2.Electrophysiological findings in persons with nyctalopia.
Annals of the Academy of Medicine, Singapore 2006;35(12):864-867
INTRODUCTIONOphthalmologists are occasionally confronted with an individual presenting with nyctalopia (i.e., a relatively greater difficulty seeing at night). When there is no accompanying abnormality seen in the fundus, visual electrophysiology becomes useful as an objective means of assessing rod (scotopic) photoreceptor function or pathway defects.
MATERIALS AND METHODSA retrospective study was performed on 50 consecutive patients, aged less than 40 years, with seemingly normal fundi and good vision [visual acuity (VA) >6/12] presenting to the Visual Electrodiagnostic Unit, Singapore National Eye Centre, for the investigation of nyctalopia over a 2-year period. Subjective scotopic threshold sensitivity (STS) and objective full-field electroretinogram (ERG) were performed. Persons with abnormal test results were identified.
RESULTSNormal ERG scotopic responses were obtained in 74% of subjects. There was no significant difference in age, refraction and STS levels between subjects with abnormal and normal ERG. In the group with abnormal scotopic ERG responses, 9 were identified to have nonspecific rod dysfunction, 2 had rod-cone dystrophies and 2 had ERG changes suggestive of congenital stationary night blindness (CSNB).
CONCLUSIONA large number of subjects presenting with nyctalopia had normal ERG findings. We can only assume that in these patients, no significant rod pathway dysfunction exists and that optical (e.g., night or instrument myopia) and psychological aetiologies should be considered. The fact that an abnormal result occurs in 26%, however, suggests that ncytalopia should be evaluated with electrophysiolgoical testing even when the fundi appear normal.
Adult ; Comorbidity ; Electroretinography ; Female ; Humans ; Male ; Night Blindness ; epidemiology ; physiopathology ; Refraction, Ocular ; Retinal Diseases ; epidemiology ; etiology ; physiopathology ; Retrospective Studies
4.Amblyopia therapy in Asian children: factors affecting visual outcome and parents' perception of children's attitudes towards amblyopia treatment.
Singapore medical journal 2019;60(6):291-297
INTRODUCTION:
Amblyopia treatment in the form of glasses and/or patching in children poses a great challenge to parents. This study aimed to assess the factors that influence visual outcome in amblyopia and children's perception towards treatment.
METHODS:
180 children (aged 3.0-7.0 years) with newly diagnosed amblyopia were recruited. The effects of age, gender, type of amblyopia, treatment and compliance on visual outcome at one year were assessed. Parents completed a questionnaire on children's attitudes towards amblyopia treatment.
RESULTS:
150 (83%) children with a mean age of 5.2 ± 0.8 years returned for follow-up at one year. 130 (87%) had refractive amblyopia and 20 (13%) had strabismic and refractive-strabismic amblyopia. Visual acuity (VA) of 6/9 or better in the amblyopic eye was achieved in 121 (81%) children. On multivariable analysis, poor responders were more likely to have initial VA of worse than 6/15 (relative risk [RR] 4.17, 95% confidence interval [CI] 1.58-11.00, p = 0.004), prescribed combined (glasses and patching) treatment (RR 2.83, 95% CI 1.02-7.83, p = 0.045) and poor compliance (RR 6.10, 95% CI 1.90-19.57, p = 0.002) after adjustment for age, gender and type of amblyopia. While 7% of children initially reacted poorly to treatment, 5% remained uncooperative at the first follow-up visit. Children had difficulty with schoolwork (5%), mood changes (6%) and social problems (2%) associated with treatment.
CONCLUSION
Most children with amblyopia respond well to treatment, but more care (i.e. more parental education and closer follow-up) may be needed in children who are non-compliant and have poorer initial VA.
5.Safety and Efficacy of Chloral Hydrate Sedation in Paediatric Sedation for Ophthalmic Procedures.
Amy Mh CHAN ; Geok Koon TAN ; Huey Peng LOH ; Sock Huang LIM ; Audrey Wl CHIA
Annals of the Academy of Medicine, Singapore 2017;46(4):138-144
INTRODUCTIONChloral hydrate (CH) sedation is routinely used in paediatric ophthalmic examination in Singapore as an alternative to examination under general anaesthesia. Despite CH's traditionally high success rates and relatively low rate of adverse events, there is little data on its safety and efficacy as a sedative for ophthalmic procedures in an Asian population.
MATERIALS AND METHODSA retrospective chart review was performed, including children who underwent CH sedation at the Singapore National Eye Centre from January 2012 to January 2015. Participants were given an initial dose of CH and a top-up dose if required. Univariate and multivariate analyses were performed on data collected.
RESULTSCH sedation was successful in 144 of 153 children (94.1%). Of the 20 (13.0%) who required a top-up dose, 4 failed to sedate. The mean sedation onset was 29.4 minutes (SD: 24.3) and mean sedation duration was 56.5 minutes (SD: 24.0), with more than a third lasting more than 1 hour. The age of children, rather than initial dose of CH, was more relevant in determining success of sedation. Children who were >6 years old were 20.3 times more likely to fail sedation than those aged <2 years. During sedation, depression in the heart rate and a transient reduction of oxygen saturation was documented. All children recovered well post-sedation.
