Myopia and educational attainment in 421,116 young Singaporean males

Data of 421,116 Singaporean males aged 15 to 25 (mean 17.75) years who underwent compulsory medical examination in 1974-84 and 1987-91 were used to estimate the prevalence of myopia and to study the correlation between the prevalence and severity of myopia and educational attainment. The estimated myopia prevalence rate was 26.3% in 1974-84 and 43.3% in 1987-91. This rise in the rate was accompanied by an increase in the proportion of males who achieved higher levels of education over the same period. The overall myopia prevalence rate was 30.4%. Both the prevalence and severity of myopia were higher as the level of education attained increased. The myopia prevalence rate was 15.4% in males with no formal education and increased steadily through groups with intermediate education to 65.2% among those with GCE 'A' level education, 57.5% among diploma holders and 65.1% among university graduates in 1987-91. Seventy out of 173 (40%) myopes with no formal education compared to 1035 out of 1612 (64%) myopes with university degrees had unaided visual acuity worse than 6/60 in 1987-91. Our findings confirm indications from other sources that the association between the prevalence and severity of myopia and education attainment is real. A combination of genetic and environmental factors may be the cause of this association.

Xq28: epidemiology and sex-linkage between red-green colour blindness and G6PD deficiency

Xq28 is the genetic locus of two closely associated conditions of red-green colour blindness and G6PD deficiency. Epidemiologically, both rank among the more frequent sex-linked clinical problems that affect military servicemen in Singapore. This retrospective study is based on the findings of 35714 subjects screened at the Medical Classification Centre--Central Manpower Base (MCC--CMPB) over an eighteen-month period using pseudoisochromatic and fluorescent techniques as well as anomaloscopic and spectrometric methods. The overall prevalence rates of red-green colour blindness, G6PD deficiency and association were determined to be 4.8%, 2.2% and 0.1% respectively. Malays showed the highest prevalence rates among the major races. Statistically significant difference was found with regards to the prevalence rates of G6PD deficiency and its association with red-green colour blindness. Review of literature yielded comparable results with a few local studies of good sample size done over the past twenty years. Sex-linkage analysis was hindered by the lack of pedigree studies.

The application of disposable contact lenses in the Navy

With the recent advent of disposable contact lenses, many of the problems which have been hindering the military application of contact lenses have been overcome. Fifty-five myopic naval personnel with no previous contact lens experience were put through a three-week study using these contact lenses. The aim was to test the feasibility of supplying bespectacled myopic seamen with contact lenses at the outset of operational missions. Seven developed conjunctival injection which caused them to discontinue contact lens wear. Of the remaining 48, however, a vast majority showed preference for contact lenses when compared to spectacles in the work environments that they were exposed to. With contact lenses, 95.8% had comparable or better vision during the day and 85.4% during the night. No serious ocular complications were noted and only minor findings were detected in the 96 eyes at the end of three weeks of contact lens wear.

Mandibulo-facial dysostosis--the eye signs of a case study

The mandibulo-facial dysostosis syndrome (Treacher-Collins syndrome) was first described in 1889. It is a syndrome with multiple presentations, the classification for which was devised by Franceschetti and Zwahlen in 1944. The eye signs are an important part of this syndrome. In addition to the main ocular features of colobomata of the lower eyelids and an anti-mongoloid slant, many other eye signs have been reported. An 18-year-old Indian male was found to have features not previously described. These are high myopia, dermolipoma, lens subluxation and secondary glaucoma.

A study of amblyopia in 18-19 year old males

During a vision screening of 6,556 National Service pre-enlistees aged 18-19 years at the Medical Classification Centre of Central Manpower Base, 48 subjects were found to have visual acuity of 6/12 or less in one or both eyes in the absence of ocular pathology. The prevalence of amblyopia in this population is 0.73%. Amblyopia was due to anisometropia in 24 cases (50%), strabismus in 9 cases (18.7%), high astigmatism (meridional) in 7 cases (14.5%) and other causes or a combination of factors in 8 cases (16.7%). Strabismic amblyopia is most commonly associated with esotropia. There is a positive association between the severity of amblyopia and the degree of strabismus in strabismic amblyopes. Meridional amblyopia tends to be less severe than most other types of amblyopia. The amblyopes were detected late (average 7-10 years of age) and orthoptic treatment of a small minority of them upon diagnosis was unsuccessful.