Contents
Partial reversibele loss of sight in one or both eyes, in the absence of ophthalmoscopic or other marked objective signs.
- Functional Amblyopia
- Physical suppression of retinal image
- Casue: anisometropic, strabismic or stimulus deprivation (amblyopia ex anopsia)
Etiology
Amblyogenic factors:
During visual development (birth to 6-7 years)
- Visual (form sense): Anisometropia
- Light deprivation: Congenital cataract
- Abnormal binocular interaction: Strabismus
Classification
- Strabismic amblyopia (M/C)
- Stimulus deprivation amblyopia (amblyopia ex anosmia)
- Congenital/traumatic cataract, complete ptosis, dense central corneal opacity
- Anisometropic amblyopia
- High degree of refractive error in fellow eye
- Anisohypermetropic > anisomyopic
- Isoametropic amblyopia
- Bilateral uncorrected high refractive error
- Meridional amblyopia
- Uncorrected astigmatic refractive error
- Selective amblyopia for specific visual meridian
Presentation
- Visual acuity reduced
- Effect of normal density filter
- Crowding phenomenon
- Fixation pattern
- Colour vision
Management
- Occlusion therapy (mainstay): Occlusion of normal eye to force use of amblyopic eye
- Penalization: Blurring of vision of normal eye
- Types:
- Atropine penalization
- Optical penalization
- Types:
- Pleoptic exercises: To reestablish foveal fixation
- Pharmacological manipulation
- Perceptual learning
- Computerized home vision therapy (CHVT)