 participants. After adjusting for age, sex, and systemic factors, IOP was higher (15.87 vs 14.86 mm Hg, P < .001) and CCT was thinner (540.6 vs 543.4 μm, P = .03) in eyes with vs without corneal arcus. In multiple linear regression models, eyes with corneal arcus had on average 1.14 mm Hg higher IOP than eyes without corneal arcus. In the presence of corneal arcus, the linear correlations of CCT × IOP and of corneal curvature radius × IOP were altered. The prevalence of ocular hypertension, but not primary open-angle glaucoma, was significantly higher among participants with corneal arcus than among participants without corneal arcus (P = .02).
Corneal arcus was associated with higher IOP and lower CCT independent of age, sex, and systemic and ocular factors. Further research is required to investigate the clinical implications of these findings for IOP assessment in eyes with corneal arcus.
Archives of ophthalmology 11/2010; 128(11):1455-61. DOI:10.1001/archophthalmol.2010.252 · 4.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To examine the impact of symptomatic dry eye on vision-related daily activities.
A population-based survey of eye diseases was conducted on 3280 (78.7% response rate) Malay persons aged >or=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.
In 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).
Symptomatic 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.
[Show abstract][Hide abstract] ABSTRACT: 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.
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.
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.
[Show abstract][Hide abstract] ABSTRACT: To describe the prevalence and the risk factors of undercorrected refractive error in an adult urban Malay population.
This population-based, cross-sectional study was conducted in Singapore in 3280 Malay adults, aged 40 to 80 years. All individuals were examined at a centralized clinic and underwent standardized interviews and assessment of refractive errors and presenting and best corrected visual acuities. Distance presenting visual acuity was monocularly measured by using a logarithm of the minimum angle of resolution (logMAR) number chart at a distance of 4 m, with the participants wearing their "walk-in" optical corrections (spectacles or contact lenses), if any. Refraction was determined by subjective refraction by trained, certified study optometrists. Best corrected visual acuity was monocularly assessed and recorded in logMAR scores using the same test protocol as was used for presenting visual acuity. Undercorrected refractive error was defined as an improvement of at least 0.2 logMAR (2 lines equivalent) in the best corrected visual acuity compared with the presenting visual acuity in the better eye.
The mean age of the subjects included in our study was 58 +/- 11 years, and 52% of the subjects were women. The prevalence rate of undercorrected refractive error among Singaporean Malay adults in our study (n = 3115) was 20.4% (age-standardized prevalence rate, 18.3%). More of the women had undercorrected refractive error than the men (21.8% vs. 18.8%, P = 0.04). Undercorrected refractive error was also more common in subjects older than 50 years than in subjects aged 40 to 49 years (22.6% vs. 14.3%, P < 0.001). Non-spectacle wearers were more likely to have undercorrected refractive errors than were spectacle wearers (24.4% vs. 14.4%, P < 0.001). Persons with primary school education or less were 1.89 times (P = 0.03) more likely to have undercorrected refractive errors than those with post-secondary school education or higher. In contrast, persons with a history of eye disease were 0.74 times (P = 0.003) less likely to have undercorrected refractive errors. The proportion of undercorrected refractive error among the Singaporean Malay adults with refractive errors was higher than that of the Singaporean Chinese adults with refractive errors.
Undercorrected refractive error is a significant cause of correctable visual impairment among Singaporean Malay adults, affecting one in five persons.
[Show abstract][Hide abstract] ABSTRACT: To study the prevalence, associated factors and impact of symptomatic dry eye in an Asian population.
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).
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).
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.
[Show abstract][Hide abstract] ABSTRACT: To describe the prevalence and causes of low vision and blindness in a Malay population.
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.
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.
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.
Archives of ophthalmology 09/2008; 126(8):1091-9. DOI:10.1001/archopht.126.8.1091 · 4.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Refractive errors, especially if undercorrected, are a common and important cause of poor vision, particularly in Asia. The knowledge and beliefs of refractive errors and possible impact of undercorrection in a population-based study in Singapore are described.
This study was a substudy on 503 subjects with refractive error from a population-based survey of 3280 adult Malays in Singapore aged 40 to 80 years. The Health Belief Model was used to develop a questionnaire, subjects with refractive errors were evaluated on their health beliefs towards adopting health-seeking behaviour for correction of refractive error, and the responses were compared between undercorrected subjects and subjects with corrected refractive errors.
Of persons with myopia, 79.5% had heard of myopia, 79.2% of hyperopes had heard of hyperopia, while only 7.7% of those with astigmatism had heard of astigmatism. Adults who had never previously visited an eye-care specialist were less likely to have heard of astigmatism and to know that they have refractive error (p<0.01). Adults with undercorrected refractive error were more likely to be female (61.1% vs 49.3%) and not wear spectacles (41.7% vs 22.3%). Knowledge on astigmatism (1.4% vs 5.6%) and refractive errors (62.6% vs 77.5%) were significantly lower in the undercorrected group.