CONCLUSIONCH is a very useful sedative for paediatric ophthalmic procedures, especially in younger children. Children over 4 years old were more likely to fail sedation and require top-up doses. Alternative means of sedation may need to be considered in these cases.
6.An Ecologic Study of Trends in the Prevalence of Myopia in Chinese Adults in Singapore Born from the 1920s to 1980s.
Sonoko SENSAKI ; Charumathi SABANAYAGAM ; Pavan K VERKICHARLA ; Adeola AWODELE ; Kok Hian TAN ; Audrey CHIA ; Seang Mei SAW
Annals of the Academy of Medicine, Singapore 2017;46(6):229-236
INTRODUCTIONThis study aimed to investigate secular trends in the prevalence of myopia over 6 decades (from the 1920s to 1980s) in Chinese adults in Singapore.
MATERIALS AND METHODSParental myopia prevalence was estimated using a parent-completed questionnaire in paediatric cohorts that included: 1) The Singapore Cohort Of Risk factors for Myopia (SCORM), 2) The Strabismus, Amblyopia and Refractive Error in Singaporean Children (STARS), and 3) The Growing Up in Singapore Towards healthy Outcomes (GUSTO). Published estimates for myopia prevalence from 5 adult studies in Singapore were reviewed. Secular trends in the prevalence of myopia were correlated with changes in the education system.
RESULTSThe prevalence of parental myopia in SCORM (n = 2943), STARS (n = 4938), and GUSTO (n = 1072) was 47.8%, 53.4%, and 73.4%, respectively; corresponding calendar years these parents might have started schooling were 1966, 1973, and 1983 (born in 1960, 1967, and 1977), respectively. Mean age of parents was 41.3, 40.1, and 33.4 years, respectively. Prevalence of myopia in adult studies in persons who started elementary school in 1928, 1934, 1938, 1939, 1942, 1948, 1952, 1958, 1962, 1972, 1982, and 1995 were 36.4%, 39.7%, 30.0%, 31.5%, 33.0%, 26.4%, 32.5%, 48.7%, 39.4%, 52.0%, 82.2%, and 85.9%, respectively.
CONCLUSIONDuring the past few decades, the prevalence of myopia increased rapidly, especially in persons who started elementary school after the 1980s (born after 1970). The education system was expanded after Singapore's independence in 1965, and the new education system was introduced in 1978. These changes, together with increasing intensive schooling, may have contributed to the increase in myopia prevalence.
7.Myopia in young patients with type 1 diabetes mellitus.
Swati HANDA ; Audrey CHIA ; Hla Myint HTOON ; Pin Min LAM ; Fabian YAP ; Yvonne LING ;
Singapore medical journal 2015;56(8):450-454
INTRODUCTIONThis study aimed to evaluate the proportion of young patients with type 1 diabetes mellitus (T1DM) who have myopia, as well as the risk factors associated with myopia in this group.
METHODSIn this cross-sectional study, patients aged < 21 years with T1DM for ≥ 1 year underwent a comprehensive eye examination. Presence of parental myopia, and average hours of near-work and outdoor activity were estimated using a questionnaire. Annualised glycosylated haemoglobin (HbA1c), defined as the mean of the last three HbA1c readings taken over the last year, was calculated. Multivariate analysis using genetic, environmental and diabetes-related factors was done to evaluate risk factors associated with myopia.
RESULTSOf the 146 patients (mean age 12.5 ± 3.6 years) recruited, 66.4% were Chinese and 57.5% were female. Myopia (i.e. spherical equivalent [SE] of -0.50 D or worse) was present in 96 (65.8%) patients. The proportion of patients with myopia increased from 25.0% and 53.6% in those aged < 7.0 years and 7.0-9.9 years, respectively, to 59.2% and 78.4% in those aged 10.0-11.9 years and ≥ 12.0 years, respectively. Higher levels of SE were associated with lower parental myopia (p = 0.024) and higher annualised HbA1c (p = 0.011).
CONCLUSIONCompared to the background population, the proportion of myopia in young patients with T1DM was higher in those aged < 10 years but similar in the older age group. Myopia was associated with a history of parental myopia. Environmental risk factors and poor glycaemic control were not related to higher myopia risk.
Adolescent ; Asian Continental Ancestry Group ; Child ; Child, Preschool ; Cross-Sectional Studies ; Diabetes Mellitus, Type 1 ; complications ; ethnology ; Female ; Glycated Hemoglobin A ; analysis ; Humans ; Male ; Multivariate Analysis ; Myopia ; complications ; ethnology ; therapy ; Ophthalmology ; methods ; Refractive Errors ; Risk Factors ; Young Adult