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CHAPTER III
THEORETICAL AND CONCEPTUAL SCHEME
3.1 Theoretical Scheme
(+) (-)
3.2 Conceptual scheme
Early-onset
Early adult -onset
Late adult-onset Keratoconus Corneal astigmatism Myopia
Risk factors:
history of myopia
PDGFRA gene
PDGF receptor alpha on fibroblasts of stromal cornea PDGF
Normal production of
collagen in stromal cornea
Decrease production of
collagen in stromal cornea
Steepening of corneal curvature
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Based on the theoretical scheme above, some of the variables are
intentionally omitted. On this research only PDGFRA gene polymorphism that
had been examined to see its association with early-onset myopia.
3.3 Hypothesis
3.3.1 Research Hypothesis
1. The distribution of mutant allele polymorphisms in PDGFRA gene is
bigger in the subject with early-onset myopia than in normal subject.
2. PDGFRA gene polymorphism, parental history, near work, reading in
dim light, outdoor activity, sex, and corneal curvature are correlated to
early-onset myopia in South Sumatera population.
3.3.2 Null Hypothesis
1. The distribution of mutant allele polymorphisms in PDGFRA gene is
equal between the subject with early-onset myopia and in normal
subject.
2. PDGFRA gene polymorphism, parental history, near work, reading in
dim light, outdoor activity, sex, and corneal curvature are not correlated
to early-onset myopia in South Sumatera population. PDGFRA gene
polymorphism
Early-onset myopia Corneal