The lack of knowledge and awareness of refractive errors are important risk factors for undercorrected refractive error in an urban Singapore population.
The British journal of ophthalmology 07/2008; 93(1):4-10. DOI:10.1136/bjo.2007.132506 · 2.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To describe a series of cases of diffuse lamellar keratitis (DLK) after laser in situ keratomileusis (LASIK) associated with intraoperative use of a surgical marker pen.
Singapore National Eye Centre, Singapore, Singapore.
A review of all 115 patients (125 eyes) who had myopic LASIK from July 23 to July 26, 2007, was performed to determine whether eyes in which the Codman surgical marker pen (Johnson & Johnson Medical) was used intraoperatively developed postoperative DLK.
Nine of 12 eyes that had LASIK or flap relifting with a Codman surgical marker pen developed grade 1 to grade 3 DLK on the first postoperative day. The 113 other eyes that had LASIK in the same week with another brand of surgical marker pen (Securline, Precision Dynamics Corp.) did not develop DLK. All eyes with DLK were treated with intensive topical steroid therapy. The DLK resolved in 2 eyes after the steroid treatment; 7 eyes required flap relifting with interface irrigation. One month postoperatively, 6 eyes with DLK had an uncorrected visual acuity of 6/7.5 or better. Two eyes developed central corneal scarring with consecutive hyperopia with a best corrected visual acuity of 6/12 after 1 month.
There was a strong association between the occurrence of DLK after LASIK with the use of the Codman surgical marker pen. One or more constituents of the ink in the Codman pen may have been responsible for this series of cases.
Journal of Cataract and Refractive Surgery 06/2008; 34(6):974-9. DOI:10.1016/j.jcrs.2008.02.014 · 2.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To assess the prevalence and types of glaucoma in an Asian Malay population.
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.
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).
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.
[Show abstract][Hide abstract] ABSTRACT: To determine the prevalence and causes of amblyopia in young adult Chinese, Indian, and Malay men in Singapore.
A population-based cross-sectional study.
Best-corrected visual acuities of all Singaporean men born in the years 1978 to 1983 were measured before enlistment into military service. Those with BCVA of 6/12 or worse were examined by an ophthalmologist for the presence of amblyopia and other causes.
Of the 122,596 men examined, there were 428 with amblyopia, an overall prevalence of 0.35%. The prevalence was similar among Chinese (0.34%), Malays (0.37%), and Indians (0.41%, P = .52). Anisometropic amblyopia was the most common type of amblyopia and strabismic amblyopia was more common in Indians. There were little racial differences in the prevalence of meridional or form deprivation amblyopia.
The overall prevalence of amblyopia was low and was similar among the three racial groups in young adult Singaporean males.
American Journal of Ophthalmology 10/2005; 140(3):551-2. DOI:10.1016/j.ajo.2005.03.029 · 3.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate the risk factors, clinical presentation and surgical outcomes of retinal detachment (RD) among Chinese, Malay and Indian residents in Singapore.
A retrospective descriptive study from January 1995 to December 1998. All RD operations performed at a tertiary ophthalmic center in Singapore were initially identified from a computerized audit database. Case records data of all Malay and Indian patients as well as a 10% randomized sample of Chinese patients were retrieved and analyzed. Tractional and exudative RD's were excluded.
Of the Singapore residents who had a RD operation over the 4-year period, 597 (89.6%) were Chinese, 47 (7.1%) were Malays and 22 (3.3%) were Indians. The age (mean: 46.1 +/- 15.5 years), gender distribution (70.5% males) and presenting visual acuities were similar in the 3 races. The most common site of the retinal break(s) was the superotemporal retina (44.9%), followed by the inferotemporal retina (15.3%). Chinese patients were more likely to have multiple or indeterminate breaks (p = 0.09) and macula-on RD (p = 0.04), compared to Malays and Indians. The distribution of known risk factors (myopia, lattice degeneration, prior cataract surgery and prior ocular trauma) was similar between the three races. The majority of patients required a scleral buckling operation either in isolation (71.3%), or in combination with vitrectomy (19.4%), and only 10 (7.8%) had vitrectomies without buckles. At 6 months postoperatively, anatomical success (defined as an attached retina on ocular examination) and functional success (defined as visual acuities of 6/60 or better) were achieved in 108 (94.7%) and 62 patients (54.4%), respectively, with no significant racial variation seen. The overall rate of redetachment after the initial operation was low (9.3%).
Variation in risk factors, clinical presentations and postoperative outcomes of retinal detachment appears to be minimal among Chinese, Malays and Indians in Singapore.
International Ophthalmology 02/2001; 24(2):101-6. DOI:10.1023/A:1016306609978 · 0.55 Impact Factor