between age 6 months and 6 yrs. Old (US Study) -33% Hyperopia -22.5% Astigmatism -9.5% Myopia -5% Binocular vision disorder -21.1% Strabismus -7.9% Amblyopia -1% Accommodative disorder Amblyopic -Characteristics(strab/Ref): 3 causes- strabismus, refractive, deprivation. Strabismus (amblyopia of arrest)-VA never achieved b/c hasn’t been used Refractive(amblyopia of extinction)- VA lost due to cortical inhibition from the good eye Deprivation (ie. Congenital cataract) Amblyopia Work-up 2. Pinhole- if improvement but still not 20/20, further testing all with PH 3. IFA testing- do freg seeing curve-use tumbling E’s out of 4 a. if IFA= IA, then it’s amblyopia of arrest b. if IFA= 20/20, amblyopia of extinction c. if IA< IFA< 20/20, partial due to amblyopia 4. test for eccentric fixation- for visuoscopy, test preferred eye first, 5. BV assessment: unilateral cover test, alternating cover test, 4D prism 6. Ocular health assessment; color vision for Optic nerve dysfunction, Amsler Grid, Pupil test, fundus, ND filter, VER’s Prognosis: Case Hx; child’s diseases?, cataract? Major prediction-if IFA>IA---good -any strab, onset, freg, laterality, -center fixation—good, unsteady eccentric fixation is better than steady - refractive, extinction-good, strab, arrest—bad - bifoveal fixation important if ARC stops bifoveal, cause of amblyopia cannot be removed - previous training? Severity? - Myopia-good, hyperopia-bad - Age, health, motivation Goal: spare eye at least 20/40 Treatment; 1. refraction (eg. Aniseikonia) -convert unilateral strab to alternating -eliminate eccentric fixation 2. monocular stimulation under binocular condition -modified Brock 3. patching 5 hr/day for 6 weeks 下一篇: 激光治近视 奥妙何在 |
