Done - VISUAL DEVELOPMENT
Done - VISUAL DEVELOPMENT
Done - VISUAL DEVELOPMENT
Department of Ophthalmology
Medical Faculty Sriwijaya University
Refractive state
Refractive state depend on
Corneal power
Starting 52 D at birth Flattening 46 D by 6 months Reaching their adult power of 42 44 D by age 12
Axial length
Increases by about 4 mm in the first 6 months of life Until 13 years growth slows only about 1 mm
Visual Acuity
Methods used to determine visual acuity in preverbal infants and toddlers:
Visual Evoke Potential (VEP) Preferential Looking (PL)
PL Studies estimate the vision of a new born 20/600 Improving to 20/120 by 3 months To 20/60 by 6 months VEP: to 20/20 by age 6 7 months
Stereoacuity
Stereoacuity reaches 60 sec arc by about 5 6 months
Refractive Errors
Infants are hyperopic at birth Become slightly more hyperopic until age 7 Myopic shift until age 16 Changes in refractive error very widely If myopia presents before age 10: high risk of eventual progression to myopia of 6 D or greater Oblique astigmatism is common in infant and often regresses
Perinatal problems
Prematurity Intrauterine growth retardation Fetal distress
Examinations
Visual fixation Crispness and equality of pupillary light responses Ocular alignment and motility Presence of nystagmus or roving eye movements A detailed fundus examinations
Nystagmus
Decreased vision begin at age 2-3 months not at birth
Electroretinography (ERG)
Can aid in diagnosis of a number of retinal disorder
Additional testing
VEP, USG, CT Scan, MRI