Abnormal correspondence Flashcards
(30 cards)
What is anisometropia?
A condition where the two eyes have unequal refractive power.
It can lead to amblyopia if untreated.
Define foveal fixation.
The act of fixating on a target using the fovea, the central region of the retina.
Important for high-acuity vision.
What is parafoveal fixation?
Fixation that occurs outside the fovea, often in the parafoveal region.
May be used in conditions like microtropia.
Differentiate between normal correspondence and abnormal correspondence.
Normal correspondence occurs when the images from both eyes are fused correctly, while abnormal correspondence involves a misalignment in visual perception.
This can lead to diplopia or suppression.
What is microtropia with identity?
A type of microtropia where there is no manifest deviation; fixation is coincident with the angle of deviation.
Often associated with harmonious anomalous correspondence.
What is microtropia without identity?
Microtropia characterized by a very small manifest deviation that may be associated with central fixation.
It does not coincide with the angle of deviation.
What is primary microtropia?
Microtropia that is the initial defect, without a history of larger angle strabismus.
It may accompany other forms of strabismus.
What is secondary microtropia?
Microtropia that develops after treatment for a larger angle manifest deviation.
It may present as residual microesotropia.
Define monofixation syndrome.
A condition where a person can only fixate with one eye while the other eye is suppressed.
Often leads to reduced stereoacuity.
What is central suppression scotoma?
A visual field defect where the central vision is suppressed, often observed in strabismic conditions.
It can affect visual acuity.
What does crowding refer to in vision?
The phenomenon where visual acuity is reduced in the presence of nearby visual stimuli.
Commonly seen in amblyopia.
What is fixation ophthalmoscopy?
A technique used to assess fixation stability and quality of vision.
It helps diagnose conditions like microtropia.
What is visuoscopy?
A method to evaluate visual function and fixation patterns.
Useful in diagnosing amblyopia and strabismus.
What does the 4 PD prism reflex test assess?
It evaluates the presence of a deviation in ocular alignment.
Typically uses base-out (BO) and base-in (BI) prisms.
Differentiate between simultaneous PCT and alternate PCT.
Simultaneous PCT assesses the manifest component, while alternate PCT evaluates both manifest and latent components.
Both are crucial in strabismus assessment.
What is manifest strabismus?
A condition where there is a noticeable misalignment of the eyes at all times.
In contrast to latent strabismus, which is only present under certain conditions.
What is associated latent strabismus?
A type of strabismus that is not always observable and may become apparent under specific conditions.
It can complicate the diagnosis of manifest strabismus.
What is the aim of amblyopia treatment?
To achieve the best possible visual acuity (VA) in each eye and maintain it.
Early intervention is crucial for effective management.
What does BSV stand for?
Bifoveal single vision.
It refers to the ability to use both eyes together to perceive a single image.
What is the role of the cover test (CT) in strabismus assessment?
To determine the presence and type of ocular deviation.
Includes near and distance assessments.
What is sensory fusion?
The ability of the brain to combine visual information from both eyes into a single image.
Essential for depth perception and stereoacuity.
What is motor fusion?
The ability to align the eyes to maintain single vision.
It compensates for any latent strabismus.
What is stereoacuity?
The ability to perceive depth and three-dimensional structure from visual input.
Typically reduced in conditions like microtropia.
Fill in the blank: Microtropia is characterized by _______.
small angle manifest strabismus (10 PD or less).
It may also involve an associated latent strabismus.
