9 - Exodeviations Flashcards
FdR d’exotropie
Risk factors for exotropia include
* Maternal substance abuse
* Smoking during pregnancy
* Premature birth
* Perinatal morbidity
* Genetic anomalies
* Family history of strabismus
* Uncorrected refractive errors
(Pseudoexotropia)
Définir la Pseudoexotropie
The term pseudoexotropia refers to an appearance of exodeviation when in fact the eyes are properly aligned.
(Pseudoexotropia)
Prévalence de la Pseudoexotropia?
Pseudoexotropia is much less common than pseudoesotropia
(Pseudoexotropia)
Causes/Exemples de Pseudoexotropia (x2)?
May occur when there is a wide interpupillary distance or a positive angle kappa with or without other ocular abnormalities
(Exophoria)
Définir l’Exophorie
Exophoria is an exodeviation controlled by fusion under normal binocular viewing conditions.
(Exophoria)
Comment détecter l’Exophorie?
An exophoria is detected when binocular vision is interrupted, as during an alternate cover test or monocular visual acuity testing.
(Exophoria)
Prévalence de l’Exophorie?
Exophoria is relatively common
(Exophoria)
L’Exophorie est-elle symptomatique ou asymptomatique généralement?
Patients are usually asymptomatic, although with prolonged near work, they may experience asthenopia.
(Exophoria)
Exemple de précipitants qui causent une décompensation de l’Exophorie en Exotropie?
Decompensation of an exophoria to an exotropia may occur when the patient is ill or under the influence of sedatives or alcohol.
(Exophoria)
Est-il recommandé de traiter l’exophorie?
Treatment is recommended when an exophoria becomes symptomatic
Quel est le type de manifest exodeviation le plus fréquent?
Intermittent exotropia is the most common type of manifest exodeviation.
(Intermittent exotropia)
Vers quel âge se manifeste l’exotropie Intermittente ?
The onset of intermittent exotropia is usually before age 5 years, and the exotropia typically continues into adulthood.
(Intermittent exotropia)
Circonstances où l’Intermittent exotropia devient manifeste?
The exodeviation becomes manifest during times of
* Visual inattention
* Fatigue
* Stress
* Illness
* Exposure to bright light
Parents of affected children often report that the exotropia occurs late in the day or when the child is daydreaming or tired.
(Intermittent exotropia)
Impact de la lumière sur l’Intermittent exotropia?
Exposure to bright light often causes exodeviation and a reflex closure of 1 eye (which is why strabismus is sometimes referred to as a “squint”).
(Intermittent exotropia)
Exodéviation est-elle plus prononcée lors VP ou VL?
Exodeviations are usually larger when the patient views distant targets, and they may be difficult to elicit at near.
(Intermittent exotropia)
Autres signes/éléments associés à l’Intermittent exotropia
Intermittent exotropia can be associated with small hypertropias, A and V patterns (see Chapter 10), and overelevation and underelevation in adduction (see Chapter 11).
(Intermittent exotropia)
Évolution de l’Intermittent exotropia si non traitée?
Left untreated, intermittent exotropia may remain stable, resolve, or progress, sometimes to constant exotropia.
(Intermittent exotropia)
Est-ce que la diplopie chez les patients avec intermittent exotropia est fréquente?
Because of suppression, children younger than 10 years with intermittent exotropia rarely report diplopia.
(Intermittent exotropia)
Est-ce que les enfants avec Intermittent exotropia maintiennent une bonne fonction binoculaire?
- They retain normal retinal correspondence and good binocular function when orthotropic.
- Amblyopia may occur if the strabismus is poorly controlled or becomes constant.
(Intermittent exotropia)
Catégorisation du contrôle de l’Intermittent exotropia
Exodeviation control may be categorized as follows:
* Good control: Exotropia manifests only after cover testing, and the patient resumes fusion rapidly without blinking or refixating.
* Fair control: Exotropia manifests after fusion is disrupted by cover testing, and the patient resumes fusion only after blinking or refixating.
* Poor control: Exotropia manifests spontaneously and may remain manifest for an extended time.
Some ophthalmologists use the Newcastle Control Score for Intermittent Exotropia to quantitatively grade the control exhibited by patients with this deviation.
(Intermittent exotropia)
Qu’est-ce que le Newcastle Control Score for Intermittent Exotropia?
- Pour l’évaluation de l’Exodeviation control
- Le score incorporate data from both the clinic visit and from symptoms experienced at home and are scored from 0 to 9, with 9 being the worst control.
Pour quel type de déviation oculaire utilise-t-on le Newcastle Control Score?
For Intermittent Exotropia
(Intermittent exotropia)
Concernant l’Intermittent exotropia, quel test est-il préférable de faire en premier à l’e/o et pourquoi?
Because visual acuity and alignment tests are dissociating and may adversely affect assessment of strabismus control, they should be performed after sensory tests for stereopsis and fusion.
(Intermittent exotropia)
Pour l’intermittent exotropia, la déviation est-elle plus grande lors de la fixation de près ou de loin ? Pourquoi?
- The deviation at near fixation is often smaller than the deviation at distance fixation.
- This difference is usually due to tenacious proximal fusion, a slow- to- dissipate fusion mechanism at near.
- The difference may sometimes be due to a high accommodative convergence/accommodation (AC/A) ratio, but a high AC/A ratio occurs much less commonly in exotropia than in esotropia
(Intermittent exotropia)
Que signifie basic intermittent exotropia
The exodeviation is termed basic intermittent exotropia when the size of the deviation at distance fixation is within 10 prism diopters (D) of the deviation size at near fixation.
(Intermittent exotropia)
V ou F : No children have a larger deviation at near than at distance in Intermittent exotropia
Faux. Some children have a larger deviation at near than at distance; this is distinct from convergence insufficiency.
(Intermittent exotropia)
Que faire si on mesure une exodéviation at distance qui est > 10D de celle at near fixation dans l’Intermittent exotropia?
- When the exodeviation at distance is larger than the deviation at near fixation by 10D or more, the near exodeviation should be remeasured after 1 eye is occluded for 30–60 minutes (the patch test).
- The patch test eliminates the effects of tenacious proximal fusion, helping distinguish between pseudodivergence excess and true divergence excess.
- A patient with pseudodivergence excess has similar distance and near measurements after the patch test.
- A patient with true divergence excess continues to have a significantly larger exodeviation at distance.
Many patients with true divergence excess also have a high AC/A ratio.
* For these patients, the AC/A ratio can be determined by measuring the near deviation with and without +3.00 diopter (D) lenses (while the patient wears corrective lenses, if necessary), after the patch test is completed. The measurements are then compared.
* Alternatively, the distance deviation can be measured with and without −2.00 D lenses to determine the AC/A ratio.