Strabismus: Paralytic vs. Concomitant
Ophthalmology: Ocular Motility Disorders
Comparison Table
| Feature | Paralytic (Incomitant) | Concomitant |
|---|---|---|
| Deviation | Varies with the direction of gaze. | Constant in all directions. |
| Diplopia | Present (primary symptom). | Absent (due to suppression). |
| Head Posture | Abnormal (to avoid diplopia). | Usually normal. |
| Etiology | Neurological or muscular palsy. | Refractive or muscle imbalance. |
High-Yield NEET Pearls
- Paralytic Squint: Primary deviation (fixation with normal eye) is less than secondary deviation (fixation with paretic eye). This is Hering’s Law in action.
- Concomitant Squint: Primary and secondary deviations are equal. Often associated with amblyopia in children.
- Diplopia Field: In paralytic squint, the false image is always projected in the direction of the action of the paralyzed muscle.
- Management: Paralytic requires addressing the underlying cause (e.g., vascular, compressive). Concomitant requires refractive correction, occlusion therapy (for amblyopia), or surgery.