Evaluation of Refractive Status and Ophthalmological Problems of Prematurity
Condition: Prematurity
MeSH terms: Premature Birth
Study type: Observational

Summary: 
      Children born with very low birth weight and extremely low birth weight are at increased risk
      of various ophthalmic challenges such as retinopathy of prematurity (ROP), refractive error,
      strabismus, cerebral visual impairment, colour vision deficits, reduced contrast sensitivity
      (CS), visual field defects, and decreased visual acuity (VA). Many of these factors are not
      independent of each other. Among them, refractive error is a really common disorder. These
      can cause significant disability which can impact life's activities and, qualities.
      Currently, no standard guidelines are available toward the provision of ophthalmic follow up
      care for preterm infants. It is important to survey the prevalence of different ophthalmic
      sequelae in Taiwan, to identify the risk factors of developing these sequelae, and,
      furthermore, to build up a screening program. The preterm population has heterogeneous
      conditions to developing ophthalmic sequelae. National Taiwan University Hospital (NTUH) is
      now in charge of a big part of intense care for these low birth weight preterm neonates. With
      detailed medical record done of these children during care in the neonatal unit, we are
      competence for this meaningful program.
    

Detailed description: 
      Improved neonatal care has resulted in the reduced mortality of preterm infants, especially
      in the very low birth weight and extremely low birth weight groups. However, this reduced
      mortality can be associated with long-term medical sequelae. For example, preterm infants are
      at increased risk of chronic illnesses such as cerebral palsy and asthma, as well as having
      poor motor skills, poor adaptive functioning, and low intelligence quotient.

      As for the ophthalmic problems, ophthalmic challenges following preterm birth are numerous
      and morbid ocular conditions are not rare. The threat to visual development of prematurity
      does not end when the retina is fully vascularised and the risk of ROP has passed. The risk
      of blindness for babies of birth weight <1500 g is increased over 25 times compared to
      children born at full term. The conditions which result severe visual loss include ROP,
      cerebral vision impairment, cataracts and optic atrophy, whereas other conditions, primarily
      amblyopia, may result in better visual outcome. Effects of prematurity on ocular and
      neurological development include retinopathy of prematurity (ROP), refractive error,
      strabismus, cerebral visual impairment, colour vision deficits, reduced contrast sensitivity
      (CS), visual field defects, and decreased visual acuity (VA). Many of these factors are not
      independent of each other. Among them, refractive error is a really common disorder. These
      can cause significant disability which can impact life's activities and, qualities.

      There are numerous reports of an increase refractive errors and amblyogenic factors in the
      low birth weight population relative to children born at full term. However, no formal
      database was established in Taiwan. Today in Taiwan, with increasing level of educational and
      living standard, the prevalence and severity of myopia and other refractive errors appear to
      be an upward trend. The rate is much higher than other developed countries and both genetic
      and environmental factors are crucial to it. Under such as a special condition, the tendency
      of increasing refractive errors and amblyogenic factors in the low birth weight children is
      questionable and need our effort to identify them.

      Currently, no standard guidelines are available toward the provision of ophthalmic follow up
      care for preterm infants. For most preterm children born in Taiwan, between the time of
      discharge from the neonatal unit until national screening at 6-7 years of age (receiving
      education in elementary school), there is no routine ophthalmic surveillance. Due to the
      concern of life's activities and qualities of these children, it is important to survey the
      prevalence of different ophthalmic sequelae in Taiwan, to identify the risk factors of
      developing these sequelae, and, furthermore, to build up a screening program. The preterm
      population has heterogeneous conditions to developing ophthalmic sequelae. To use limited
      health service resources efficiently, it would be helpful to identify those who are at high
      risk of developing ophthalmic sequelae. National Taiwan University Hospital (NTUH), as one of
      the largest tertiary medical centers in northern Taiwan, is now in charge of a big part of
      intense care for these low birth weight preterm neonates. With detailed medical record done
      of these children during care in the neonatal unit, we are competence for this meaningful
      program.
    

Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Children with premature birth history born between January 1, 1999 and December 30, 2001 in
        National Taiwan University Hospital