Strabismus - Ocular Misalignment - Differential Diagnosis Algorithm Phoria: • Latent deviation • Symmetrical corneal light reflex, • Negative cover test positive cover/uncover test • Esophoria (eye moves medial -> centre when uncovered) • Exophoria (eye moves lateral -> centre when uncovered) Tropia: • Manifest deviation • Asymmetrical light reflex, • Positive cover test Non-paretic - Comitant Angle of misalignment unchanged with direction of gaze • Accommodative Esotropia (onset 2-4yrs, hyperopic) • Congenital Esotropia (contralateral eye deviates medial -> straight when ipsilateral covered) • Exotropia (contralateral eye deviates lateral -> straight when ipsilateral covered) Paretic - Horizontal (eso/exotropia): • CN VI problem (eye cannot abduct) Paretic - Horizontal and/or vertical (Eso/exotropia, hyper/hypotopia, mixed): • CN Ill Problem (eye is depressed and abducted, ptosis, large/unreactive pupil) • CN IV Problem (eye cannot depress when looking medially) #Strabismus #Ocular #Eyeball #Misalignment #Differential #Diagnosis #Algorithm #Causes #Ophthalmology
