Heterophoria Flashcards
(22 cards)
What is the definition of heterophoria?
Both visual axes are directed towards the fixation point but deviate on dissociation.
Reference: BIOS, 2012
What is a latent deviation in the context of heterophoria?
No manifest deviation seen on Cover Test; latent deviation detected on Alternate Cover Test.
What is the prevalence of heterophoria in the general population?
Very common; most people have a small, well compensated (controlled) heterophoria.
What is BSV and how does it relate to heterophoria?
BSV stands for binocular single vision; it is present if motor fusion amplitude is sufficient to maintain comfortable BSV.
What happens when motor fusion amplitude is insufficient in heterophoria?
The heterophoria becomes ‘decompensated’ causing visual symptoms or manifest strabismus.
What are the types of heterophoria based on direction?
- Esophoria = inward deviation
- Exophoria = outward deviation
- Hyperphoria = upward deviation
- Hypophoria = downward deviation
- Orthophoria = no heterophoria.
What does the cover test assess in relation to heterophoria?
It assesses size, direction, and recovery of deviations.
Which type of heterophoria is indicated by a deviation when the patient is dissociated?
Both exophoria and esophoria can be indicated based on the direction of deviation.
What is the significance of recovery in the cover test?
Recovery can be classified as rapid, good, slow, or delayed.
What symptoms might a patient with heterophoria experience?
- Diplopia
- Asthenopia
- Headaches
- Eye strain
- Blurred vision.
What factors can lead to decompensation in heterophoria?
- Optical factors
- Medical factors
- Other factors.
What role does refraction play in the management of heterophoria?
Refraction is important for correcting uncorrected or under-corrected refractive errors.
What is the purpose of orthoptic exercises in managing heterophoria?
To improve fusional amplitude and relative convergence.
What are the management options for heterophoria?
- Conservative
- Orthoptic exercises
- Optical correction
- Prisms
- Invasive options like surgery.
What is the purpose of using prisms in heterophoria management?
To reduce the amount of heterophoria to control.
What is the aim of surgical management for heterophoria?
To reduce the angle of deviation and restore ocular alignment.
Fill in the blank: A well-controlled phoria is characterized by _______.
Intermittent manifest strabismus with rapid recovery.
True or False: Decompensated heterophoria is usually asymptomatic in adults.
False.
What is the role of diagnostic prisms in the assessment of heterophoria?
To determine how much prism is needed to relieve symptoms and level of control.
What is the significance of sensory fusion tests in heterophoria assessment?
To evaluate the ability to combine images from both eyes.
What is the definition of orthophoria?
No heterophoria (NAD).
What are the potential outcomes of botulinum toxin injections in heterophoria management?
Temporarily paralyzes the function of extraocular muscles, effective in managing decompensating esophoria and exophoria.
