Hyperopia Treatment Study 1 (HTS1) - Glasses vs Observation
Condition: Hyperopia
MeSH terms: Hyperopia
Study type: Interventional

Summary: 
      The purpose of this study is to compare visual acuity outcomes and development of strabismus
      after a 3-year follow-up period in children age 12 to <72 months with moderate hyperopia
      (spherical equivalent +3.00D to +6.00D) who are prescribed glasses either immediately or only
      after confirmation of pre-specified deterioration criteria.
    

Detailed description: 
      Moderate and high hyperopia are associated with the development of strabismus and amblyopia.
      The primary aims of treatment for asymptomatic moderate and high hyperopia in preschool
      children are to facilitate the development of normal visual acuity and to prevent the
      development of esotropia and amblyopia. Treatment consists of optical correction, typically
      using glasses. For children with high hyperopia (>+5.00D) and without strabismus or
      amblyopia, there is general consensus that a correction should be prescribed. Nevertheless,
      for children with moderate hyperopia (+3.00D to +5.00D) without strabismus or amblyopia,
      there is less consensus among pediatric eye care professionals. A survey by Lyons et al found
      that for a 2-year-old child with hyperopia greater than +3.00D, 65% of optometrists would
      prescribe glasses compared to 25% of ophthalmologists; for a 4-year old with hyperopia
      greater than +3.00D, 67% of optometrists would prescribe compared with 42% of
      ophthalmologists. The American Association for Pediatric Ophthalmology and Strabismus (AAPOS)
      recommends correcting +4.00D or more in 2 to 7 year olds and the American Academy of
      Ophthalmology recommends a threshold of +4.50D for correction in 2-to 3-year olds. Unlike
      ophthalmology, optometry does not provide specific recommendations based on age and level of
      refractive error. Such variation in practice highlights the lack of rigorously collected
      scientific evidence for the management of this condition. Across all levels of hyperopia,
      most ophthalmologists and optometrists usually prescribe less than the full cycloplegic
      refraction (71% in the Lyons survey) when no strabismus or amblyopia is present.

      The rationale for proactively correcting moderate hyperopia in an asymptomatic child is the
      prevention of esotropia, amblyopia, or asthenopia. The argument against correcting moderate
      hyperopia in an asymptomatic child is the expense and inconvenience of glasses that might be
      unnecessary and the potential disruption of emmetropization in infants and toddlers. At
      present, it remains uncertain whether correction of moderate hyperopia is beneficial in terms
      of visual acuity outcomes or strabismus development. There is some evidence that using
      partial correction of hyperopia allows emmetropization to take place.

      If refractive correction of moderate hyperopia does not reduce the incidence of amblyopia
      and/or esotropia compared to no refractive correction, then glasses can be avoided. However,
      if correcting moderate hyperopia does reduce the development of amblyopia and/or esotropia,
      then the benefits of preemptive refractive correction will have been identified.
    

Intervention name(s): Glasses
Intervention type(s): Procedure
Intervention description(s): Glasses will be prescribed at enrollment with the sphere cut symmetrically by 1.00D and full cylinder correction.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Hyperopia; Glasses